Science.gov

Sample records for human hypoxanthine phosphoribosyltransferase

  1. Role of human hypoxanthine guanine phosphoribosyltransferase in activation of the antiviral agent T-705 (favipiravir).

    PubMed

    Naesens, Lieve; Guddat, Luke W; Keough, Dianne T; van Kuilenburg, André B P; Meijer, Judith; Vande Voorde, Johan; Balzarini, Jan

    2013-10-01

    6-Fluoro-3-hydroxy-2-pyrazinecarboxamide (T-705) is a novel antiviral compound with broad activity against influenza virus and diverse RNA viruses. Its active metabolite, T-705-ribose-5'-triphosphate (T-705-RTP), is recognized by influenza virus RNA polymerase as a substrate competing with GTP, giving inhibition of viral RNA synthesis and lethal virus mutagenesis. Which enzymes perform the activation of T-705 is unknown. We here demonstrate that human hypoxanthine guanine phosphoribosyltransferase (HGPRT) converts T-705 into its ribose-5'-monophosphate (RMP) prior to formation of T-705-RTP. The anti-influenza virus activity of T-705 and T-1105 (3-hydroxy-2-pyrazinecarboxamide; the analog lacking the 6-fluoro atom) was lost in HGPRT-deficient Madin-Darby canine kidney cells. This HGPRT dependency was confirmed in human embryonic kidney 293T cells undergoing HGPRT-specific gene knockdown followed by influenza virus ribonucleoprotein reconstitution. Knockdown for adenine phosphoribosyltransferase (APRT) or nicotinamide phosphoribosyltransferase did not change the antiviral activity of T-705 and T-1105. Enzymatic assays showed that T-705 and T-1105 are poor substrates for human HGPRT having Km(app) values of 6.4 and 4.1 mM, respectively. Formation of the RMP metabolites by APRT was negligible, and so was the formation of the ribosylated metabolites by human purine nucleoside phosphorylase. Phosphoribosylation and antiviral activity of the 2-pyrazinecarboxamide derivatives was shown to require the presence of the 3-hydroxyl but not the 6-fluoro substituent. The crystal structure of T-705-RMP in complex with human HGPRT showed how this compound binds in the active site. Since conversion of T-705 by HGPRT appears to be inefficient, T-705-RMP prodrugs may be designed to increase the antiviral potency of this new antiviral agent.

  2. Absence of hypoxanthine:guanine phosphoribosyltransferase activity in murine Dunn osteosarcoma

    SciTech Connect

    Abelson, H.T.; Gorka, C.

    1983-09-01

    The transplantable murine Dunn osteosarcoma has no detectable hypoxanthine:guanine phosphoribosyltransferase (EC 2.4.2.8) activity. This was established from the tumors directly and from tissue culture cell lines derived from the tumor using a variety of assays: e.g., no (3H)hypoxanthine uptake into tumor or tissue culture cells, no conversion of (3H)hypoxanthine to (3H)IMP by cell extracts from tumors or tissue culture cells, no growth of tissue culture cells in hypoxanthine:aminopterin:thymidine medium, and normal growth of these cells in 10 microM 6-mercaptopurine. Ten human osteosarcomas have been assayed, and two have no apparent hypoxanthine:guanine phosphoribosyltransferase enzyme activity. After high-dose methotrexate treatment in vivo, murine tumors could be selectively killed and normal tissues could be spared by using a rescue regimen of hypoxanthine-thymidine-allopurinol.

  3. Human Adenovirus Type 2 but Not Adenovirus Type 12 Is Mutagenic at the Hypoxanthine Phosphoribosyltransferase Locus of Cloned Rat Liver Epithelial Cells

    PubMed Central

    Paraskeva, Christos; Roberts, Carl; Biggs, Paul; Gallimore, Phillip H.

    1983-01-01

    Using resistance to the base analog 8-azaguanine as a genetic marker, we showed that adenovirus type 2, but not adenovirus type 12, is mutagenic at the hypoxanthine phosphoribosyltransferase locus of cloned diploid rat liver epithelial cells. Adenovirus type 2 increased the frequency of 8-azaguanine-resistant colonies by up to ninefold over the spontaneous frequency, depending on expression time and virus dose. PMID:6572280

  4. Hypoxanthine phosphoribosyltransferase: radiochemical assay procedures for the forward and reverse reactions

    SciTech Connect

    Smithers, G.W.; O'Sullivan, W.J.

    1985-02-15

    Simple and rapid radiochemical assay procedures for the forward (IMP synthesis) and reverse (IMP pyrophosphorolysis) reactions catalyzed by hypoxanthine phosphoribosyltransferase have been developed. Enzyme activity in the forward direction was assessed by measuring the amount of (8-/sup 14/C)IMP formed from (8-/sup 14/C)hypoxanthine following their separation by polyethyleneimine-cellulose TLC in methanol:water (1:1, v/v). (8-/sup 14/C)IMP has been synthesized from (8-/sup 14/C)hypoxanthine, using hypoxanthine phosphoribosyltransferase derived from human brain, with subsequent purification by elution from phenyl boronate-agarose. Enzyme activity in the reverse direction was assessed by measuring the amount of (8-/sup 14/C)uric acid formed from the labeled IMP following their separation by polyethyleneimine-cellulose TLC in 0.2 M LiCl saturated with boric acid (pH 4.5):95% ethanol (1:1, v/v), the transferase reaction being coupled with excess xanthine oxidase and catalase to overcome the unfavorable equilibrium.

  5. Acyclic Immucillin Phosphonates. Second-Generation Inhibitors of Plasmodium falciparum Hypoxanthine- Guanine-Xanthine Phosphoribosyltransferase

    SciTech Connect

    Hazelton, Keith Z.; Ho, Meng-Chaio; Cassera, Maria B.; Clinch, Keith; Crump, Douglas R.; Rosario Jr., Irving; Merino, Emilio F.; Almo, Steve C.; Tyler, Peter C.; Schramm, Vern L.

    2012-06-22

    We found that Plasmodium falciparum is the primary cause of deaths from malaria. It is a purine auxotroph and relies on hypoxanthine salvage from the host purine pool. Purine starvation as an antimalarial target has been validated by inhibition of purine nucleoside phosphorylase. Hypoxanthine depletion kills Plasmodium falciparum in cell culture and in Aotus monkey infections. Hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT) from P. falciparum is required for hypoxanthine salvage by forming inosine 5'-monophosphate, a branchpoint for all purine nucleotide synthesis in the parasite. We present a class of HGXPRT inhibitors, the acyclic immucillin phosphonates (AIPs), and cell permeable AIP prodrugs. The AIPs are simple, potent, selective, and biologically stable inhibitors. The AIP prodrugs block proliferation of cultured parasites by inhibiting the incorporation of hypoxanthine into the parasite nucleotide pool and validates HGXPRT as a target in malaria.

  6. Crystal structures of Apo and GMP bound hypoxanthine-guanine phosphoribosyltransferase from Legionella pneumophila and the implications in gouty arthritis.

    PubMed

    Zhang, Nannan; Gong, Xiaojian; Lu, Min; Chen, Xiaofang; Qin, Ximing; Ge, Honghua

    2016-06-01

    Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) (EC 2.4.2.8) reversibly catalyzes the transfer of the 5-phophoribosyl group from 5-phosphoribosyl-alpha-1-pyrophosphate (PRPP) to hypoxanthine or guanine to form inosine monophosphate (IMP) or guanosine monophosphate (GMP) in the purine salvage pathway. To investigate the catalytic mechanism of this enzyme in the intracellular pathogen Legionella pneumophila, we determined the crystal structures of the L. pneumophila HGPRT (LpHGPRT) both in its apo-form and in complex with GMP. The structures reveal that LpHGPRT comprises a core domain and a hood domain which are packed together to create a cavity for GMP-binding and the enzymatic catalysis. The binding of GMP induces conformational changes of the stable loop II. This new binding site is closely related to the Gout arthritis-linked human HGPRT mutation site (Ser103Arg). Finally, these structures of LpHGPRT provide insights into the catalytic mechanism of HGPRT.

  7. Effects of acyclovir and its metabolites on hypoxanthine-guanine phosphoribosyltransferase.

    PubMed

    Tuttle, J V; Krenitsky, T A; Elion, G B

    1983-10-15

    Acyclovir [9-(2-hydroxyethoxymethyl)guanine], a clinically useful anti-herpesvirus agent, was a weak inhibitor (Ki = 190 microM) of hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) from human erythrocytes. Nevertheless, this acyclic nucleoside analog was a more effective inhibitor than were its natural counterparts, guanosine (Ki = 1400 microM) and deoxyguanosine (Ki = 570 microM). The two oxidized metabolites of acyclovir, 9-carboxymethoxymethylguanine (Ki = 720 microM) and 8-hydroxy-9-(2-hydroxyethoxymethyl)guanine (Ki greater than 2000 microM), were less inhibitory than was the parent drug. None of the phosphorylated metabolites of acyclovir was as potent an inhibitor of HGPRTase as was GMP (Ki = 4 microM). However, the Ki value for acyclovir monophosphate was similar to that of dGMP (12 microM). The Ki values for acyclovir diphosphate (8.3 microM) and triphosphate (30 microM) were less than those for dGDP (110 microM) and dGTP (140 microM). The levels of these phosphate esters of acyclovir in cultured monkey kidney (Vero) and human embryo fibroblast (WI38) cells exposed to therapeutic levels of the drug were well below the observed Ki values. However, in herpesvirus-infected WI38 cells the levels of the phosphate esters of acyclovir were high enough potentially to inhibit the enzyme. Although inhibition of this enzyme by the phosphorylated metabolites of acyclovir may occur in these infected cells, concentrations of the drug very much higher than the EC50 concentration were required to achieve inhibitory levels. It is, therefore, unlikely that this inhibition contributes significantly to the antiviral activity.

  8. Cloning and expression of the hypoxanthine-guanine phosphoribosyltransferase from Leishmania donovani.

    PubMed

    Allen, T E; Hwang, H Y; Jardim, A; Olafson, R; Ullman, B

    1995-07-01

    The gene encoding the hypoxanthine-guanine phosphoribosyltransferase (HGPRT) enzyme from Leishmania donovani has been cloned and sequenced. The hgprt open reading frame encoded a polypeptide of 211 amino acids that exhibited 3 regions of significant homology with other eukaryotic HGPRTs and a C-terminal tripeptide compatible with a glycosomal targeting signal. Northern blot analysis of L. donovani RNA revealed two hgprt transcripts, a 1.9-kb mRNA and a 1.7-kb transcript. The expression of the 1.7-kb hgprt mRNA and the activity of HGPRT enzyme were both augmented approx. 5-fold in parasites incubated in the absence of purines. Southern blots of genomic DNA indicated only a single hgprt locus within the L. donovani genome. Overexpression of L. donovani hgprt in E. coli complemented genetic deficiencies in hypoxanthine and guanine phosphoribosylating activities and yielded abundant quantities of enzymatically active HGPRT. The recombinant HGPRT was purified to homogeneity and recognized hypoxanthine, guanine and allopurinol, but not adenine or xanthine, as substrates. The hgprt clone and pure HGPRT protein provide essential reagents for validating HGPRT as a therapeutic target for the treatment of leishmaniasis and other diseases of parasitic origin. PMID:8577321

  9. Generation of hypoxanthine phosphoribosyltransferase gene knockout rabbits by homologous recombination and gene trapping through somatic cell nuclear transfer.

    PubMed

    Yin, Mingru; Jiang, Weihua; Fang, Zhenfu; Kong, Pengcheng; Xing, Fengying; Li, Yao; Chen, Xuejin; Li, Shangang

    2015-11-02

    The rabbit is a common animal model that has been employed in studies on various human disorders, and the generation of genetically modified rabbit lines is highly desirable. Female rabbits have been successfully cloned from cumulus cells, and the somatic cell nuclear transfer (SCNT) technology is well established. The present study generated hypoxanthine phosphoribosyltransferase (HPRT) gene knockout rabbits using recombinant adeno-associated virus-mediated homologous recombination and SCNT. Gene trap strategies were employed to enhance the gene targeting rates. The male and female gene knockout fibroblast cell lines were derived by different strategies. When male HPRT knockout cells were used for SCNT, no live rabbits were obtained. However, when female HPRT(+/-) cells were used for SCNT, live, healthy rabbits were generated. The cloned HPRT(+/-) rabbits were fertile at maturity. We demonstrate a new technique to produce gene-targeted rabbits. This approach may also be used in the genetic manipulation of different genes or in other species.

  10. Crystallization of human nicotinamide phosphoribosyltransferase

    SciTech Connect

    Takahashi, Ryo; Nakamura, Shota; Yoshida, Takuya; Kobayashi, Yuji; Ohkubo, Tadayasu

    2007-05-01

    Human nicotinamide phosphoribosyltransferase has been crystallized using microseeding methods and X-ray diffraction data have been collected at 2.0 Å resolution. In the NAD biosynthetic pathway, nicotinamide phosphoribosyltransferase (NMPRTase; EC 2.4.2.12) plays an important role in catalyzing the synthesis of nicotinamide mononucleotide from nicotinamide and 5′-phosphoribosyl-1′-pyrophosphate. Because the diffraction pattern of the initally obtained crystals was not suitable for structure analysis, the crystal quality was improved by successive use of the microseeding technique. The resultant crystals diffracted to 2.0 Å resolution. These crystals belonged to space group P21, with unit-cell parameters a = 60.56, b = 106.40, c = 82.78 Å. Here, the crystallization of human NMPRTase is reported in the free form; the crystals should be useful for inhibitor-soaking experiments on the enzyme.

  11. Purine synthesis de novo and salvage in hypoxanthine phosphoribosyltransferase-deficient mice.

    PubMed

    Allsop, J; Watts, R W

    1990-01-01

    Extreme degrees of hypoxanthine phosphoribosyltransferase (HPRT) deficiency in man are associated with gross sex-linked neurological dysfunction, gout and urinary stones (the Lesch-Nyhan or 'complete HPRT-deficiency' syndrome). The less severe degrees of enzyme deficiency (sex-linked recessive gout and/or urolithiasis or the 'partial HPRT-deficiency' syndrome) may be associated with minor neurological manifestations. Whole body purine synthesis de novo is accelerated in both these groups of patients. A strain of mice with an experimentally produced mutation at the HPRT locus showed some residual 'apparent HPRT activity' in brain, liver, testicular, splenic, kidney and ovarian tissues but not in erythrocyte haemolysates. The mutation removes exons 1 and 2 of the coding region of the gene together with the promotor and about 10 kb of upstream sequence from the gene. It is therefore possible that the observed 'apparent HPRT activity' in these mice is due to the operation of an alternative metabolic pathway. Purine synthesis de novo was markedly accelerated in their brain, testicular, splenic and kidney tissues. It was not accelerated in the liver tissue of male mice hemizygous for the mutation and the degree of acceleration in the female homozygotes only just reached statistical significance at the p = 0.02 level. This observation casts doubt on the importance of modulations in the rate of hepatic purine synthesis de novo as a mechanism for maintaining a steady supply of purines for translocation to other organs.

  12. Amplification of Adenine Phosphoribosyltransferase Suppresses the Conditionally Lethal Growth and Virulence Phenotype of Leishmania donovani Mutants Lacking Both Hypoxanthine-guanine and Xanthine Phosphoribosyltransferases*

    PubMed Central

    Boitz, Jan M.; Ullman, Buddy

    2010-01-01

    Leishmania donovani cannot synthesize purines de novo and obligatorily scavenge purines from the host. Previously, we described a conditional lethal Δhgprt/Δxprt mutant of L. donovani (Boitz, J. M., and Ullman, B. (2006) J. Biol. Chem. 281, 16084–16089) that establishes that L. donovani salvages purines primarily through hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and xanthine phosphoribosyltransferase (XPRT). Unlike wild type L. donovani, the Δhgprt/Δxprt knock-out cannot grow on 6-oxypurines and displays an absolute requirement for adenine or adenosine and 2′-deoxycoformycin, an inhibitor of parasite adenine aminohydrolase activity. Here, we demonstrate that the ability of Δhgprt/Δxprt parasites to infect mice was profoundly compromised. Surprisingly, mutant parasites that survived the initial passage through mice partially regained their virulence properties, exhibiting a >10-fold increase in parasite burden in a subsequent mouse infection. To dissect the mechanism by which Δhgprt/Δxprt parasites persisted in vivo, suppressor strains that had regained their capacity to grow under restrictive conditions were cloned from cultured Δhgprt/Δxprt parasites. The ability of these suppressor clones to grow in and metabolize 6-oxypurines could be ascribed to a marked amplification and overexpression of the adenine phosphoribosyltransferase (APRT) gene. Moreover, transfection of Δhgprt/Δxprt cells with an APRT episome recapitulated the suppressor phenotype in vitro and enabled growth on 6-oxypurines. Biochemical studies further showed that hypoxanthine, unexpectedly, was an inefficient substrate for APRT, evidence that could account for the ability of the suppressors to metabolize hypoxanthine. Subsequent analysis implied that APRT amplification was also a potential contributory mechanism by which Δhgprt/Δxprt parasites displayed persistence and increased virulence in mice. PMID:20363738

  13. High level expression in Escherichia coli of soluble, enzymatically active schistosomal hypoxanthine/guanine phosphoribosyltransferase and trypanosomal ornithine decarboxylase.

    PubMed Central

    Craig, S P; Yuan, L; Kuntz, D A; McKerrow, J H; Wang, C C

    1991-01-01

    The bacterial alkaline phosphatase (phoA) promoter and signal peptide have been used previously to control recombinant expression and secretion of eukaryotic proteins in Escherichia coli. Other reports have shown that this expression system can generate relatively modest levels of active hypoxanthine/guanine phosphoribosyltransferase (HPRT; hypoxanthine phosphoribosyltransferase; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8), which carries part of the signal peptide but remains in the cytosol of the bacteria. Herein, the phoA promoter without its associated signal peptide is used to regulate expression of the HPRT of Schistosoma mansoni and the ornithine decarboxylase (ODC; L-ornithine carboxy-lyase, EC 4.1.1.17) of Trypanosoma brucei, two enzymes that have been identified as potential targets for antiparasitic chemotherapy. The levels of recombinant expression range from 20% to 60% of the total bacterial protein, and the majority of both recombinant enzymes was soluble. The specific activity for the recombinant trypanosomal ODC was one-third to two-thirds that of the authentic native enzyme and yields were predicted to be 15-30 mg of active enzyme per liter of bacterial culture. The specific activity for the recombinant schistosomal HPRT was equivalent to that for the native enzyme purified from schistosomes and up to 10 mg of enzymatically active HPRT has been purified from a 0.5-liter culture of treated bacteria. These results represent a break-through in recombinant expression of HPRT and ODC. Images PMID:2006185

  14. Nicotinamide Phosphoribosyltransferase in Human Diseases

    PubMed Central

    Zhang, Li Qin; Heruth, Daniel P.; Ye, Shui Qing

    2011-01-01

    Nicotinamide phosphoribosyltransferase (NAMPT) was first reported as a pre-B-cell colony enhancing factor in 1994 with little notice, but it has received increasing attention in recent years due to accumulating evidence indicating that NAMPT is a pleiotropic protein such as a growth factor, a cytokine, an enzyme and a visfatin. Now, NAMPT has been accepted as an official name of this protein. Because of NAMPT’s multiple functions in a variety of physiological processes, their dysregulations have been implicated in the pathogenesis of a number of human diseases or conditions such as acute lung injury, aging, atherosclerosis, cancer, diabetes, rheumatoid arthritis and sepsis. This review will cover the current understanding of NAMPT’s structure and functions with an emphasis on recent progress of nicotinamide phosphoribosyltransferase’s pathological roles in various human diseases and conditions. Future directions on exploring its Terra incognita will be offered in the end. PMID:22140607

  15. Gene mapping in marsupials and monotremes, V. Synteny between hypoxanthine phosphoribosyltransferase and phosphoglycerate kinase in the platypus.

    PubMed

    Watson, J M; Graves, J A

    1988-01-01

    In order to extend comparative mapping studies to the monotreme mammals (subclass Prototheria), somatic-cell hybrids were obtained between Chinese-hamster cells deficient in hypoxanthine phosphoribosyltransferase (HPRT) and platypus fibroblasts. The characteristics of these hybrids closely resemble those of metatherian x eutherian hybrids, in that they are recovered at low frequency and they rapidly segregate and fragment platypus chromosomes. Biochemical and cytological studies of the hybrids, their subclones and HPRT-deficient revertants indicate that phosphoglycerate kinase is syntenic with HPRT in the platypus (as it is in other mammals); however, the studies do not permit chromosomal assignment of the syntenic group. The implications of the chromosomal location of this ancient synteny group for the evolution of the mammalian X chromosome are discussed.

  16. Crystal structure of human nicotinic acid phosphoribosyltransferase.

    PubMed

    Marletta, Ada Serena; Massarotti, Alberto; Orsomando, Giuseppe; Magni, Giulio; Rizzi, Menico; Garavaglia, Silvia

    2015-01-01

    Nicotinic acid phosphoribosyltransferase (EC 2.4.2.11) (NaPRTase) is the rate-limiting enzyme in the three-step Preiss-Handler pathway for the biosynthesis of NAD. The enzyme catalyzes the conversion of nicotinic acid (Na) and 5-phosphoribosyl-1-pyrophosphate (PRPP) to nicotinic acid mononucleotide (NaMN) and pyrophosphate (PPi). Several studies have underlined the importance of NaPRTase for NAD homeostasis in mammals, but no crystallographic data are available for this enzyme from higher eukaryotes. Here, we report the crystal structure of human NaPRTase that was solved by molecular replacement at a resolution of 2.9 Å in its ligand-free form. Our structural data allow the assignment of human NaPRTase to the type II phosphoribosyltransferase subfamily and reveal that the enzyme consists of two domains and functions as a dimer with the active site located at the interface of the monomers. The substrate-binding mode was analyzed by molecular docking simulation and provides hints into the catalytic mechanism. Moreover, structural comparison of human NaPRTase with the other two human type II phosphoribosyltransferases involved in NAD biosynthesis, quinolinate phosphoribosyltransferase and nicotinamide phosphoribosyltransferase, reveals that while the three enzymes share a conserved overall structure, a few distinctive structural traits can be identified. In particular, we show that NaPRTase lacks a tunnel that, in nicotinamide phosphoribosiltransferase, represents the binding site of its potent and selective inhibitor FK866, currently used in clinical trials as an antitumoral agent. PMID:26042198

  17. Deletion screening at the hypoxanthine-guanine phosphoribosyltransferase locus in Chinese hamster cells using the polymerase chain reaction

    SciTech Connect

    Xu, Z.D.; Yu, Y.J.; Hsie, A.W.; Caskey, C.T.; Rossiter, B.; Gibbs, R.A. )

    1989-01-01

    We have developed a rapid screening method using the polymerase chain reaction (PCR) for detecting deletion mutations at the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus in Chinese hamster cells. DNA was extracted from spontaneous and ultraviolet (UV) light- and X-ray-induced hprt-deficient mutants. Two primer sets were used to amplify 276 bp and 344 bp fragments containing the entire exon 3 and exon 9 coding sequence, respectively. The PCR was performed using Taq DNA polymerase for 40 cycles, and the PCR product was directly analyzed for the presence of the respective amplified DNA using electrophoresis on agarose gels stained with ethidium bromide. With this assay, we have analyzed 39 independently derived hprt-deficient mutants. Four of ten spontaneous mutants were found to have deletions in exon 9. UV light produced mutants with predominantly wild-type amplification patterns (10/14). X-ray induced mostly deletion patterns (11/15); six of these occurred only in exon 9, and five occurred in both exons 3 and 9. These observations are consistent with the classical notion that UV light induces predominantly missense mutations and X-ray produces a high proportion of deletion mutations. Deletion mutations occurred most frequently at the 3' end of the hprt gene, suggesting the possible existence of hot spots for deletions in this region. The PCR assay for deletion detection has the advantage that it can be completed in less than 4 hr without using radioisotopes. This assay should be useful for routine deletion screening.

  18. Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

    SciTech Connect

    Jett, J.

    1994-12-01

    While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

  19. Hypoxanthine-guanine phosphoribosyltransferase and inosine 5'-monophosphate dehydrogenase activities in three mammalian species: aquatic (Mirounga angustirostris), semi-aquatic (Lontra longicaudis annectens) and terrestrial (Sus scrofa).

    PubMed

    Barjau Pérez-Milicua, Myrna; Zenteno-Savín, Tania; Crocker, Daniel E; Gallo-Reynoso, Juan P

    2015-01-01

    Aquatic and semiaquatic mammals have the capacity of breath hold (apnea) diving. Northern elephant seals (Mirounga angustirostris) have the ability to perform deep and long duration dives; during a routine dive, adults can hold their breath for 25 min. Neotropical river otters (Lontra longicaudis annectens) can hold their breath for about 30 s. Such periods of apnea may result in reduced oxygen concentration (hypoxia) and reduced blood supply (ischemia) to tissues. Production of adenosine 5'-triphosphate (ATP) requires oxygen, and most mammalian species, like the domestic pig (Sus scrofa), are not adapted to tolerate hypoxia and ischemia, conditions that result in ATP degradation. The objective of this study was to explore the differences in purine synthesis and recycling in erythrocytes and plasma of three mammalian species adapted to different environments: aquatic (northern elephant seal) (n = 11), semiaquatic (neotropical river otter) (n = 4), and terrestrial (domestic pig) (n = 11). Enzymatic activity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) was determined by spectrophotometry, and activity of inosine 5'-monophosphate dehydrogenase (IMPDH) and the concentration of hypoxanthine (HX), inosine 5'-monophosphate (IMP), adenosine 5'-monophosphate (AMP), adenosine 5'-diphosphate (ADP), ATP, guanosine 5'-diphosphate (GDP), guanosine 5'-triphosphate (GTP), and xanthosine 5'-monophosphate (XMP) were determined by high-performance liquid chromatography (HPLC). The activities of HGPRT and IMPDH and the concentration of HX, IMP, AMP, ADP, ATP, GTP, and XMP in erythrocytes of domestic pigs were higher than in erythrocytes of northern elephant seals and river otters. These results suggest that under basal conditions (no diving, sleep apnea or exercise), aquatic, and semiaquatic mammals have less purine mobilization than their terrestrial counterparts.

  20. Hypoxanthine-guanine phosphoribosyltransferase and inosine 5'-monophosphate dehydrogenase activities in three mammalian species: aquatic (Mirounga angustirostris), semi-aquatic (Lontra longicaudis annectens) and terrestrial (Sus scrofa).

    PubMed

    Barjau Pérez-Milicua, Myrna; Zenteno-Savín, Tania; Crocker, Daniel E; Gallo-Reynoso, Juan P

    2015-01-01

    Aquatic and semiaquatic mammals have the capacity of breath hold (apnea) diving. Northern elephant seals (Mirounga angustirostris) have the ability to perform deep and long duration dives; during a routine dive, adults can hold their breath for 25 min. Neotropical river otters (Lontra longicaudis annectens) can hold their breath for about 30 s. Such periods of apnea may result in reduced oxygen concentration (hypoxia) and reduced blood supply (ischemia) to tissues. Production of adenosine 5'-triphosphate (ATP) requires oxygen, and most mammalian species, like the domestic pig (Sus scrofa), are not adapted to tolerate hypoxia and ischemia, conditions that result in ATP degradation. The objective of this study was to explore the differences in purine synthesis and recycling in erythrocytes and plasma of three mammalian species adapted to different environments: aquatic (northern elephant seal) (n = 11), semiaquatic (neotropical river otter) (n = 4), and terrestrial (domestic pig) (n = 11). Enzymatic activity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) was determined by spectrophotometry, and activity of inosine 5'-monophosphate dehydrogenase (IMPDH) and the concentration of hypoxanthine (HX), inosine 5'-monophosphate (IMP), adenosine 5'-monophosphate (AMP), adenosine 5'-diphosphate (ADP), ATP, guanosine 5'-diphosphate (GDP), guanosine 5'-triphosphate (GTP), and xanthosine 5'-monophosphate (XMP) were determined by high-performance liquid chromatography (HPLC). The activities of HGPRT and IMPDH and the concentration of HX, IMP, AMP, ADP, ATP, GTP, and XMP in erythrocytes of domestic pigs were higher than in erythrocytes of northern elephant seals and river otters. These results suggest that under basal conditions (no diving, sleep apnea or exercise), aquatic, and semiaquatic mammals have less purine mobilization than their terrestrial counterparts. PMID:26283971

  1. Purine salvage in the apicomplexan Sarcocystis neurona, and generation of hypoxanthine-xanthine-guanine phosphoribosyltransferase-deficient clones for positive-negative selection of transgenic parasites.

    PubMed

    Dangoudoubiyam, Sriveny; Zhang, Zijing; Howe, Daniel K

    2014-09-01

    Sarcocystis neurona is an apicomplexan parasite that causes severe neurological disease in horses and marine mammals. The Apicomplexa are all obligate intracellular parasites that lack purine biosynthesis pathways and rely on the host cell for their purine requirements. Hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) and adenosine kinase (AK) are key enzymes that function in two complementary purine salvage pathways in apicomplexans. Bioinformatic searches of the S. neurona genome revealed genes encoding HXGPRT, AK and all of the major purine salvage enzymes except purine nucleoside phosphorylase. Wild-type S. neurona were able to grow in the presence of mycophenolic acid (MPA) but were inhibited by 6-thioxanthine (6-TX), suggesting that the pathways involving either HXGPRT or AK are functional in this parasite. Prior work with Toxoplasma gondii demonstrated the utility of HXGPRT as a positive-negative selection marker. To enable the use of HXGPRT in S. neurona, the SnHXGPRT gene sequence was determined and a gene-targeting plasmid was transfected into S. neurona. SnHXGPRT-deficient mutants were selected with 6-TX, and single-cell clones were obtained. These Sn∆HXG parasites were susceptible to MPA and could be complemented using the heterologous T. gondii HXGPRT gene. In summary, S. neurona possesses both purine salvage pathways described in apicomplexans, thus allowing the use of HXGPRT as a positive-negative drug selection marker in this parasite.

  2. The role for an invariant aspartic acid in hypoxanthine phosphoribosyltransferases is examined using saturation mutagenesis, functional analysis, and X-ray crystallography.

    PubMed

    Canyuk, B; Focia, P J; Eakin, A E

    2001-03-01

    The role of an invariant aspartic acid (Asp137) in hypoxanthine phosphoribosyltransferases (HPRTs) was examined by site-directed and saturation mutagenesis, functional analysis, and X-ray crystallography using the HPRT from Trypanosoma cruzi. Alanine substitution (D137A) resulted in a 30-fold decrease of k(cat), suggesting that Asp137 participates in catalysis. Saturation mutagenesis was used to generate a library of mutant HPRTs with random substitutions at position 137, and active enzymes were identified by complementation of a bacterial purine auxotroph. Functional analyses of the mutants, including determination of steady-state kinetic parameters and pH-rate dependence, indicate that glutamic acid or glutamine can replace the wild-type aspartate. However, the catalytic efficiency and pH-rate profile for the structural isosteric mutant, D137N, were similar to the D137A mutant. Crystal structures of four of the mutant enzymes were determined in ternary complex with substrate ligands. Structures of the D137E and D137Q mutants reveal potential hydrogen bonds, utilizing several bound water molecules in addition to protein atoms, that position these side chains within hydrogen bond distance of the bound purine analogue, similar in position to the aspartate in the wild-type structure. The crystal structure of the D137N mutant demonstrates that the Asn137 side chain does not form interactions with the purine substrate but instead forms novel interactions that cause the side chain to adopt a nonfunctional rotamer. The results from these structural and functional analyses demonstrate that HPRTs do not require a general base at position 137 for catalysis. Instead, hydrogen bonding sufficiently stabilizes the developing partial positive charge at the N7-atom of the purine substrate in the transition-state to promote catalysis.

  3. Hypoxanthine-guanine phosphoribosyltransferase and inosine 5′-monophosphate dehydrogenase activities in three mammalian species: aquatic (Mirounga angustirostris), semi-aquatic (Lontra longicaudis annectens) and terrestrial (Sus scrofa)

    PubMed Central

    Barjau Pérez-Milicua, Myrna; Zenteno-Savín, Tania; Crocker, Daniel E.; Gallo-Reynoso, Juan P.

    2015-01-01

    Aquatic and semiaquatic mammals have the capacity of breath hold (apnea) diving. Northern elephant seals (Mirounga angustirostris) have the ability to perform deep and long duration dives; during a routine dive, adults can hold their breath for 25 min. Neotropical river otters (Lontra longicaudis annectens) can hold their breath for about 30 s. Such periods of apnea may result in reduced oxygen concentration (hypoxia) and reduced blood supply (ischemia) to tissues. Production of adenosine 5′-triphosphate (ATP) requires oxygen, and most mammalian species, like the domestic pig (Sus scrofa), are not adapted to tolerate hypoxia and ischemia, conditions that result in ATP degradation. The objective of this study was to explore the differences in purine synthesis and recycling in erythrocytes and plasma of three mammalian species adapted to different environments: aquatic (northern elephant seal) (n = 11), semiaquatic (neotropical river otter) (n = 4), and terrestrial (domestic pig) (n = 11). Enzymatic activity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) was determined by spectrophotometry, and activity of inosine 5′-monophosphate dehydrogenase (IMPDH) and the concentration of hypoxanthine (HX), inosine 5′-monophosphate (IMP), adenosine 5′-monophosphate (AMP), adenosine 5′-diphosphate (ADP), ATP, guanosine 5′-diphosphate (GDP), guanosine 5′-triphosphate (GTP), and xanthosine 5′-monophosphate (XMP) were determined by high-performance liquid chromatography (HPLC). The activities of HGPRT and IMPDH and the concentration of HX, IMP, AMP, ADP, ATP, GTP, and XMP in erythrocytes of domestic pigs were higher than in erythrocytes of northern elephant seals and river otters. These results suggest that under basal conditions (no diving, sleep apnea or exercise), aquatic, and semiaquatic mammals have less purine mobilization than their terrestrial counterparts. PMID:26283971

  4. Transition State Analogues of Plasmodium falciparum and Human Orotate Phosphoribosyltransferases*

    PubMed Central

    Zhang, Yong; Evans, Gary B.; Clinch, Keith; Crump, Douglas R.; Harris, Lawrence D.; Fröhlich, Richard F. G.; Tyler, Peter C.; Hazleton, Keith Z.; Cassera, María B.; Schramm, Vern L.

    2013-01-01

    The survival and proliferation of Plasmodium falciparum parasites and human cancer cells require de novo pyrimidine synthesis to supply RNA and DNA precursors. Orotate phosphoribosyltransferase (OPRT) is an indispensible component in this metabolic pathway and is a target for antimalarials and antitumor drugs. P. falciparum (Pf) and Homo sapiens (Hs) OPRTs are characterized by highly dissociative transition states with ribocation character. On the basis of the geometrical and electrostatic features of the PfOPRT and HsOPRT transition states, analogues were designed, synthesized, and tested as inhibitors. Iminoribitol mimics of the ribocation transition state in linkage to pyrimidine mimics using methylene or ethylene linkers gave dissociation constants (Kd) as low as 80 nm. Inhibitors with pyrrolidine groups as ribocation mimics displayed slightly weaker binding affinities for OPRTs. Interestingly, p-nitrophenyl riboside 5′-phosphate bound to OPRTs with Kd values near 40 nm. Analogues designed with a C5-pyrimidine carbon–carbon bond to ribocation mimics gave Kd values in the range of 80–500 nm. Acyclic inhibitors with achiral serinol groups as the ribocation mimics also displayed nanomolar inhibition against OPRTs. In comparison with the nucleoside derivatives, inhibition constants of their corresponding 5′-phosphorylated transition state analogues are largely unchanged, an unusual property for a nucleotide-binding site. In silico docking of the best inhibitor into the HsOPRT active site supported an extensive hydrogen bond network associated with the tight binding affinity. These OPRT transition state analogues identify crucial components of potent inhibitors targeting OPRT enzymes. Despite their tight binding to the targets, the inhibitors did not kill cultured P. falciparum. PMID:24158442

  5. Extensive regulation of nicotinate phosphoribosyltransferase (NAPRT) expression in human tissues and tumors

    PubMed Central

    Duarte-Pereira, Sara; Pereira-Castro, Isabel; Silva, Sarah S.; Correia, Mariana Gonçalves; Neto, Célia; da Costa, Luís Teixeira; Amorim, António; Silva, Raquel M.

    2016-01-01

    Nicotinamide adenine dinucleotide (NAD) is a cofactor in redox reactions and a substrate for NAD-consuming enzymes, such as PARPs and sirtuins. As cancer cells have increased NAD requirements, the main NAD salvage enzymes in humans, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinate phosphoribosyltransferase (NAPRT), are involved in the development of novel anti-cancer therapies. Knowledge of the expression patterns of both genes in tissues and tumors is critical for the use of nicotinic acid (NA) as cytoprotective in therapies using NAMPT inhibitors. Herein, we provide a comprehensive study of NAPRT and NAMPT expression across human tissues and tumor cell lines. We show that both genes are widely expressed under normal conditions and describe the occurrence of novel NAPRT transcripts. Also, we explore some of the NAPRT gene expression mechanisms. Our findings underline that the efficiency of NA in treatments with NAMPT inhibitors is dependent on the knowledge of the expression profiles and regulation of both NAMPT and NAPRT. PMID:26675378

  6. Assignment of the Gene for Adenine Phosphoribosyltransferase to Human Chromosome 16 by Mouse-Human Somatic Cell Hybridization

    PubMed Central

    Tischfield, Jay A.; Ruddle, Frank H.

    1974-01-01

    A series of mouse-human hybrids was prepared from mouse cells deficient in adenine phosphoribosyltransferase (EC 2.4.2.7) and normal human cells. The hybrids were made in medium containing adenine and alanosine, an antimetabolite known to inhibit de novo adenylic acid biosynthesis. The mouse cells, unable to utilize exogenous adenine, were killed in this medium, but the hybrids proliferated as a consequence of their retaining the human aprt gene. The hybrids were then exposed to the adenine analogs 2,6-diaminopurine and 2-fluoroadenine to select for cells that had lost this gene. Before exposure to the adenine analogs, the expression of human adenine phosphoribosyltransferase by the hybrids was strongly associated only with the presence of human chromosome 16, and afterwards this was the only human chromosome consistently lost. This observation suggests that the human aprt gene can be assigned to chromosome 16. Images PMID:4129802

  7. Interaction of the recombinant human methylpurine-DNA glycosylase (MPG protein) with oligodeoxyribonucleotides containing either hypoxanthine or abasic sites.

    PubMed Central

    Miao, F; Bouziane, M; O'Connor, T R

    1998-01-01

    Methylpurine-DNA glycosylases (MPG proteins, 3-methyladenine-DNA glycosylases) excise numerous damaged bases from DNA during the first step of base excision repair. The damaged bases removed by these proteins include those induced by both alkylating agents and/or oxidizing agents. The intrinsic kinetic parameters (k(cat) and K(m)) for the excision of hypoxanthine by the recombinant human MPG protein from a 39 bp oligodeoxyribonucleotide harboring a unique hypoxanthine were determined. Comparison with other reactions catalyzed by the human MPG protein suggests that the differences in specificity are primarily in product release and not binding. Analysis of MPG protein binding to the 39 bp oligodeoxyribonucleotide revealed that the apparent dissociation constant is of the same order of magnitude as the K(m) and that a 1:1 complex is formed. The MPG protein also forms a strong complex with the product of excision, an abasic site, as well as with a reduced abasic site. DNase I footprinting experiments with the MPG protein on an oligodeoxyribonucleotide with a unique hypoxanthine at a defined position indicate that the protein protects 11 bases on the strand with the hypoxanthine and 12 bases on the complementary strand. Competition experiments with different length, double-stranded, hypoxanthine-containing oligodeoxyribonucleotides show that the footprinted region is relatively small. Despite the small footprint, however, oligodeoxyribonucleotides comprising <15 bp with a hypoxanthine have a 10-fold reduced binding capacity compared with hypoxanthine-containing oligodeoxyribonucleotides >20 bp in length. These results provide a basis for other structural studies of the MPG protein with its targets. PMID:9705516

  8. Recycling nicotinamide. The transition-state structure of human nicotinamide phosphoribosyltransferase

    PubMed Central

    Burgos, Emmanuel S.; Vetticatt, Mathew J.; Schramm, Vern L.

    2013-01-01

    Human nicotinamide phosphoribosyltransferase (NAMPT) replenishes the NAD pool and controls the activities of sirtuins (SIRT), mono- and poly-(ADP-ribose) polymerases (PARP) and NAD nucleosidase (CD38). The nature of the enzymatic transition-state (TS) is central to understanding the function of NAMPT. We determined the TS structure for pyrophosphorolysis of nicotinamide mononucleotide (NMN) by kinetic isotope effects (KIEs). With the natural substrates, NMN and pyrophosphate (PPi), the intrinsic KIEs of [1′-14C], [1-15N], [1′-3H] and [2′-3H] are 1.047, 1.029, 1.154 and 1.093, respectively. A unique quantum computational approach was used for TS analysis that included structural elements of the catalytic site. Without constraints (e.g. imposed torsion angles), the theoretical and experimental data are in good agreement. The quantum-mechanical calculations incorporated a crucial catalytic site residue (D313), two magnesium atoms and coordinated water molecules. The transition state model predicts primary 14C, α-secondary 3H, β-secondary 3H and primary 15N KIE close to the experimental values. The analysis reveals significant ribocation character at the TS. The attacking PPi nucleophile is weakly interacting (rC-O = 2.60 Å) and the N-ribosidic C1′-N bond is highly elongated at the TS (rC-N = 2.35 Å), consistent with an ANDN mechanism. Together with the crystal structure of the NMN•PPi•Mg2•enzyme complex, the reaction coordinate is defined. The enzyme holds the nucleophile and leaving group in relatively fixed positions to create a reaction coordinate with C1′-anomeric migration from nicotinamide to the PPi. The transition state is reached by a 0.85 Å migration of C1′. PMID:23373462

  9. Nicotinamide Phosphoribosyltransferase in Malignancy

    PubMed Central

    Shackelford, Rodney E.; Mayhall, Kim; Maxwell, Nicole M.; Kandil, Emad

    2013-01-01

    Nicotinamide phosphoribosyltransferase (Nampt) catalyzes the rate-limiting step of nicotinamide adenine dinucleotide (NAD) synthesis. Both intracellular and extracellular Nampt (iNampt and eNampt) levels are increased in several human malignancies and some studies demonstrate increased iNampt in more aggressive/invasive tumors and in tumor metastases. Several different molecular targets have been identified that promote carcinogenesis following iNampt overexpression, including SirT1, CtBP, and PARP-1. Additionally, eNampt is elevated in several human cancers and is often associated with a higher tumor stage and worse prognoses. Here we review the roles of Nampt in malignancy, some of the known mechanisms by which it promotes carcinogenesis, and discuss the possibility of employing Nampt inhibitors in cancer treatment. PMID:24386506

  10. A critical role of nicotinamide phosphoribosyltransferase in human telomerase reverse transcriptase induction by resveratrol in aortic smooth muscle cells.

    PubMed

    Huang, Peixin; Riordan, Sean M; Heruth, Daniel P; Grigoryev, Dmitry N; Zhang, Li Qin; Ye, Shui Qing

    2015-05-10

    Aging is the predominant risk factor for cardiovascular diseases and contributes to a considerably more severe outcome in patients with acute myocardial infarction. Resveratrol, a polyphenol found in red wine, is a caloric restriction mimetic with potential anti-aging properties which has emerged as a beneficial nutraceutical for patients with cardiovascular disease. Although resveratrol is widely consumed as a nutritional supplement, its mechanism of action remains to be elucidated fully. Here, we report that resveratrol activates human nicotinamide phosphoribosyltransferase (NAMPT), SIRT4 and telomerase reverse transcriptase (hTERT) in human aortic smooth muscle cells. Similar observations were obtained in resveratrol treated C57BL/6J mouse heart and liver tissues. Resverotrol can also augment telomerase activity in both human pulmonary microvascular endothelial cells and A549 cells. Blocking NAMPT and SIRT4 expression prevents induction of hTERT in human aortic smooth muscle cells while overexpression of NAMPT elevates the telomerase activity induced by resveratrol in A549 cells. Together, these results identify a NAMPT-SIRT4-hTERT axis as a novel mechanism by which resveratrol may affect the anti-aging process in human aortic smooth muscle cells, mouse hearts and other cells. These findings enrich our understanding of the positive effects of resveratrol in human cardiovascular diseases.

  11. Crystal structures and inhibition of Trypanosoma brucei hypoxanthine–guanine phosphoribosyltransferase

    PubMed Central

    Terán, David; Hocková, Dana; Česnek, Michal; Zíková, Alena; Naesens, Lieve; Keough, Dianne T.; Guddat, Luke W.

    2016-01-01

    Human African Trypanosomiasis (HAT) is a life-threatening infectious disease caused by the protozoan parasite, Trypanosoma brucei (Tbr). Due to the debilitating side effects of the current therapeutics and the emergence of resistance to these drugs, new medications for this disease need to be developed. One potential new drug target is 6-oxopurine phosphoribosyltransferase (PRT), an enzyme central to the purine salvage pathway and whose activity is critical for the production of the nucleotides (GMP and IMP) required for DNA/RNA synthesis within this protozoan parasite. Here, the first crystal structures of this enzyme have been determined, these in complex with GMP and IMP and with three acyclic nucleoside phosphonate (ANP) inhibitors. The Ki values for GMP and IMP are 30.5 μM and 77 μM, respectively. Two of the ANPs have Ki values considerably lower than for the nucleotides, 2.3 μM (with guanine as base) and 15.8 μM (with hypoxanthine as base). The crystal structures show that when two of the ANPs bind, they induce an unusual conformation change to the loop where the reaction product, pyrophosphate, is expected to bind. This and other structural differences between the Tbr and human enzymes suggest selective inhibitors for the Tbr enzyme can be designed. PMID:27786284

  12. Hypoxanthine-guanine phosophoribosyltransferase (HPRT) deficiency: Lesch-Nyhan syndrome

    PubMed Central

    Torres, Rosa J; Puig, Juan G

    2007-01-01

    Deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT) activity is an inborn error of purine metabolism associated with uric acid overproduction and a continuum spectrum of neurological manifestations depending on the degree of the enzymatic deficiency. The prevalence is estimated at 1/380,000 live births in Canada, and 1/235,000 live births in Spain. Uric acid overproduction is present inall HPRT-deficient patients and is associated with lithiasis and gout. Neurological manifestations include severe action dystonia, choreoathetosis, ballismus, cognitive and attention deficit, and self-injurious behaviour. The most severe forms are known as Lesch-Nyhan syndrome (patients are normal at birth and diagnosis can be accomplished when psychomotor delay becomes apparent). Partial HPRT-deficient patients present these symptoms with a different intensity, and in the least severe forms symptoms may be unapparent. Megaloblastic anaemia is also associated with the disease. Inheritance of HPRT deficiency is X-linked recessive, thus males are generally affected and heterozygous female are carriers (usually asymptomatic). Human HPRT is encoded by a single structural gene on the long arm of the X chromosome at Xq26. To date, more than 300 disease-associated mutations in the HPRT1 gene have been identified. The diagnosis is based on clinical and biochemical findings (hyperuricemia and hyperuricosuria associated with psychomotor delay), and enzymatic (HPRT activity determination in haemolysate, intact erythrocytes or fibroblasts) and molecular tests. Molecular diagnosis allows faster and more accurate carrier and prenatal diagnosis. Prenatal diagnosis can be performed with amniotic cells obtained by amniocentesis at about 15–18 weeks' gestation, or chorionic villus cells obtained at about 10–12 weeks' gestation. Uric acid overproduction can be managed by allopurinol treatment. Doses must be carefully adjusted to avoid xanthine lithiasis. The lack of precise

  13. Prospects for cellular mutational assays in human populations

    SciTech Connect

    Mendelsohn, M.L.

    1984-06-29

    Practical, sensitive, and effective human cellular assays for detecting somatic and germinal mutations would have great value in environmental mutagenesis and carcinogenesis studies. Such assays would fill the void between human mutagenicity and the data that exist from short-term tests and from mutagenicity in other species. This paper discusses the following possible human cellular assays: (1) HPRT (hypoxanthine phosphoribosyltransferase) somatic cell mutation based on 6-thioguanine resistance; (2) hemoglobin somatic cell mutation assay; (3) glycophorin somatic cell mutation assay; and (4) LDH-X sperm cell mutation assay. 18 references.

  14. Linkage of the gene for an X-linked mental retardation disorder to a hypervariable (AGAT)n repeat motif within the human hypoxanthine phosphoribosyltransferase (HPRT) locus (Xq26).

    PubMed Central

    Huang, T H; Hejtmancik, J F; Edwards, A; Pettigrew, A L; Herrera, C A; Hammond, H A; Caskey, C T; Zoghbi, H Y; Ledbetter, D H

    1991-01-01

    We recently reported a new X-linked mental retardation (XLMR) disorder in a four-generation family of Dutch descent. Features included Dandy-Walker malformation, basal ganglia disease, and seizures. Twenty-six family members, including two living affected males and two obligate carriers, were available for study. No evidence of linkage was observed between the disease locus and RFLPs from several X-chromosome regions, including Xp21-p22 (13 markers), proximal Xq (four markers), and Xq28 (three markers). However, a new hypervariable short tandem repeat (STR) within the HPRT gene at Xq26 showed positive linkage to the disease locus, with a maximum lod score of 2.19 at a recombination fraction of 0. A second hypervariable marker in Xq26, the dinucleotide repeat XL90A3 (DXS425), showed a lod score of .84 at a recombination fraction of .11. Both the HPRT and DXS425 markers were typed in 40 CEPH families, and subsequent multipoint linkage analysis showed the following order: Xcen-DXS425-(HPRT,XLMR)-F9-qter. HPRT and these flanking markers are therefore useful for carrier detection and prenatal diagnosis in this family. This study illustrates that hypervariable STRs will be powerful tools for linkage analysis and genetic diagnosis, particularly when relatively small families are involved. Images Figure 1 PMID:1746558

  15. New hypoxanthine nucleosides with RNA antiviral activity.

    PubMed

    Nair, V; Ussery, M A

    1992-08-01

    A series of novel C-2 functionalized hypoxanthine and purine ribonucleosides have been synthesized and evaluated against exotic RNA viruses of the family or genus alpha, arena, flavi, and rhabdo. Both specific and broad-spectrum antiviral activities were discovered but only with hypoxanthine nucleosides. PMID:1444325

  16. Anti-oxidant effects of the extracts from the leaves of Chromolaena odorata on human dermal fibroblasts and epidermal keratinocytes against hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage.

    PubMed

    Thang, P T; Patrick, S; Teik, L S; Yung, C S

    2001-06-01

    In cutaneous tissue repair, oxidants and antioxidants play very important roles. In local acute and chronic wounds, oxidants are known to have the ability to cause as cell damage and may function as inhibitory factors to wound healing. The administration of anti-oxidants or free radical scavengers is reportedly helpful, notably in order to limit the delayed sequelae of thermal trauma and to enhance the healing process. Extracts from the leaves of Chromolaena odorata have been shown to be beneficial for treatment of wounds. Studies in vitro of these extracts demonstrated enhanced proliferation of fibroblasts, endothelial cells and keratinocytes, stimulation of keratinocyte migration in an in vitro wound assay, up-regulation of production by keratinocytes of extracellular matrix proteins and basement membrane components, and inhibition of collagen lattice contraction by fibroblasts. In this study, the anti-oxidant effects of both total ethanol and polyphenolic extracts from the plant leaves on hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage to human fibroblasts and keratinocytes were investigated. Cell viability was monitored by a colorimetric assay. The results showed that for fibroblasts, toxicity of hydrogen peroxide or hypoxanthine xanthine oxidase on cells was dose-dependent. Total ethanol extract (TEE) at 400 and 800 microg/ml showed maximum and consistent protective cellular effect on oxidant toxicity at low or high doses of oxidants. The 50 microg/ml concentration of TEE also had significant and slightly protective effects on fibroblasts against hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage, respectively. For keratinocytes, a dose-dependent relationship of oxidant toxicity was only seen with hydrogen peroxide but the protective action of the extract correlated with oxidant dosage. TEE at 400 and 800 microg/ml showed dose-dependent effects with both low and high concentration of oxidants. TEE at 50 microg/ml had no

  17. Interactions at the Dimer Interface Influence the Relative Efficiencies for Purine Nucleotide Synthesis and Pyrophosphorolysis in a Phosphoribosyltransferase

    SciTech Connect

    Canyuk, Bhutorn; Medrano, Francisco J.; Wenck, MaryAnne; Focia, Pamela J.; Eakin, Ann E.; Craig III, Sydney P.

    2010-03-05

    Enzymes that salvage 6-oxopurines, including hypoxanthine phosphoribosyltransferases (HPRTs), are potential targets for drugs in the treatment of diseases caused by protozoan parasites. For this reason, a number of high-resolution X-ray crystal structures of the HPRTs from protozoa have been reported. Although these structures did not reveal why HPRTs need to form dimers for catalysis, they revealed the existence of potentially relevant interactions involving residues in a loop of amino acid residues adjacent to the dimer interface, but the contributions of these interactions to catalysis remained poorly understood. The loop, referred to as active-site loop I, contains an unusual non-proline cis-peptide and is composed of residues that are structurally analogous with Leu67, Lys68, and Gly69 in the human HPRT. Functional analyses of site-directed mutations (K68D, K68E, K68N, K68P, and K68R) in the HPRT from Trypanosoma cruzi, etiologic agent of Chagas disease, show that the side-chain at position 68 can differentially influence the K{sub m} values for all four substrates as well as the k{sub cat} values for both IMP formation and pyrophosphorolysis. Also, the results for the K68P mutant are inconsistent with a cis-trans peptide isomerization-assisted catalytic mechanism. These data, together with the results of structural studies of the K68R mutant, reveal that the side-chain of residue 68 does not participate directly in reaction chemistry, but it strongly influences the relative efficiencies for IMP formation and pyrophosphorolysis, and the prevalence of lysine at position 68 in the HPRT of the majority of eukaryotes is consistent with there being a biological role for nucleotide pyrophosphorolysis.

  18. Hereditary xanthinuria. Evidence for enhanced hypoxanthine salvage.

    PubMed Central

    Mateos, F A; Puig, J G; Jiménez, M L; Fox, I H

    1987-01-01

    We tested the hypothesis that there is an enhanced rate of hypoxanthine salvage in two siblings with hereditary xanthinuria. We radiolabeled the adenine nucleotide pool with [8-14C]adenine and examined purine nucleotide degradation after intravenous fructose. The cumulative excretion of radioactivity during a 5-d period was 9.7% and 9.1% of infused radioactivity in the enzyme-deficient patients and 6.0 +/- 0.7% (mean +/- SE) in four normal subjects. Fructose infusion increased urinary radioactivity to 7.96 and 9.16 X 10(6) cpm/g creatinine in both patients and to 4.73 +/- 0.69 X 10(6) cpm/g creatinine in controls. The infusion of fructose increased total urinary purine excretion to a mean of 487% from low-normal baseline values in the patients and to 398 +/- 86% in control subjects. In the enzyme-deficient patients, the infusion of fructose elicited an increase of plasma guanosine from undetectable values to 0.7 and 0.9 microM. With adjustments made for intestinal purine loss, these data support the hypothesis that there is enhanced hypoxanthine salvage in hereditary xanthinuria. Degradation of guanine nucleotides to xanthine bypasses the hypoxanthine salvage pathway and may explain the predominance of this urinary purine compound in xanthinuria. PMID:3818951

  19. A kinetic study of hypoxanthine oxidation by milk xanthine oxidase.

    PubMed Central

    Escribano, J; Garcia-Canovas, F; Garcia-Carmona, F

    1988-01-01

    The course of the reaction sequence hypoxanthine----xanthine----uric acid catalysed by xanthine:oxygen oxidoreductase from milk was investigated on the basis of u.v. spectra taken during the course of hypoxanthine and xanthine oxidations. It was found that xanthine accumulated in the reaction mixture when hypoxanthine was used as a substrate. The time course of the concentrations of hypoxanthine, xanthine intermediate and uric acid product was simulated numerically. The mathematical model takes into account the competition of substrate, intermediate and product and the accumulation of the intermediate at the enzyme. This type of analysis permits the kinetic parameters of the enzyme for hypoxanthine and xanthine to be obtained. PMID:3196295

  20. Number and size of human X chromosome fragments transferred to mouse cells by chromosome-mediated gene transfer

    SciTech Connect

    Olsen, A.S.; McBride, O.W.; Moore, D.E.

    1981-05-01

    Labeled probes of unique-sequence human X chromosomal deoxyribonucleic acid, prepared by two different procedures, were used to measure the amount of human X chromosomal deoxyribonucleic acid in 12 mouse cell lines expressing human hypoxanthine phosphoribosyltransferase after chromosome-mediated gene transfer. The amount of X chromosomal deoxyribonucleic acid detected by this procedure ranged from undetectable levels in the three stable transformants and some unstable transformants examined to about 20% of the human X chromosome in two unstable transformants. Reassociation kinetics of the X chromosomal probe with deoxyribonucleic acid from the two unstable transformants containing 15 to 20% of the human X chromosome indicate that a single copy of these sequences is present. In one of these lines, the X chromosomal sequences exist as multiple fragments which were not concordantly segregated when the cells were selected for loss of hprt.

  1. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines

    PubMed Central

    López-Cruz, Roberto I.; Crocker, Daniel E.; Gaxiola-Robles, Ramón; Bernal, Jaime A.; Real-Valle, Roberto A.; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements. PMID:27375492

  2. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines.

    PubMed

    López-Cruz, Roberto I; Crocker, Daniel E; Gaxiola-Robles, Ramón; Bernal, Jaime A; Real-Valle, Roberto A; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements.

  3. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines.

    PubMed

    López-Cruz, Roberto I; Crocker, Daniel E; Gaxiola-Robles, Ramón; Bernal, Jaime A; Real-Valle, Roberto A; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements. PMID:27375492

  4. Ultrafast electronic deactivation dynamics of the rare natural nucleobase hypoxanthine

    NASA Astrophysics Data System (ADS)

    Röttger, Katharina; Siewertsen, Ron; Temps, Friedrich

    2012-05-01

    The electronic deactivation of the 6-oxopurine derivative hypoxanthine, its nucleoside inosine and the nucleotide inosine monophosphate have been studied by femtosecond time-resolved spectroscopy after ππ∗ photoexcitation at λ = 260 nm. The development of a highly sensitive parallel broadband (near-UV/VIS) and single-color (deep-UV) transient absorption setup enabled us to monitor the excited-state decay and the ground-state recovery dynamics in one and the same experiment. The measurements revealed similar relaxation behavior, with time constants of τ1 ≲ 0.1 ps, τ2 ≈ 0.21 ± 0.08 ps and τ3 ≈ 1.8 ± 0.4 ps, for all three investigated molecules. The observed dynamics are assumed to take place through a conical intersection involving an out-of-plane puckering mode of the six-membered ring similar to guanine.

  5. Proinflammatory actions of visfatin/nicotinamide phosphoribosyltransferase (Nampt) involve regulation of insulin signaling pathway and Nampt enzymatic activity.

    PubMed

    Jacques, Claire; Holzenberger, Martin; Mladenovic, Zvezdana; Salvat, Colette; Pecchi, Emilie; Berenbaum, Francis; Gosset, Marjolaine

    2012-04-27

    Visfatin (also termed pre-B-cell colony-enhancing factor (PBEF) or nicotinamide phosphoribosyltransferase (Nampt)) is a pleiotropic mediator acting on many inflammatory processes including osteoarthritis. Visfatin exhibits both an intracellular enzymatic activity (nicotinamide phosphoribosyltransferase, Nampt) leading to NAD synthesis and a cytokine function via the binding to its hypothetical receptor. We recently reported the role of visfatin in prostaglandin E(2) (PGE(2)) synthesis in chondrocytes. Here, our aim was to characterize the signaling pathways involved in this response in exploring both the insulin receptor (IR) signaling pathway and Nampt activity. IR was expressed in human and murine chondrocytes, and visfatin triggered Akt phosphorylation in murine chondrocytes. Blocking IR expression with siRNA or activity using the hydroxy-2-naphthalenyl methyl phosphonic acid tris acetoxymethyl ester (HNMPA-(AM)(3)) inhibitor diminished visfatin-induced PGE(2) release in chondrocytes. Moreover, visfatin-induced IGF-1R(-/-) chondrocytes released higher concentration of PGE(2) than IGF-1R(+/+) cells, a finding confirmed with an antibody that blocked IGF-1R. Using RT-PCR, we found that visfatin did not regulate IR expression and that an increased insulin release was also unlikely to be involved because insulin was unable to increase PGE(2) release. Inhibition of Nampt activity using the APO866 inhibitor gradually decreased PGE(2) release, whereas the addition of exogenous nicotinamide increased it. We conclude that the proinflammatory actions of visfatin in chondrocytes involve regulation of IR signaling pathways, possibly through the control of Nampt enzymatic activity.

  6. Isolation of the human chromosomal band Xq28 within somatic cell hybrids by fragile X site breakage

    SciTech Connect

    Warren, S.T.; Knight, S.J.L.; Peters, J.F.; Stayton, C.L.; Consalez, G.G.; Zhang, F. )

    1990-05-01

    The chromosomal fragile-site mapping to Xq27.3 is associated with a frequent form of mental retardation and is prone to breakage after induced deoxyribonucleotide pool perturbation. The human hypoxanthine phosphoribosyltransferase (HPRT) and glucose-6-phosphate dehydrogenase (G6PD) genes flank the fragile X chromosome site and can be used to monitor integrity of the site in human-hamster somatic cell hybrids deficient in the rodent forms of these activities. After induction of the fragile X site, negative selection for HPRT and positive enrichment for G6PD resulted in 31 independent colonies of HPRT{sup {minus}}, G6PD{sup +} phenotype. Southern blot analysis demonstrated the loss of all tested markers proximal to the fragile X site with retention of all tested human Xq28 loci in a majority of the hybrids. In situ hybridization with a human-specific probe demonstrated the translocation of a small amount of human DNA to rodent chromosomes in these hybrids, suggesting chromosome breakage at the fragile X site and the subsequent translocation of Xq28. Southern blot hybridization of hybrid-cell DNA, resolved by pulsed-field gel electrophoresis, for human-specific repetitive sequences revealed abundant CpG-islands within Xq28, consistent with its known gene density. The electrophoretic banding patterns of human DNA among the hybrids were remarkably consistent, suggesting that fragile X site breakage is limited to a relatively small region in Xq27-28.

  7. Molecular characterization of quinolinate phosphoribosyltransferase (QPRtase) in Nicotiana.

    PubMed

    Sinclair, S J; Murphy, K J; Birch, C D; Hamill, J D

    2000-11-01

    Quinolate acid phosphoribosyltransferase (QPRTase), a key enzyme in nicotinamide adenine dinucleotide (NAD) biosynthesis, also plays an important role in ensuring nicotinic acid is available for the synthesis of defensive pyridine alkaloids in Nicotiana species. In this study, cDNAs for QPRTase were characterized from N. rustica and N. tabacum. Deduced proteins from both cDNAs are almost identical and contain a 24 amino acid N-terminal extension, not reported in other QPRTases, that has characteristics of a mitochondrial targeting sequence. In N. tabacum and N. sylvestris, both of which contain nicotine as the major pyridine alkaloid, QPRTase transcript was detected in roots, the site of nicotine synthesis, but not in leaves. QPRTase transcript levels increased markedly in roots of both species 12-24 h after damage to aerial tissues, with a concomitant rise in transcript levels of putrescine N-methyltransferase (PMT), another key enzyme in nicotine biosynthesis. In N. glauca, however, in which anabasine represents the major pyridine alkaloid, QPRTase transcript was detected in both leaf and root tissues. Moreover, wound induction of QPRTase but not PMT was observed in leaf tissues, and not in roots, 12-24 h after wounding. Southern analysis of genomic DNA from the Nicotiana species noted above, and also several others from within the genus, suggested that QPRTase is encoded by a small gene family in all the species investigated. PMID:11198422

  8. Biochemical characterization of uracil phosphoribosyltransferase from Mycobacterium tuberculosis.

    PubMed

    Villela, Anne Drumond; Ducati, Rodrigo Gay; Rosado, Leonardo Astolfi; Bloch, Carlos Junior; Prates, Maura Vianna; Gonçalves, Danieli Cristina; Ramos, Carlos Henrique Inacio; Basso, Luiz Augusto; Santos, Diogenes Santiago

    2013-01-01

    Uracil phosphoribosyltransferase (UPRT) catalyzes the conversion of uracil and 5-phosphoribosyl-α-1-pyrophosphate (PRPP) to uridine 5'-monophosphate (UMP) and pyrophosphate (PP(i)). UPRT plays an important role in the pyrimidine salvage pathway since UMP is a common precursor of all pyrimidine nucleotides. Here we describe cloning, expression and purification to homogeneity of upp-encoded UPRT from Mycobacterium tuberculosis (MtUPRT). Mass spectrometry and N-terminal amino acid sequencing unambiguously identified the homogeneous protein as MtUPRT. Analytical ultracentrifugation showed that native MtUPRT follows a monomer-tetramer association model. MtUPRT is specific for uracil. GTP is not a modulator of MtUPRT ativity. MtUPRT was not significantly activated or inhibited by ATP, UTP, and CTP. Initial velocity and isothermal titration calorimetry studies suggest that catalysis follows a sequential ordered mechanism, in which PRPP binding is followed by uracil, and PP(i) product is released first followed by UMP. The pH-rate profiles indicated that groups with pK values of 5.7 and 8.1 are important for catalysis, and a group with a pK value of 9.5 is involved in PRPP binding. The results here described provide a solid foundation on which to base upp gene knockout aiming at the development of strategies to prevent tuberculosis.

  9. Biochemical Characterization of Uracil Phosphoribosyltransferase from Mycobacterium tuberculosis

    PubMed Central

    Villela, Anne Drumond; Ducati, Rodrigo Gay; Rosado, Leonardo Astolfi; Bloch, Carlos Junior; Prates, Maura Vianna; Gonçalves, Danieli Cristina; Ramos, Carlos Henrique Inacio; Basso, Luiz Augusto; Santos, Diogenes Santiago

    2013-01-01

    Uracil phosphoribosyltransferase (UPRT) catalyzes the conversion of uracil and 5-phosphoribosyl-α-1-pyrophosphate (PRPP) to uridine 5′-monophosphate (UMP) and pyrophosphate (PPi). UPRT plays an important role in the pyrimidine salvage pathway since UMP is a common precursor of all pyrimidine nucleotides. Here we describe cloning, expression and purification to homogeneity of upp-encoded UPRT from Mycobacterium tuberculosis (MtUPRT). Mass spectrometry and N-terminal amino acid sequencing unambiguously identified the homogeneous protein as MtUPRT. Analytical ultracentrifugation showed that native MtUPRT follows a monomer-tetramer association model. MtUPRT is specific for uracil. GTP is not a modulator of MtUPRT ativity. MtUPRT was not significantly activated or inhibited by ATP, UTP, and CTP. Initial velocity and isothermal titration calorimetry studies suggest that catalysis follows a sequential ordered mechanism, in which PRPP binding is followed by uracil, and PPi product is released first followed by UMP. The pH-rate profiles indicated that groups with pK values of 5.7 and 8.1 are important for catalysis, and a group with a pK value of 9.5 is involved in PRPP binding. The results here described provide a solid foundation on which to base upp gene knockout aiming at the development of strategies to prevent tuberculosis. PMID:23424660

  10. Nicotinamide phosphoribosyltransferase (NAMPT/PBEF/visfatin) is a tumoural cytokine released from melanoma.

    PubMed

    Grolla, Ambra A; Torretta, Simone; Gnemmi, Ilaria; Amoruso, Angela; Orsomando, Giuseppe; Gatti, Marco; Caldarelli, Antonio; Lim, Dmitry; Penengo, Lorenza; Brunelleschi, Sandra; Genazzani, Armando A; Travelli, Cristina

    2015-11-01

    High plasma levels of nicotinamide phosphoribosyltransferase (NAMPT), traditionally considered an intracellular enzyme with a key role in NAD synthesis, have been reported in several oncological, inflammatory and metabolic diseases. We now show that eNAMPT can be actively released by melanoma cells in vitro. We analysed the mechanisms of its release, and we found both classical and non-classical pathway involvement. eNAMPT released by melanoma cells, in our hands, has paracrine and autocrine effects: it activates MAPK, AKT and NF-κB pathways and increases colony formation in anchorage-independent conditions. eNAMPT also induces M1 polarization in human monocytes. Last, we demonstrate, for the first time in any cancer type, that eNAMPT levels in plasma of tumour-bearing mice increase and that this increase can be reconducted to the tumour itself. This provides an important cue on previous observations that eNAMPT is increased in patients with cancer. Moreover, silencing NAMPT in melanoma cells leads to a reduction in the tumour growth rate. Our findings extend the basis to consider eNAMPT as a cytokine involved in tumour progression. PMID:26358657

  11. Nicotinamide phosphoribosyltransferase (NAMPT/PBEF/visfatin) is a tumoural cytokine released from melanoma.

    PubMed

    Grolla, Ambra A; Torretta, Simone; Gnemmi, Ilaria; Amoruso, Angela; Orsomando, Giuseppe; Gatti, Marco; Caldarelli, Antonio; Lim, Dmitry; Penengo, Lorenza; Brunelleschi, Sandra; Genazzani, Armando A; Travelli, Cristina

    2015-11-01

    High plasma levels of nicotinamide phosphoribosyltransferase (NAMPT), traditionally considered an intracellular enzyme with a key role in NAD synthesis, have been reported in several oncological, inflammatory and metabolic diseases. We now show that eNAMPT can be actively released by melanoma cells in vitro. We analysed the mechanisms of its release, and we found both classical and non-classical pathway involvement. eNAMPT released by melanoma cells, in our hands, has paracrine and autocrine effects: it activates MAPK, AKT and NF-κB pathways and increases colony formation in anchorage-independent conditions. eNAMPT also induces M1 polarization in human monocytes. Last, we demonstrate, for the first time in any cancer type, that eNAMPT levels in plasma of tumour-bearing mice increase and that this increase can be reconducted to the tumour itself. This provides an important cue on previous observations that eNAMPT is increased in patients with cancer. Moreover, silencing NAMPT in melanoma cells leads to a reduction in the tumour growth rate. Our findings extend the basis to consider eNAMPT as a cytokine involved in tumour progression.

  12. Crystal Structure of Sus scrofa Quinolinate Phosphoribosyltransferase in Complex with Nicotinate Mononucleotide

    PubMed Central

    Youn, Hyung-Seop; Kim, Mun-Kyoung; Kang, Gil Bu; Kim, Tae Gyun; Lee, Jung-Gyu; An, Jun Yop; Park, Kyoung Ryoung; Lee, Youngjin; Kang, Jung Youn; Song, Hye-Eun; Park, Inju; Cho, Chunghee; Fukuoka, Shin-Ichi; Eom, Soo Hyun

    2013-01-01

    We have determined the crystal structure of porcine quinolinate phosphoribosyltransferase (QAPRTase) in complex with nicotinate mononucleotide (NAMN), which is the first crystal structure of a mammalian QAPRTase with its reaction product. The structure was determined from protein obtained from the porcine kidney. Because the full protein sequence of porcine QAPRTase was not available in either protein or nucleotide databases, cDNA was synthesized using reverse transcriptase-polymerase chain reaction to determine the porcine QAPRTase amino acid sequence. The crystal structure revealed that porcine QAPRTases have a hexameric structure that is similar to other eukaryotic QAPRTases, such as the human and yeast enzymes. However, the interaction between NAMN and porcine QAPRTase was different from the interaction found in prokaryotic enzymes, such as those of Helicobacter pylori and Mycobacterium tuberculosis. The crystal structure of porcine QAPRTase in complex with NAMN provides a structural framework for understanding the unique properties of the mammalian QAPRTase active site and designing new antibiotics that are selective for the QAPRTases of pathogenic bacteria, such as H. pylori and M. tuberculosis. PMID:23626766

  13. Dissociative electron attachment to the gas-phase nucleobase hypoxanthine

    NASA Astrophysics Data System (ADS)

    Dawley, M. Michele; Tanzer, Katrin; Carmichael, Ian; Denifl, Stephan; Ptasińska, Sylwia

    2015-06-01

    We present high-resolution measurements of the dissociative electron attachment (DEA) to isolated gas-phase hypoxanthine (C5H4N4O, Hyp), a tRNA purine base. The anion mass spectra and individual ion efficiency curves from Hyp were measured as a function of electron energy below 9 eV. The mass spectra at 1 and 6 eV exhibit the highest anion yields, indicating possible common precursor ions that decay into the detectable anionic fragments. The (Hyp - H) anion (C5H3N4O-) exhibits a sharp resonant peak at 1 eV, which we tentatively assign to a dipole-bound state of the keto-N1H,N9H tautomer in which dehydrogenation occurs at either the N1 or N9 position based upon our quantum chemical computations (B3LYP/6-311+G(d,p) and U(MP2-aug-cc-pVDZ+)) and prior studies with adenine. This closed-shell dehydrogenated anion is the dominant fragment formed upon electron attachment, as with other nucleobases. Seven other anions were also observed including (Hyp - NH)-, C4H3N4-/C4HN3O-, C4H2N3-, C3NO-/HC(HCN)CN-, OCN-, CN-, and O-. Most of these anions exhibit broad but weak resonances between 4 and 8 eV similar to many analogous anions from adenine. The DEA to Hyp involves significant fragmentation, which is relevant to understanding radiation damage of biomolecules.

  14. Dissociative electron attachment to the gas-phase nucleobase hypoxanthine

    SciTech Connect

    Dawley, M. Michele; Tanzer, Katrin; Denifl, Stephan E-mail: Sylwia.Ptasinska.1@nd.edu; Carmichael, Ian; Ptasińska, Sylwia E-mail: Sylwia.Ptasinska.1@nd.edu

    2015-06-07

    We present high-resolution measurements of the dissociative electron attachment (DEA) to isolated gas-phase hypoxanthine (C{sub 5}H{sub 4}N{sub 4}O, Hyp), a tRNA purine base. The anion mass spectra and individual ion efficiency curves from Hyp were measured as a function of electron energy below 9 eV. The mass spectra at 1 and 6 eV exhibit the highest anion yields, indicating possible common precursor ions that decay into the detectable anionic fragments. The (Hyp − H) anion (C{sub 5}H{sub 3}N{sub 4}O{sup −}) exhibits a sharp resonant peak at 1 eV, which we tentatively assign to a dipole-bound state of the keto-N1H,N9H tautomer in which dehydrogenation occurs at either the N1 or N9 position based upon our quantum chemical computations (B3LYP/6-311+G(d,p) and U(MP2-aug-cc-pVDZ+)) and prior studies with adenine. This closed-shell dehydrogenated anion is the dominant fragment formed upon electron attachment, as with other nucleobases. Seven other anions were also observed including (Hyp − NH){sup −}, C{sub 4}H{sub 3}N{sub 4}{sup −}/C{sub 4}HN{sub 3}O{sup −}, C{sub 4}H{sub 2}N{sub 3}{sup −}, C{sub 3}NO{sup −}/HC(HCN)CN{sup −}, OCN{sup −}, CN{sup −}, and O{sup −}. Most of these anions exhibit broad but weak resonances between 4 and 8 eV similar to many analogous anions from adenine. The DEA to Hyp involves significant fragmentation, which is relevant to understanding radiation damage of biomolecules.

  15. Mutation induction in human lymphoid cells by energetic heavy ions

    NASA Astrophysics Data System (ADS)

    Kronenberg, A.

    1994-10-01

    One of the concerns for extended space flight outside the magnetosphere is exposure to galactic cosmic radiation. In the series of studies presented herein, the mutagenic effectiveness of high energy heavy ions is examined using human B-lymphoblastoid cells across an LET range from 32keV/μm to 190 keV/μm. Mutations were scored for an autosomal locus, thymidine kinase (tk), and for an X-linked locus, hypoxanthine phosphoribosyltransferase (hprt). For each of the radiations studied, the autosomal locus is more sensitive to mutation induction than is the X-linked locus. When mutational yields are expressed in terms of particle fluence, the two loci respond quite differently across the range of LET. The action cross section for mutation induction peaks at 61 keV/μm for the tk locus and then declines for particles of higher LET, including Fe ions. For the hprt locus, the action cross section for mutation is maximal at 95 keV/μm but is relatively constant across the range from 61 keV/μm to 190 keV/gmm. The yields of hprt-deficient mutants obtained after HZE exposure to TK6 lymphoblasts may be compared directly with published data on the induction of hprt-deficient mutants in human neonatal fibroblasts exposed to similar ions. The action cross section for induction of hprt-deficient mutants by energetic Fe ions is more than 10-fold lower for lymphoblastoid cells than for fibroblasts.

  16. True Niacin Deficiency in Quinolinic Acid Phosphoribosyltransferase (QPRT) Knockout Mice.

    PubMed

    Shibata, Katsumi

    2015-01-01

    Pyridine nucleotide coenzymes (PNCs) are involved in over 500 enzyme reactions. PNCs are biosynthesized from the amino acid L-tryptophan (L-Trp), as well as the vitamin niacin. Hence, "true" niacin-deficient animals cannot be "created" using nutritional techniques. We wanted to establish a truly niacin-deficient model animal using a protocol that did not involve manipulating dietary L-Trp. We generated mice that are missing the quinolinic acid phosphoribosyltransferase (QPRT) gene. QPRT activity was not detected in qprt(-/-)mice. The qprt(+/+), qprt(+/-) or qprt(-/-) mice (8 wk old) were fed a complete diet containing 30 mg nicotinic acid (NiA) and 2.3 g L-Trp/kg diet or an NiA-free diet containing 2.3 g L-Trp/kg diet for 23 d. When qprt(-/-)mice were fed a complete diet, food intake and body weight gain did not differ from those of the qprt(+/+) and the qprt(+/-) mice. On the other hand, in the qprt(-/-) mice fed the NiA-free diet, food intake and body weight were reduced to 60% (p<0.01) and 70% (p<0.05) of the corresponding values for the qprt(-/-) mice fed the complete diet at day 23, respectively. The nutritional levels of niacin such as blood and liver NAD concentrations were also lower in the qprt(-/-) mice than in the qprt(+/+) and the qprt(+/-) mice. Urinary excretion of quinolinic acid was greater in the qprt(-/-) mice than in the qprt(+/+) and the qprt(+/-) mice (p<0.01). These data suggest that we generated truly niacin-deficient mice. PMID:26598832

  17. Phenotype and Genotype Characterization of Adenine Phosphoribosyltransferase Deficiency

    PubMed Central

    Bollée, Guillaume; Dollinger, Cécile; Boutaud, Lucile; Guillemot, Delphine; Bensman, Albert; Harambat, Jérôme; Deteix, Patrice; Daudon, Michel; Knebelmann, Bertrand

    2010-01-01

    Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive disorder causing 2,8-dihydroxyadenine stones and renal failure secondary to intratubular crystalline precipitation. Little is known regarding the clinical presentation of APRT deficiency, especially in the white population. We retrospectively reviewed all 53 cases of APRT deficiency (from 43 families) identified at a single institution between 1978 and 2009. The median age at diagnosis was 36.3 years (range 0.5 to 78.0 years). In many patients, a several-year delay separated the onset of symptoms and diagnosis. Of the 40 patients from 33 families with full clinical data available, 14 (35%) had decreased renal function at diagnosis. Diagnosis occurred in six (15%) patients after reaching ESRD, with five diagnoses made at the time of disease recurrence in a renal allograft. Eight (20%) patients reached ESRD during a median follow-up of 74 months. Thirty-one families underwent APRT sequencing, which identified 54 (87%) mutant alleles on the 62 chromosomes analyzed. We identified 18 distinct mutations. A single T insertion in a splice donor site in intron 4 (IVS4 + 2insT), which produces a truncated protein, accounted for 40.3% of the mutations. We detected the IVS4 + 2insT mutation in two (0.98%) of 204 chromosomes of healthy newborns. This report, which is the largest published series of APRT deficiency to date, highlights the underdiagnosis and potential severity of this disease. Early diagnosis is crucial for initiation of effective treatment with allopurinol and for prevention of renal complications. PMID:20150536

  18. True Niacin Deficiency in Quinolinic Acid Phosphoribosyltransferase (QPRT) Knockout Mice.

    PubMed

    Shibata, Katsumi

    2015-01-01

    Pyridine nucleotide coenzymes (PNCs) are involved in over 500 enzyme reactions. PNCs are biosynthesized from the amino acid L-tryptophan (L-Trp), as well as the vitamin niacin. Hence, "true" niacin-deficient animals cannot be "created" using nutritional techniques. We wanted to establish a truly niacin-deficient model animal using a protocol that did not involve manipulating dietary L-Trp. We generated mice that are missing the quinolinic acid phosphoribosyltransferase (QPRT) gene. QPRT activity was not detected in qprt(-/-)mice. The qprt(+/+), qprt(+/-) or qprt(-/-) mice (8 wk old) were fed a complete diet containing 30 mg nicotinic acid (NiA) and 2.3 g L-Trp/kg diet or an NiA-free diet containing 2.3 g L-Trp/kg diet for 23 d. When qprt(-/-)mice were fed a complete diet, food intake and body weight gain did not differ from those of the qprt(+/+) and the qprt(+/-) mice. On the other hand, in the qprt(-/-) mice fed the NiA-free diet, food intake and body weight were reduced to 60% (p<0.01) and 70% (p<0.05) of the corresponding values for the qprt(-/-) mice fed the complete diet at day 23, respectively. The nutritional levels of niacin such as blood and liver NAD concentrations were also lower in the qprt(-/-) mice than in the qprt(+/+) and the qprt(+/-) mice. Urinary excretion of quinolinic acid was greater in the qprt(-/-) mice than in the qprt(+/+) and the qprt(+/-) mice (p<0.01). These data suggest that we generated truly niacin-deficient mice.

  19. Adenine Phosphoribosyltransferase in Plant Tissues: Some Effects of Kinetin on Enzymic Activity 1

    PubMed Central

    Nicholls, P. B.; Murray, A. W.

    1968-01-01

    Adenine phosphoribosyltransferase activity was measured in extracts of soybean (Glycine max var. Acme) callus and of senescing barley leaves (Hordeum distichon c.v. Prior). The enzyme from soybean callus had Michaelis constants for adenine and 5-phosphoribosyl pyrophosphate of 1.5 and 7.5 μm respectively and was inhibited by AMP and stimulated by ATP. The presence of kinetin was found to considerably increase the activity of adenine phosphoribosyltransferase in extracts of soybean callus and senescing barley leaves. PMID:16656820

  20. Plasma hypoxanthine: a marker for hypoxic-ischaemic induced periventricular leucomalacia?

    PubMed Central

    Russell, G A; Jeffers, G; Cooke, R W

    1992-01-01

    Cerebral ischaemia of the immature brain may result in cavitating periventricular leucomalacia (PVL), an important association of cerebral palsy. Hypoxanthine measured by high performance liquid chromatography was used as a marker of peripartum hypoxia and ischaemia in 116 infants at risk of PVL. PVL was detected by ultrasound. The 81 infants who were unaffected had median (range) gestation of 30 weeks (24-32), weight of 1336 g (724-3790), and a plasma hypoxanthine concentration of 7.8 mumol/l (2.4-48.9). The seven infants who had cavitating PVL had a median gestation of 28 weeks (26-30), weight of 1165 g (682-1860), and a hypoxanthine concentration of 31.9 mumol/l (7.1-149). Cavitating PVL was significantly dependent only on hypoxanthine when controlling for the effects of weight and gestation. This suggests that peripartum hypoxia-ischaemia may be one of the aetiological factors in cavitating PVL. Oxidation of hypoxanthine during reperfusion generates free radicals which may contribute to the tissue destruction of PVL. The association of hypoxia-ischaemia with PVL suggests that PVL may be modified by reducing free radical activity. PMID:1586176

  1. Variable stability of a selectable provirus after retroviral vector gene transfer into human cells.

    PubMed Central

    Jolly, D J; Willis, R C; Friedmann, T

    1986-01-01

    Human lymphoblasts deficient in the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) were infected with an amphotropic helper-free retroviral vector expressing human HPRT cDNA. The stability and expression of the HPRT provirus in five cell lines with different proviral integration sites were examined by determining HPRT mutation and reversion frequencies and by blot hybridization studies. Mutation to the HPRT-negative phenotype occurred at frequencies of approximately 4 X 10(-5) to 3 X 10(-6) per generation. Most mutations in each of the five cell lines were associated with partial or complete deletions or rearrangements of the provirus. Several mutants retained a grossly intact HPRT provirus, and in one such mutant HPRT shutdown resulted from a revertible epigenetic mechanism that was not associated with global changes in proviral methylation. Therefore, mutation and shutdown of the HPRT provirus in human lymphoblasts result from mechanisms similar to those reported for several other avian and mammalian replication-competent retroviruses. Images PMID:3023873

  2. Proinflammatory Actions of Visfatin/Nicotinamide Phosphoribosyltransferase (Nampt) Involve Regulation of Insulin Signaling Pathway and Nampt Enzymatic Activity*

    PubMed Central

    Jacques, Claire; Holzenberger, Martin; Mladenovic, Zvezdana; Salvat, Colette; Pecchi, Emilie; Berenbaum, Francis; Gosset, Marjolaine

    2012-01-01

    Visfatin (also termed pre-B-cell colony-enhancing factor (PBEF) or nicotinamide phosphoribosyltransferase (Nampt)) is a pleiotropic mediator acting on many inflammatory processes including osteoarthritis. Visfatin exhibits both an intracellular enzymatic activity (nicotinamide phosphoribosyltransferase, Nampt) leading to NAD synthesis and a cytokine function via the binding to its hypothetical receptor. We recently reported the role of visfatin in prostaglandin E2 (PGE2) synthesis in chondrocytes. Here, our aim was to characterize the signaling pathways involved in this response in exploring both the insulin receptor (IR) signaling pathway and Nampt activity. IR was expressed in human and murine chondrocytes, and visfatin triggered Akt phosphorylation in murine chondrocytes. Blocking IR expression with siRNA or activity using the hydroxy-2-naphthalenyl methyl phosphonic acid tris acetoxymethyl ester (HNMPA-(AM)3) inhibitor diminished visfatin-induced PGE2 release in chondrocytes. Moreover, visfatin-induced IGF-1R−/− chondrocytes released higher concentration of PGE2 than IGF-1R+/+ cells, a finding confirmed with an antibody that blocked IGF-1R. Using RT-PCR, we found that visfatin did not regulate IR expression and that an increased insulin release was also unlikely to be involved because insulin was unable to increase PGE2 release. Inhibition of Nampt activity using the APO866 inhibitor gradually decreased PGE2 release, whereas the addition of exogenous nicotinamide increased it. We conclude that the proinflammatory actions of visfatin in chondrocytes involve regulation of IR signaling pathways, possibly through the control of Nampt enzymatic activity. PMID:22399297

  3. Inhibition of Nicotinamide Phosphoribosyltransferase Reduces Neutrophil-Mediated Injury in Myocardial Infarction

    PubMed Central

    Bauer, Inga; Braunersreuther, Vincent; Bruzzone, Santina; Akhmedov, Alexander; Lüscher, Thomas F.; Speer, Timo; Poggi, Alessandro; Mannino, Elena; Pelli, Graziano; Galan, Katia; Bertolotto, Maria; Lenglet, Sébastien; Garuti, Anna; Montessuit, Christophe; Lerch, René; Pellieux, Corinne; Vuilleumier, Nicolas; Dallegri, Franco; Mage, Jacqueline; Sebastian, Carlos; Mostoslavsky, Raul; Gayet-Ageron, Angèle; Patrone, Franco; Mach, François; Nencioni, Alessio

    2013-01-01

    Abstract Aims: Nicotinamide phosphoribosyltransferase (Nampt) is a key enzyme for nicotinamide adenine dinucleotide (NAD+) biosynthesis, and recent evidence indicates its role in inflammatory processes. Here, we investigated the potential effects of pharmacological Nampt inhibition with FK866 in a mouse myocardial ischemia/reperfusion model. In vivo and ex vivo mouse myocardial ischemia/reperfusion procedures were performed. Results: Treatment with FK866 reduced myocardial infarct size, neutrophil infiltration, and reactive oxygen species (ROS) generation within infarcted hearts in vivo in a mouse model of ischemia and reperfusion. The benefit of FK866 was not shown in the Langendorff model (ex vivo model of working heart without circulating leukocytes), suggesting a direct involvement of these cells in cardiac injury. Sera from FK866-treated mice showed reduced circulating levels of the neutrophil chemoattractant CXCL2 and impaired capacity to prime migration of these cells in vitro. The release of CXCL8 (human homolog of murine chemokine CXCL2) by human peripheral blood mononuclear cells (PBMCs) and Jurkat cells was also reduced by FK866, as well as by sirtuin (SIRT) inhibitors and SIRT6 silencing, implying a pivotal role for this NAD+-dependent deacetylase in the production of this chemokine. Innovation: The pharmacological inhibition of Nampt might represent an effective approach to reduce neutrophilic inflammation- and oxidative stress-mediated tissue damage in early phases of reperfusion after a myocardial infarction. Conclusions: Nampt inhibition appears as a new strategy to dampen CXCL2-induced neutrophil recruitment and thereby reduce neutrophil-mediated tissue injury in mice. Antioxid. Redox Signal. 18, 630–641. PMID:22452634

  4. Co-mutagenicity of coumarin (1,2-benzopyrone) with aflatoxin B1 and human liver S9 in mammalian cells.

    PubMed

    Goeger, D E; Hsie, A W; Anderson, K E

    1999-06-01

    Coumarin (1,2-benzopyrone), a natural dietary constituent and drug currently under evaluation for treatment of certain cancers and lymphedema, reduces polycyclic aromatic hydrocarbon-induced neoplasms in rodents. Because most rodents metabolize coumarin through 3,4-epoxidation, whereas 7-hydroxylation predominates in humans, their suitability as a model for coumarin effects in humans has been questioned. We examined coumarin chemoprotection against the promutagen and dietary contaminant aflatoxin B1 with human liver S9 bioactivation in the Chinese hamster ovary cell/hypoxanthine-guanine phosphoribosyltransferase mutation assay. Coumarin in the absence of aflatoxin B1 was not mutagenic or cytotoxic up to 500 microM. When included with either 1 or 10 microM aflatoxin B1, coumarin produced a dose-dependent increase in mutant frequency and cytotoxicity. At concentrations greater than 50 microM, coumarin stimulated human liver S9 bioactivation of aflatoxin B1 to the mutagenic 8,9-epoxide. This increase was 12- and fivefold at 500 microM coumarin with 1 and 10 microM aflatoxin B1, respectively, compared with incubations with aflatoxin B1 alone. These findings differ from previous results with liver S9 from other species, and indicate that coumarin co-mutagenicity with aflatoxin B1 and human liver S9 is through increased aflatoxin B1 bioactivation.

  5. Novel mutations in the human HPRT gene.

    PubMed

    Nguyen, Khue Vu; Naviaux, Robert K; Paik, Kacie K; Nyhan, William L

    2011-06-01

    Inherited mutation of a purine salvage enzyme, hypoxanthine guanine phosphoribosyltransferase (HPRT), gives rise to Lesch-Nyhan Syndrome (LNS) or HPRT-related gout. Here, we report five novel independent mutations in the coding region of the HPRT gene from five unrelated male patients manifesting different clinical phenotypes associated with LNS: exon 2: c.133A > G, p.45R > G; c.35A > C, p.12D > A; c.88delG; exon 7: c.530A > T, p.177D > V; and c.318 + 1G > C: IVS3 + 1G > C splice site mutation.

  6. Hypoxanthine: A Universal Metabolic Indicator of Training Status in Competitive Sports.

    PubMed

    Zieliński, Jacek; Kusy, Krzysztof

    2015-10-01

    Cardiorespiratory and biochemical indicators typically used by contemporary elite athletes seem to have limited applicability. According to some recent studies, purine metabolism better reflects exercise response and muscle adaptation in this group. We propose using purine derivatives, especially plasma hypoxanthine concentration, as indicators of training status in consecutive training phases in highly trained athletes.

  7. Inosine and hypoxanthine as novel biomarkers for cardiac ischemia: From bench to point-of-care

    PubMed Central

    Farthing, Don E; Farthing, Christine A

    2015-01-01

    Cardiac ischemia associated with acute coronary syndrome and myocardial infarction is a leading cause of mortality and morbidity in the world. A rapid detection of the ischemic events is critically important for achieving timely diagnosis, treatment and improving the patient's survival and functional recovery. This minireview provides an overview on the current biomarker research for detection of acute cardiac ischemia. We primarily focus on inosine and hypoxanthine, two by-products of ATP catabolism. Based on our published findings of elevated plasma concentrations of inosine/hypoxanthine in animal laboratory and clinical settings, since 2006 we have originally proposed that these two purine molecules can be used as rapid and sensitive biomarkers for acute cardiac ischemia at its very early onset (within 15 min), hours prior to the release of heart tissue necrosis biomarkers such as cardiac troponins. We further developed a chemiluminescence technology, one of the most affordable and sensitive analytical techniques, and we were able to reproducibly quantify and differentiate total hypoxanthine concentrations in the plasma samples from healthy individuals versus patients suffering from ischemic heart disease. Additional rigorous clinical studies are needed to validate the plasma inosine/hypoxanthine concentrations, in conjunction with other current cardiac biomarkers, for a better revelation of their diagnostic potentials for early detection of acute cardiac ischemia. PMID:25956679

  8. Ternary complex structure of human HGPRTase, PRPP, Mg2+, and the inhibitor HPP reveals the involvement of the flexible loop in substrate binding.

    PubMed Central

    Balendiran, G. K.; Molina, J. A.; Xu, Y.; Torres-Martinez, J.; Stevens, R.; Focia, P. J.; Eakin, A. E.; Sacchettini, J. C.; Craig, S. P.

    1999-01-01

    Site-directed mutagenesis was used to replace Lys68 of the human hypoxanthine phosphoribosyltransferase (HGPRTase) with alanine to exploit this less reactive form of the enzyme to gain additional insights into the structure activity relationship of HGPRTase. Although this substitution resulted in only a minimal (one- to threefold) increase in the Km values for binding pyrophosphate or phosphoribosylpyrophosphate, the catalytic efficiencies (k(cat)/Km) of the forward and reverse reactions were more severely reduced (6- to 30-fold), and the mutant enzyme showed positive cooperativity in binding of alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP) and nucleotide. The K68A form of the human HGPRTase was cocrystallized with 7-hydroxy [4,3-d] pyrazolo pyrimidine (HPP) and Mg PRPP, and the refined structure reported. The PRPP molecule built into the [(Fo - Fc)phi(calc)] electron density shows atomic interactions between the Mg PRPP and enzyme residues in the pyrophosphate binding domain as well as in a long flexible loop (residues Leu101 to Gly111) that closes over the active site. Loop closure reveals the functional roles for the conserved SY dipeptide of the loop as well as the molecular basis for one form of gouty arthritis (S103R). In addition, the closed loop conformation provides structural information relevant to the mechanism of catalysis in human HGPRTase. PMID:10338013

  9. Effects of Hypoxanthine Substitution in Peptide Nucleic Acids Targeting KRAS2 Oncogenic mRNA Molecules: Theory and Experiment

    PubMed Central

    Sanders, Jeffrey M.; Wampole, Matthew E.; Chen, Chang-Po; Sethi, Dalip; Singh, Amrita; Dupradeau, François-Yves; Wang, Fan; Gray, Brian D.; Thakur, Mathew L.; Wickstrom, Eric

    2013-01-01

    Genetic disorders can arise from single base substitutions in a single gene. A single base substitution for wild type guanine in the twelfth codon of KRAS2 mRNA occurs frequently to initiate lung, pancreatic, and colon cancer. We have observed single base mismatch specificity in radioimaging of mutant KRAS2 mRNA in tumors in mice by in vivo hybridization with radiolabeled peptide nucleic acid (PNA) dodecamers. We hypothesized that multi-mutant specificity could be achieved with a PNA dodecamer incorporating hypoxanthine, which can form Watson-Crick basepairs with adenine, cytosine, thymine, and uracil. Using molecular dynamics simulations and free energy calculations, we show that hypoxanthine substitutions in PNAs are tolerated in KRAS2 RNA-PNA duplexes where wild type guanine is replaced by mutant uracil or adenine in RNA. To validate our predictions, we synthesized PNA dodecamers with hypoxanthine, and then measured the thermal stability of RNA-PNA duplexes. Circular dichroism thermal melting results showed that hypoxanthine-containing PNAs are more stable in duplexes where hypoxanthine-adenine and hypoxanthine-uracil base pairs are formed than single mismatch duplexes or duplexes containing hypoxanthine-guanine opposition. PMID:23972113

  10. Anthranilate synthase/anthranilate 5-phosphoribosyl 1-pyrophosphate phosphoribosyltransferase from Aerobacter aerogenes

    PubMed Central

    Egan, A. F.; Gibson, F.

    1972-01-01

    1. Anthranilate synthase and phosphoribosyltransferase from Aerobacter aerogenes purify simultaneously and sediment together on sucrose gradients, showing that they occur as an enzyme aggregate. Both activities of the intact aggregate are subject to inhibition by tryptophan. 2. By using appropriate auxotrophic mutants it was shown that an intact active enzyme aggregate is formed when the components come from separate mutant strains. An intact active aggregate can also be formed when one component is from Escherichia coli and the other from A. aerogenes. 3. Phosphoribosyltransferase of A. aerogenes is active when not in an aggregate with anthranilate synthase, but is not subject to tryptophan inhibition, indicating that the inhibitor site is on the anthranilate synthase component. 4. Anthranilate synthase can be active and sensitive to tryptophan inhibition when complexed with an inactive phosphoribosyltransferase. 5. Kinetic studies on the anthranilate synthase activity show that tryptophan is a competitive inhibitor with respect to chorismate and a non-competitive inhibitor with respect to either glutamine or NH4+ ions. This is consistent with a sequential mechanism of the ordered type in which chorismate is the first reactant. PMID:4352716

  11. Urinary Hypoxanthine as a Measure of Increased ATP Utilization in Late Preterm Infants

    PubMed Central

    Holden, Megan S.; Hopper, Andrew; Slater, Laurel; Asmerom, Yayesh; Esiaba, Ijeoma; Boskovic, Danilo S.; Angeles, Danilyn M.

    2015-01-01

    Objective To examine the effect of neonatal morbidity on ATP breakdown in late preterm infants. Study Design Urinary hypoxanthine concentration, a marker of ATP breakdown, was measured from 82 late preterm infants on days of life (DOL) 3 to 6 using high-performance liquid chromatography. Infants were grouped according to the following diagnoses: poor nippling alone (n = 8), poor nippling plus hyperbilirubinemia (n = 21), poor nippling plus early respiratory disease (n = 26), and respiratory disease alone (n = 27). Results Neonates with respiratory disease alone had significantly higher urinary hypoxanthine over DOL 3 to 6 when compared with neonates with poor nippling (P = .020), poor nippling plus hyperbilirubinemia (P < .001), and poor nippling plus early respiratory disease (P = .017). Neonates with poor nippling who received respiratory support for 2 to 3 days had significantly higher hypoxanthine compared with infants who received respiratory support for 1 day (P = .017) or no days (P = .007). Conclusions These findings suggest that respiratory disorders significantly increase ATP degradation in late premature infants. PMID:26413195

  12. Inhibition of Nicotinamide Phosphoribosyltransferase (NAMPT), an Enzyme Essential for NAD+ Biosynthesis, Leads to Altered Carbohydrate Metabolism in Cancer Cells.

    PubMed

    Tan, Bo; Dong, Sucai; Shepard, Robert L; Kays, Lisa; Roth, Kenneth D; Geeganage, Sandaruwan; Kuo, Ming-Shang; Zhao, Genshi

    2015-06-19

    Nicotinamide phosphoribosyltransferase (NAMPT) has been extensively studied due to its essential role in NAD(+) biosynthesis in cancer cells and the prospect of developing novel therapeutics. To understand how NAMPT regulates cellular metabolism, we have shown that the treatment with FK866, a specific NAMPT inhibitor, leads to attenuation of glycolysis by blocking the glyceraldehyde 3-phosphate dehydrogenase step (Tan, B., Young, D. A., Lu, Z. H., Wang, T., Meier, T. I., Shepard, R. L., Roth, K., Zhai, Y., Huss, K., Kuo, M. S., Gillig, J., Parthasarathy, S., Burkholder, T. P., Smith, M. C., Geeganage, S., and Zhao, G. (2013) Pharmacological inhibition of nicotinamide phosphoribosyltransferase (NAMPT), an enzyme essential for NAD(+) biosynthesis, in human cancer cells: metabolic basis and potential clinical implications. J. Biol. Chem. 288, 3500-3511). Due to technical limitations, we failed to separate isotopomers of phosphorylated sugars. In this study, we developed an enabling LC-MS methodology. Using this, we confirmed the previous findings and also showed that NAMPT inhibition led to accumulation of fructose 1-phosphate and sedoheptulose 1-phosphate but not glucose 6-phosphate, fructose 6-phosphate, and sedoheptulose 7-phosphate as previously thought. To investigate the metabolic basis of the metabolite formation, we carried out biochemical and cellular studies and established the following. First, glucose-labeling studies indicated that fructose 1-phosphate was derived from dihydroxyacetone phosphate and glyceraldehyde, and sedoheptulose 1-phosphate was derived from dihydroxyacetone phosphate and erythrose via an aldolase reaction. Second, biochemical studies showed that aldolase indeed catalyzed these reactions. Third, glyceraldehyde- and erythrose-labeling studies showed increased incorporation of corresponding labels into fructose 1-phosphate and sedoheptulose 1-phosphate in FK866-treated cells. Fourth, NAMPT inhibition led to increased glyceraldehyde and

  13. Thirdhand smoke causes DNA damage in human cells.

    PubMed

    Hang, Bo; Sarker, Altaf H; Havel, Christopher; Saha, Saikat; Hazra, Tapas K; Schick, Suzaynn; Jacob, Peyton; Rehan, Virender K; Chenna, Ahmed; Sharan, Divya; Sleiman, Mohamad; Destaillats, Hugo; Gundel, Lara A

    2013-07-01

    Exposure to thirdhand smoke (THS) is a newly described health risk. Evidence supports its widespread presence in indoor environments. However, its genotoxic potential, a critical aspect in risk assessment, is virtually untested. An important characteristic of THS is its ability to undergo chemical transformations during aging periods, as demonstrated in a recent study showing that sorbed nicotine reacts with the indoor pollutant nitrous acid (HONO) to form tobacco-specific nitrosamines (TSNAs) such as 4-(methylnitrosamino)-4-(3-pyridyl)butanal (NNA) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The goal of this study was to assess the genotoxicity of THS in human cell lines using two in vitro assays. THS was generated in laboratory systems that simulated short (acute)- and long (chronic)-term exposures. Analysis by liquid chromatography-tandem mass spectrometry quantified TSNAs and common tobacco alkaloids in extracts of THS that had sorbed onto cellulose substrates. Exposure of human HepG2 cells to either acute or chronic THS for 24h resulted in significant increases in DNA strand breaks in the alkaline Comet assay. Cell cultures exposed to NNA alone showed significantly higher levels of DNA damage in the same assay. NNA is absent in freshly emitted secondhand smoke, but it is the main TSNA formed in THS when nicotine reacts with HONO long after smoking takes place. The long amplicon-quantitative PCR assay quantified significantly higher levels of oxidative DNA damage in hypoxanthine phosphoribosyltransferase 1 (HPRT) and polymerase β (POLB) genes of cultured human cells exposed to chronic THS for 24h compared with untreated cells, suggesting that THS exposure is related to increased oxidative stress and could be an important contributing factor in THS-mediated toxicity. The findings of this study demonstrate for the first time that exposure to THS is genotoxic in human cell lines. PMID:23462851

  14. Transfer of cloned human class I major histocompatibility complex genes into HLA mutant human lymphoblastoid cells.

    PubMed Central

    Shimizu, Y; Koller, B; Geraghty, D; Orr, H; Shaw, S; Kavathas, P; DeMars, R

    1986-01-01

    Three new kinds of recombinant DNA constructs were used to transfer cloned human class I HLA genes (A2 and B8) into unique HLA mutant lymphoblastoid cells: pHeBo(x): a class I gene, "x," in plasmid vector pHeBo, which contains a hygromycin resistance gene and Epstein-Barr virus oriP element that sustains extrachromosomal replication; pHPT(x): gene x in a vector with a hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene; pHPTe(x): gene x in a vector with the HPRT gene and oriP element. Cell surface class I antigen expression was strong in transferents made with class I-deficient lymphoblastoid cell line mutants .144 (A-null), .53 (B-null), and .184 (A-null, B-null). Transferents expressing HLA-A2 were recognized specifically by HLA-A2-specific cytotoxic T lymphocytes. When introduced on either of the vectors with the Epstein-Barr virus oriP element, the class I gene replicated extrachromosomally and was lost at rates of 0.2 to 0.3 per cell division. When introduced with vector pHPT (lacking Epstein-Barr virus oriP), the B8 gene was inserted at different chromosomal locations. Introduction of the HLA-B8 gene failed to restore antigen expression by HLA-B-null mutant .174, providing evidence that, unlike mutants exemplified by .53, .144, and .184, some HLA antigen loss mutants are deficient in a trans-acting function needed for class I antigen expression. Of more general interest, the results obtained with HLA class I genes in vectors that replicate extrachromosomally suggest ways of relating genic expression to chromatin structure and function and of attempting to clone functional human centromeres. Images PMID:3023867

  15. Transfer of cloned human class I major histocompatibility complex genes into HLA mutant human lymphoblastoid cells.

    PubMed

    Shimizu, Y; Koller, B; Geraghty, D; Orr, H; Shaw, S; Kavathas, P; DeMars, R

    1986-04-01

    Three new kinds of recombinant DNA constructs were used to transfer cloned human class I HLA genes (A2 and B8) into unique HLA mutant lymphoblastoid cells: pHeBo(x): a class I gene, "x," in plasmid vector pHeBo, which contains a hygromycin resistance gene and Epstein-Barr virus oriP element that sustains extrachromosomal replication; pHPT(x): gene x in a vector with a hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene; pHPTe(x): gene x in a vector with the HPRT gene and oriP element. Cell surface class I antigen expression was strong in transferents made with class I-deficient lymphoblastoid cell line mutants .144 (A-null), .53 (B-null), and .184 (A-null, B-null). Transferents expressing HLA-A2 were recognized specifically by HLA-A2-specific cytotoxic T lymphocytes. When introduced on either of the vectors with the Epstein-Barr virus oriP element, the class I gene replicated extrachromosomally and was lost at rates of 0.2 to 0.3 per cell division. When introduced with vector pHPT (lacking Epstein-Barr virus oriP), the B8 gene was inserted at different chromosomal locations. Introduction of the HLA-B8 gene failed to restore antigen expression by HLA-B-null mutant .174, providing evidence that, unlike mutants exemplified by .53, .144, and .184, some HLA antigen loss mutants are deficient in a trans-acting function needed for class I antigen expression. Of more general interest, the results obtained with HLA class I genes in vectors that replicate extrachromosomally suggest ways of relating genic expression to chromatin structure and function and of attempting to clone functional human centromeres. PMID:3023867

  16. Adenine phosphoribosyltransferase from Sulfolobus solfataricus is an enzyme with unusual kinetic properties and a crystal structure that suggests it evolved from a 6-oxopurine phosphoribosyltransferase.

    PubMed

    Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen; Christoffersen, Stig; Poulsen, Jens-Christian Navarro; Mølgaard, Anne; Kadziola, Anders

    2015-04-14

    The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2 was subjected to crystallographic, kinetic, and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5-phosphoribosyl-α-1-pyrophosphate (PRPP) and adenine or the product adenosine monophosphate (AMP) or the inhibitor adenosine diphosphate (ADP) in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its evolutionary origin in this family of PRTases. Only the N-terminal two-thirds of the polypeptide chain folds as a traditional type I PRTase with a five-stranded β-sheet surrounded by helices. The C-terminal third adopts an unusual three-helix bundle structure that together with the nucleobase-binding loop undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor ADP binds like the product AMP with both the α- and β-phosphates occupying the 5'-phosphoribosyl binding site. The enzyme shows activity over a wide pH range, and the kinetic and ligand binding properties depend on both pH and the presence/absence of phosphate in the buffers. A slow hydrolysis of PRPP to ribose 5-phosphate and pyrophosphate, catalyzed by the enzyme, may be facilitated by elements in the C-terminal three-helix bundle part of the protein. PMID:25790177

  17. Isolation of the human chromosomal band Xq28 within somatic cell hybrids by fragile X site breakage.

    PubMed Central

    Warren, S T; Knight, S J; Peters, J F; Stayton, C L; Consalez, G G; Zhang, F P

    1990-01-01

    The chromosomal fragile-site mapping to Xq27.3 is associated with a frequent form of mental retardation and is prone to breakage after induced deoxyribonucleotide pool perturbation. The human hypoxanthine phosphoribosyltransferase (HPRT) and glucose-6-phosphate dehydrogenase (G6PD) genes flank the fragile X chromosome site and can be used to monitor integrity of the site in human-hamster somatic cell hybrids deficient in the rodent forms of these activities. After induction of the fragile X site, negative selection for HPRT and positive enrichment for G6PD resulted in 31 independent colonies of HPRT-,G6PD+ phenotype. Southern blot analysis demonstrated the loss of all tested markers proximal to the fragile X site with retention of all tested human Xq28 loci in a majority of the hybrids. In situ hybridization with a human-specific probe demonstrated the translocation of a small amount of human DNA to rodent chromosomes in these hybrids, suggesting chromosome breakage at the fragile X site and the subsequent translocation of Xq28. Southern blot hybridization of hybrid-cell DNA, resolved by pulsed-field gel electrophoresis, for human-specific repetitive sequences revealed abundant CpG-islands within Xq28, consistent with its known gene density. The electrophoretic banding patterns of human DNA among the hybrids were remarkably consistent, suggesting that fragile X site breakage is limited to a relatively small region in Xq27-28. These somatic cell hybrids, containing Xq27.3-qter as the sole human DNA, will aid the search for DNA associated with the fragile X site and will augment the high resolution genomic analysis of Xq28, including the identification of candidate genes for genetic-disease loci mapping to this region. Images PMID:2339126

  18. Photoion mass spectroscopy and valence photoionization of hypoxanthine, xanthine and caffeine

    NASA Astrophysics Data System (ADS)

    Feyer, Vitaliy; Plekan, Oksana; Richter, Robert; Coreno, Marcello; Prince, Kevin C.

    2009-03-01

    Photoionization mass spectra of hypoxanthine, xanthine and caffeine were measured using the photoelectron-photoion coincidence technique and noble gas resonance radiation at energies from 8.4 to 21.2 eV for ionization. The fragmentation patterns for these compounds show that hydrogen cyanide is the main neutral loss species at higher photon energies, while photoionization below 16.67 eV led predominantly to the parent ion. The valence photoelectron spectra of this family of molecules were measured over an extended energy range, including the inner C, N and O 2s valence orbitals. The observed ion fragments were related to ionization of the valence orbitals.

  19. Structure of Plasmodium falciparum orotate phosphoribosyltransferase with autologous inhibitory protein–protein interactions

    SciTech Connect

    Kumar, Shiva; Krishnamoorthy, Kalyanaraman; Mudeppa, Devaraja G.; Rathod, Pradipsinh K.

    2015-04-21

    P. falciparum orotate phosphoribosyltransferase, a potential target for antimalarial drugs and a conduit for prodrugs, crystallized as a structure with eight molecules per asymmetric unit that included some unique parasite-specific auto-inhibitory interactions between catalytic dimers. The most severe form of malaria is caused by the obligate parasite Plasmodium falciparum. Orotate phosphoribosyltransferase (OPRTase) is the fifth enzyme in the de novo pyrimidine-synthesis pathway in the parasite, which lacks salvage pathways. Among all of the malaria de novo pyrimidine-biosynthesis enzymes, the structure of P. falciparum OPRTase (PfOPRTase) was the only one unavailable until now. PfOPRTase that could be crystallized was obtained after some low-complexity sequences were removed. Four catalytic dimers were seen in the asymmetic unit (a total of eight polypeptides). In addition to revealing unique amino acids in the PfOPRTase active sites, asymmetric dimers in the larger structure pointed to novel parasite-specific protein–protein interactions that occlude the catalytic active sites. The latter could potentially modulate PfOPRTase activity in parasites and possibly provide new insights for blocking PfOPRTase functions.

  20. Mutagenesis in human cells with accelerated H and Fe ions

    NASA Technical Reports Server (NTRS)

    Kronenberg, Amy

    1994-01-01

    The overall goals of this research were to determine the risks of mutation induction and the spectra of mutations induced by energetic protons and iron ions at two loci in human lymphoid cells. During the three year grant period the research has focused in three major areas: (1) the acquisition of sufficient statistics for human TK6 cell mutation experiments using Fe ions (400 MeV/amu), Fe ions (600 MeV/amu) and protons (250 MeV/amu); (2) collection of thymidine kinase- deficient (tk) mutants or hypoxanthine phosphoribosyltransferase deficient (hprt) mutants induced by either Fe 400 MeV/amu, Fe 600 MeV/amu, or H 250 MeV/amu for subsequent molecular analysis; and (3) molecular characterization of mutants isolated after exposure to Fe ions (600 MeV/amu). As a result of the shutdown of the BEVALAC heavy ion accelerator in December 1992, efforts were rearranged somewhat in time to complete our dose-response studies and to complete mutant collections in particular for the Fe ion beams prior to the shutdown. These goals have been achieved. A major effort was placed on collection, re-screening, and archiving of 3 different series of mutants for the various particle beam exposures: tk-ng mutants, tk-sg mutants, and hprt-deficient mutants. Where possible, groups of mutants were isolated for several particle fluences. Comparative analysis of mutation spectra has occured with characterization of the mutation spectrum for hprt-deficient mutants obtained after exposure of TK6 cells to Fe ions (600 MeV/amu) and a series of spontaneous mutants.

  1. Genetic Regulation of Charged Particle Mutagenesis in Human Cells

    NASA Technical Reports Server (NTRS)

    Kronenberg, Amy; Gauny, S.; Cherbonnel-Lasserre, C.; Liu, W.; Wiese, C.

    1999-01-01

    Our studies use a series of syngeneic, and where possible, isogenic human B-lymphoblastoid cell lines to assess the genetic factors that modulate susceptibility apoptosis and their impact on the mutagenic risks of low fluence exposures to 1 GeV Fe ions and 55 MeV protons. These ions are representative of the types of charged particle radiation that are of particular significance for human health in the space radiation environment. The model system employs cell lines derived from the male donor WIL-2. These cells have a single X chromosome and they are hemizygous for one mutation marker, hypoxanthine phosphoribosyltransferase (HPRT). TK6 and WTK1 cells were each derived from descendants of WIL-2 and were each selected as heterozygotes for a second mutation marker, the thymidine kinase (TK) gene located on chromosome 17q. The HPRT and TK loci can detect many different types of mutations, from single basepair substitutions up to large scale loss of heterozygosity (LOH). The single expressing copy of TK in the TK6 and WTKI cell lines is found on the same copy of chromosome 17, and this allele can be identified by a restriction fragment length polymorphism (RFLP) identified when high molecular weight DNA is digested by the SacI restriction endonuclease and hybridized against the cDNA probe for TK. A large series of polymorphic linked markers has been identified that span more than 60 cM of DNA (approx. 60 megabasepairs) and distinguish the copy of chromosome 17 bearing the initially active TK allele from the copy of chromosome 17 bearing the silent TK allele in both TK6 and WTKI cells. TK6 cells express normal p53 protein while WTKI cells express homozygous mutant p53. Expression of mutant p53 can increase susceptibility to x-ray-induced mutations. It's been suggested that the increased mutagenesis in p53 mutant cells might be due to reduced apoptosis.

  2. In vivo cancer gene therapy by adenovirus-mediated transfer of a bifunctional yeast cytosine deaminase/uracil phosphoribosyltransferase fusion gene.

    PubMed

    Erbs, P; Regulier, E; Kintz, J; Leroy, P; Poitevin, Y; Exinger, F; Jund, R; Mehtali, M

    2000-07-15

    Direct transfer of prodrug activation systems into tumors was demonstrated to be an attractive method for the selective in vivo elimination of tumor cells. However, most current suicide gene therapy strategies are still handicapped by a poor efficiency of in vivo gene transfer and a limited bystander cell killing effect. In this study, we describe a novel and highly potent suicide gene derived from the Saccharomyces cerevisiae cytosine deaminase (FCY1) and uracil phosphoribosyltransferase genes (FUR1). This suicide gene, designated FCU1, encodes a bifunctional chimeric protein that combines the enzymatic activities of FCY1 and FUR1 and efficiently catalyzes the direct conversion of 5-FC, a nontoxic antifungal agent, into the toxic metabolites 5-fluorouracil and 5-fluorouridine-5'monophosphate, thus bypassing the natural resistance of certain human tumor cells to 5-fluorouracil. Unexpectedly, although the uracil phosphoribosyltransferase activity of FCU1 was equivalent to that encoded by FUR1, its cytosine deaminase activity was 100-fold higher than the one encoded by FCY1. As a consequence, tumor cells transduced with an adenovirus expressing FCU1 (Ad-FCU1) were sensitive to concentrations of 5-FC 1000-fold lower than the ones used for cells transduced with a vector expressing FCY1 (Ad-FCY1). Furthermore, bystander cell killing was also more effective in cells transduced with Ad-FCU1 than in cultures infected with Ad-FCY1 or Ad-FUR1, alone or in combination. Finally, intratumoral injections of Ad-FCU1 into allo- or xenogeneic tumors implanted s.c. into mice, with concomitant systemic administration of 5-FC, led to substantial delays in tumor growth. These unique properties make of the FCU1/5-FC prodrug activation system a novel and powerful candidate for cancer gene therapy strategies. PMID:10919655

  3. Preparing a new biosensor for hypoxanthine determination by immobilization of xanthine oxidase and uricase in polypyrrole-polyvinyl sulphonate film.

    PubMed

    Görgülü, Mustafa; Çete, Servet; Arslan, Halit; Yaşar, Ahmet

    2013-10-01

    In this study, a new amperometric biosensor for the determination of hypoxanthine was developed. To this aim, polypyrrole-polyvinyl sulphonate films were prepared on the platinum electrode by the electropolymerization of pyrrole in the presence of polyvinyl sulphonate. Xanthine oxidase and uricase enzymes were immobilized in polypyrrole-polyvinyl sulphonate via the entrapment method. Optimum conditions of enzyme electrode were determined. Hypoxanthine detection is based on the oxidation of hydrogen peroxide at +400 mV produced by the enzymatic reaction on the enzyme electrode surface. The linear working range of biosensor for hypoxanthine was determined. The effects of pH and temperature on the response of the hypoxanthine biosensor were investigated. Optimum pH and temperature were measured as 8 and 30°C, respectively. Operational and storage stability of the biosensor were determined. After 20 assays, the biosensor sustained 74.5% of its initial performance. After 33 days, the biosensor lost 36% of its initial performance. The performance of the biosensor was tested in real samples.

  4. Nicotinamide Phosphoribosyltransferase Attenuates Methotrexate Response in Juvenile Idiopathic Arthritis and In Vitro.

    PubMed

    Funk, R S; Singh, R; Pramann, L; Gigliotti, N; Islam, S; Heruth, D P; Ye, S Q; Chan, M A; Leeder, J S; Becker, M L

    2016-06-01

    Variability in response to methotrexate (MTX) in the treatment of juvenile idiopathic arthritis (JIA) remains unpredictable and poorly understood. Based on previous studies implicating an interaction between nicotinamide phosphoribosyltransferase (NAMPT) expression and MTX therapy in inflammatory arthritis, we hypothesized that increased NAMPT expression would be associated with reduced therapeutic response to MTX in patients with JIA. A significant association was found between increased plasma concentrations of NAMPT and reduced therapeutic response in patients with JIA treated with MTX. Inhibition of NAMPT in cell culture by either siRNA-based gene silencing or pharmacological inhibition with FK-866 was found to result in a fourfold increase in the pharmacological activity of MTX. Collectively, these findings provide evidence that NAMPT inhibits the pharmacological activity of MTX and may represent a predictive biomarker of response, as well as a therapeutic target, in the treatment of JIA with MTX. PMID:27166432

  5. Gold(I)-triphenylphosphine complexes with hypoxanthine-derived ligands: in vitro evaluations of anticancer and anti-inflammatory activities.

    PubMed

    Křikavová, Radka; Hošek, Jan; Vančo, Ján; Hutyra, Jakub; Dvořák, Zdeněk; Trávníček, Zdeněk

    2014-01-01

    A series of gold(I) complexes involving triphenylphosphine (PPh3) and one N-donor ligand derived from deprotonated mono- or disubstituted hypoxanthine (HLn) of the general composition [Au(Ln)(PPh3)] (1-9) is reported. The complexes were thoroughly characterized, including multinuclear high resolution NMR spectroscopy as well as single crystal X-ray analysis (for complexes 1 and 3). The complexes were screened for their in vitro cytotoxicity against human cancer cell lines MCF7 (breast carcinoma), HOS (osteosarcoma) and THP-1 (monocytic leukaemia), which identified the complexes 4-6 as the most promising representatives, who antiproliferative activity was further tested against A549 (lung adenocarcinoma), G-361 (melanoma), HeLa (cervical cancer), A2780 (ovarian carcinoma), A2780R (ovarian carcinoma resistant to cisplatin), 22Rv1 (prostate cancer) cell lines. Complexes 4-6 showed a significantly higher in vitro anticancer effect against the employed cancer cells, except for G-361, as compared with the commercially used anticancer drug cisplatin, with IC50 ≈ 1-30 µM. Anti-inflammatory activity was evaluated in vitro by the assessment of the ability of the complexes to modulate secretion of the pro-inflammatory cytokines, i.e. tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), in the lipopolysaccharide-activated macrophage-like THP-1 cell model. The results of this study identified the complexes as auspicious anti-inflammatory agents with similar or better activity as compared with the clinically applied gold-based antiarthritic drug Auranofin. In an effort to explore the possible mechanisms responsible for the biological effect, the products of interactions of selected complexes with sulfur-containing biomolecules (L-cysteine and reduced glutathione) were studied by means of the mass-spectrometry study. PMID:25226034

  6. Gold(I)-Triphenylphosphine Complexes with Hypoxanthine-Derived Ligands: In Vitro Evaluations of Anticancer and Anti-Inflammatory Activities

    PubMed Central

    Křikavová, Radka; Hošek, Jan; Vančo, Ján; Hutyra, Jakub; Dvořák, Zdeněk; Trávníček, Zdeněk

    2014-01-01

    A series of gold(I) complexes involving triphenylphosphine (PPh3) and one N-donor ligand derived from deprotonated mono- or disubstituted hypoxanthine (HLn) of the general composition [Au(Ln)(PPh3)] (1–9) is reported. The complexes were thoroughly characterized, including multinuclear high resolution NMR spectroscopy as well as single crystal X-ray analysis (for complexes 1 and 3). The complexes were screened for their in vitro cytotoxicity against human cancer cell lines MCF7 (breast carcinoma), HOS (osteosarcoma) and THP-1 (monocytic leukaemia), which identified the complexes 4–6 as the most promising representatives, who antiproliferative activity was further tested against A549 (lung adenocarcinoma), G-361 (melanoma), HeLa (cervical cancer), A2780 (ovarian carcinoma), A2780R (ovarian carcinoma resistant to cisplatin), 22Rv1 (prostate cancer) cell lines. Complexes 4–6 showed a significantly higher in vitro anticancer effect against the employed cancer cells, except for G-361, as compared with the commercially used anticancer drug cisplatin, with IC50 ≈ 1–30 µM. Anti-inflammatory activity was evaluated in vitro by the assessment of the ability of the complexes to modulate secretion of the pro-inflammatory cytokines, i.e. tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), in the lipopolysaccharide-activated macrophage-like THP-1 cell model. The results of this study identified the complexes as auspicious anti-inflammatory agents with similar or better activity as compared with the clinically applied gold-based antiarthritic drug Auranofin. In an effort to explore the possible mechanisms responsible for the biological effect, the products of interactions of selected complexes with sulfur-containing biomolecules (L-cysteine and reduced glutathione) were studied by means of the mass-spectrometry study. PMID:25226034

  7. UV radiation induces delayed hyperrecombination associated with hypermutation in human cells.

    PubMed

    Durant, Stephen T; Paffett, Kimberly S; Shrivastav, Meena; Timmins, Graham S; Morgan, William F; Nickoloff, Jac A

    2006-08-01

    Ionizing radiation induces delayed genomic instability in human cells, including chromosomal abnormalities and hyperrecombination. Here, we investigate delayed genome instability of cells exposed to UV radiation. We examined homologous recombination-mediated reactivation of a green fluorescent protein (GFP) gene in p53-proficient human cells. We observed an approximately 5-fold enhancement of delayed hyperrecombination (DHR) among cells surviving a low dose of UV-C (5 J/m2), revealed as mixed GFP+/- colonies. UV-B did not induce DHR at an equitoxic (75 J/m2) dose or a higher dose (150 J/m2). UV is known to induce delayed hypermutation associated with increased oxidative stress. We found that hypoxanthine phosphoribosyltransferase (HPRT) mutation frequencies were approximately 5-fold higher in strains derived from GFP+/- (DHR) colonies than in strains in which recombination was directly induced by UV (GFP+ colonies). To determine whether hypermutation was directly caused by hyperrecombination, we analyzed hprt mutation spectra. Large-scale alterations reflecting large deletions and insertions were observed in 25% of GFP+ strains, and most mutants had a single change in HPRT. In striking contrast, all mutations arising in the hypermutable GFP+/- strains were small (1- to 2-base) changes, including substitutions, deletions, and insertions (reminiscent of mutagenesis from oxidative damage), and the majority were compound, with an average of four hprt mutations per mutant. The absence of large hprt deletions in DHR strains indicates that DHR does not cause hypermutation. We propose that UV-induced DHR and hypermutation result from a common source, namely, increased oxidative stress. These two forms of delayed genome instability may collaborate in skin cancer initiation and progression. PMID:16880516

  8. Overlapping protein-binding sites within a negative regulatory element modulate the brain-preferential expression of the human HPRT gene

    SciTech Connect

    Rincon-Limas, D.E.; Amaya-Manzanares, E.; Nino-Rosales, M.L.

    1994-09-01

    The hypoxanthine phosphoribosyltransferase (HPRT) gene, whose deficiency in humans causes the Lesch-Nyhan syndrome, is constitutively expressed at low levels in all tissues but at higher levels in the brain, the significance and mechanism of which is unknown. Towards dissecting this molecular mechanism, we have previously identified a 182 bp element (hHPRT-NE) within the 5{prime}-flanking region of the human HPRT gene which is involved not only in conferring neuronal specificity but also in repressing gene expression in non-neuronal tissues. Here we report that this element interacts with different nuclear proteins, some of which are present specifically in neuronal cells (complex I) and others of which are present in cells showing constitutive expression of the gene (complex II). In addition, we found that complex I factors are expressed in human NT2/D1 cells following induction of neuronal differentiation by retinoic acid. This finding correlates with an increase of HPRT gene transcription following neuronal differentiation, as demonstrated by RT-PCR and RNAase protection assays. We also mapped the binding sites for both complexes to a 60 bp region which, when tested by transient transfections in cultured fibroblasts, functioned as a repressor element. Methylation interference footprinting revealed a minimal unique DNA motif as the binding site for nuclear proteins from both neuronal and non-neuronal sources. Moreover, UV-crosslinking experiments showed that both complexes are formed by the association of several distinct proteins. Strikingly, site-directed mutagenesis of the footprinted region indicated that different nucleotides are essential for the association of these two complexes. These data suggest that differential formation of DNA-protein complexes at this regulatory domain could be a major determinant in the brain-preferential expression of the human HPRT gene.

  9. A Mycobacterial Phosphoribosyltransferase Promotes Bacillary Survival by Inhibiting Oxidative Stress and Autophagy Pathways in Macrophages and Zebrafish*

    PubMed Central

    Mohanty, Soumitra; Jagannathan, Lakshmanan; Ganguli, Geetanjali; Padhi, Avinash; Roy, Debasish; Alaridah, Nader; Saha, Pratip; Nongthomba, Upendra; Godaly, Gabriela; Gopal, Ramesh Kumar; Banerjee, Sulagna; Sonawane, Avinash

    2015-01-01

    Mycobacterium tuberculosis employs various strategies to modulate host immune responses to facilitate its persistence in macrophages. The M. tuberculosis cell wall contains numerous glycoproteins with unknown roles in pathogenesis. Here, by using Concanavalin A and LC-MS analysis, we identified a novel mannosylated glycoprotein phosphoribosyltransferase, encoded by Rv3242c from M. tuberculosis cell walls. Homology modeling, bioinformatic analyses, and an assay of phosphoribosyltransferase activity in Mycobacterium smegmatis expressing recombinant Rv3242c (MsmRv3242c) confirmed the mass spectrometry data. Using Mycobacterium marinum-zebrafish and the surrogate MsmRv3242c infection models, we proved that phosphoribosyltransferase is involved in mycobacterial virulence. Histological and infection assays showed that the M. marinum mimG mutant, an Rv3242c orthologue in a pathogenic M. marinum strain, was strongly attenuated in adult zebrafish and also survived less in macrophages. In contrast, infection with wild type and the complemented ΔmimG:Rv3242c M. marinum strains showed prominent pathological features, such as severe emaciation, skin lesions, hemorrhaging, and more zebrafish death. Similarly, recombinant MsmRv3242c bacteria showed increased invasion in non-phagocytic epithelial cells and longer intracellular survival in macrophages as compared with wild type and vector control M. smegmatis strains. Further mechanistic studies revealed that the Rv3242c- and mimG-mediated enhancement of intramacrophagic survival was due to inhibition of autophagy, reactive oxygen species, and reduced activities of superoxide dismutase and catalase enzymes. Infection with MsmRv3242c also activated the MAPK pathway, NF-κB, and inflammatory cytokines. In summary, we show that a novel mycobacterial mannosylated phosphoribosyltransferase acts as a virulence and immunomodulatory factor, suggesting that it may constitute a novel target for antimycobacterial drugs. PMID:25825498

  10. A mycobacterial phosphoribosyltransferase promotes bacillary survival by inhibiting oxidative stress and autophagy pathways in macrophages and zebrafish.

    PubMed

    Mohanty, Soumitra; Jagannathan, Lakshmanan; Ganguli, Geetanjali; Padhi, Avinash; Roy, Debasish; Alaridah, Nader; Saha, Pratip; Nongthomba, Upendra; Godaly, Gabriela; Gopal, Ramesh Kumar; Banerjee, Sulagna; Sonawane, Avinash

    2015-05-22

    Mycobacterium tuberculosis employs various strategies to modulate host immune responses to facilitate its persistence in macrophages. The M. tuberculosis cell wall contains numerous glycoproteins with unknown roles in pathogenesis. Here, by using Concanavalin A and LC-MS analysis, we identified a novel mannosylated glycoprotein phosphoribosyltransferase, encoded by Rv3242c from M. tuberculosis cell walls. Homology modeling, bioinformatic analyses, and an assay of phosphoribosyltransferase activity in Mycobacterium smegmatis expressing recombinant Rv3242c (MsmRv3242c) confirmed the mass spectrometry data. Using Mycobacterium marinum-zebrafish and the surrogate MsmRv3242c infection models, we proved that phosphoribosyltransferase is involved in mycobacterial virulence. Histological and infection assays showed that the M. marinum mimG mutant, an Rv3242c orthologue in a pathogenic M. marinum strain, was strongly attenuated in adult zebrafish and also survived less in macrophages. In contrast, infection with wild type and the complemented ΔmimG:Rv3242c M. marinum strains showed prominent pathological features, such as severe emaciation, skin lesions, hemorrhaging, and more zebrafish death. Similarly, recombinant MsmRv3242c bacteria showed increased invasion in non-phagocytic epithelial cells and longer intracellular survival in macrophages as compared with wild type and vector control M. smegmatis strains. Further mechanistic studies revealed that the Rv3242c- and mimG-mediated enhancement of intramacrophagic survival was due to inhibition of autophagy, reactive oxygen species, and reduced activities of superoxide dismutase and catalase enzymes. Infection with MsmRv3242c also activated the MAPK pathway, NF-κB, and inflammatory cytokines. In summary, we show that a novel mycobacterial mannosylated phosphoribosyltransferase acts as a virulence and immunomodulatory factor, suggesting that it may constitute a novel target for antimycobacterial drugs. PMID:25825498

  11. A mycobacterial phosphoribosyltransferase promotes bacillary survival by inhibiting oxidative stress and autophagy pathways in macrophages and zebrafish.

    PubMed

    Mohanty, Soumitra; Jagannathan, Lakshmanan; Ganguli, Geetanjali; Padhi, Avinash; Roy, Debasish; Alaridah, Nader; Saha, Pratip; Nongthomba, Upendra; Godaly, Gabriela; Gopal, Ramesh Kumar; Banerjee, Sulagna; Sonawane, Avinash

    2015-05-22

    Mycobacterium tuberculosis employs various strategies to modulate host immune responses to facilitate its persistence in macrophages. The M. tuberculosis cell wall contains numerous glycoproteins with unknown roles in pathogenesis. Here, by using Concanavalin A and LC-MS analysis, we identified a novel mannosylated glycoprotein phosphoribosyltransferase, encoded by Rv3242c from M. tuberculosis cell walls. Homology modeling, bioinformatic analyses, and an assay of phosphoribosyltransferase activity in Mycobacterium smegmatis expressing recombinant Rv3242c (MsmRv3242c) confirmed the mass spectrometry data. Using Mycobacterium marinum-zebrafish and the surrogate MsmRv3242c infection models, we proved that phosphoribosyltransferase is involved in mycobacterial virulence. Histological and infection assays showed that the M. marinum mimG mutant, an Rv3242c orthologue in a pathogenic M. marinum strain, was strongly attenuated in adult zebrafish and also survived less in macrophages. In contrast, infection with wild type and the complemented ΔmimG:Rv3242c M. marinum strains showed prominent pathological features, such as severe emaciation, skin lesions, hemorrhaging, and more zebrafish death. Similarly, recombinant MsmRv3242c bacteria showed increased invasion in non-phagocytic epithelial cells and longer intracellular survival in macrophages as compared with wild type and vector control M. smegmatis strains. Further mechanistic studies revealed that the Rv3242c- and mimG-mediated enhancement of intramacrophagic survival was due to inhibition of autophagy, reactive oxygen species, and reduced activities of superoxide dismutase and catalase enzymes. Infection with MsmRv3242c also activated the MAPK pathway, NF-κB, and inflammatory cytokines. In summary, we show that a novel mycobacterial mannosylated phosphoribosyltransferase acts as a virulence and immunomodulatory factor, suggesting that it may constitute a novel target for antimycobacterial drugs.

  12. In vivo mutations in human blood cells: biomarkers for molecular epidemiology.

    PubMed Central

    Albertini, R J; Nicklas, J A; Fuscoe, J C; Skopek, T R; Branda, R F; O'Neill, J P

    1993-01-01

    Mutations arising in vivo in recorder genes of human blood cells provide biomarkers for molecular epidemiology by serving as surrogates for cancer-causing genetic changes. Current markers include mutations of the glycophorin-A (GPA) or hemoglobin (Hb) genes, measured in red blood cells, or mutations of the hypoxanthine-guanine phosphoribosyltransferase (hprt) or HLA genes, measured in T-lymphocytes. Mean mutant frequencies (variant frequencies) for normal young adults are approximately: Hb (4 x 10(-8)) < hprt (5 x 10(-6)) = GPA (10 x 10(-6)) < HLA (30 x 10(-6)). Mutagen-exposed individuals show decided elevations. Molecular mutational spectra are also being defined. For the hprt marker system, about 15% of background mutations are gross structural alterations of the hprt gene (e.g., deletions); the remainder are point mutations (e.g., base substitutions or frameshifts). Ionizing radiations result in dose-related increases in total gene deletions. Large deletions may encompass several megabases as shown by co-deletions of linked markers. Possible hprt spectra for defining radiation and chemical exposures are being sought. In addition to their responsiveness to environmental mutagens/carcinogens, three additional findings suggest that the in vivo recorder mutations are relevant in vivo surrogates for cancer mutations. First, a large fraction of GPA and HLA mutations show exchanges due to homologous recombination, an important mutational event in cancer. Second, hprt mutations arise preferentially in dividing T-cells, which can accumulate additional mutations in the same clone, reminiscent of the multiple hits required in the evolution of malignancy.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8319611

  13. Development of a Novel High-Density [3H]Hypoxanthine Scintillation Proximity Assay To Assess Plasmodium falciparum Growth.

    PubMed

    de Cózar, Cristina; Caballero, Iván; Colmenarejo, Gonzalo; Sanz, Laura M; Álvarez-Ruiz, Emilio; Gamo, Francisco-Javier; Cid, Concepción

    2016-10-01

    The discovery and development of new antimalarial drugs are becoming imperative because of the spread of resistance to current clinical treatments. The lack of robustly validated antimalarial targets and the difficulties with the building in of whole-cell activity in screening hits are hampering target-based approaches. However, phenotypic screens of structurally diverse molecule libraries are offering new opportunities for the identification of novel antimalarials. Several methodologies can be used to determine the whole-cell in vitro potencies of antimalarial hits. The [(3)H]hypoxanthine incorporation assay is considered the "gold standard" assay for measurement of the activity of antimalarial compounds against intraerythrocytic forms of Plasmodium falciparum However, the method has important limitations, as the assay is not amenable for high-throughput screening since it remains associated with the 96-well plate format. We have overcome this drawback by adapting the [(3)H]hypoxanthine incorporation method to a 384-well high-density format by coupling a homogeneous scintillation proximity assay (SPA) and thus eliminating the limiting filtration step. This SPA has been validated using a diverse set of 1,000 molecules, including both a representative set from the Tres Cantos Antimalarial Set (TCAMS) of compounds and molecules inactive against whole cells. The results were compared with those from the P. falciparum lactate dehydrogenase whole-cell assay, another method that is well established as a surrogate for parasite growth and is amenable for high-throughput screening. The results obtained demonstrate that the SPA-based [(3)H]hypoxanthine incorporation assay is a suitable design that is adaptable to high-throughput antimalarial drug screening and that maintains the features, robustness, and reliability of the standard filtration hypoxanthine incorporation method.

  14. Substrate Orientation and Catalytic Specificity in the Action of Xanthine Oxidase: The Sequential Hydroxylation of Hypoxanthine to Uric Acid

    SciTech Connect

    Cao, Hongnan; Pauff, James M.; Hille, Russ

    2010-11-29

    Xanthine oxidase is a molybdenum-containing enzyme catalyzing the hydroxylation of a sp{sup 2}-hybridized carbon in a broad range of aromatic heterocycles and aldehydes. Crystal structures of the bovine enzyme in complex with the physiological substrate hypoxanthine at 1.8 {angstrom} resolution and the chemotherapeutic agent 6-mercaptopurine at 2.6 {angstrom} resolution have been determined, showing in each case two alternate orientations of substrate in the two active sites of the crystallographic asymmetric unit. One orientation is such that it is expected to yield hydroxylation at C-2 of substrate, yielding xanthine. The other suggests hydroxylation at C-8 to give 6,8-dihydroxypurine, a putative product not previously thought to be generated by the enzyme. Kinetic experiments demonstrate that >98% of hypoxanthine is hydroxylated at C-2 rather than C-8, indicating that the second crystallographically observed orientation is significantly less catalytically effective than the former. Theoretical calculations suggest that enzyme selectivity for the C-2 over C-8 of hypoxanthine is largely due to differences in the intrinsic reactivity of the two sites. For the orientation of hypoxanthine with C-2 proximal to the molybdenum center, the disposition of substrate in the active site is such that Arg880 and Glu802, previous shown to be catalytically important for the conversion of xanthine to uric acid, play similar roles in hydroxylation at C-2 as at C-8. Contrary to the literature, we find that 6,8-dihydroxypurine is effectively converted to uric acid by xanthine oxidase.

  15. Development of a Novel High-Density [3H]Hypoxanthine Scintillation Proximity Assay To Assess Plasmodium falciparum Growth.

    PubMed

    de Cózar, Cristina; Caballero, Iván; Colmenarejo, Gonzalo; Sanz, Laura M; Álvarez-Ruiz, Emilio; Gamo, Francisco-Javier; Cid, Concepción

    2016-10-01

    The discovery and development of new antimalarial drugs are becoming imperative because of the spread of resistance to current clinical treatments. The lack of robustly validated antimalarial targets and the difficulties with the building in of whole-cell activity in screening hits are hampering target-based approaches. However, phenotypic screens of structurally diverse molecule libraries are offering new opportunities for the identification of novel antimalarials. Several methodologies can be used to determine the whole-cell in vitro potencies of antimalarial hits. The [(3)H]hypoxanthine incorporation assay is considered the "gold standard" assay for measurement of the activity of antimalarial compounds against intraerythrocytic forms of Plasmodium falciparum However, the method has important limitations, as the assay is not amenable for high-throughput screening since it remains associated with the 96-well plate format. We have overcome this drawback by adapting the [(3)H]hypoxanthine incorporation method to a 384-well high-density format by coupling a homogeneous scintillation proximity assay (SPA) and thus eliminating the limiting filtration step. This SPA has been validated using a diverse set of 1,000 molecules, including both a representative set from the Tres Cantos Antimalarial Set (TCAMS) of compounds and molecules inactive against whole cells. The results were compared with those from the P. falciparum lactate dehydrogenase whole-cell assay, another method that is well established as a surrogate for parasite growth and is amenable for high-throughput screening. The results obtained demonstrate that the SPA-based [(3)H]hypoxanthine incorporation assay is a suitable design that is adaptable to high-throughput antimalarial drug screening and that maintains the features, robustness, and reliability of the standard filtration hypoxanthine incorporation method. PMID:27458216

  16. Determination of Xanthine in the Presence of Hypoxanthine by Adsorptive Stripping Voltammetry at the Mercury Film Electrode

    PubMed Central

    Farias, Percio Augusto Mardini; Castro, Arnaldo Aguiar

    2014-01-01

    A stripping method for the determination of xanthine in the presence of hypoxanthine at the submicromolar concentration levels is described. The method is based on controlled adsorptive accumulation at the thin-film mercury electrode followed by a fast linear scan voltammetric measurement of the surface species. Optimum experimental conditions were found to be the use of 1.0 × 10−3 mol L−1 NaOH solution as supporting electrolyte, an accumulation potential of 0.00 V for xanthine and −0.50 V for hypoxanthine–copper, and a linear scan rate of 200 mV second−1. The response of xanthine is linear over the concentration ranges of 20–140 ppb. For an accumulation time of 30 minutes, the detection limit was found to be 36 ppt (2.3 × 10−10 mol L−1). Adequate conditions for measuring the xanthine in the presence of hypoxanthine, copper and other metals, uric acid, and other nitrogenated bases were also investigated. The utility of the method is demonstrated by the presence of xanthine associated with hypoxanthine, uric acid, nitrogenated bases, ATP, and ssDNA. PMID:24940040

  17. Differentiation alters the unstable expression of adenine phosphoribosyltransferase in mouse teratocarcinoma cells.

    PubMed

    Turker, M S; Tischfield, J A; Rabinovitch, P; Stambrook, P J; Trill, J J; Smith, A C; Ogburn, C E; Martin, G M

    1986-01-01

    Three multipotent mouse teratocarcinoma stem lines, all exhibiting unstable expression for the purine salvage enzyme adenine phosphoribosyltransferase (APRT) were used for the isolation of differentiated cell lines from neoplasms developed in syngeneic mice. Two of the stem cell lines (DAP1B and DAP1C) exhibited homozygous deficiencies for APRT expression while the third stem cell line (E140) exhibited a heterozygous deficiency (Turker, M.S., Smith, A.C., and Martin, G.M.; Somat. Cell Mol. Genet.; 10:55-69; 1984). A total of 16 morphologically differentiated cell lines were established from these neoplasms; most were no longer tumorigenic. Differentiated cell lines derived from the E140-induced tumors segregated homozygous deficient mutants in a single step, consistent with their retention of the heterozygous deficient state. Differentiated homozygous deficient cell lines gave rise to phenotypic revertants at very high frequencies (10(-1) to 10(-2)). The majority of these putative revertants, however, yielded cell-free extracts with little or no detectable APRT activity. These putative revertants were capable of adenine salvage and were therefore termed APRT pseudorevertants. Since the APRT pseudorevertant phenotype was only observed in the differentiated progeny of the APRT deficient stem cell lines, we conclude that this change in the nature of the revertant phenotype was a consequence of cellular differentiation.

  18. Increasing NAD synthesis in muscle via nicotinamide phosphoribosyltransferase is not sufficient to promote oxidative metabolism.

    PubMed

    Frederick, David W; Davis, James G; Dávila, Antonio; Agarwal, Beamon; Michan, Shaday; Puchowicz, Michelle A; Nakamaru-Ogiso, Eiko; Baur, Joseph A

    2015-01-16

    The NAD biosynthetic precursors nicotinamide mononucleotide and nicotinamide riboside are reported to confer resistance to metabolic defects induced by high fat feeding in part by promoting oxidative metabolism in skeletal muscle. Similar effects are obtained by germ line deletion of major NAD-consuming enzymes, suggesting that the bioavailability of NAD is limiting for maximal oxidative capacity. However, because of their systemic nature, the degree to which these interventions exert cell- or tissue-autonomous effects is unclear. Here, we report a tissue-specific approach to increase NAD biosynthesis only in muscle by overexpressing nicotinamide phosphoribosyltransferase, the rate-limiting enzyme in the salvage pathway that converts nicotinamide to NAD (mNAMPT mice). These mice display a ∼50% increase in skeletal muscle NAD levels, comparable with the effects of dietary NAD precursors, exercise regimens, or loss of poly(ADP-ribose) polymerases yet surprisingly do not exhibit changes in muscle mitochondrial biogenesis or mitochondrial function and are equally susceptible to the metabolic consequences of high fat feeding. We further report that chronic elevation of muscle NAD in vivo does not perturb the NAD/NADH redox ratio. These studies reveal for the first time the metabolic effects of tissue-specific increases in NAD synthesis and suggest that critical sites of action for supplemental NAD precursors reside outside of the heart and skeletal muscle. PMID:25411251

  19. Kinetic analysis and chemical modification studies of nicotinate phosphoribosyltransferase from yeast

    SciTech Connect

    Hess, S.L.

    1988-01-01

    Nicotinate phosphoribosyltransferase (NaPRTase) from Baker's yeast catalyzes the formation of nicotinate mononucleotide (NaMN) and pyrophosphate from phosphoribosyl {alpha}-1-pyrophosphate and nicotinate, concomitant with ATP hydrolysis. Using purified NaPRTase, initial velocity measurements were performed varying one substrate concentration at different fixed levels of the second substrate and maintaining the third substrate constant. Subsequently, an exchange of label was observed between ATP and ({sup 14}C)-ADP. This rate of exchange was inhibited by PRibPP and pyrophosphate. Incubations of NaPRTase with pyridoxal 5{prime}-phosphate followed by sodium borohydride reduction led to inactivation of the enzyme. Pyridoxal was a less effective inhibitor than pyridoxal 5{prime}-phosphate. The inactivation of the enzyme by pyridoxal 5{prime}-phosphate was reversible upon flow dialysis, whereas reduction of the enzyme-pyridoxal complex with sodium borohydride rendered the inhibition irreversible. The presence of ATP or PRibPP, with or with Mg{sup 2+}, provided protection against this inactivation, while a kinetic analysis revealed the inhibition to be competitive, and noncompetitive, respectively. One mole of ({sup 3}H)-pyridoxal phosphate was required to completely inactivate the enzyme, which was reduced in the presence of MgATP and MgPRibPP to 0.2 and 0.6, respectively. No incorporation of pyridoxal 5{prime}-phosphate was observed in the combination of both of the two substrates.

  20. Increasing NAD synthesis in muscle via nicotinamide phosphoribosyltransferase is not sufficient to promote oxidative metabolism.

    PubMed

    Frederick, David W; Davis, James G; Dávila, Antonio; Agarwal, Beamon; Michan, Shaday; Puchowicz, Michelle A; Nakamaru-Ogiso, Eiko; Baur, Joseph A

    2015-01-16

    The NAD biosynthetic precursors nicotinamide mononucleotide and nicotinamide riboside are reported to confer resistance to metabolic defects induced by high fat feeding in part by promoting oxidative metabolism in skeletal muscle. Similar effects are obtained by germ line deletion of major NAD-consuming enzymes, suggesting that the bioavailability of NAD is limiting for maximal oxidative capacity. However, because of their systemic nature, the degree to which these interventions exert cell- or tissue-autonomous effects is unclear. Here, we report a tissue-specific approach to increase NAD biosynthesis only in muscle by overexpressing nicotinamide phosphoribosyltransferase, the rate-limiting enzyme in the salvage pathway that converts nicotinamide to NAD (mNAMPT mice). These mice display a ∼50% increase in skeletal muscle NAD levels, comparable with the effects of dietary NAD precursors, exercise regimens, or loss of poly(ADP-ribose) polymerases yet surprisingly do not exhibit changes in muscle mitochondrial biogenesis or mitochondrial function and are equally susceptible to the metabolic consequences of high fat feeding. We further report that chronic elevation of muscle NAD in vivo does not perturb the NAD/NADH redox ratio. These studies reveal for the first time the metabolic effects of tissue-specific increases in NAD synthesis and suggest that critical sites of action for supplemental NAD precursors reside outside of the heart and skeletal muscle.

  1. Targeting Nicotinamide Phosphoribosyltransferase as a Potential Therapeutic Strategy to Restore Adult Neurogenesis.

    PubMed

    Wang, Shu-Na; Xu, Tian-Ying; Li, Wen-Lin; Miao, Chao-Yu

    2016-06-01

    Adult neurogenesis is the process of generating new neurons throughout life in the olfactory bulb and hippocampus of most mammalian species, which is closely related to aging and disease. Nicotinamide phosphoribosyltransferase (NAMPT), also an adipokine known as visfatin, is the rate-limiting enzyme for mammalian nicotinamide adenine dinucleotide (NAD) salvage synthesis by generating nicotinamide mononucleotide (NMN) from nicotinamide. Recent findings from our laboratory and other laboratories have provided much evidence that NAMPT might serve as a therapeutic target to restore adult neurogenesis. NAMPT-mediated NAD biosynthesis in neural stem/progenitor cells is important for their proliferation, self-renewal, and formation of oligodendrocytes in vivo and in vitro. Therapeutic interventions by the administration of NMN, NAD, or recombinant NAMPT are effective for restoring adult neurogenesis in several neurological diseases. We summarize adult neurogenesis in aging, ischemic stroke, traumatic brain injury, and neurodegenerative disease and review the advances of targeting NAMPT in restoring neurogenesis. Specifically, we provide emphasis on the P7C3 family, a class of proneurogenic compounds that are potential NAMPT activators, which might shed light on future drug development in neurogenesis restoration. PMID:27018006

  2. Orotate phosphoribosyltransferase is overexpressed in malignant pleural mesothelioma: Dramatically responds one case in high OPRT expression

    PubMed Central

    Hamamoto, Yoichiro; Takeoka, Shinjiro; Mouri, Atsuto; Fukusumi, Munehisa; Wakuda, Kazushige; Ibe, Tatsuya; Honma, Chie; Arimoto, Yoshihito; Yamada, Kazuaki; Wagatsuma, Miyuki; Tashiro, Akito; Kamoshida, Shingo; Kamimura, Mitsuhiro

    2016-01-01

    ABSTRACT Objective: Malignant pleural mesothelioma (MPM) is a rare and aggressive, treatment-resistant cancer. Pemetrexed, an inhibitor of thymidylate synthase (TS), is used worldwide for MPM as a first-line chemotherapy regimen. However, there is little consensus for a second-line chemotherapy. S-1, a highly effective dihydropyrimidine dehydrogenase (DPD)-inhibitory fluoropyrimidine, mainly acts via a TS inhibitory mechanism similar to pemetrexed. Orotate phosphoribosyltransferase (OPRT) is a key enzyme related to the first step activation of 5-fluorouracil (5-FU) for inhibiting RNA synthesis. We investigated 5-FU related-metabolism proteins, especially focusing on OPRT expression, in MPM Methods and Patients: Fifteen MPM patients who were diagnosed between July 2004 and December 2013 were enrolled. We examined the protein levels of 5-FU metabolism-related enzymes (TS, DPD, OPRT, and thymidine phosphorylase [TP]) in 14 cases Results: High TS, DPD, OPRT, and TP expressions were seen in 28.6%, 71.4%, 85.7%, and 35.7% of patients, respectively. We found that OPRT expression was extremely high in MPM tissue. We experienced one remarkable case of highly effective S-1 combined therapy for pemetrexed refractory MPM. This case also showed high OPRT protein expression Conclusion: The present study suggests that OPRT expression is high in MPM tumors. Although pemetrexed is mainly used for MPM chemotherapy as a TS inhibitor, S-1 has potential as an anticancer drug not only as a TS inhibitor but also inhibiting RNA synthesis through the OPRT pathway. This is the first report investigating OPRT protein expressions in MPM. PMID:27274438

  3. Establishment of true niacin deficiency in quinolinic acid phosphoribosyltransferase knockout mice.

    PubMed

    Terakata, Miki; Fukuwatari, Tsutomu; Sano, Mitsue; Nakao, Natsuki; Sasaki, Ryuzo; Fukuoka, Shin-Ichi; Shibata, Katsumi

    2012-12-01

    Pyridine nucleotide coenzymes are involved in >500 enzyme reactions and are biosynthesized from the amino acid L-tryptophan (L-Trp) as well as the vitamin niacin. Hence, "true" niacin-deficient animals cannot be "created" using nutritional techniques. We wanted to establish a truly niacin-deficient model animal using a protocol that did not involve manipulating dietary L-Trp. We generated mice that are missing the quinolinic acid (QA) phosphoribosyltransferase (QPRT) gene. QPRT activity was not detected in qprt(-/-)mice. The qprt(+/+), qprt(+/-), or qprt(-/-) mice (8 wk old) were fed a complete diet containing 30 mg nicotinic acid (NiA) and 2.3 g L-Trp/kg diet or an NiA-free diet containing 2.3 g L-Trp/kg diet for 23 d. When qprt(-/-)mice were fed a complete diet, food intake and body weight gain did not differ from those of the qprt(+/+) and qprt(+/-) mice. On the contrary, in the qprt(-/-) mice fed the NiA-free diet, food intake and body weight were reduced to 60% (P < 0.01) and 70% (P < 0.05) of the corresponding values for the qprt(-/-) mice fed the complete diet at d 23, respectively. The nutritional levels of niacin, such as blood and liver NAD concentrations, were also lower in the qprt(-/-) mice than in the qprt(+/+) and the qprt(+/-) mice. Urinary excretion of QA was greater in the qprt(-/-) mice than in the qprt(+/+) and qprt(+/-) mice (P < 0.01). These data suggest that we generated truly niacin-deficient mice.

  4. An ultrasensitive electrochemical sensor for simultaneous determination of xanthine, hypoxanthine and uric acid based on Co doped CeO2 nanoparticles.

    PubMed

    Lavanya, N; Sekar, C; Murugan, R; Ravi, G

    2016-08-01

    A novel electrochemical sensor has been fabricated using Co doped CeO2 nanoparticles for selective and simultaneous determination of xanthine (XA), hypoxanthine (HXA) and uric acid (UA) in a phosphate buffer solution (PBS, pH5.0) for the first time. The Co-CeO2 NPs have been prepared by microwave irradiation method and characterized by Powder XRD, Raman spectroscopy, HRTEM and VSM measurements. The electrochemical behaviours of XA, HXA and UA at the Co-CeO2 NPs modified glassy carbon electrode (GCE) were studied by cyclic voltammetry and square wave voltammetry methods. The modified electrode exhibited remarkably well-separated anodic peaks corresponding to the oxidation of XA, HXA and UA over the concentration range of 0.1-1000, 1-600 and 1-2200μM with detection limits of 0.096, 0.36, and 0.12μM (S/N=3), respectively. For simultaneous detection by synchronous change of the concentrations of XA, HXA and UA, the linear responses were in the range of 1-400μM each with the detection limits of 0.47, 0.26, and 0.43μM (S/N=3), respectively. The fabricated sensor was further applied to the detection of XA, HXA and UA in human urine samples with good selectivity and high reproducibility.

  5. Progress and recent advances in fabrication and utilization of hypoxanthine biosensors for meat and fish quality assessment: a review.

    PubMed

    Lawal, Abdulazeez T; Adeloju, Samuel B

    2012-10-15

    This review provides an update on the research conducted on the fabrication and utilization of hypoxanthine (Hx) biosensors published over the past four decades. In particular, the review focuses on progress made in the development and use of Hx biosensors for the assessment of fish and meat quality which has dominated research in this area. The various fish and meat freshness indexes that have been proposed over this period are highlighted. Furthermore, recent developments and future advances in the use of screen-printed electrodes and nanomaterials for achieving improved performances for the reliable determination of Hx in fish and meat are discussed.

  6. Analysis of abnormalities in purine metabolism leading to gout and to neurological dysfunctions in man.

    PubMed Central

    Curto, R; Voit, E O; Cascante, M

    1998-01-01

    A modelling approach is used to analyse diseases associated with purine metabolism in man. The specific focus is on deficiencies in two enzymes, hypoxanthine:guanine phosphoribosyltransferase and adenylosuccinate lyase. These deficiencies can lead to a number of symptoms, including neurological dysfunctions and mental retardation. Although the biochemical mechanisms of dysfunctions associated with adenylosuccinate lyase deficiency are not completely understood, there is at least general agreement in the literature about possible causes. Simulations with our model confirm that accumulation of the two substrates of the enzyme can lead to significant biochemical imbalance. In hypoxanthine:guanine phosphoribosyltransferase deficiency the biochemical mechanisms associated with neurological dysfunctions are less clear. Model analyses support some old hypotheses but also suggest new indicators for possible causes of neurological dysfunctions associated with this deficiency. Hypoxanthine:guanine phosphoribosyltransferase deficiency is known to cause hyperuricaemia and gout. We compare the relative importance of this deficiency with other known causes of gout in humans. The analysis suggests that defects in the excretion of uric acid are more consequential than defects in uric acid synthesis such as hypoxanthine:guanine phosphoribosyltransferase deficiency. PMID:9445373

  7. Adenine phosphoribosyltransferase (APRT) deficiency: a new genetic mutation with early recurrent renal stone disease in kidney transplantation

    PubMed Central

    Micheli, Vanna; Massarino, Fabio; Jacomelli, Gabriella; Bertelli, Matteo; Corradi, Maria Rita; Guerrini, Andrea; Cucchiara, Antonino; Ravetti, Jean Louis; Negretti, Laura; Cannella, Giuseppe

    2010-01-01

    Adenine phosphoribosyltransferase (APRT) deficiency, a rare inborn error inherited as an autosomic recessive trait, presents with 2,8-dihydroxyadenine (2,8-DHA) crystal nephropathy. We describe clinical, biochemical and molecular findings in a renal transplant recipient with renal failure, 2,8-DHA stones and no measurable erythrocyte APRT activity. Homozygous C > G substitution at −3 in the splicing site of exon 2 (IVS2 −3 c > g) was found in the APRT gene. The patient’s asymptomatic brother was heterozygous for such mutation, and his APRT activity was 23% of controls. A splicing alteration leading to incorrect gene transcription and virtually absent APRT activity is seemingly associated with the newly identified mutation. PMID:25984046

  8. Adenine phosphoribosyltransferase (APRT) deficiency: a new genetic mutation with early recurrent renal stone disease in kidney transplantation.

    PubMed

    Micheli, Vanna; Massarino, Fabio; Jacomelli, Gabriella; Bertelli, Matteo; Corradi, Maria Rita; Guerrini, Andrea; Cucchiara, Antonino; Ravetti, Jean Louis; Negretti, Laura; Cannella, Giuseppe

    2010-10-01

    Adenine phosphoribosyltransferase (APRT) deficiency, a rare inborn error inherited as an autosomic recessive trait, presents with 2,8-dihydroxyadenine (2,8-DHA) crystal nephropathy. We describe clinical, biochemical and molecular findings in a renal transplant recipient with renal failure, 2,8-DHA stones and no measurable erythrocyte APRT activity. Homozygous C > G substitution at -3 in the splicing site of exon 2 (IVS2 -3 c > g) was found in the APRT gene. The patient's asymptomatic brother was heterozygous for such mutation, and his APRT activity was 23% of controls. A splicing alteration leading to incorrect gene transcription and virtually absent APRT activity is seemingly associated with the newly identified mutation.

  9. Archaeal DNA Polymerase-B as a DNA Template Guardian: Links between Polymerases and Base/Alternative Excision Repair Enzymes in Handling the Deaminated Bases Uracil and Hypoxanthine

    PubMed Central

    Ishino, Sonoko; Connolly, Bernard A.

    2016-01-01

    In Archaea repair of uracil and hypoxanthine, which arise by deamination of cytosine and adenine, respectively, is initiated by three enzymes: Uracil-DNA-glycosylase (UDG, which recognises uracil); Endonuclease V (EndoV, which recognises hypoxanthine); and Endonuclease Q (EndoQ), (which recognises both uracil and hypoxanthine). Two archaeal DNA polymerases, Pol-B and Pol-D, are inhibited by deaminated bases in template strands, a feature unique to this domain. Thus the three repair enzymes and the two polymerases show overlapping specificity for uracil and hypoxanthine. Here it is demonstrated that binding of Pol-D to primer-templates containing deaminated bases inhibits the activity of UDG, EndoV, and EndoQ. Similarly Pol-B almost completely turns off EndoQ, extending earlier work that demonstrated that Pol-B reduces catalysis by UDG and EndoV. Pol-B was observed to be a more potent inhibitor of the enzymes compared to Pol-D. Although Pol-D is directly inhibited by template strand uracil, the presence of Pol-B further suppresses any residual activity of Pol-D, to near-zero levels. The results are compatible with Pol-D acting as the replicative polymerase and Pol-B functioning primarily as a guardian preventing deaminated base-induced DNA mutations. PMID:27721668

  10. Effect of NADH on hypoxanthine hydroxylation by native NAD+-dependent xanthine oxidoreductase of rat liver, and the possible biological role of this effect.

    PubMed Central

    Kamiński, Z W; Jezewska, M M

    1981-01-01

    The course of the reaction sequence hypoxanthine leads to xanthine leads to uric acid, catalysed by the NAD+-dependent activity of xanthine oxidoreductase, was investigated under conditions either of immediate oxidation of the NADH formed or of NADH accumulation. The enzymic preparation was obtained from rat liver, and purified 75-fold (as compared with the 25000 g supernatant) on a 5'-AMP-Sepharose 4B column; in this preparation the NAD+-dependent activity accounted for 100% of total xanthine oxidoreductase activity. A spectrophotometric method was developed for continuous measurements of changes in the concentrations of the three purines involved. The time course as well as the effects of the concentrations of enzyme and of hypoxanthine were examined. NADH produced by the enzyme lowered its activity by 50%, resulting in xanthine accumulation and in decreases of uric acid formation and of hypoxanthine utilization. The inhibition of the Xanthine oxidoreductase NAD+-dependent activity by NADH is discussed as a possible factor in the regulation of IMP biosynthesis by the 'de novo' pathway or (from unchanged hypoxanthine) by ther salvage pathway. PMID:6952874

  11. Cyto- and genotoxicity of ultrafine TiO2 particles in cultured human lymphoblastoid cells.

    PubMed

    Wang, Jing J; Sanderson, Barbara J S; Wang, He

    2007-04-01

    Titanium dioxide is frequently used in the production of paints, paper, plastics, welding rod-coating material, and cosmetics, because of its low toxicity. However, recent studies have shown that nano-sized or ultrafine TiO(2) (UF-TiO(2)) (<100 nm in diameter) can generate pulmonary fibrosis and lung tumor in rats. Cytotoxicity induced by UF-TiO(2) in rat lung alveolar macrophages was also observed. This generates great concern about the possible adverse effects of UF-TiO(2) for humans. The cytotoxicity and genotoxicity of UF-TiO(2) were investigated using the methyl tetrazolium cytotoxicity (MTT) assay, the population growth assay, the apoptosis assay by flow cytometry, the cytokinesis block micronucleus (CBMN) assay, the comet assay, and the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation assay. WIL2-NS cells were incubated for 6, 24 and 48 h with 0, 26, 65 and 130 microg/ml UF-TiO(2). Significant decreases in viability were seen in the MTT assay at higher doses; for example, 61, 7 and 2% relative viability at 130 microg/ml for 6, 24 and 48-h exposure (P<0.01). A dose-dependent relationship was observed, while a time-dependent relationship was seen only at the highest dose (130 microg/ml) after exposure for 24 and 48 h. Treatment with 130 microg/ml UF-TiO(2) induced approximately 2.5-fold increases in the frequency of micronucleated binucleated cells (P<0.01). In addition, a significant reduction in the cytokinesis block proliferation index was observed by the CBMN assay (P<0.05). In the comet assay, treatment with 65 microg/ml UF-TiO(2) induced approximately 5-fold increases in olive tail moment (P<0.05). In the HPRT mutation assay, treatment with 130 microg/ml UF-TiO(2) induced approximately 2.5-fold increases in the mutation frequency (P<0.05). The results of this study indicate that UF-TiO(2) can cause genotoxicity and cytotoxicity in cultured human cells.

  12. Identification of stable reference genes for gene expression analysis of three-dimensional cultivated human bone marrow-derived mesenchymal stromal cells for bone tissue engineering.

    PubMed

    Rauh, Juliane; Jacobi, Angela; Stiehler, Maik

    2015-02-01

    The principles of tissue engineering (TE) are widely used for bone regeneration concepts. Three-dimensional (3D) cultivation of autologous human mesenchymal stromal cells (MSCs) on porous scaffolds is the basic prerequisite to generate newly formed bone tissue. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is a specific and sensitive analytical tool for the measurement of mRNA-levels in cells or tissues. For an accurate quantification of gene expression levels, stably expressed reference genes (RGs) are essential to obtain reliable results. Since the 3D environment can affect a cell's morphology, proliferation, and gene expression profile compared with two-dimensional (2D) cultivation, there is a need to identify robust RGs for the quantification of gene expression. So far, this issue has not been adequately investigated. The aim of this study was to identify the most stably expressed RGs for gene expression analysis of 3D-cultivated human bone marrow-derived MSCs (BM-MSCs). For this, we analyzed the gene expression levels of n=31 RGs in 3D-cultivated human BM-MSCs from six different donors compared with conventional 2D cultivation using qRT-PCR. MSCs isolated from bone marrow aspirates were cultivated on human cancellous bone cube scaffolds for 14 days. Osteogenic differentiation was assessed by cell-specific alkaline phosphatase (ALP) activity and expression of osteogenic marker genes. Expression levels of potential reference and target genes were quantified using commercially available TaqMan(®) assays. mRNA expression stability of RGs was determined by calculating the coefficient of variation (CV) and using the algorithms of geNorm and NormFinder. Using both algorithms, we identified TATA box binding protein (TBP), transferrin receptor (p90, CD71) (TFRC), and hypoxanthine phosphoribosyltransferase 1 (HPRT1) as the most stably expressed RGs in 3D-cultivated BM-MSCs. Notably, genes that are routinely used as RGs, for example, beta actin

  13. Down-Regulation of a Nicotinate Phosphoribosyltransferase Gene, OsNaPRT1, Leads to Withered Leaf Tips1[OPEN

    PubMed Central

    Ren, Deyong; Li, Gengmi; Jiang, Liang; Hu, Xingming; Ye, Weijun; Zhu, Li; Hu, Jiang; Zhang, Guangheng; Gao, Zhenyu; Guo, Longbiao

    2016-01-01

    Premature leaf senescence affects plant growth and yield in rice. NAD plays critical roles in cellular redox reactions and remains at a sufficient level in the cell to prevent cell death. Although numerous factors affecting leaf senescence have been identified, few involving NAD biosynthetic pathways have been described for plants. Here, we report the cloning and characterization of Leaf Tip Senescence 1 (LTS1) in rice (Oryza sativa), a recessive mutation in the gene encoding O. sativa nicotinate phosphoribosyltransferase (OsNaPRT1) in the NAD salvage pathway. A point mutation in OsNaPRT1 leads to dwarfism and the withered leaf tip phenotype, and the lts1 mutant displays early leaf senescence compared to the wild type. Leaf nicotinate and nicotinamide contents are elevated in lts1, while NAD levels are reduced. Leaf tissue of lts1 exhibited significant DNA fragmentation and H2O2 accumulation, along with up-regulation of genes associated with senescence. The lts1 mutant also showed reduced expression of SIR2-like genes (OsSRT1 and OsSRT2) and increased acetylation of histone H3K9. Down-regulation of OsSRTs induced histone H3K9 acetylation of senescence-related genes. These results suggest that deficiency in the NAD salvage pathway can trigger premature leaf senescence due to transcriptional activation of senescence-related genes. PMID:27208230

  14. Down-Regulation of a Nicotinate Phosphoribosyltransferase Gene, OsNaPRT1, Leads to Withered Leaf Tips.

    PubMed

    Wu, Liwen; Ren, Deyong; Hu, Shikai; Li, Gengmi; Dong, Guojun; Jiang, Liang; Hu, Xingming; Ye, Weijun; Cui, Yongtao; Zhu, Li; Hu, Jiang; Zhang, Guangheng; Gao, Zhenyu; Zeng, Dali; Qian, Qian; Guo, Longbiao

    2016-06-01

    Premature leaf senescence affects plant growth and yield in rice. NAD plays critical roles in cellular redox reactions and remains at a sufficient level in the cell to prevent cell death. Although numerous factors affecting leaf senescence have been identified, few involving NAD biosynthetic pathways have been described for plants. Here, we report the cloning and characterization of Leaf Tip Senescence 1 (LTS1) in rice (Oryza sativa), a recessive mutation in the gene encoding O. sativa nicotinate phosphoribosyltransferase (OsNaPRT1) in the NAD salvage pathway. A point mutation in OsNaPRT1 leads to dwarfism and the withered leaf tip phenotype, and the lts1 mutant displays early leaf senescence compared to the wild type. Leaf nicotinate and nicotinamide contents are elevated in lts1, while NAD levels are reduced. Leaf tissue of lts1 exhibited significant DNA fragmentation and H2O2 accumulation, along with up-regulation of genes associated with senescence. The lts1 mutant also showed reduced expression of SIR2-like genes (OsSRT1 and OsSRT2) and increased acetylation of histone H3K9. Down-regulation of OsSRTs induced histone H3K9 acetylation of senescence-related genes. These results suggest that deficiency in the NAD salvage pathway can trigger premature leaf senescence due to transcriptional activation of senescence-related genes. PMID:27208230

  15. Metabolic engineering of the purine biosynthetic pathway in Corynebacterium glutamicum results in increased intracellular pool sizes of IMP and hypoxanthine

    PubMed Central

    2012-01-01

    Background Purine nucleotides exhibit various functions in cellular metabolism. Besides serving as building blocks for nucleic acid synthesis, they participate in signaling pathways and energy metabolism. Further, IMP and GMP represent industrially relevant biotechnological products used as flavor enhancing additives in food industry. Therefore, this work aimed towards the accumulation of IMP applying targeted genetic engineering of Corynebacterium glutamicum. Results Blocking of the degrading reactions towards AMP and GMP lead to a 45-fold increased intracellular IMP pool of 22 μmol gCDW-1. Deletion of the pgi gene encoding glucose 6-phosphate isomerase in combination with the deactivated AMP and GMP generating reactions, however, resulted in significantly decreased IMP pools (13 μmol gCDW-1). Targeted metabolite profiling of the purine biosynthetic pathway further revealed a metabolite shift towards the formation of the corresponding nucleobase hypoxanthine (102 μmol gCDW-1) derived from IMP degradation. Conclusions The purine biosynthetic pathway is strongly interconnected with various parts of the central metabolism and therefore tightly controlled. However, deleting degrading reactions from IMP to AMP and GMP significantly increased intracellular IMP levels. Due to the complexity of this pathway further degradation from IMP to the corresponding nucleobase drastically increased suggesting additional targets for future strain optimization. PMID:23092390

  16. Sensitivity of somatic mutations in human umbilical cord blood to maternal environments.

    PubMed

    Manchester, D K; Nicklas, J A; O'Neill, J P; Lippert, M J; Grant, S G; Langlois, R G; Moore, D H; Jensen, R H; Albertini, R J; Bigbee, W L

    1995-01-01

    To assess the potential effect of maternal environments on human embryonic/fetal somatic mutation, we measured the frequencies of hypoxanthine-guanine phosphoribosyltransferase (HPRT, hprt gene), mutant T lymphocytes (Mf), and glycophorin A (GPA) variant erythrocytes (Vf) of both allele-loss (phi/N) and allele-loss-and-duplication (N/N) phenotypes in umbilical cord blood. The mean hprt Mf (1.40 +/- 1.11 x 10(-6), N = 66) and GPA Vf (phi/N 4.0 +/- 2.2 x 10(-6), N = 114; N/N 2.7 +/- 2.0 x 10(-6), N = 91) were significantly lower than those previously reported for adult populations. In addition, the hprt Mf was significantly higher than that of a published study of newborn cord blood samples from a geographically distant population (0.64 +/- 0.41 x 10(-6), N = 45, P < 0.01; t test, P < 0.01, Mann-Whitney U test). An examination of the demographic data from these two populations led to the sampling of 10 additional newborns specifically matched to the published study for maternal socioeconomic status. The hprt Mf (0.70 +/- 0.49 x 10(-6)) of this selected population was consistent with the published report and significantly lower than that of our initial population (P < 0.03, t test; P < 0.01, Mann-Whitney U test). These results indicate that there is an environmental effect related to maternal socioeconomic status on the frequency of embryonic/fetal somatic mutations. Molecular analyses of hprt mutants from this cohort with elevated Mf revealed a significant decrease in the relative contribution of gross structural mutations to the overall Mf (25 of 38, 66% vs. 34 of 41, 83%, P = 0.024, chi 2 test), suggesting that the higher Mf resulted from an elevated level of "point" mutations. No individual maternal demographic or environmental factor was identified as contributing more significantly than other any factor to the observed variability in hprt Mf or GPA Vf.

  17. Human hybrid hybridoma

    SciTech Connect

    Tiebout, R.F.; van Boxtel-Oosterhof, F.; Stricker, E.A.M.; Zeijlemaker, W.P.

    1987-11-15

    Hybrid hybridomas are obtained by fusion of two cells, each producing its own antibody. Several authors have reported the construction of murine hybrid hybridomas with the aim to obtain bispecific monoclonal antibodies. The authors have investigated, in a model system, the feasibility of constructing a human hybrid hybridoma. They fused two monoclonal cell lines: an ouabain-sensitive and azaserine/hypoxanthine-resistant Epstein-Barr virus-transformed human cell line that produces an IgG1kappa antibody directed against tetanus toxiod and an azaserine/hypoxanthine-sensitive and ouabain-resistant human-mouse xenohybrid cell line that produces a human IgG1lambda antibody directed against hepatitis-B surface antigen. Hybrid hybridoma cells were selected in culture medium containing azaserine/hypoxanthine and ouabain. The hybrid nature of the secreted antibodies was analyzed by means of two antigen-specific immunoassay. The results show that it is possible, with the combined use of transformation and xenohybridization techniques, to construct human hybrid hybridomas that produce bispecific antibodies. Bispecific antibodies activity was measured by means of two radioimmunoassays.

  18. The pyrimidine biosynthesis operon of the thermophile Bacillus caldolyticus includes genes for uracil phosphoribosyltransferase and uracil permease.

    PubMed Central

    Ghim, S Y; Neuhard, J

    1994-01-01

    A 3-kb DNA segment of the Bacillus caldolyticus genome including the 5' end end of the pyr cluster has been cloned and sequenced. The sequence revealed the presence of two open reading frames, pyrR and pyrP, located immediately upstream of the previously sequenced pyrB gene encoding the pyrimidine biosynthesis enzyme aspartate transcarbamoylase. The pyrR and pyrP genes encoded polypeptides with calculated molecular masses of 19.9 and 45.2 kDa, respectively. Expression of these ORFs was confirmed by analysis of plasmid-encoded polypeptides in minicells. Sequence alignment and complementation analyses identified the pyrR gene product as a uracil phosphoribosyltransferase and the pyrP gene product as a membrane-bound uracil permease. By using promoter expression vectors, a 650-bp EcoRI-HincII fragment, including the 5' end of pyrR and its upstream region, was found to contain the pyr operon promoter. The transcriptional start point was located by primer extension at a position 153 bp upstream of the pyrR translation initiation codon, 7 bp 3' of a sequence resembling a sigma A-dependent Bacillus subtilis promoter. This established the following organization of the ten cistrons within the pyr operon: promoter-pyrR-pyrP-pyrB-pyrC-pyrAa-pyrA b-orf2-pyrD-pyrF-pyrE. The nucleotide sequences of the region upstream of pyrR and of the pyrR-pyrP and pyrP-pyrB intercistronic regions indicated that the transcript may form two mutually exclusive secondary structures within each of these regions. One of these structures resembled a rho-independent transcriptional terminator. The possible implication of these structures for pyrimidine regulation of the operon is discussed. Images PMID:8206848

  19. Biochemical Characterization of Quinolinic Acid Phosphoribosyltransferase from Mycobacterium tuberculosis H37Rv and Inhibition of Its Activity by Pyrazinamide

    PubMed Central

    Kim, Hyun; Shibayama, Keigo; Rimbara, Emiko; Mori, Shigetarou

    2014-01-01

    Quinolinic acid phosphoribosyltransferase (QAPRTase, EC 2.4.2.19) is a key enzyme in the de novo pathway of nicotinamide adenine dinucleotide (NAD) biosynthesis and a target for the development of new anti-tuberculosis drugs. QAPRTase catalyzes the synthesis of nicotinic acid mononucleotide from quinolinic acid (QA) and 5-phosphoribosyl-1-pyrophosphate (PRPP) through a phosphoribosyl transfer reaction followed by decarboxylation. The crystal structure of QAPRTase from Mycobacterium tuberculosis H37Rv (MtQAPRTase) has been determined; however, a detailed functional analysis of MtQAPRTase has not been published. Here, we analyzed the enzymatic activities of MtQAPRTase and determined the effect on catalysis of the anti-tuberculosis drug pyrazinamide (PZA). The optimum temperature and pH for MtQAPRTase activity were 60°C and pH 9.2. MtQAPRTase required bivalent metal ions and its activity was highest in the presence of Mg2+. Kinetic analyses revealed that the Km values for QA and PRPP were 0.08 and 0.39 mM, respectively, and the kcat values for QA and PRPP were 0.12 and 0.14 [s-1], respectively. When the amino acid residues of MtQAPRTase, which may interact with QA, were substituted with alanine residues, catalytic activity was undetectable. Further, PZA, which is an anti-tuberculosis drug and a structural analog of QA, markedly inhibited the catalytic activity of MtQAPRTase. The structure of PZA may provide the basis for the design of new inhibitors of MtQAPRTase. These findings provide new insights into the catalytic properties of MtQAPRTase. PMID:24949952

  20. Association of Nicotinamide Phosphoribosyltransferase (NAMPT) Gene Polymorphisms and of Serum NAMPT Levels with Dilated Cardiomyopathy in a Chinese Population

    PubMed Central

    Dou, Qingyu; Peng, Ying; Zhou, Bin; Zhang, Kui; Lin, Jing; Dai, Xiaohui; Zhang, Lin; Rao, Li

    2015-01-01

    Nicotinamide phosphoribosyltransferase (NAMPT) has crucial roles for myocardial development, cardiomyocyte energy metabolism and cell death/survival by regulating NAD+-dependent sirtuin-1 (SIRT1) deacetylase. This study aimed to determine if the single nucleotide polymorphisms (SNPs) of the NAMPT gene may affect the susceptibility and prognosis for patients with dilated cardiomyopathy (DCM) and to describe the association of serum NAMPT levels with clinical features of DCM. Three SNPs (rs61330082, rs2505568, and rs9034) were analyzed by the polymerase chain reaction-restriction fragment length polymorphism method in a case-control study of 394 DCM patients and 395 controls from China. Serum NAMPT levels were measured by enzyme-linked immunosorbent assay kits. The homozygote for the minor allele at rs2505568 and rs9034 could not be detected in this study. Rs9034 T allele and CT genotype were associated with increased DCM risk (OR: 1.63, 95% CI = 1.16–2.27, p = 0.005 and OR: 1.72, 95% CI = 1.20–2.50, p = 0.0027, respectively). Nominally significant decreased DCM risk was found to be associated with the A allele and AT genotype of rs2505568 (OR: 0.48, 95% CI = 0.35–0.67, p < 0.0001 and OR: 0.44, 95% CI = 0.31–0.62, p < 0.0001, respectively), but it should be interpreted with caution because of Hardy-Weinberg disequilibrium in the control group. Of five haplotypes constructed, TAC (rs61330082-rs2505568-rs9034) was a protective haplotype to DCM (OR: 0.22, 95% CI = 0.13–0.39, p = 1.84 × 10−8). The Cox multivariate survival analysis indicated that the rs9034 CT genotype (hazard ratio (HR): 0.59, 95% CI = 0.37–0.96, p = 0.03) was an independently multivariate predictor for longer overall survival in DCM patients. Serum NAMPT levels were significantly higher in the DCM group than controls (p < 0.0001) and gradually increased with the increase of New York Heart Association grade in DCM patients. However, there was a lack of association of the three SNPs with

  1. The role of human cytochrome P4503A4 in biotransformation of tissue-specific derivatives of 7H-dibenzo[c,g]carbazole

    SciTech Connect

    Mesarosova, Monika; Valovicova, Zuzana; Srancikova, Annamaria; Krajcovicova, Zdenka; Milcova, Alena; Sokolova, Romana; Schmuczerova, Jana; Topinka, Jan; Gabelova, Alena

    2011-09-15

    The environmental pollutant 7H-dibenzo[c,g]carbazole (DBC) and its derivative, 5,9-dimethylDBC (DiMeDBC), produced significant and dose-dependent levels of micronuclei followed by a substantial increase in the frequency of apoptotic cells in the V79MZh3A4 cell line stably expressing the human cytochrome P450 (hCYP) 3A4. In contrast, neither micronuclei nor apoptosis were found in cells exposed to the sarcomagenic carcinogen, N-methylDBC (N-MeDBC). A slight but significant level of gene mutations and DNA adducts detected in V79MZh3A4 cells treated with N-MeDBC, only at the highest concentration (30 {mu}M), revealed that this sarcomagenic carcinogen was also metabolized by hCYP3A4. Surprisingly, DBC increased the frequency of 6-thioguanine resistant (6-TG{sup r}) mutations only at the highest concentration (30 {mu}M), while DiMeDBC failed to increase the frequency of these mutations. The resistance to 6-thioguanine is caused by the mutations in the hypoxanthine-guanine phosphoribosyltransferase (Hprt) gene. The molecular analysis of the coding region of Hprt gene showed a deletion of the entire exon 8 in DiMeDBC-induced 6-TG{sup r} mutants, while no changes in the nucleotide sequences were identified in 6-TG{sup r} mutants produced by DBC and N-MeDBC. Based on our results, we suggest that hCYP3A4 is involved in the metabolism of DBC and its tissue-specific derivatives. While hCYP3A4 probably plays an important role in biotransformation of the liver carcinogens, DBC and DiMeDBC, it might only have a marginal function in N-MeDBC metabolism. - Highlights: > DBC activation via CYP3A4 resulted in micronuclei, DNA adduct formation and mutations in V79MZh3A4 cells. > The CYP3A4-mediated DiMeDBC activation caused micronuclei followed by apoptosis in V79MZh3A4 cells. > The genotoxic effects produced by N-MeDBC in V79MZh3A4 cells were negligible. > The hCYP3A4 may play an important role in DBC and DiMeDBC metabolism. > The CYP3A4 might only have a marginal function in N

  2. Bilirubin UDP-Glucuronosyltransferase 1A1 (UGT1A1) Gene Promoter Polymorphisms and HPRT, Glycophorin A, and Micronuclei Mutant Frequencies in Human Blood

    SciTech Connect

    Grant, D; Hall, I J; Eastmond, D; Jones, I M; Bell, D A

    2004-10-06

    A dinucleotide repeat polymorphism (5-, 6-, 7-, or 8-TA units) has been identified within the promoter region of UDP-glucuronosyltransferase 1A1 gene (UGT1A1). The 7-TA repeat allele has been associated with elevated serum bilirubin levels that cause a mild hyperbilirubinemia (Gilbert's syndrome). Studies suggest that promoter transcriptional activity of UGT1A1 is inversely related to the number of TA repeats and that unconjugated bilirubin concentration increases directly with the number of TA repeat elements. Because bilirubin is a known antioxidant, we hypothesized that UGT1A1 repeats associated with higher bilirubin may be protective against oxidative damage. We examined the effect of UGT1A1 genotype on somatic mutant frequency in the hypoxanthine-guanine phosphoribosyl-transferase (HPRT) gene in human lymphocytes and the glycophorin A (GPA) gene of red blood cells (both N0, NN mutants), and the frequency of lymphocyte micronuclei (both kinetochore (K) positive or micronuclei K negative) in 101 healthy smoking and nonsmoking individuals. As hypothesized, genotypes containing 7-TA and 8-TA displayed marginally lower GPA{_}NN mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). In contrast, our analysis showed that lower expressing UGT1A1 alleles (7-TA and 8-TA) were associated with modestly increased HPRT mutation frequency (p<0.05) while the same low expression genotypes were not significantly associated with micronuclei frequencies (K-positive or K-negative) when compared to high expression genotypes (5-TA and 6-TA). We found weak evidence that UGT1A1 genotypes containing 7-TA and 8-TA were associated with increased GPA{_}N0 mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). These data suggest that UGT1A1 genotype may modulate somatic mutation of some types, in some cell lineages, by a mechanism not involving bilirubin antioxidant activity. More detailed studies examining UGT1A1 promoter variation, oxidant/antioxidant balance and genetic

  3. Simultaneous assay of glucose, lactate, L-glutamate and hypoxanthine levels in a rat striatum using enzyme electrodes based on neutral red-doped silica nanoparticles.

    PubMed

    Zhang, Fen-Fen; Wan, Qiao; Li, Chen-Xin; Wang, Xiao-Li; Zhu, Zi-Qiang; Xian, Yue-Zhong; Jin, Li-Tong; Yamamoto, Katsunobu

    2004-10-01

    An electrochemical method suitable for the simultaneous measurement of cerebral glucose, lactate, L-glutamate and hypoxanthine concentrations from in vivo microdialysis sampling has been successfully performed for the first time using a neutral red-doped silica (NRDS) nanoparticle-derived enzyme sensor system. These uniform NRDS nanoparticles (about 50 +/- 3 nm) were prepared by a water-in-oil (W/O) microemulsion method, and characterized by a TEM technique. The neutral red-doped interior maintained its high electron-activity, while the exterior nano-silica surface prevented the mediator from leaching out into the aqueous solution, and showed high biocompability. These nanoparticles were then mixing with the glucose oxidase (GOD), lactate oxidase (LOD), L-glutamate oxidase (L-GLOD) or xanthine oxidase (XOD), and immobilized on four glassy carbon electrodes, respectively. A thin Nafion film was coated on the enzyme layer to prevent interference from molecules such as ascorbic acid and uric acid in the dialysate. The high sensitivity of the NRDS modified enzyme electrode system enables the simultaneous monitoring of trace levels of glucose, L-glutamate, lactate and hypoxanthine in diluted dialysate samples from a rat striatum. PMID:15517210

  4. Studies on the energy metabolism of opossum (Didelphis virginiana) erythrocytes: V. Utilization of hypoxanthine for the synthesis of adenine and guanine nucleotides in vitro

    SciTech Connect

    Bethlenfalvay, N.C.; White, J.C.; Chadwick, E.; Lima, J.E. )

    1990-06-01

    High pressure liquid radiochromatography was used to test the ability of opossum erythrocytes to incorporate tracer amounts of (G-{sup 3}H) hypoxanthine (Hy) into ({sup 3}H) labelled triphosphates of adenine and guanine. In the presence of supraphysiologic (30 mM) phosphate which is optimal for PRPP synthesis, both ATP and GTP are extensively labelled. When physiologic (1 mM) medium phosphate is used, red cells incubated under an atmosphere of nitrogen accumulate ({sup 3}H) ATP in a linear fashion suggesting ongoing PRPP synthesis in red cells whose hemoglobin is deoxygenated. In contrast, a lesser increase of labelled ATP is observed in cells incubated under oxygen, suggesting that conditions for purine nucleotide formation from ambient Hy are more favorable in the venous circulation.

  5. Unravelling the potential of a new uracil phosphoribosyltransferase (UPRT) from Arabidopsis thaliana in sensitizing HeLa cells towards 5-fluorouracil.

    PubMed

    Narayanan, Sharmila; Sanpui, Pallab; Sahoo, Lingaraj; Ghosh, Siddhartha Sankar

    2016-10-01

    In silico studies with uracil phosphoribosyltransferase from Arabidopsis thaliana (AtUPRT) revealed its lower binding energies for uracil and 5-fluorouracil (5-FU) as compared to those of bacterial UPRT indicating the prospective of AtUPRT in gene therapy implications. Hence, AtUPRT was cloned and stably expressed in cervical cancer cells (HeLa) to investigate the effect of prodrug 5-FU on these transfected cancer cells. The treatment of AtUPRT-expressing HeLa (HeLa-UPP) cells with 5-FU for 72h resulted in significant decrease in cell viability. Moreover, 5-FU was observed to induce apoptosis and perturb mitochondrial membrane potential in HeLa-UPP cells. While cell cycle analysis revealed significant S-phase arrest as a result of 5-FU treatment in HeLa-UPP cells, quantitative gene expression analysis demonstrated simultaneous upregulation of important cell cycle related genes, cyclin D1 and p21. The survival fractions of non-transfected, vector-transfected and AtUPRT-transfected HeLa cells, following 5-FU treatment, were calculated to be 0.425, 0.366 and 0.227, respectively.

  6. Identification of a compound heterozygote for adenine phosphoribosyltransferase deficiency (APRT*J/APART*Q0) leading to 2,8-dihydroxyadenine urolithiasis.

    PubMed

    Kamatani, N; Kuroshima, S; Yamanaka, H; Nakashe, S; Take, H; Hakoda, M

    1990-10-01

    Homozygous deficiency of a purine salvage enzyme, adenine phosphoribosyltransferase (APRT), causes urolithiasis and renal failure. There are two known types of homozygous APRT deficiencies; type I patients completely lack APRT activity while type II patients only partially lack such activity. All type II patients possess at least one APRT*J allele with a substitution from ATG (Met) to ACG (Thr) at codon 136. Type I patients are considered to possess two alleles (APRT*Q0) both of which code for complete deficiencies. Thus, some patients with type II APRT deficiencies may have a genotype of APRT*J/APRT*Q0. As no individuals with such a genotype have previously been identified, we performed extensive analysis on four members of a family by (1) the T-cell method for the identification of a homozygote, (2) the B-cell method for the identification of heterozygotes, and (3) oligonucleotide hybridization after in vitro amplification of a part of genomic APRT sequence for the identification of APRT*J and non-APRT*J alleles. We report here the first evidence that 2,8-dihydroxyadenine urolithiasis developed in a boy aged 2 years with a genotype of APRT*J/APRT*Q0.

  7. Ab initio insight into ultrafast nonadiabatic decay of hypoxanthine: keto-N7H and keto-N9H tautomers.

    PubMed

    Guo, Xugeng; Lan, Zhenggang; Cao, Zexing

    2013-07-14

    Nonadiabatic dynamics simulations at the SA-CASSCF level were performed for the two most stable keto-N7H and keto-N9H tautomers of hypoxanthine in order to obtain deep insight into the lifetime of the optically bright S1((1)ππ*) excited state and the relevant decay mechanisms. Supporting calculations on the ground-state (S0) equilibrium structures and minima on the crossing seams of both tautomers were carried out at the MR-CIS and CASSCF levels. These studies indicate that there are four slightly different kinds of conical intersections in each tautomer, exhibiting a chiral character, each of which dominates a barrierless reaction pathway. Moreover, both tautomers reveal the ultrafast S1→ S0 decay, in which the S1 state of keto-N9H in the gas phase has a lifetime of 85.5 fs, whereas that of keto-N7H has a longer lifetime of 137.7 fs. An excellent agreement is found between the present results and the experimental value of 130 ± 20 fs in aqueous solution (Chen and Kohler, Phys. Chem. Chem. Phys., 2012, 14, 10677-10689).

  8. The role of the C-terminal region on the oligomeric state and enzymatic activity of Trypanosoma cruzi hypoxanthine phosphoribosyl transferase.

    PubMed

    Valsecchi, Wanda M; Cousido-Siah, Alexandra; Defelipe, Lucas A; Mitschler, André; Podjarny, Alberto; Santos, Javier; Delfino, José M

    2016-06-01

    Hypoxanthine phosphoribosyl transferase from Trypanosoma cruzi (TcHPRT) is a critical enzyme for the survival of the parasite. This work demonstrates that the full-length form in solution adopts a stable and enzymatically active tetrameric form, exhibiting large inter-subunit surfaces. Although this protein irreversibly aggregates during unfolding, oligomerization is reversible and can be modulated by low concentrations of urea. When the C-terminal region, which is predicted as a disordered stretch, is excised by proteolysis, TcHPRT adopts a dimeric state, suggesting that the C-terminal region acts as a main guide for the quaternary arrangement. These results are in agreement with X-ray crystallographic data presented in this work. On the other hand, the C-terminal region exhibits a modulatory role on the enzyme, as attested by the enhanced activity observed for the dimeric form. Bisphosphonates act as substrate-mimetics, uncovering long-range communications among the active sites. All in all, this work contributes to establish new ways applicable to the design of novel inhibitors that could eventually result in new drugs against parasitic diseases. PMID:26969784

  9. Differences in nitric oxide steady states between arginine, hypoxanthine, uracil auxotrophs (AHU) and non-AHU strains of Neisseria gonorrhoeae during anaerobic respiration in the presence of nitrite.

    PubMed

    Barth, Kenneth; Clark, Virginia L

    2008-08-01

    Neisseria gonorrhoeae can grow by anaerobic respiration using nitrite as an alternative electron acceptor. Under these growth conditions, N. gonorrhoeae produces and degrades nitric oxide (NO), an important host defense molecule. Laboratory strain F62 has been shown to establish and maintain a NO steady-state level that is a function of the nitrite reductase/NO reductase ratio and is independent of cell number. The nitrite reductase activities (122-197 nmol NO2 reduced x min(-1) x OD600(-1)) and NO reductase activities (88-155 nmol NO reduced x min(-1) x OD600(-1)) in a variety of gonococcal clinical isolates were similar to the specific activities seen in F62 (241 nmol NO2 reduced x min(-1) x OD600(-1) and 88 nmol NO reduced x min(-1) x OD600(-1), respectively). In seven gonococcal strains, the NO steady-state levels established in the presence of nitrite were similar to that of F62 (801-2121 nmol x L-1 NO), while six of the strains, identified as arginine, hypoxanthine, and uracil auxotrophs (AHU), that cause asymptomatic infection in men had either two- to threefold (373-579 nmol x L-1 NO) or about 100-fold (13-24 nmol x L-1 NO) lower NO steady-state concentrations. All tested strains in the presence of a NO donor, 2,2'-(hydroxynitrosohydrazono)bis-ethanimine/NO, quickly lowered and maintained NO levels in the noninflammatory range of NO (<300 nmol x L-1). The generation of a NO steady-state concentration was directly affected by alterations in respiratory control in both F62 and an AHU strain, although differences in membrane function are suspected to be responsible for NO steady-state level differences in AHU strains.

  10. Molecular analyses of in vivo hprt mutations in human T-lymphocytes: IV. Studies in newborns

    SciTech Connect

    McGinniss, M.J.; Nicklas, J.A.; Albertini, R.J. )

    1989-01-01

    In order to characterize in vivo gene mutations that occur during fetal development, molecular analyses were undertaken of mutant 6-thioguanine resistant T-lymphocytes isolated from placental cord blood samples of 13 normal male newborns. These mutant T-cells were studied to define hypoxanthine-guanine phosphoribosyltransferase (hprt) gene structural alterations and to determine T-cell receptor (TCR) gene rearrangement patterns. Structural hprt alterations, as shown by Southern blot analyses, occurred in 85% of these mutant clones. These alterations consisted mostly of deletion of exons 2 and 3. These findings contrast with the 10-20% of gross structural alterations occurring randomly across the entire gene previously reported for T-cell mutants isolated from normal young adults. Iterative analyses of hprt structural alterations and TCR gene rearrangement patterns show that approximately one-third of the newborn derived mutants may have originated as pre- or intrathymic hprt mutations. This too contrasts with previous findings in adults where the background in vivo hprt mutations appeared to originate in postthymic T-lymphocytes.

  11. Human somatic mutation assays as biomarkers of carcinogenesis.

    PubMed Central

    Compton, P J; Hooper, K; Smith, M T

    1991-01-01

    This paper describes four assays that detect somatic gene mutations in humans: the hypoxanthine-guanine phosphoribosyl transferase assay, the glycophorin A assay, the HLA-A assay, and the sickle cell hemoglobin assay. Somatic gene mutation can be considered a biomarker of carcinogenesis, and assays for somatic mutation may assist epidemiologists in studies that attempt to identify factors associated with increased risks of cancer. Practical aspects of the use of these assays are discussed. PMID:1954924

  12. Human somatic mutation assays as biomarkers of carcinogenesis

    SciTech Connect

    Compton, P.J.E.; Smith, M.T. ); Hooper, K. )

    1991-08-01

    This paper describes four assays that detect somatic gene mutations in humans: the hypoxanthine-guanine phosphoribosyl transferase assay, the glycophorin A assay, the HLA-A assay, and the sickle cell hemoglobin assay. Somatic gene mutations can be considered a biomarker of carcinogenesis, and assays for somatic mutation may assist epidemiologists in studies that attempt to identify factors associated with increased risks of cancer. Practical aspects of the use of these assays are discussed.

  13. Development of a new reporter gene system--dsRed/xanthine phosphoribosyltransferase-xanthine for molecular imaging of processes behind the intact blood-brain barrier.

    PubMed

    Doubrovin, Mikhail; Ponomarev, Vladimir; Serganova, Inna; Soghomonian, Suren; Myagawa, Tadashi; Beresten, Tatiana; Ageyeva, Lyudmila; Sadelain, Michel; Koutcher, Jason; Blasberg, Ronald G; Tjuvajev, Juri G Gelovani

    2003-04-01

    We report the development of a novel dual-modality fusion reporter gene system consisting of Escherichia coli xanthine phosphoribosyltransferase (XPRT) for nuclear imaging with radiolabeled xanthine and Discosoma red fluorescent protein for optical fluorescent imaging applications. The dsRed/XPRT fusion gene was successfully created and stably transduced into RG2 glioma cells, and both reporters were shown to be functional. The level of dsRed fluorescence directly correlated with XPRT enzymatic activity as measured by ribophosphorylation of [14C]-xanthine was in vitro (Ki = 0.124 +/- 0.008 vs. 0.00031 +/- 0.00005 mL/min/g in parental cell line), and [*]-xanthine octanol/water partition coefficient was 0.20 at pH = 7.4 (logP = -0.69), meeting requirements for the blood-brain barrier (BBB) penetrating tracer. In the in vivo experiment, the concentration of [14C]-xanthine in the normal brain varied from 0.20 to 0.16 + 0.05% dose/g under 0.87 + 0.24% dose/g plasma radiotracer concentration. The accumulation in vivo in the transfected flank tumor was to 2.4 +/- 0.3% dose/g, compared to 0.78 +/- 0.02% dose/g and 0.64 +/- 0.05% dose/g in the control flank tumors and intact muscle, respectively. [14C]-Xanthine appeared to be capable of specific accumulation in the transfected infiltrative brain tumor (RG2-dsRed/XPRT), which corresponded to the 585 nm fluorescent signal obtained from the adjacent cryosections. The images of endogenous gene expression with the "sensory system" have to be normalized for the transfection efficiency based on the "beacon system" image data. Such an approach requires two different "reporter genes" and two different "reporter substrates." Therefore, the novel dsRed/XPRT fusion gene can be used as a multimodality reporter system in the biological applications requiring two independent reporter genes, including the cells located behind the BBB.

  14. Molecular analysis of mutations affecting hprt mRNA splicing in human T-lymphocytes in vivo

    SciTech Connect

    Rossi, A.M. Pisa Univ. ); Tates, A.D.; van Zeeland, A.A.; Vrieling, H. )

    1992-01-01

    Molecular analysis of hypoxanthine-guanine phosphoribosyltransferase (hprt) cDNA from 6-thioguanine-resistant T-lymphocytes cloned from smoking and non-smoking adult donors showed that 35% of these mutants were defective in splicing of hprt mRNA. Among a set of 42 hprt splice mutants, the authors observed (1) complete loss of one or more exons, (2) partial loss of one exon, or (3) inclusion of part of an intron sequence between adjacent exons. Loss of exon 4 was significantly more frequent than of the other exons, suggesting that the sequences that regulate splicing of this exon are either larger than those of the other exons or especially prone to mutation. In order to identify the molecular nature of DNA alterations causing aberrant splicing of hprt mRNA, 17 splice mutants were analyzed in more detail by sequencing the genomic regions flanking the mis-spliced exon. Base pair substitutions or small deletions causing defective splicing were either detected in exon sequences or in splice site consensus sequences of introns.

  15. A simple and sensitive method for estimating the concentration and synthesis of 5-phosphoribosyl 1-pyrophosphate in red blood cells.

    PubMed

    Tax, W J; Veerkamp, J H

    1977-07-15

    A method is presented for the determination of 5-phosphoribosyl 1-pyrophosphate (PRPP), which is based on the release of 14CO2 from [carboxyl-14C]-orotic acid by the consecutive action of orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. The assay is simpler and less time-consuming than most methods currently employed and is equally sensitive. The method proved to be suitable for measuring low concentrations of PRPP such as found in human erythrocytes and fibroblasts. An increased PRPP concentration was observed in erythrocytes from patients with partial or complete deficiency of hypoxanthine-guanine phospho-ribosyltransferase. frp, sp,e (but not all) gouty patients and from a patient with deficiency of purine nucleoside phosphorylase. PRPP synthetase activity was measured with a method similar to the assay for PRPP. In erythrocytes with an increased PRPP concentration, PRPP synthetase activity was found to be normal at both optimal and suboptimal substrate concentrations.

  16. A simple and sensitive method for estimating the concentration and synthesis of 5-phosphoribosyl 1-pyrophosphate in red blood cells.

    PubMed

    Tax, W J; Veerkamp, J H

    1977-07-15

    A method is presented for the determination of 5-phosphoribosyl 1-pyrophosphate (PRPP), which is based on the release of 14CO2 from [carboxyl-14C]-orotic acid by the consecutive action of orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. The assay is simpler and less time-consuming than most methods currently employed and is equally sensitive. The method proved to be suitable for measuring low concentrations of PRPP such as found in human erythrocytes and fibroblasts. An increased PRPP concentration was observed in erythrocytes from patients with partial or complete deficiency of hypoxanthine-guanine phospho-ribosyltransferase. frp, sp,e (but not all) gouty patients and from a patient with deficiency of purine nucleoside phosphorylase. PRPP synthetase activity was measured with a method similar to the assay for PRPP. In erythrocytes with an increased PRPP concentration, PRPP synthetase activity was found to be normal at both optimal and suboptimal substrate concentrations. PMID:195752

  17. Lesch-Nyhan variant syndrome: real-time rt-PCR for mRNA quantification in variable presentation in three affected family members.

    PubMed

    Nguyen, Khue Vu; Naviaux, Robert K; Paik, Kacie K; Nakayama, Tomohiro; Nyhan, William L

    2012-01-01

    Inherited mutations of hypoxanthine guanine phosphoribosyltransferase (HPRT) give rise to Lesch-Nyhan syndrome (LNS) or variants (LNV). We report molecular insights from real-time RT-PCR for HPRT mRNA quantification into the mechanism by which a single mutation located in exon 7 of the HPRT gene: c.500G>T, p.R167M, led to different clinical phenotypes from three male LNV-affected patients in the same family manifesting parallel differences in enzymatic activities. This approach can be applied for understanding genotype-phenotype correlations for other human genetic diseases.

  18. Quantitative assay for mutation in diploid human lymphoblasts using microtiter plates

    SciTech Connect

    Furth, E.A.; Thilly, W.G.; Penman, B.W.; Liber, H.L.; Rand, W.M.

    1981-01-01

    A microtiter plating technique which eliminates the need for soft agar and fibroblast feeder layers to determine the colony-forming ability of diploid human lymphoblast lines was described. The calculation of cloning efficiency is based on the Poisson distribution, and a statistical method for calculating confidence intervals is presented. This technique has been applied to the comcomitant examination of induced mutation at the putative loci for hypoxanthine guanine phosphoribosyl transferase, thymidine, kinase, and Na/sup +//K/sup +/ adenosine triphosphatase.

  19. Functional identification of the hypoxanthine/guanine transporters YjcD and YgfQ and the adenine transporters PurP and YicO of Escherichia coli K-12.

    PubMed

    Papakostas, Konstantinos; Botou, Maria; Frillingos, Stathis

    2013-12-27

    The evolutionarily broad family nucleobase-cation symporter-2 (NCS2) encompasses transporters that are conserved in binding site architecture but diverse in substrate selectivity. Putative purine transporters of this family fall into one of two homology clusters: COG2233, represented by well studied xanthine and/or uric acid permeases, and COG2252, consisting of transporters for adenine, guanine, and/or hypoxanthine that remain unknown with respect to structure-function relationships. We analyzed the COG2252 genes of Escherichia coli K-12 with homology modeling, functional overexpression, and mutagenesis and showed that they encode high affinity permeases for the uptake of adenine (PurP and YicO) or guanine and hypoxanthine (YjcD and YgfQ). The two pairs of paralogs differ clearly in their substrate and ligand preferences. Of 25 putative inhibitors tested, PurP and YicO recognize with low micromolar affinity N(6)-benzoyladenine, 2,6-diaminopurine, and purine, whereas YjcD and YgfQ recognize 1-methylguanine, 8-azaguanine, 6-thioguanine, and 6-mercaptopurine and do not recognize any of the PurP ligands. Furthermore, the permeases PurP and YjcD were subjected to site-directed mutagenesis at highly conserved sites of transmembrane segments 1, 3, 8, 9, and 10, which have been studied also in COG2233 homologs. Residues irreplaceable for uptake activity or crucial for substrate selectivity were found at positions occupied by similar role amino acids in the Escherichia coli xanthine- and uric acid-transporting homologs (XanQ and UacT, respectively) and predicted to be at or around the binding site. Our results support the contention that the distantly related transporters of COG2233 and COG2252 use topologically similar side chain determinants to dictate their function and the distinct purine selectivity profiles.

  20. IgA class switch in I alpha exon-deficient mice. Role of germline transcription in class switch recombination.

    PubMed Central

    Harriman, G R; Bradley, A; Das, S; Rogers-Fani, P; Davis, A C

    1996-01-01

    Studies have implicated defective Ig class switch in the pathogenesis of IgA deficiency. To understand better the molecular events that regulate IgA class switch, a 1.4-kb region of the IgA locus containing the I alpha exon was replaced with a human hypoxanthine phosphoribosyltransferase minigene by gene targeting in murine embryonic stem cells. The I alpha exon-deficient mice derived from these embryonic stem cells had normal IgA levels in serum and secretions and normal numbers of IgA B cells in Peyer's patches and spleen. Further, I alpha exon-deficient B cells efficiently underwent IgA class switch in vitro, despite the absence of I alpha exon-containing germline transcripts. Notably, I alpha exon-deficient B cells did not require TGF-beta for IgA class switch since stimulation with LPS alone led to IgA expression. Nonetheless, whereas I alpha exon-deficient B cells constitutively expressed human hypoxanthine phosphoribosyltransferase transcripts, they did not produce IgA in the absence of LPS stimulation. These results demonstrate that the I alpha exon or transcripts containing the I alpha exon are not required for IgA class switch. Further, the effects of TGF-beta on I alpha locus transcription can be supplanted by expression of a heterologous minigene at that locus, but a second signal is required for the induction of IgA class switch. PMID:8567970

  1. Nature of 6-methylpurine inhibition and characterization of two 6-methylpurine-resistant mutants of Neurospora crassa.

    PubMed Central

    Pendyala, L; Smyth, J; Wellman, A M

    1979-01-01

    6-Methylpurine, an analog of adenine, inhibits the growth of Neurospora crassa. From kinetic studies it was found that 6-methylpurine is converted to its nucleotide form by adenine phosphoribosyltransferase (EC 2.4.2.7), and inhibits the de novo purine biosynthesis. Adenine relieves the growth inhibition caused by 6-methylpurine, whereas hypoxanthine is not very effective. Studies dealing with hypoxanthine utilization in the presence of 6-methylpurine indicated a severely reduced uptake of hypoxanthine and a general slowdown in its further metabolism. Two mutants (Mepr-3 and Mepr-10) which are resistant to 6-methylpurine were characterized. Studies of purine base uptake and the in vivo and in vitro conversion to nucleotides indicated that Mepr-10 may be an adenine phosphoribosyltransferase-defective mutant, whereas Mepr-3 may be a mutant with altered feedback response to 6-methylpurine. Both mutants showed a severely lowered hypoxanthine phosphoribosyltransferase activity, but because 6-methylpurine did not have any effect on the conversion of hypoxanthine to IMP in the wild type, it was concluded that 6-methylpurine resistance in these mutants cannot be due to lowered hypoxanthine phosphoribosyltransferase activity, but rather that the lowering of enzyme activity may be a secondary effect. PMID:153898

  2. Orotate phosphoribosyltransferase from baker's yeast: I. Kinetic analysis, chemical modification, and proton NMR spectroscopy of the enzyme substrate complex. II. Amino acid analysis and NMR spectroscopy of the protein

    SciTech Connect

    Strauss, R.S.

    1986-01-01

    Kinetic analysis of the effect of pH on the reversible reaction catalyzed by orotate phosphoribosyltransferase (OPRTase) from Baker's yeast revealed that different amino acid residues may enable the enzyme-catalyzed reactions to proceed in the forward and reverse directions, respectively. For the forward reaction, there appear to be at least two critical amino acid residues (pK's 4.6 and 7.1) which must be in a deprotonated state to reach a maximum activity near pH 8 which is maintained through pH 9.5. For the reverse reaction, maximum activity is reached near pH 7 (pK's at 5.4) and then the activity decreases at higher pH (pK's at 7.9 and possibly above 9). A theoretical proton NMR spectrum was generated for OPRTase, based on its amino acid composition. The spectrum thus produced has a similar number of major peaks to that of the actual spectrum taken at 300 MHz. Spectra collected at various pH values between 8 and 5, were consistent with the maintenance of the gross conformational structure of the enzyme over that pH range.

  3. A QM/MM MD insight into photodynamics of hypoxanthine: distinct nonadiabatic decay behaviors between keto-N7H and keto-N9H tautomers in aqueous solution.

    PubMed

    Guo, Xugeng; Zhao, Yuan; Cao, Zexing

    2014-08-01

    Extensive ab initio surface-hopping dynamics simulations have been used to explore the excited-state nonadiabatic decay of two biologically relevant hypoxanthine keto-N7H and keto-N9H tautomers in aqueous solution. QM/MM calculations and QM/MM-based MD simulations predict different hydrogen bonding networks around these nucleobase analogues, which influence their photodynamical properties remarkably. Furthermore, different solvent effects on the conical intersection formation of keto-N7H and keto-N9H were found in excited-state MD simulations, which also change the lifetimes of the excited states. In comparison with the gas-phase situation, the S1 → S0 nonradiative decay of keto-N7H is slightly faster, while this decay process of keto-N9H becomes much slower in water. The presence of π-electron hydrogen bonds in the solvated keto-N7H is considered to facilitate the S1 → S0 nonradiative decay process.

  4. Selective removal of ATP degradation products from food matrices II: Rapid screening of hypoxanthine and inosine by molecularly imprinted matrix solid-phase dispersion for evaluation of fish freshness.

    PubMed

    Cela-Pérez, M C; Barbosa-Pereira, L; Vecino, X; Pérez-Ameneiro, M; Lasagabaster Latorre, Aurora; López-Vilariño, J M; González Rodríguez, M V; Moldes, A B; Cruz, J M

    2015-04-01

    A water compatible molecularly imprinted polymer (MIP), synthesized using theophylline (TPH) as dummy-template and acrylamide (AM) as functional monomer, has been employed as supporting material in matrix solid-phase dispersion combined with ultra performance liquid chromatography-photodiode array detection (MSPD-UPLC-PDA) for selective determination of adenosine triphosphate (ATP) derivatives in fish samples. ATP degradation products are used as freshness index for assessment of fish quality. The solid sample was directly blended with MIP in MSPD procedure resulting in sample disruption and subsequent adsorption of the compounds on the MIP. By using n-hexane and ammonium hydroxide aqueous solution at pH 9 as the washing and elution solvent, respectively, satisfactory recoveries and clean chromatograms have been obtained. Good linearity for hypoxanthine (HYP) and inosine (INO) has been observed with correlation coefficients (R(2)) of 0.9987 and 0.9986, respectively. The recoveries of the two ATP derivatives at three different spiked levels ranged from 106.5% to 113.4% for HYP and from 103.1% to 111.2% for INO, with average relative standard deviations lower than 4.2% in both cases. This new method, which is rapid, simple and sensitive, can be used as an alternative tool to conventional tedious methods. PMID:25640126

  5. Morin, a dietary bioflavonol suppresses monosodium urate crystal-induced inflammation in an animal model of acute gouty arthritis with reference to NLRP3 inflammasome, hypo-xanthine phospho-ribosyl transferase, and inflammatory mediators.

    PubMed

    Dhanasekar, Chitra; Rasool, Mahaboobkhan

    2016-09-01

    The anti-inflammatory effect of morin, a dietary bioflavanol was explored on monosodium urate (MSU) crystal-induced inflammation in rats, an experimental model for acute gouty arthritis. Morin treatment (30mg/kg b.wt) significantly attenuated the ankle swelling and the levels of lipid peroxidation, nitric oxide, serum pro-inflammatory cytokines (tumor necrosis factor (TNF) -α, interleukin (IL)-1β, and IL-6), monocyte chemoattractant protein (MCP)-1, vascular endothelial growth factor (VEGF), prostaglandin E2 (PGE2), and articular elastase along with an increased anti-oxidant status (catalase (CAT) and superoxide dismutase (SOD)) in the joint homogenate of MSU crystal-induced rats. Histological assessment revealed that morin limited the diffusion of joint space, synovial hyperplasia, and inflammatory cell infiltrations. The mRNA expression of NLRP3 (nucleotide oligomerization domain (NOD)-like receptor family, pyrin domain containing 3) inflammasome, caspase-1, pro-inflammatory cytokines, MCP-1, inflammatory enzymes (inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2)), and nuclear factor-kappa B (NF-κB) p65 was found downregulated and HPRT (hypo-xanthine phospho-ribosyl transferase) mRNA expression was upregulated in morin treated MSU crystal-induced rats. In addition, morin treatment reduced the protein expression of NF-κB p65, p-NF-κB p65, iNOS, COX-2, and TNF-α. The results clearly demonstrated that morin exert a potent anti-inflammatory effect on MSU crystal-induced inflammation in rats.

  6. Effect of saccharin on metabolic cooperation between human fibroblasts

    SciTech Connect

    Mosser, D.D.; Bols, N.C.

    1983-01-01

    Autoradiography was used to study the effect of saccharin on metabolic cooperation between human diploid fibroblasts. When the donors, HGPRT+ cells, and recipients, HGPRT- cells, were plated together in the presence of saccharin, all the interactions that developed in 4 and 24 h were positive for metabolic cooperation. When saccharin was added after donor cells and recipient cells had made contact, the proportion of interactions that were positive for metabolic cooperation was unchanged but the number of grains over primary recipients was reduced. However, in donor cells saccharin caused a reduction in (/sup 3/H)hypoxanthine incorporation into both acid-soluble and acid-insoluble fractions, although the relative distribution of radioactivity between these two fractions and between the phosphorylated and non-phosphorylated derivatives of (/sup 3/H)hypoxanthine was unchanged. Metabolic cooperation was studied under conditions in which the number of grains over the nuclei of both the primary recipient and the primary recipient's donor could be counted. The change in the number of grains over these two cell types in response to saccharin was compared and found to be the same. Thus in normal human fibroblasts saccharin does not appear to affect metabolic cooperation, which is a measure of cell-to-cell communication.

  7. Hypoxanthine-guanine phosphoribosyl transferase deficiency.

    PubMed

    de Bruyn, C H

    1976-02-29

    In man congential lack of enzyme of the purine salvage system, hypoxanthineguanine phosphoribosyl transferase (HG-PRT E.C. 2.4.2.8), is mostly accompanied by a picture known as the Lesch-Nyhan snydrome. The degree of deficiency may vary from zero to a few percent of normal activity but a correlation between the severity of HG-PRT deficiency and the clinical picture has not been observed, no more than a correlation HG-PRT deficiency and neurological dysfunction. But individuals with undetectable HG-PRT activity but without the Lesch-Nyhan syndrome have been described. Patients with partial HG-PRT defiency have clinically distinctive findings. Sometimes mild neurological abnormalities are observed. Because of marked overproduction of ric acid severe gouty arthritis and renal dysfunction are often encountered in both complete and partial deficiency. There is considerable molecular heterogeneity in HG-PRT deficiency in man. Mutant ebnzymes may exhibit different kinetic and electrophoretic properties, indicating that hterwe might be a mutation on the structural gene coding for HG-PRT. Lack of HG-PRT disturbs purine interconversions profoundly. In addition to an important function of HG-PRT in the uptake of the purine hypoxantine and guanine into the cell, the effective uptake of inosine, guanosine and adenosine also seems to be dependent on HG-PRT...

  8. Attenuated Variants of Lesch-Nyhan Disease

    ERIC Educational Resources Information Center

    Jinnah, H. A.; Ceballos-Picot, Irene; Torres, Rosa J.; Visser, Jasper E.; Schretlen, David J.; Verdu, Alfonso; Larovere, Laura E.; Chen, Chung-Jen; Cossu, Antonello; Wu, Chien-Hui; Sampat, Radhika; Chang, Shun-Jen; de Kremer, Raquel Dodelson; Nyhan, William; Harris, James C.; Reich, Stephen G.; Puig, Juan G.

    2010-01-01

    Lesch-Nyhan disease is a neurogenetic disorder caused by deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase. The classic form of the disease is described by a characteristic syndrome that includes overproduction of uric acid, severe generalized dystonia, cognitive disability and self-injurious behaviour. In addition to the…

  9. Rapid and High-Throughput Detection and Quantitation of Radiation Biomarkers in Human and Nonhuman Primates by Differential Mobility Spectrometry-Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Chen, Zhidan; Coy, Stephen L.; Pannkuk, Evan L.; Laiakis, Evagelia C.; Hall, Adam B.; Fornace, Albert J.; Vouros, Paul

    2016-10-01

    Radiation exposure is an important public health issue due to a range of accidental and intentional threats. Prompt and effective large-scale screening and appropriate use of medical countermeasures (MCM) to mitigate radiation injury requires rapid methods for determining the radiation dose. In a number of studies, metabolomics has identified small-molecule biomarkers responding to the radiation dose. Differential mobility spectrometry-mass spectrometry (DMS-MS) has been used for similar compounds for high-throughput small-molecule detection and quantitation. In this study, we show that DMS-MS can detect and quantify two radiation biomarkers, trimethyl-L-lysine (TML) and hypoxanthine. Hypoxanthine is a human and nonhuman primate (NHP) radiation biomarker and metabolic intermediate, whereas TML is a radiation biomarker in humans but not in NHP, which is involved in carnitine synthesis. They have been analyzed by DMS-MS from urine samples after a simple strong cation exchange-solid phase extraction (SCX-SPE). The dramatic suppression of background and chemical noise provided by DMS-MS results in an approximately 10-fold reduction in time, including sample pretreatment time, compared with liquid chromatography-mass spectrometry (LC-MS). DMS-MS quantitation accuracy has been verified by validation testing for each biomarker. Human samples are not yet available, but for hypoxanthine, selected NHP urine samples (pre- and 7-d-post 10 Gy exposure) were analyzed, resulting in a mean change in concentration essentially identical to that obtained by LC-MS (fold-change 2.76 versus 2.59). These results confirm the potential of DMS-MS for field or clinical first-level rapid screening for radiation exposure.

  10. Rapid and High-Throughput Detection and Quantitation of Radiation Biomarkers in Human and Nonhuman Primates by Differential Mobility Spectrometry-Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Chen, Zhidan; Coy, Stephen L.; Pannkuk, Evan L.; Laiakis, Evagelia C.; Hall, Adam B.; Fornace, Albert J.; Vouros, Paul

    2016-07-01

    Radiation exposure is an important public health issue due to a range of accidental and intentional threats. Prompt and effective large-scale screening and appropriate use of medical countermeasures (MCM) to mitigate radiation injury requires rapid methods for determining the radiation dose. In a number of studies, metabolomics has identified small-molecule biomarkers responding to the radiation dose. Differential mobility spectrometry-mass spectrometry (DMS-MS) has been used for similar compounds for high-throughput small-molecule detection and quantitation. In this study, we show that DMS-MS can detect and quantify two radiation biomarkers, trimethyl-L-lysine (TML) and hypoxanthine. Hypoxanthine is a human and nonhuman primate (NHP) radiation biomarker and metabolic intermediate, whereas TML is a radiation biomarker in humans but not in NHP, which is involved in carnitine synthesis. They have been analyzed by DMS-MS from urine samples after a simple strong cation exchange-solid phase extraction (SCX-SPE). The dramatic suppression of background and chemical noise provided by DMS-MS results in an approximately 10-fold reduction in time, including sample pretreatment time, compared with liquid chromatography-mass spectrometry (LC-MS). DMS-MS quantitation accuracy has been verified by validation testing for each biomarker. Human samples are not yet available, but for hypoxanthine, selected NHP urine samples (pre- and 7-d-post 10 Gy exposure) were analyzed, resulting in a mean change in concentration essentially identical to that obtained by LC-MS (fold-change 2.76 versus 2.59). These results confirm the potential of DMS-MS for field or clinical first-level rapid screening for radiation exposure.

  11. Rapid and High-Throughput Detection and Quantitation of Radiation Biomarkers in Human and Nonhuman Primates by Differential Mobility Spectrometry-Mass Spectrometry.

    PubMed

    Chen, Zhidan; Coy, Stephen L; Pannkuk, Evan L; Laiakis, Evagelia C; Hall, Adam B; Fornace, Albert J; Vouros, Paul

    2016-10-01

    Radiation exposure is an important public health issue due to a range of accidental and intentional threats. Prompt and effective large-scale screening and appropriate use of medical countermeasures (MCM) to mitigate radiation injury requires rapid methods for determining the radiation dose. In a number of studies, metabolomics has identified small-molecule biomarkers responding to the radiation dose. Differential mobility spectrometry-mass spectrometry (DMS-MS) has been used for similar compounds for high-throughput small-molecule detection and quantitation. In this study, we show that DMS-MS can detect and quantify two radiation biomarkers, trimethyl-L-lysine (TML) and hypoxanthine. Hypoxanthine is a human and nonhuman primate (NHP) radiation biomarker and metabolic intermediate, whereas TML is a radiation biomarker in humans but not in NHP, which is involved in carnitine synthesis. They have been analyzed by DMS-MS from urine samples after a simple strong cation exchange-solid phase extraction (SCX-SPE). The dramatic suppression of background and chemical noise provided by DMS-MS results in an approximately 10-fold reduction in time, including sample pretreatment time, compared with liquid chromatography-mass spectrometry (LC-MS). DMS-MS quantitation accuracy has been verified by validation testing for each biomarker. Human samples are not yet available, but for hypoxanthine, selected NHP urine samples (pre- and 7-d-post 10 Gy exposure) were analyzed, resulting in a mean change in concentration essentially identical to that obtained by LC-MS (fold-change 2.76 versus 2.59). These results confirm the potential of DMS-MS for field or clinical first-level rapid screening for radiation exposure. Graphical Abstract ᅟ. PMID:27392730

  12. Rapid and High-Throughput Detection and Quantitation of Radiation Biomarkers in Human and Nonhuman Primates by Differential Mobility Spectrometry-Mass Spectrometry.

    PubMed

    Chen, Zhidan; Coy, Stephen L; Pannkuk, Evan L; Laiakis, Evagelia C; Hall, Adam B; Fornace, Albert J; Vouros, Paul

    2016-10-01

    Radiation exposure is an important public health issue due to a range of accidental and intentional threats. Prompt and effective large-scale screening and appropriate use of medical countermeasures (MCM) to mitigate radiation injury requires rapid methods for determining the radiation dose. In a number of studies, metabolomics has identified small-molecule biomarkers responding to the radiation dose. Differential mobility spectrometry-mass spectrometry (DMS-MS) has been used for similar compounds for high-throughput small-molecule detection and quantitation. In this study, we show that DMS-MS can detect and quantify two radiation biomarkers, trimethyl-L-lysine (TML) and hypoxanthine. Hypoxanthine is a human and nonhuman primate (NHP) radiation biomarker and metabolic intermediate, whereas TML is a radiation biomarker in humans but not in NHP, which is involved in carnitine synthesis. They have been analyzed by DMS-MS from urine samples after a simple strong cation exchange-solid phase extraction (SCX-SPE). The dramatic suppression of background and chemical noise provided by DMS-MS results in an approximately 10-fold reduction in time, including sample pretreatment time, compared with liquid chromatography-mass spectrometry (LC-MS). DMS-MS quantitation accuracy has been verified by validation testing for each biomarker. Human samples are not yet available, but for hypoxanthine, selected NHP urine samples (pre- and 7-d-post 10 Gy exposure) were analyzed, resulting in a mean change in concentration essentially identical to that obtained by LC-MS (fold-change 2.76 versus 2.59). These results confirm the potential of DMS-MS for field or clinical first-level rapid screening for radiation exposure. Graphical Abstract ᅟ.

  13. Characterization of a TK6-Bcl-xL gly-159-ala Human Lymphoblast Clone

    SciTech Connect

    Chyall, L.: Gauny, S.; Kronenberg, A.

    2006-01-01

    TK6 cells are a well-characterized human B-lymphoblast cell line derived from WIL-2 cells. A derivative of the TK6 cell line that was stably transfected to express a mutated form of the anti-apoptotic protein Bcl-xL (TK6-Bcl-xL gly-159- ala clone #38) is compared with the parent cell line. Four parameters were evaluated for each cell line: growth under normal conditions, plating efficiency, and frequency of spontaneous mutation to 6‑thioguanine resistance (hypoxanthine phosphoribosyl transferase locus) or trifluorothymidine resistance (thymidine kinase locus). We conclude that the mutated Bcl-xL protein did not affect growth under normal conditions, plating efficiency or spontaneous mutation frequencies at the thymidine kinase (TK) locus. Results at the hypoxanthine phosphoribosyl transferase (HPRT) locus were inconclusive. A mutant fraction for TK6‑Bcl-xL gly-159-ala clone #38 cells exposed to 150cGy of 160kVp x-rays was also calculated. Exposure to x-irradiation increased the mutant fraction of TK6‑Bcl-xL gly-159-ala clone #38 cells.

  14. Thymine and guanine base specificity of human myeloma proteins with anti-DNA activity.

    PubMed Central

    Zouali, M; Stollar, B D

    1986-01-01

    To further our understanding of the molecular basis of DNA-autoantibody interactions, we have characterized the specificities of three IgG human myeloma proteins that bind DNA. We measured their binding to synthetic single- and double-stranded homopolynucleotides, random and alternating copolymers, oligonucleotides, and nucleotides or nucleosides conjugated to non-nucleic acid carriers. All three antibodies bound single-stranded nucleic acids, including both polyribonucleotides and polydeoxyribonucleotides. They varied in relative affinities for polynucleotides of varying base composition. Polymers containing the purines guanine or hypoxanthine and/or the pyrimidine thymine were most reactive with all three proteins. A myeloma protein that reacted with poly(G), poly(I), or poly(dT) also bound to the corresponding nucleosides or nucleotides conjugated to bovine serum albumin. None of the antibodies reacted with base-paired double-helical polynucleotides (double-stranded RNA, RNA-DNA hybrid or double-stranded DNA). The results indicate that base specificity is prominent in their reactions and that the accessible epitopes in single-stranded polynucleotides become masked upon base pairing in double-stranded helices. These findings suggest a model in which positions N1 and O6 of guanine and hypoxanthine and N3 and O4 of thymine interact with amino acids of the antibody-combining site. PMID:3771789

  15. Phagocytes as Carcinogens: Malignant Transformation Produced by Human Neutrophils

    NASA Astrophysics Data System (ADS)

    Weitzman, Sigmund A.; Weitberg, Alan B.; Clark, Edward P.; Stossel, Thomas P.

    1985-03-01

    In a study of the relation between chronic inflammation and carcinogenesis, C3H mouse fibroblasts of the 10T 1/2 clone 8 line (10T 1/2 cells) were exposed to human neutrophils stimulated to synthesize reactive oxygen intermediates or to a cell-free enzymatic system generating superoxide (xanthine oxidase plus hypoxanthine). After exposure, the 10T 1/2 cells were either placed in tissue culture or immediately injected into athymic nude mice. Both malignant and benign tumors developed in the mice injected with treated cells, but not in those injected with control cells; in one instance cells grown from one of the benign tumors subsequently developed a malignant phenotype. Malignant transformation was also observed in treated cells in the experiments in vitro.

  16. GMP synthase is essential for viability and infectivity of Trypanosoma brucei despite a redundant purine salvage pathway

    PubMed Central

    Li, Qiong; Leija, Christopher; Rijo-Ferreira, Filipa; Chen, Jun; Cestari, Igor; Stuart, Kenneth; Tu, Benjamin P.; Phillips, Margaret A.

    2015-01-01

    Summary The causative agent of human African trypanosomiasis, Trypanosoma brucei, lacks de novo purine biosynthesis and depends on purine salvage from the host. The purine salvage pathway is redundant and contains two routes to guanosine-5′-monophosphate (GMP) formation: conversion from xanthosine-5′-monophosphate (XMP) by GMP synthase (GMPS) or direct salvage of guanine by hypoxanthine-guanine phosphoribosyltransferase (HGPRT). We show recombinant T. brucei GMPS efficiently catalyzes GMP formation. Genetic knockout of GMPS in bloodstream parasites led to depletion of guanine nucleotide pools and was lethal. Growth of gmps null cells was only rescued by supraphysiological guanine concentrations (100 μM) or by expression of an extrachromosomal copy of GMPS. Hypoxanthine was a competitive inhibitor of guanine rescue, consistent with a common uptake/metabolic conversion mechanism. In mice, gmps null parasites were unable to establish an infection demonstrating that GMPS is essential for virulence and that plasma guanine is insufficient to support parasite purine requirements. These data validate GMPS as a potential therapeutic target for treatment of HAT. The ability to strategically inhibit key metabolic enzymes in the purine pathway unexpectedly bypasses its functional redundancy by exploiting both the nature of pathway flux and the limited nutrient environment of the parasite's extracellular niche. PMID:26043892

  17. [Effect of 5-FU on the utilization of purine and pyrimidine by human gastric cancer cells (KATO III)].

    PubMed

    Usami, M; Wang, J; Yasuda, I; Saitoh, Y; Yumisashi, T; Abe, K

    1995-05-01

    Effect of utilization of purine and pyrimidine in the culture medium by human gastric cancer cells (KATO III) was evaluated. Nucleosides mixture solution (OG-VI), consisting of inosine, guanosine 5' monophosphate (5'GMP), cytidine, uridine and thymidine (4: 4: 4: 3: 1 in molar ratio) was used and their levels in the culture medium was measured by HPLC after 3 day culture. Purine, inosine and 5' GMP, in the medium almost decreased and purine base, xanthine and hypoxanthine levels increased, but changes in pyrimidine level were minimal. 5-FU decreased purine and increased pyrimidine consumption. Addition of nucleosides mixture did not enhance the cellular proliferation, but inhibited growth when given in higher concentrations. Nucleoside mixture solution enhanced growth inhibition by 5-FU and it is a potential biochemical modulator of 5-FU metabolism in human cancer cells. PMID:7755382

  18. Insights into the pyrimidine biosynthetic pathway of human malaria parasite Plasmodium falciparum as chemotherapeutic target.

    PubMed

    Krungkrai, Sudaratana R; Krungkrai, Jerapan

    2016-06-01

    Malaria is a major cause of morbidity and mortality in humans. Artemisinins remain as the first-line treatment for Plasmodium falciparum (P. falciparum) malaria although drug resistance has already emerged and spread in Southeast Asia. Thus, to fight this disease, there is an urgent need to develop new antimalarial drugs for malaria chemotherapy. Unlike human host cells, P. falciparum cannot salvage preformed pyrimidine bases or nucleosides from the extracellular environment and relies solely on nucleotides synthesized through the de novo biosynthetic pathway. This review presents significant progress on understanding the de novo pyrimidine pathway and the functional enzymes in the human parasite P. falciparum. Current knowledge in genomics and metabolomics are described, particularly focusing on the parasite purine and pyrimidine nucleotide metabolism. These include gene annotation, characterization and molecular mechanism of the enzymes that are different from the human host pathway. Recent elucidation of the three-dimensional crystal structures and the catalytic reactions of three enzymes: dihydroorotate dehydrogenase, orotate phosphoribosyltransferase, and orotidine 5'-monophosphate decarboxylase, as well as their inhibitors are reviewed in the context of their therapeutic potential against malaria. PMID:27262062

  19. Insights into the pyrimidine biosynthetic pathway of human malaria parasite Plasmodium falciparum as chemotherapeutic target.

    PubMed

    Krungkrai, Sudaratana R; Krungkrai, Jerapan

    2016-06-01

    Malaria is a major cause of morbidity and mortality in humans. Artemisinins remain as the first-line treatment for Plasmodium falciparum (P. falciparum) malaria although drug resistance has already emerged and spread in Southeast Asia. Thus, to fight this disease, there is an urgent need to develop new antimalarial drugs for malaria chemotherapy. Unlike human host cells, P. falciparum cannot salvage preformed pyrimidine bases or nucleosides from the extracellular environment and relies solely on nucleotides synthesized through the de novo biosynthetic pathway. This review presents significant progress on understanding the de novo pyrimidine pathway and the functional enzymes in the human parasite P. falciparum. Current knowledge in genomics and metabolomics are described, particularly focusing on the parasite purine and pyrimidine nucleotide metabolism. These include gene annotation, characterization and molecular mechanism of the enzymes that are different from the human host pathway. Recent elucidation of the three-dimensional crystal structures and the catalytic reactions of three enzymes: dihydroorotate dehydrogenase, orotate phosphoribosyltransferase, and orotidine 5'-monophosphate decarboxylase, as well as their inhibitors are reviewed in the context of their therapeutic potential against malaria.

  20. Targeted delivery of a suicide gene to human colorectal tumors by a conditionally replicating vaccinia virus.

    PubMed

    Foloppe, J; Kintz, J; Futin, N; Findeli, A; Cordier, P; Schlesinger, Y; Hoffmann, C; Tosch, C; Balloul, J-M; Erbs, P

    2008-10-01

    We have generated a thymidine kinase gene-deleted vaccinia virus (VV) (Copenhagen strain) that expressed the fusion suicide gene FCU1 derived from the yeast cytosine deaminase and uracil phosphoribosyltransferase genes. Intratumoral inoculation of this thymidine kinase gene-deleted VV encoding FCU1 (VV-FCU1) in the presence of systemically administered prodrug 5-fluorocytosine (5-FC) produced statistically significant reductions in the growth of subcutaneous human colon cancer in nude mice compared with thymidine kinase gene-deleted VV treatments or with control 5-fluorouracil alone. A limitation of prodrug therapies has often been the requirement for the direct injection of the virus into relatively large, accessible tumors. Here we demonstrate vector targeting of tumors growing subcutaneously following systemic administration of VV-FCU1. More importantly we also demonstrate that the systemic injection of VV-FCU1 in nude mice bearing orthotopic liver metastasis of a human colon cancer, with concomitant administration of 5-FC, leads to substantial tumor growth retardation. In conclusion, the insertion of the fusion FCU1 suicide gene potentiates the oncolytic efficiency of the thymidine kinase gene-deleted VV and represents a potentially efficient means for gene therapy of distant metastasis from colon and other cancers. PMID:18480846

  1. In vitro evaluation of genotoxic effects under magnetic resonant coupling wireless power transfer.

    PubMed

    Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

    2015-04-01

    Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity. PMID:25853218

  2. Data supporting the design and evaluation of a universal primer pair for pseudogene-free amplification of HPRT1 in real-time PCR

    PubMed Central

    Valadan, Reza; Hedayatizadeh-Omran, Akbar; Alhosseini-Abyazani, Mahdyieh Naghavi; Amjadi, Omolbanin; Rafiei, Alireza; Tehrani, Mohsen; Alizadeh-Navaei, Reza

    2015-01-01

    Hypoxanthine-guanine phosphoribosyltransferase 1 (HPRT1) is a common housekeeping gene for sample normalization in the quantitative reverse transcriptase polymerase chain (qRT-PCR). However, co-amplification of HPRT1 pseudogenes may affect accurate results obtained in qRT-PCR. We designed a primer pair (HPSF) for pseudogene-free amplification of HPRT1 in qRT-PCR [1]. We showed specific amplification of HPRT1 mRNA in some common laboratory cell lines, including HeLa, NIH/3T3, CHO, BHK, COS-7 and VERO. This article provides data supporting the presence and location of HPRT1 pseudogenes within human and mouse genome, and the strategies used for designing primers that avoid the co-amplification of contaminating pseudogenes in qRT-PCR. In silico analysis of human genome showed three homologous sequences for HPRT1 on chromosomes 4, 5 and 11. The mRNA sequence of HPRT1 was aligned with the pseudogenes, and the primers were designed toward 5′ end of HPRT1 mRNA that was only specific to HPRT1 mRNA not to the pseudogenes. The standard curve plot generated by HPSF primers showed the correlation coefficient of 0.999 and the reaction efficiency of 99.5%. Our findings suggest that HPSF primers can be recommended as a candidate primer pair for accurate and reproducible qRT-PCR assays. PMID:26217821

  3. In Vitro Evaluation of Genotoxic Effects under Magnetic Resonant Coupling Wireless Power Transfer

    PubMed Central

    Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

    2015-01-01

    Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity. PMID:25853218

  4. Data supporting the design and evaluation of a universal primer pair for pseudogene-free amplification of HPRT1 in real-time PCR.

    PubMed

    Valadan, Reza; Hedayatizadeh-Omran, Akbar; Alhosseini-Abyazani, Mahdyieh Naghavi; Amjadi, Omolbanin; Rafiei, Alireza; Tehrani, Mohsen; Alizadeh-Navaei, Reza

    2015-09-01

    Hypoxanthine-guanine phosphoribosyltransferase 1 (HPRT1) is a common housekeeping gene for sample normalization in the quantitative reverse transcriptase polymerase chain (qRT-PCR). However, co-amplification of HPRT1 pseudogenes may affect accurate results obtained in qRT-PCR. We designed a primer pair (HPSF) for pseudogene-free amplification of HPRT1 in qRT-PCR [1]. We showed specific amplification of HPRT1 mRNA in some common laboratory cell lines, including HeLa, NIH/3T3, CHO, BHK, COS-7 and VERO. This article provides data supporting the presence and location of HPRT1 pseudogenes within human and mouse genome, and the strategies used for designing primers that avoid the co-amplification of contaminating pseudogenes in qRT-PCR. In silico analysis of human genome showed three homologous sequences for HPRT1 on chromosomes 4, 5 and 11. The mRNA sequence of HPRT1 was aligned with the pseudogenes, and the primers were designed toward 5' end of HPRT1 mRNA that was only specific to HPRT1 mRNA not to the pseudogenes. The standard curve plot generated by HPSF primers showed the correlation coefficient of 0.999 and the reaction efficiency of 99.5%. Our findings suggest that HPSF primers can be recommended as a candidate primer pair for accurate and reproducible qRT-PCR assays.

  5. Molecular epidemiology studies on occupational and environmental exposure to mutagens and carcinogens, 1997-1999.

    PubMed Central

    Srám, R J; Binková, B

    2000-01-01

    Molecular epidemiology is a new and evolving area of research, combining laboratory measurement of internal dose, biologically effective dose, biologic effects, and influence of individual susceptibility with epidemiologic methodologies. Biomarkers evaluated were selected according to basic scheme: biomarkers of exposure--metabolites in urine, DNA adducts, protein adducts, and Comet assay parameters; biomarkers of effect--chromosomal aberrations, sister chromatid exchanges, micronuclei, mutations in the hypoxanthine-guanine phosphoribosyltransferase gene, and the activation of oncogenes coding for p53 or p21 proteins as measured on protein levels; biomarkers of susceptibility--genetic polymorphisms of genes CYP1A1, GSTM1, GSTT1, NAT2. DNA adducts measured by 32P-postlabeling are the biomarker of choice for the evaluation of exposure to polycyclic aromatic hydrocarbons. Protein adducts are useful as a biomarker for exposure to tobacco smoke (4-aminobiphenyl) or to smaller molecules such as acrylonitrile or 1,3-butadiene. Of the biomarkers of effect, the most common are cytogenetic end points. Epidemiologic studies support the use of chromosomal breakage as a relevant biomarker of cancer risk. The use of the Comet assay and methods analyzing oxidative DNA damage needs reliable validation for human biomonitoring. Until now there have not been sufficient data to interpret the relationship between genotypes, biomarkers of exposure, and biomarkers of effect for assessing the risk of human exposure to mutagens and carcinogens. PMID:10698723

  6. Purine Salvage Pathways among Borrelia Species▿

    PubMed Central

    Pettersson, Jonas; Schrumpf, Merry E.; Raffel, Sandra J.; Porcella, Stephen F.; Guyard, Cyril; Lawrence, Kevin; Gherardini, Frank C.; Schwan, Tom G.

    2007-01-01

    Genome sequencing projects on two relapsing fever spirochetes, Borrelia hermsii and Borrelia turicatae, revealed differences in genes involved in purine metabolism and salvage compared to those in the Lyme disease spirochete Borrelia burgdorferi. The relapsing fever spirochetes contained six open reading frames that are absent from the B. burgdorferi genome. These genes included those for hypoxanthine-guanine phosphoribosyltransferase (hpt), adenylosuccinate synthase (purA), adenylosuccinate lyase (purB), auxiliary protein (nrdI), the ribonucleotide-diphosphate reductase alpha subunit (nrdE), and the ribonucleotide-diphosphate reductase beta subunit (nrdF). Southern blot assays with multiple Borrelia species and isolates confirmed the presence of these genes in the relapsing fever group of spirochetes but not in B. burgdorferi and related species. TaqMan real-time reverse transcription-PCR demonstrated that the chromosomal genes (hpt, purA, and purB) were transcribed in vitro and in mice. Phosphoribosyltransferase assays revealed that, in general, B. hermsii exhibited significantly higher activity than did the B. burgdorferi cell lysate, and enzymatic activity was observed with adenine, hypoxanthine, and guanine as substrates. B. burgdorferi showed low but detectable phosphoribosyltransferase activity with hypoxanthine even though the genome lacks a discernible ortholog to the hpt gene in the relapsing fever spirochetes. B. hermsii incorporated radiolabeled hypoxanthine into RNA and DNA to a much greater extent than did B. burgdorferi. This complete pathway for purine salvage in the relapsing fever spirochetes may contribute, in part, to these spirochetes achieving high cell densities in blood. PMID:17502392

  7. Antitumor potential of three herbal extracts against human oral squamous cell lines.

    PubMed

    Chu, Qing; Satoh, Kazue; Kanamoto, Taisei; Terakubo, Shigemi; Nakashima, Hideki; Wang, Qintao; Sakagami, Hiroshi

    2009-08-01

    Three Chinese herbal extracts of Drynaria baronii, Angelica sinensis and Cornus officinalis Sieb. et Zucc (referred to as DB, AS, CO, respectively) were investigated for their antitumor potential. These extracts showed very weak cytotoxicity against all nine cultured human cells (normal and tumor cells), but with some tumor-specific cytotoxicity displayed by DB and CO. These extracts showed little or no growth stimulation effects at lower concentrations (so-called 'hormetic effect'). Human oral squamous cell carcinoma cell lines (HSC-2, NA) were relatively resistant to committing apoptosis, as compared with human promyelocytic leukemia HL-60 cells. Electron-spin resonance spectroscopy shows that DB and CO scavenged superoxide anion (generated by hypoxanthine and xanthine oxidase reaction) and hydroxyl radical (generated by Fenton reaction) more efficiently than AS. DB and CO, but not AS, produced broad radical peak(s) and enhanced the superoxide scavenging activity of vitamin C. However, none of the extracts clearly enhanced the cytotoxicity of mitoxantrone, an anthracycline antitumor antibiotic. DB, but not CO and AS, showed weak anti-HIV activity. These data demonstrate several unique antitumor properties of DB. PMID:19661337

  8. Oxidative Stress Kills Human Primary Oligodendrocytes Via Neutral Sphingomyelinase: Implications for Multiple Sclerosis

    PubMed Central

    Jana, Arundhati

    2007-01-01

    Multiple sclerosis (MS) is the most common human demyelinating disease of the central nervous system where oxidative stress has been proposed to play an important role in oligodendroglial death. However, molecular mechanisms that couple oxidative stress to the loss of oligodendrocytes are poorly understood. This study underlines the importance of neutral sphingomyelinase–ceramide pathway in mediating oxidative stress-induced apoptosis and cell death of human primary oligodendrocytes. Various oxidative stress-inducing agents, such as, superoxide radical produced by hypoxanthine and xanthine oxidase, hydrogen peroxide, aminotriazole capable of inhibiting catalase and increasing intracellular level of H2O2, or reduced glutathione-depleting diamide induced the activation of neutral sphingomyelinase and the production of ceramide. It is interesting to note that antisense knockdown of neutral but not acidic sphingomyelinase ablated oxidative stress-induced apoptosis and cell death in human primary oligodendrocytes. This study identifies neutral but not acidic sphingomyelinase as a target for possible therapeutic intervention in MS. PMID:18040843

  9. Characterization of a human antigen specific helper factor

    SciTech Connect

    Richardson, B.

    1986-03-01

    While antigen (Ag) specific helper factors have been characterized in mice, similar molecules have not been identified in humans. To characterize human antigen specific helper molecules, an IL-2 dependent tetanus toxoid (T.T.) reactive T cell line was fused with a 6-thioguanine resistant CEM line, and hybrids selected in medium containing hypoxanthine and azaserine. Hybrids were screened by culturing the cells with /sup 35/S-Met then reacting the supernatants with T.T. or hepatitis vaccine immobilized on nitrocellulose. One hybrid, TT6BA-O, was identified which secreted a Met-containing molecule which bound T.T. but not hepatitis vaccine. Supernatants from TT6BA-O, but not the parent CEM line, when added to autologous peripheral blood mononuclear cells (PBMC's) stimulated secretion of T.T. specific antibodies (Abs). Specificity controls demonstrated that TT6BA-O supernatant did not induce antibodies to diphtheria toxoid, hepatitis vaccine or pneumococcal polysaccharide, and total immunoglobulin (lg) synthesis was minimally increased. In contrast, pokeweed mitogen stimulated significant lg synthesis as well as Ab's to pneumococcal polysaccharide and T.T. TT6BA-O supernatant induced anti-T.T.Ab's in autologous PBMC's but not PBMC's from 3 unrelated donors, suggesting that the activity of the helper factor is restricted, possibly by the MHC. The molecular weight of the helper factor was estimated at 100,000-150,000 by Sephacryl S-300 chromatography. Finally, the helper factor could be demonstrated to bind and elute from sephorose-immobilized T.T. and anti-DR antisera, but not anti-lg antisera or the T40/25 monoclonal antibody, which binds a nonpolymorphic determinant on the human T cell receptor. These results demonstrate that human Ag specific helper factors exist, bind antigen and bear class II MHC determinants.

  10. A Nampt inhibitor FK866 mimics vitamin B3 deficiency by causing senescence of human fibroblastic Hs68 cells via attenuation of NAD(+)-SIRT1 signaling.

    PubMed

    Song, Tuzz-Ying; Yeh, Shu-Lan; Hu, Miao-Lin; Chen, Mei-Yau; Yang, Nae-Cherng

    2015-12-01

    Vitamin B3 (niacin) deficiency can cause pellagra with symptoms of dermatitis, diarrhea and dementia. However, it is unclear whether the vitamin B3 deficiency causes human aging. FK866 (a Nampt inhibitor) can reduce intracellular NAD(+) level and induce senescence of human Hs68 cells. However, the mechanisms underlying FK866-induced senescence of Hs68 cells are unclear. In this study, we used FK866 to mimic the effects of vitamin B3 deficiency to reduce the NAD(+) level and investigated the mechanisms of FK866-induced senescence of Hs68 cells. We hypothesized that FK866 induced the senescence of Hs68 cells via an attenuation of NAD(+)-silent information regulator T1 (SIRT1) signaling. We found that FK866 induced cell senescence and diminished cellular NAD(+) levels and SIRT1 activity (detected by acetylation of p53), and these effects were dramatically antagonized by co-treatment with nicotinic acid, nicotinamide, or NAD(+). In contrast, the protein expression of SIRT1, AMP-activated protein kinase, mammalian target of rapamycin, and nicotinamide phosphoribosyltransferase (Nampt) was not affected by FK866. In addition, the role of GSH in the FK866-induced cells senescence may be limited, as N-acetylcysteine did not antagonize FK866-induced cell senescence. These results suggest that FK866 induces cell senescence via attenuation of NAD(+)-SIRT1 signaling. The effects of vitamin B3 deficiency on human aging warrant further investigation.

  11. DNA adduct formation in relation to lymphocyte mutations and lung tumor induction in F344 rats treated with the environmental pollutant 1,6-dinitropyrene.

    PubMed Central

    Smith, B A; Fullerton, N F; Aidoo, A; Heflich, R H; Beland, F A

    1993-01-01

    Epidemiological studies suggest an association between exposure to diesel emissions and an increased incidence of lung and bladder cancer in humans. Of the compounds associated with diesel emissions, 1,6-dinitropyrene is a particularly potent mutagen and carcinogen. In these experiments we administered [4,5,9,10-3H]1,6-dinitropyrene (30 or 100 micrograms) directly to the lungs of F344 rats according to a protocol known to induce lung tumors and characterized the DNA adducts present in the target tissue. In addition, we examined the adducts present in spleen lymphocytes and assayed for the induction of mutations at the hypoxanthine-guanine phosphoribosyltransferase locus in these cells, as measured by the frequency of 6-thioguanine-resistant (TGr) T-lymphocytes. Adduct formation was detected in both lung and spleen lymphocyte DNA, with the extent of binding being dose-dependent in the lymphocytes but not the lung. 32P-Postlabeling analyses indicated the formation of a major DNA adduct, N-(deoxyguanosin-8-yl)-1-amino-6- nitropyrene, in both tissues. 1,6-Dinitropyrene treatment resulted in a dose-dependent increase in TGr T-lymphocytes, with the increase being detected for at least 21 weeks after treatment. These data indicate that 1,6-dinitropyrene is metabolically activated by nitroreduction to form DNA adducts in both the target tissue and spleen lymphocytes and that a tumorigenic dose results in a significant induction of TGr T-lymphocytes. Images FIGURE 2. PMID:8319643

  12. Escape from Het-6 Incompatibility in Neurospora Crassa Partial Diploids Involves Preferential Deletion within the Ectopic Segment

    PubMed Central

    Smith, M. L.; Yang, C. J.; Metzenberg, R. L.; Glass, N. L.

    1996-01-01

    Self-incompatible het-6(OR)/het-6(PA) partial diploids of Neurospora crassa were selected from a cross involving the translocation strain, T(IIL -> IIIR)AR18, and a normal sequence strain. About 25% of the partial diploids exhibited a marked increase in growth rate after 2 weeks, indicating that ``escape'' from het-6 incompatibility had occurred. Near isogenic tester strains with different alleles (het-6(OR) and het-6(PA)) were constructed and used to determine that 80 of 96 escape strains tested were het-6(PA), retaining the het-6 allele found in the normal-sequence LGII position; 16 were het-6(OR), retaining the allele in the translocated position. Restriction fragment length polymorphisms in 45 escape strains were examined with probes made from cosmids that spanned the translocated region. Along with electrophoretic analysis of chromosomes from three escape strains, RFLPs showed that escape is associated with deletion of part of one or the other of the duplicated DNA segments. Deletions ranged in size from ~70 kbp up to putatively the entire 270-kbp translocated region but always included a 35-kbp region wherein we hypothesize het-6 is located. The deletion spectrum at het-6 thus resembles other cases where mitotic deletions occur such as of tumor suppressor genes and of the hprt gene (coding for hypoxanthine-guanine phosphoribosyl-transferase) in humans. PMID:8889517

  13. Study of gene-specific DNA repair in the comet assay with padlock probes and rolling circle amplification.

    PubMed

    Henriksson, Sara; Shaposhnikov, Sergey; Nilsson, Mats; Collins, Andrew

    2011-04-25

    We used padlock probes to study the rate of gene specific repair of three genes, OGG1 (8-oxoguanine-DNA glycosylase-1), XPD (xeroderma pigmentosum group D), and HPRT (hypoxanthine-guanine phosphoribosyltransferase) in human lymphocytes, in relation to the repair rate of Alu repeats and total genomic DNA. Padlock probes offer highly specific detection of short target sequences by combining detection by ligation and signal amplification. In this approach only genes in sequences containing strand breaks, which become single-stranded in the tail, are available for hybridisation. Thus the total number of signals from the padlock probes per comet gives a direct measure of the amount of damage (strand-breaks) present and allows the repair process to be monitored. This method could provide insights on the organisation of genomic DNA in the comet tail. Alu repeat containing DNA was repaired rapidly in comparison with total genomic DNA, and the studied genes were generally repaired more rapidly than the Alu repeats.

  14. The multifocality of bronchioloalveolar lung carcinoma: evidence and implications of a multiclonal origin.

    PubMed

    Barsky, S H; Grossman, D A; Ho, J; Holmes, E C

    1994-08-01

    Bronchioloalveolar lung carcinoma (BAC) is a unique type of lung cancer with distinguishing pathologic, biologic, epidemiologic, and perhaps etiologic features that set it apart from all other forms of lung cancer, including general adenocarcinoma, into which it is traditionally grouped. Recent studies at our institution have demonstrated a near exponential increase in BAC cases with 25% showing evidence of multifocality. Although some theories suggest that this multifocality is caused by intrapulmonary aerosol/aspiration or lymphatic spread, this study provides evidence for multiclonality as the basis for some cases of multifocal BAC by exploiting a novel strategy for clonality determinations that involves polymerase chain reaction amplification of a 511-base pair region located within the first intron of the human hypoxanthine phosphoribosyltransferase gene, a site that contains inactive X chromosomal obligately methylated HpaII/MspI sites and single-base allelic polymorphisms in 5 to 10% of females. BAC cells, obtained by enzymatic dissociation of different fresh/paraffin-embedded tumoral foci from polymorphic individuals with multilobar or bilateral BAC, were sorted to homogeneity with a fluorescein-conjugated anticarcinoembryonic antigen and then subjected to genomic DNA extraction and HpaII digestion before polymerase chain reaction amplification and subsequent analysis of the product on denaturing gradient gel electrophoresis. The differing migrations of the single homoduplexes generated were indicative of BAC clonal nonidentity or multiclonality in three separate cases. The demonstration of multiclonality in some cases of BAC provides an alternate explanation for multifocality. PMID:7527541

  15. Reduced levels of dopamine and altered metabolism in brains of HPRT knock-out rats: a new rodent model of Lesch-Nyhan Disease

    PubMed Central

    Meek, Stephen; Thomson, Alison J.; Sutherland, Linda; Sharp, Matthew G. F.; Thomson, Julie; Bishop, Valerie; Meddle, Simone L.; Gloaguen, Yoann; Weidt, Stefan; Singh-Dolt, Karamjit; Buehr, Mia; Brown, Helen K.; Gill, Andrew C.; Burdon, Tom

    2016-01-01

    Lesch-Nyhan disease (LND) is a severe neurological disorder caused by loss-of-function mutations in the gene encoding hypoxanthine phosphoribosyltransferase (HPRT), an enzyme required for efficient recycling of purine nucleotides. Although this biochemical defect reconfigures purine metabolism and leads to elevated levels of the breakdown product urea, it remains unclear exactly how loss of HPRT activity disrupts brain function. As the rat is the preferred rodent experimental model for studying neurobiology and diseases of the brain, we used genetically-modified embryonic stem cells to generate an HPRT knock-out rat. Male HPRT-deficient rats were viable, fertile and displayed normal caged behaviour. However, metabolomic analysis revealed changes in brain biochemistry consistent with disruption of purine recycling and nucleotide metabolism. Broader changes in brain biochemistry were also indicated by increased levels of the core metabolite citrate and reduced levels of lipids and fatty acids. Targeted MS/MS analysis identified reduced levels of dopamine in the brains of HPRT-deficient animals, consistent with deficits noted previously in human LND patients and HPRT knock-out mice. The HPRT-deficient rat therefore provides a new experimental platform for future investigation of how HPRT activity and disruption of purine metabolism affects neural function and behaviour. PMID:27185277

  16. Differential expression proteomics of human colorectal cancer based on a syngeneic cellular model for the progression of adenoma to carcinoma.

    PubMed

    Roth, Udo; Razawi, Hanieh; Hommer, Julia; Engelmann, Katja; Schwientek, Tilo; Müller, Stefan; Baldus, Stephan E; Patsos, Georgios; Corfield, Anthony P; Paraskeva, Christos; Hanisch, Franz-Georg

    2010-01-01

    This is the first differential expression proteomics study on a human syngeneic cellular in vitro progression model of the colorectal adenoma-to-carcinoma sequence, the anchorage-dependent non-tumorigenic adenoma derived cell line AA/C1 and the derived anchorage-independent and tumorigenic carcinoma cell line AA/C1/SB10C. The study is based on quantitative 2-DE and is complemented by Western blot validation. Excluding redundancies due to proteolysis and post-translational modified isoforms of over 2000 protein spots, 13 proteins were revealed as regulated with statistical variance being within the 95th confidence level and were identified by peptide mass fingerprinting in MALDI MS. Progression-associated proteins belong to the functional complexes of anaerobic glycolysis/gluconeogenesis, steroid biosynthesis, prostaglandin biosynthesis, the regulation and maintenance of the cytoskeleton, protein biosynthesis and degradation, the regulation of apoptosis or other functions. Partial but significant overlap was revealed with previous proteomics and transcriptomics studies in colorectal carcinoma. Among upregulated proteins we identified 3-HMG-CoA synthase, protein phosphatase 1, prostaglandin E synthase 2, villin 1, annexin A1, triosephosphate isomerase, phosphoserine aminotransferase 1, fumarylacetoacetate hydrolase and pyrroline-5-carboxylate reductase 1 (PYCR1), while glucose-regulated protein 78, cathepsin D, lamin A/C and quinolate phosphoribosyltransferase were downregulated.

  17. Expression and regulation of INTELECTIN1 in human granulosa-lutein cells: role in IGF-1-induced steroidogenesis through NAMPT.

    PubMed

    Cloix, Lucie; Reverchon, Maxime; Cornuau, Marion; Froment, Pascal; Ramé, Christelle; Costa, Caroline; Froment, Gisèle; Lecomte, Pierre; Chen, Wenyong; Royère, Dominique; Guerif, Fabrice; Dupont, Joëlle

    2014-08-01

    INTELECTIN (ITLN) is an adipokine involved in the regulation of insulin sensitivity and inflammatory and immunity responses. Serum ITLN levels are lower in obese, diabetic, and polycystic ovary syndrome (PCOS) women than in control subjects. ITLN has never been studied in ovarian cells. Here, we identified ITLN1 in human ovarian follicles and investigated the molecular mechanisms involved in the regulation of its expression in response to the insulin sensitizers metformin and rosiglitazone, in human granulosa-lutein cells (hGLCs) and in a human ovarian granulosa-like tumor cell line (KGN). We also studied the effects of human recombinant ITLN1 (hRom1) on steroid production and on the activation of various signaling pathways. Using RT-PCR, immunoblotting, and immunohistochemistry, we found that INTL1 is present in human follicular cells. Using ELISA, we showed that INTL levels are similar in plasma and follicular fluid (FF) in control patients, whereas they are higher in FF than in plasma in PCOS patients. In KGN cells and hGLCs, insulin (10(-8) M), insulin-like growth factor-1 (IGF-1; 10(-8) M), and metformin (10(-2) M or 10(-3) M) increased INTL1 expression (mRNA and protein) after 12 and 24 h of stimulation. For metformin, this effect was mediated by adenosine monophosphate-activated kinase (PRKA). Furthermore, hRom1 increased nicotinamide phosphoribosyltransferase (NAMPT) expression in KGN and hGLCs. We also showed that hRom1 increased IGF-1-induced progesterone and estradiol secretion and this was associated with an increase in the STAR and CYP19A1 protein levels and an increase in IGF-1R signaling. Furthermore, all these data were abolished when NAMPT was knocked down in KGN cells, suggesting that INTL1 improves IGF-1-induced steroidogenesis through induction of NAMPT in hGLCs. PMID:24943040

  18. The human homolog of Escherichia coli endonuclease V is a nucleolar protein with affinity for branched DNA structures.

    PubMed

    Fladeby, Cathrine; Vik, Erik Sebastian; Laerdahl, Jon K; Gran Neurauter, Christine; Heggelund, Julie E; Thorgaard, Eirik; Strøm-Andersen, Pernille; Bjørås, Magnar; Dalhus, Bjørn; Alseth, Ingrun

    2012-01-01

    Loss of amino groups from adenines in DNA results in the formation of hypoxanthine (Hx) bases with miscoding properties. The primary enzyme in Escherichia coli for DNA repair initiation at deaminated adenine is endonuclease V (endoV), encoded by the nfi gene, which cleaves the second phosphodiester bond 3' of an Hx lesion. Endonuclease V orthologs are widespread in nature and belong to a family of highly conserved proteins. Whereas prokaryotic endoV enzymes are well characterized, the function of the eukaryotic homologs remains obscure. Here we describe the human endoV ortholog and show with bioinformatics and experimental analysis that a large number of transcript variants exist for the human endonuclease V gene (ENDOV), many of which are unlikely to be translated into functional protein. Full-length ENDOV is encoded by 8 evolutionary conserved exons covering the core region of the enzyme, in addition to one or more 3'-exons encoding an unstructured and poorly conserved C-terminus. In contrast to the E. coli enzyme, we find recombinant ENDOV neither to incise nor bind Hx-containing DNA. While both enzymes have strong affinity for several branched DNA substrates, cleavage is observed only with E. coli endoV. We find that ENDOV is localized in the cytoplasm and nucleoli of human cells. As nucleoli harbor the rRNA genes, this may suggest a role for the protein in rRNA gene transactions such as DNA replication or RNA transcription.

  19. The Human Homolog of Escherichia coli Endonuclease V Is a Nucleolar Protein with Affinity for Branched DNA Structures

    PubMed Central

    Laerdahl, Jon K.; Gran Neurauter, Christine; Heggelund, Julie E.; Thorgaard, Eirik; Strøm-Andersen, Pernille; Bjørås, Magnar; Dalhus, Bjørn; Alseth, Ingrun

    2012-01-01

    Loss of amino groups from adenines in DNA results in the formation of hypoxanthine (Hx) bases with miscoding properties. The primary enzyme in Escherichia coli for DNA repair initiation at deaminated adenine is endonuclease V (endoV), encoded by the nfi gene, which cleaves the second phosphodiester bond 3′ of an Hx lesion. Endonuclease V orthologs are widespread in nature and belong to a family of highly conserved proteins. Whereas prokaryotic endoV enzymes are well characterized, the function of the eukaryotic homologs remains obscure. Here we describe the human endoV ortholog and show with bioinformatics and experimental analysis that a large number of transcript variants exist for the human endonuclease V gene (ENDOV), many of which are unlikely to be translated into functional protein. Full-length ENDOV is encoded by 8 evolutionary conserved exons covering the core region of the enzyme, in addition to one or more 3′-exons encoding an unstructured and poorly conserved C-terminus. In contrast to the E. coli enzyme, we find recombinant ENDOV neither to incise nor bind Hx-containing DNA. While both enzymes have strong affinity for several branched DNA substrates, cleavage is observed only with E. coli endoV. We find that ENDOV is localized in the cytoplasm and nucleoli of human cells. As nucleoli harbor the rRNA genes, this may suggest a role for the protein in rRNA gene transactions such as DNA replication or RNA transcription. PMID:23139746

  20. Method for the production of human T-T cell hybrids and production suppressor factor by human T-T cell hybrids

    SciTech Connect

    Platsoucas, C.

    1989-06-27

    This patent describes a method for production of human T-T cell hybrids which produce Suppressor Factor wherein cells of lymphoid origin are fused with comprises: (a) mixing cells from a first parent cell line comprising a non-mutagenized Jurkat lymoblastoid T cell line, wherein the Jurkat lymphoblastoid cells are not sensitive and cannot be killed by hypoxanthine-aminopterin-thymidine medium, with a second parent cell comprising mitogen or alloantigen activated peripheral blood leukocyte T cells or purified T-cells, (b) allowing the first and second parent cells to fuse in the presence of polyethylene glycol for about 10-20 minutes with gentle agitation to generate hybrids in the cell mixture, (c) incubating the cell mixture containing the hybrids and the first and second parent cells, after removal of the polyethylene glycol, for periods of between one to sixty days at 37{sup 0} in 5% CO/sub 2/, (d) selecting for the hybrids by separating the hybrids from the first parent Jurkat lymphoblastoid cells by coloning in agar medium wherein the hybrids form colonies, (e) recovering the hybrids that form colonies in agar medium and expanding them in culture, and (f) determining the presence of Suppressor Factor in the culture and recovering the T-T cell hybrids which produce suppressor factor.

  1. Capillary bioreactors based on human purine nucleoside phosphorylase: a new approach for ligands identification and characterization.

    PubMed

    de Moraes, Marcela Cristina; Ducati, Rodrigo Gay; Donato, Augusto José; Basso, Luiz Augusto; Santos, Diógenes Santiago; Cardoso, Carmen Lucia; Cass, Quezia Bezerra

    2012-04-01

    The enzyme purine nucleoside phosphorylase (PNP) is a target for the discovery of new lead compounds employed on the treatment severe T-cell mediated disorders. Within this context, the development of new, direct, and reliable methods for ligands screening is an important task. This paper describes the preparation of fused silica capillaries human PNP (HsPNP) immobilized enzyme reactor (IMER). The activity of the obtained IMER is monitored on line in a multidimensional liquid chromatography system, by the quantification of the product formed throughout the enzymatic reaction. The K(M) value for the immobilized enzyme was about twofold higher than that measured for the enzyme in solution (255 ± 29.2 μM and 133 ± 14.9 μM, respectively). A new fourth-generation immucillin derivative (DI4G; IC(50)=40.6 ± 0.36 nM), previously identified and characterized in HsPNP free enzyme assays, was used to validate the IMER as a screening method for HsPNP ligands. The validated method was also used for mechanistic studies with this inhibitor. This new approach is a valuable tool to PNP ligand screening, since it directly measures the hypoxanthine released by inosine phosphorolysis, thus furnishing more reliable results than those one used in a coupled enzymatic spectrophotometric assay.

  2. Cellular and molecular effects for mutation induction in normal human cells irradiated with accelerated neon ions.

    PubMed

    Suzuki, Masao; Tsuruoka, Chizuru; Kanai, Tatsuaki; Kato, Takeshi; Yatagai, Fumio; Watanabe, Masami

    2006-02-22

    We investigated the linear energy transfer (LET) dependence of mutation induction on the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in normal human fibroblast-like cells irradiated with accelerated neon-ion beams. The cells were irradiated with neon-ion beams at various LETs ranging from 63 to 335 keV/microm. Neon-ion beams were accelerated by the Riken Ring Cyclotron at the Institute of Physical and Chemical Research in Japan. Mutation induction at the HPRT locus was detected to measure 6-thioguanine-resistant clones. The mutation spectrum of the deletion pattern of exons of mutants was analyzed using the multiplex polymerase chain reaction (PCR). The dose-response curves increased steeply up to 0.5 Gy and leveled off or decreased between 0.5 and 1.0 Gy, compared to the response to (137)Cs gamma-rays. The mutation frequency increased up to 105 keV/microm and then there was a downward trend with increasing LET values. The deletion pattern of exons was non-specific. About 75-100% of the mutants produced using LETs ranging from 63 to 335 keV/mum showed all or partial deletions of exons, while among gamma-ray-induced mutants 30% showed no deletions, 30% partial deletions and 40% complete deletions. These results suggested that the dose-response curves of neon-ion-induced mutations were dependent upon LET values, but the deletion pattern of DNA was not.

  3. A system for assaying homologous recombination at the endogenous human thymidine kinase gene

    SciTech Connect

    Benjamin, M.B.; Little, J.B. ); Potter, H. ); Yandell, D.W. Massachusetts Eye and Ear Infirmary, Boston Harvard Medical School, Boston, MA )

    1991-08-01

    A system for assaying human interchromosomal recombination in vitro was developed, using a cell line containing two different mutant thymidine kinase genes (TK) on chromosomes 17. Heteroalleles were generated in the TK{sup +/+} parent B-lymphoblast cell line WIL-2 by repeated exposure to the alkylating nitrogen mustard ICR-191, which preferentially causes +1 or {minus}1 frameshifts. Resulting TK{sup {minus}/{minus}} mutants were selected in medium containing the toxic thymidine analog trifluorothymidine. In two lines, heterozygous frameshifts were located in exons 4 and 7 of the TK gene separated by {approx}8 kilobases. These lines undergo spontaneous reversion to TK{sup +} at a frequency of < 10{sup {minus}7}, and revertants can be selected in cytidine/hypoxanthine/aminopterin/thymidine medium. The nature and location of these heteroallelic mutations make large deletions, rearrangements, nondisjunction, and reduplication unlikely mechanisms for reversion to TK{sup +}. The mode of reversion to TK{sup +} was specifically assessed by DNA sequencing, use of single-strand conformation polymorphisms, and analysis of various restriction fragment length polymorphisms (RFLPs) linked to the TK gene on chromosome 17. The data suggest that a proportion of revertants has undergone recombination and gene conversion at the TK locus, with concomitant loss of frameshifts and allele loss at linked RFLPs. Models are presented for the origin of two recombinants.

  4. Increased antibody responses to human papillomavirus type 16 L1 protein expressed by recombinant vaccinia virus lacking serine protease inhibitor genes.

    PubMed

    Zhou, J; Crawford, L; McLean, L; Sun, X Y; Stanley, M; Almond, N; Smith, G L

    1990-09-01

    The L1 gene of human papillomavirus type 16 (HPV-16) driven by the vaccinia virus major late 4b gene promoter has been inserted into three different sites of the vaccinia virus genome. Insertion into the thymidine kinase (TK) gene was achieved by selection of TK- mutants in BUdR on TK- cells. Insertion into two vaccinia virus serine protease inhibitor (serpin) genes was achieved by co-insertion of the Escherichia coli xanthine guanine phosphoribosyltransferase gene linked to the vaccinia virus 7.5K promoter and selection of mycophenolic acid-resistant recombinant viruses. Each recombinant virus expressed a 57K L1 protein at similar levels and with similar kinetics. However, immunization of mice with these recombinant viruses induced different levels of antibody to the L1 protein. Viruses lacking serpin genes B13R and B24R induced significantly higher antibody levels than did viruses lacking the TK gene. The presence of functional B13R and B24R gene products is therefore somehow immunosuppressive at least for antibody responses to the L1 protein of HPV-16.

  5. Differential Proteomic Analysis of Human Placenta-Derived Mesenchymal Stem Cells Cultured on Normal Tissue Culture Surface and Hyaluronan-Coated Surface

    PubMed Central

    Wong, Tzyy Yue; Chen, Ying-Hui; Liu, Szu-Heng; Solis, Mairim Alexandra; Yu, Chen-Hsiang; Chang, Chiung-Hsin; Huang, Lynn L. H.

    2016-01-01

    Our previous results showed that hyaluronan (HA) preserved human placenta-derived mesenchymal stem cells (PDMSC) in a slow cell cycling mode similar to quiescence, the pristine state of stem cells in vivo, and HA was found to prevent murine adipose-derived mesenchymal stem cells from senescence. Here, stable isotope labeling by amino acid in cell culture (SILAC) proteomic profiling was used to evaluate the effects of HA on aging phenomenon in stem cells, comparing (1) old and young passage PDMSC cultured on normal tissue culture surface (TCS); (2) old passage on HA-coated surface (CHA) compared to TCS; (3) old and young passage on CHA. The results indicated that senescence-associated protein transgelin (TAGLN) was upregulated in old TCS. Protein CYR61, reportedly senescence-related, was downregulated in old CHA compared to old TCS. The SIRT1-interacting Nicotinamide phosphoribosyltransferase (NAMPT) increased by 2.23-fold in old CHA compared to old TCS, and is 0.48-fold lower in old TCS compared to young TCS. Results also indicated that components of endoplasmic reticulum associated degradation (ERAD) pathway were upregulated in old CHA compared to old TCS cells, potentially for overcoming stress to maintain cell function and suppress senescence. Our data points to pathways that may be targeted by HA to maintain stem cells youth. PMID:27057169

  6. Differential Proteomic Analysis of Human Placenta-Derived Mesenchymal Stem Cells Cultured on Normal Tissue Culture Surface and Hyaluronan-Coated Surface.

    PubMed

    Wong, Tzyy Yue; Chen, Ying-Hui; Liu, Szu-Heng; Solis, Mairim Alexandra; Yu, Chen-Hsiang; Chang, Chiung-Hsin; Huang, Lynn L H

    2016-01-01

    Our previous results showed that hyaluronan (HA) preserved human placenta-derived mesenchymal stem cells (PDMSC) in a slow cell cycling mode similar to quiescence, the pristine state of stem cells in vivo, and HA was found to prevent murine adipose-derived mesenchymal stem cells from senescence. Here, stable isotope labeling by amino acid in cell culture (SILAC) proteomic profiling was used to evaluate the effects of HA on aging phenomenon in stem cells, comparing (1) old and young passage PDMSC cultured on normal tissue culture surface (TCS); (2) old passage on HA-coated surface (CHA) compared to TCS; (3) old and young passage on CHA. The results indicated that senescence-associated protein transgelin (TAGLN) was upregulated in old TCS. Protein CYR61, reportedly senescence-related, was downregulated in old CHA compared to old TCS. The SIRT1-interacting Nicotinamide phosphoribosyltransferase (NAMPT) increased by 2.23-fold in old CHA compared to old TCS, and is 0.48-fold lower in old TCS compared to young TCS. Results also indicated that components of endoplasmic reticulum associated degradation (ERAD) pathway were upregulated in old CHA compared to old TCS cells, potentially for overcoming stress to maintain cell function and suppress senescence. Our data points to pathways that may be targeted by HA to maintain stem cells youth. PMID:27057169

  7. Lesch-Nyhan Syndrome in a Family with a Deletion Followed by an Insertion within the HPRT1 Gene.

    PubMed

    Nguyen, Khue Vu; Nyhan, William L

    2015-01-01

    Lesch-Nyhan syndrome (LNS) is a rare X-linked inherited neurogenetic disorder of purine metabolism in which the enzyme, hypoxanthine-guanine phosphoribosyltransferase(HGprt) is defective. The authors report a novel mutation which led to LNS in a family with a deletion followed by an insertion (INDELS) via the serial replication slippage mechanism: c.428_432delTGCAGinsAGCAAA, p.Met143Lysfs*12 in exon 6 of HPRT1 gene. Molecular diagnosis discloses the genetic heterogeneity of HPRT1 gene responsible for HGprt deficiency. It allows fast, accurate carrier detection and genetic counseling. PMID:25965333

  8. Genotoxicity of 2,6- and 3,5-Dimethylaniline in Cultured Mammalian Cells: The Role of Reactive Oxygen Species

    PubMed Central

    Chao, Ming-Wei; Kim, Min Young; Wogan, Gerald N.

    2012-01-01

    Several alkylanilines with structures more complex than toluidines have been associated epidemiologically with human cancer. Their mechanism of action remains largely undetermined, and there is no reported evidence that it replicates that of multicyclic aromatic amines even though the principal metabolic pathways of P450-mediated hydroxylation and phase II conjugation are very similar. As a means to elucidate their mechanisms of action, lethality and mutagenicity in the adenine phosphoribosyltransferase (aprt +/−) gene induced in several Chinese hamster ovary cell types by 2,6- and 3,5-dimethylaniline (2,6-DMA, 3,5-DMA) and their N- and ring-hydroxyl derivatives (N-OH-2,6-DMA, N-OH-3,5-DMA, 2,6-DMAP, 3,5-DMAP) were assessed. Dose-response relationships were determined in the parental AA8 cell line, its repair-deficient UV5 subclone and other repair-deficient 5P3NAT2 or -proficient 5P3NAT2R9 subclones engineered to express mouse cytochrome P4501A2 (CYP1A2) and human N-acetyltransferase (NAT2), and also in AS52 cells harboring the bacterial guanine-hypoxanthine phosphoribosyltransferase (gpt) gene. Mutations in the gpt gene of AS52 cells were characterized and found to be dominated by G:C to A:T and A:T to G:C transitions. Separately, treatment of AS52 cells with N-OH-2,6-DMA, N-OH-3,5-DMA, 2,6-DMAP, 3,5-DMAP, and 3,5-DMAP led to intracellular production of reactive oxygen species (ROS) for at least 24h after removal of the mutagens in every case. Using the comet assay, DNA strand breaks were observed in a dose-dependent manner in AS52 cells when treated with each of the four N-OH-2,6-DMA, N-OH-3,5-DMA, 2,6-DMAP, and 3,5-DMAP derivatives. Comparative evaluation of the results indicates that the principal mechanism of mutagenic action is likely to be through redox cycling of intracellularly bound aminophenol/quinone imine structures to generate ROS rather than through formation of covalent DNA adducts. PMID:22831970

  9. Assay method for monitoring the inhibitory effects of antimetabolites on the activity of inosinate dehydrogenase in intact human CEM lymphocytes.

    PubMed Central

    Balzarini, J; De Clercq, E

    1992-01-01

    A rapid and convenient method has been developed to monitor the inhibition of inosinate (IMP) dehydrogenase by antimetabolites in intact human CEM lymphocytes. This method is based on the determination of 3H release from [2,8-3H]hypoxanthine ([2,8-3H]Hx) or [2,8-3H]inosine ([2,8-3H]Ino). The validity of this procedure was assessed by evaluating IMP dehydrogenase inhibition in intact CEM cells by the well-known IMP dehydrogenase inhibitors ribavirin, mycophenolic acid and tiazofurin. As reference materials, several compounds that are targeted at other enzymes in de novo purine nucleotide anabolism (i.e. hadacidine, acivicin) or catabolism (i.e. 8-aminoguanosine, allopurinol) were evaluated. There was a strong correlation between the inhibitory effects of the IMP dehydrogenase inhibitors (ribavirin, mycophenolic acid, tiazofurin) on 3H release from [2,8-3H]Hx and [2,8-3H]Ino in intact CEM cells and their ability to decrease intracellular GTP pool levels. The other compounds (hadacidine, acivicin, 8-aminoguanosine, allopurinol) had no marked effect on 3H release from [2,8-3H]Hx. Using this method, we demonstrated that the novel ribavirin analogue, 5-ethynyl-1-beta-D-ribofuranosylimidazole-4-carboxamide, is a potent inhibitor of IMP dehydrogenase in intact cells. PMID:1359876

  10. Human See, Human Do.

    ERIC Educational Resources Information Center

    Tomasello, Michael

    1997-01-01

    A human demonstrator showed human children and captive chimpanzees how to drag food or toys closer using a rakelike tool. One side of the rake was less efficient than the other for dragging. Chimps tried to reproduce results rather than methods while children imitated and used the more efficient rake side. Concludes that imitation leads to…

  11. Synthesis and antiviral properties of (+/-)-5'-noraristeromycin and related purine carbocyclic nucleosides. A new lead for anti-human cytomegalovirus agent design.

    PubMed

    Patil, S D; Schneller, S W; Hosoya, M; Snoeck, R; Andrei, G; Balzarini, J; De Clercq, E

    1992-09-01

    (+/-)-5'-Noraristeromycin (3) has been prepared in three steps beginning with the 2,3-O-isopropylidene derivative of (+/-)-(1 alpha, 2 beta, 3 beta, 4 alpha)-4-amino-1,2,3-cyclopentanetriol (7). Also prepared from the same starting material were the related hypoxanthine (4), guanine (5), and 2,6-diaminopurine (6) analogues. Compounds 3-6 were evaluated for antiviral activity against a large number of viruses with marked activity being observed for 3 towards vaccinia virus, human cytomegalovirus, vesicular stomatitis virus, parainfluenza (type 3) virus, measles virus, respiratory syncytial virus, reovirus (type 1), and the arenaviruses Junin and Tacaribe. None of the compounds showed cytotoxicity to the host cell monolayers used in the antiviral studies. Both 3 and 6 have been found to be inhibitors of S-adenosyl-L-homocysteine hydrolase (AdoHcy hydrolase), which likely accounts for their antiviral activity. Inhibition of AdoHcy hydrolase represents a new approach to human cytomegalovirus drug design that should be pursued. Also, the activity of 3 should be further scrutinized for the treatment of pox-, rhabdo-, paramyxo-, reo-, and arenavirus infections. PMID:1326633

  12. Silencing expression of the catalytic subunit of DNA-dependent protein kinase by small interfering RNA sensitizes human cells for radiation-induced chromosome damage, cell killing, and mutation

    NASA Technical Reports Server (NTRS)

    Peng, Yuanlin; Zhang, Qinming; Nagasawa, Hatsumi; Okayasu, Ryuichi; Liber, Howard L.; Bedford, Joel S.

    2002-01-01

    Targeted gene silencing in mammalian cells by RNA interference (RNAi) using small interfering RNAs (siRNAs) was recently described by Elbashir et al. (S. M. Elbashir et al., Nature (Lond.), 411: 494-498, 2001). We have used this methodology in several human cell strains to reduce expression of the Prkdc (DNA-PKcs) gene coding for the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) that is involved in the nonhomologous end joining of DNA double-strand breaks. We have also demonstrated a radiosensitization for several phenotypic endpoints of radiation damage. In low-passage normal human fibroblasts, siRNA knock-down of DNA-PKcs resulted in a reduced capacity for restitution of radiation-induced interphase chromosome breaks as measured by premature chromosome condensation, an increased yield of acentric chromosome fragments at the first postirradiation mitosis, and an increased radiosensitivity for cell killing. For three strains of related human lymphoblasts, DNA-PKcs-targeted siRNA transfection resulted in little or no increase in radiosensitivity with respect to cell killing, a 1.5-fold decrease in induced mutant yield in TK6- and p53-null NH32 cells, but about a 2-fold increase in induced mutant yield in p53-mutant WTK1 cells at both the hypoxanthine quanine phosphoribosyl transferase (hprt) and the thymidine kinase loci.

  13. ALDH16A1 is a novel non-catalytic enzyme that may be involved in the etiology of gout via protein–protein interactions with HPRT1

    PubMed Central

    Vasiliou, Vasilis; Sandoval, Monica; Backos, Donald S.; Jackson, Brian C.; Chen, Ying; Reigan, Philip; Lanaspa, Miguel A.; Johnson, Richard J.; Koppaka, Vindhya; Thompson, David C.

    2013-01-01

    Gout, a common form of inflammatory arthritis, is strongly associated with elevated uric acid concentrations in the blood (hyperuricemia). A recent study in Icelanders identified a rare missense single nucleotide polymorphism (SNP) in the ALDH16A1 gene, ALDH16A1*2, to be associated with gout and serum uric acid levels. ALDH16A1 is a novel and rather unique member of the ALDH superfamily in relation to its gene and protein structures. ALDH16 genes are present in fish, amphibians, protista, bacteria but absent from archaea, fungi and plants. In most mammalian species, two ALDH16A1 spliced variants (ALDH16A1, long form and ALDH16A1_v2, short form) have been identified and both are expressed in HepG-2, HK-2 and HK-293 human cell lines. The ALDH16 proteins contain two ALDH domains (as opposed to one in the other members of the superfamily), four transmembrane and one coiled-coil domains. The active site of ALDH16 proteins from bacterial, frog and lower animals contain the catalytically important cysteine residue (Cys-302); this residue is absent from the mammalian and fish orthologs. Molecular modeling predicts that both the short and long forms of human ALDH16A1 protein would lack catalytic activity but may interact with the hypoxanthine-guanine phosphoribosyltransferase (HPRT1) protein, a key enzyme involved in uric acid metabolism and gout. Interestingly, such protein-protein interactions with HPRT1 are predicted to be impaired for the long or short forms of ALDH16A1*2. These results lead to the intriguing possibility that association between ALDH16A1 and HPRT1 may be required for optimal HPRT activity with disruption of this interaction possibly contributing to the hyperuricemia seen in ALDH16A1*2 carriers. PMID:23348497

  14. Mild Lesch-Nyhan Disease in a Boy with a Null Mutation in HPRT1: An Exception to the Known Genotype-Phenotype Correlation.

    PubMed

    Bayat, Allan; Christensen, Mette; Wibrand, Flemming; Duno, Morten; Lund, Allan

    2015-01-01

    Hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency results in a continuous spectrum of clinical phenotypes though all include overproduction of uric acid with hyperuricaemia, urate nephrolithiasis and gout. HPRT1 mutations that result in very low or no HPRT enzyme activities are generally associated with the classic Lesch-Nyhan disease (LND) phenotype with intellectual disability, motor handicap and self-injurious behaviour. Mutations that permit a higher residual HPRT activity are seen in some patients with the milder LND variant phenotypes with varying degrees of cognitive, motor handicap and maladaptive behaviour without recurrent self-injury. We present a boy with a LND variant phenotype due to a deletion of exon 5 of HPRT1 predicted to fully abolish HPRT activity. Metabolic analysis confirms lack of significant residual enzyme activity. The boy, currently age 10, presented with hyperuricaemia, hypotonia, developmental delay and extrapyramidal and pyramidal involvement. He has never shown any signs of self-injurious or maladaptive behaviour. This boy is one of the rare cases with a suspected null mutation in HPRT1 that associates with a milder than expected phenotype with lack of self-injurious behaviour. Key Clinical Message HPRT1 mutations that result in very low or no hypoxanthine-guanine phosphoribosyltransferase enzyme activities are generally associated with the classic Lesch-Nyhan disease. This report presents one of the rare cases with a null mutation in the HPRT1 gene that associates with a milder than expected phenotype with lack of self-injurious behaviour.

  15. Human Development, Human Evolution.

    ERIC Educational Resources Information Center

    Smillie, David

    One of the truly remarkable events in human evolution is the unprecedented increase in the size of the brain of "Homo" over a brief span of 2 million years. It would appear that some significant selective pressure or opportunity presented itself to this branch of the hominid line and caused a rapid increase in the brain, introducing a wholly new…

  16. Fast and reliable screening of mutations in human tumors: use of multiple fluorescence-based long linker arm nucleotides assay (mf-LLA).

    PubMed

    Marcelino, L A; Galvin, M; Martins, G M; Proença, M J; Mayrand, E; Rueff, J A; Monteiro, C J

    1999-06-01

    Human tumor samples were screened for point mutations by adapting a mobility-shift assay to automated DNA sizing. This screen identifies the type of point mutation and relative amount of mutated DNA sequences present in a sample. Test samples having known hypoxanthine-guanine phosphoribosyl transferase (hprt)/exon-3 sequence mutations were characterized by: (i) PCR amplification, (ii) fluorescent dye-primer extension with 36-atom linker derived deoxycytosine or deoxyuridine triphosphate and the remaining three natural nucleotides and (iii) sizing of the resulting fluorescently labeled modified strands, using an automated DNA sequencer. Routinely, a range of sizes is observed among the sequence variants of a single DNA target sequence. This is because nucleotide analogs are incorporated into DNA strands in a sequence-dependent manner, resulting in composition-dependent electrophoretic mobility. Thus, point mutations are identified as shifts in mobility between the fluorescently labeled modified strands of the control and test samples. The twenty different hprt/exon-3 single-base substitution mutations tested were easily identified, even at fourfold dilution with control DNA.

  17. A critical intracellular concentration of fully reduced non-methylated folate polyglutamates prevents macrocytosis and diminished growth rate of human cell line K562 in culture.

    PubMed Central

    Watkins, D; Cooper, B A

    1983-01-01

    Growth rate of human leukaemic cell line K562 was independent of intracellular folate concentration when this was greater than 1.5 microM. When intracellular folate concentration was less than 1.5 microM, the rate of growth was proportional to the logarithm of intracellular concentration of non-methylated fully reduced folates, but not to the logarithm of the intracellular concentration of N5-methyltetrahydropteroylglutamate. Intracellular folate concentration sufficient to support an optimal growth rate was maintained by either DL-N5-formyltetrahydropteroylglutamate or DL-N5-methyltetrahydropteroylglutamate at a 100-fold lower concentration than pteroylglutamate. Addition of hypoxanthine to culture medium partially restored growth of folate-depleted cells: thymidine had no effect on growth rate either alone or in combination with thymidine. Folate-depleted cells with diminished growth rate were larger than replete cells, but did not have megaloblastic morphology. The mitotic index was not decreased in cultures with diminished growth rate. The rate of growth and cell size of K562 cells is thus dependent on a critical intracellular concentration of non-methylated tetrahydrofolates, which may be maintained by different concentrations of either reduced folates or pteroylglutamate. PMID:6577860

  18. Release of nucleosides from canine and human hearts as an index of prior ischemia.

    PubMed

    Fox, A C; Reed, G E; Meilman, H; Silk, B B

    1979-01-01

    During ischemia, myocardial adenosine triphosphate is degraded to adenosine, inosine and hypoxanthine. These nucleosides are released into coronary venous blood and may provide an index of ischemia; adenosine may also participate in the autoregulation of coronary flow. In dogs, the temporal relations between reactive hyperemic flow and nucleoside concentrations in regional venous blood were correlated after brief occlusions of a segmental coronary artery. Reactive hyperemia and adenosine release peaked together in 10 seconds, persisted for 10 to 30 seconds and then decreased in a pattern consistent with the hypothesis that they are related. During initial reflow after 45 seconds of ischemia, mean concentrations of adenosine, inosine and hypoxanthine increased, respectively, to 52, 67 and 114 nmol/100 ml plasma; after 5 minutes of ischemia, the respective levels increased to 58, 1,570 and 1,134 nmol and fell quickly. In nine patients there was a similar release of nucleosides into coronary sinus blood during reperfusion after 59 to 80 minutes of ischemic arrest during cardiac surgery. With initial reflow, adenosine, inosine and hypoxanthine levels reached 65, 655 and 917 nmol/100 ml of blood, respectively. Inosine and hypoxanthine concentrations remained high for 5 to 10 minutes after cardiac beating resumed, often when production of lactate had decreased. The results indicate that postischemic release of nucleosides reaches significant levels in man as well as animals, is parallel with the duration of ischemia, is temporary and may be a useful supplement to measurement of lactate as an index of prior myocardial ischemia. PMID:758770

  19. Human Health

    MedlinePlus

    ... effects of climate change Video not supported Human Health Climate change threatens human health and well-being ... Copy link to clipboard Key Message: Wide-ranging Health Impacts Climate change threatens human health and well- ...

  20. Loss of Dopamine Phenotype Among Midbrain Neurons in Lesch–Nyhan Disease

    PubMed Central

    Göttle, Martin; Prudente, Cecilia N.; Fu, Rong; Sutcliffe, Diane; Pang, Hong; Cooper, Deborah; Veledar, Emir; Glass, Jonathan D.; Gearing, Marla; Visser, Jasper E.; Jinnah, H. A.

    2016-01-01

    Objective Lesch–Nyhan disease (LND) is caused by congenital deficiency of the purine recycling enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt). Affected patients have a peculiar neurobehavioral syndrome linked with reductions of dopamine in the basal ganglia. The purpose of the current studies was to determine the anatomical basis for the reduced dopamine in human brain specimens collected at autopsy. Methods Histopathological studies were conducted using autopsy tissue from 5 LND cases and 6 controls. Specific findings were replicated in brain tissue from an HGprt-deficient knockout mouse using immunoblots, and in a cell model of HGprt deficiency by flow-activated cell sorting (FACS). Results Extensive histological studies of the LND brains revealed no signs suggestive of a degenerative process or other consistent abnormalities in any brain region. However, neurons of the substantia nigra from the LND cases showed reduced melanization and reduced immunoreactivity for tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis. In the HGprt-deficient mouse model, immunohistochemical stains for TH revealed no obvious loss of midbrain dopamine neurons, but quantitative immunoblots revealed reduced TH expression in the striatum. Finally, 10 independent HGprt-deficient mouse MN9D neuroblastoma lines showed no signs of impaired viability, but FACS revealed significantly reduced TH immunoreactivity compared to the control parent line. Interpretation These results reveal an unusual phenomenon in which the neurochemical phenotype of dopaminergic neurons is not linked with a degenerative process. They suggest an important relationship between purine recycling pathways and the neurochemical integrity of the dopaminergic phenotype. PMID:24891139

  1. Alkyltransferase-mediated toxicity of bis-electrophiles in mammalian cells

    PubMed Central

    Kalapila, Aley G.; Pegg, Anthony E.

    2009-01-01

    The primary function of O6-alkylguanine-DNA alkyltransferase (AGT) is to maintain genomic integrity in the face of damage by both endogenous and exogenous alkylating agents. However, paradoxically, bacterial and mammalian AGTs have been shown to increase cytotoxicity and mutagenicity of dihaloalkanes and other bis-electrophiles when expressed in bacterial cells. We have extended these studies to mammalian cells using CHO cells that lack AGT expression and CHO cells stably transfected with a plasmid that expresses human AGT. The cytotoxicity of 1,2-dibromoethane, dibromomethane and epibromohydrin was significantly increased by the presence of AGT but cytotoxicity of butadiene diepoxide was not affected. Mutations caused by these agents were assessed using hypoxanthine-guanine phosphoribosyltransferase (HPRT) as a reporter gene. There was a small (c. 2–3-fold) but statistically significant AGT-mediated increase in mutations caused by 1,2-dibromoethane, dibromomethane and epibromohydrin. Analysis of the mutation spectrum induced by 1,2-dibromoethane showed that the presence of AGT also altered the types of mutations with an increase in total base substitution mutants due to a rise in transversions at both G:C and A:T sites. AGT expression also led to mutations arising from the transcribed strand, which were not seen in cells lacking AGT. Although the frequency of deletion mutations was decreased by AGT expression, the formation of large deletions (≥3 exons) was increased. This work demonstrates that interaction of AGT with some bis-electrophiles can cause mutagenicity and diminished cell survival in mammalian cells. It is consistent with the hypothesis that DNA-AGT cross-links, which have been characterized in experiments with purified AGT protein and such bis-electrophiles, can be formed in mammalian cells. PMID:19941875

  2. Comparative mapping of the constitutional and tumor-associated 11;22 translocations.

    PubMed Central

    Budarf, M; Sellinger, B; Griffin, C; Emanuel, B S

    1989-01-01

    The reciprocal t(11;22)(q23;q11) is the most common non-Robertsonian constitutional translocation in humans. The tumor-associated 11;22 rearrangement of Ewing sarcoma (ES) and peripheral neuroepithelioma (NE) is cytologically very similar to the 11;22 constitutional rearrangement. Using immunoglobulin light-chain constant region, ETS1 probes, and the technique of in situ hybridization, we previously were able to show that the constitutional and ES/NE breakpoints are different. As a first step toward isolating these translocation junctions and to further distinguish between them, we have made somatic cell hybrids. Cells from a constitutional 46,XX,inv(9),t(11;22) carrier and from an ES cell line with a t(11;22) were separately fused to a hypoxanthine-guanine phosphoribosyltransferase-deficient Chinese hamster cell line (RJK88). Resulting clones were screened with G-banding and Southern hybridization. Hybrid clones derived from the constitutional t(11;22) were established which contained the der(22) and both the der(22) and the der(11). Hybrid clones derived from the ES cell line containing the der(11) were isolated. Using the technique of Southern hybridization we have sublocalized the loci; ApoA1/C3, CD3D, ETS1, PBGD, THY1, D11S29, D11S34, and D11S147 to the region between the two breakpoints on chromosome 11 and V lambda I, V lambda VI, V lambda VII, and D22S10 to the region between the breakpoints on chromosome 22. Using anonymous DNA probes, we found that D22S9 and D22S24 map proximal to the constitutional breakpoint and that D22S15 and D22S32 map distal to the ES breakpoint on chromosome 22. Images Figure 1 Figure 2 Figure 5 PMID:2741943

  3. Identification of Selective Lead Compounds for Treatment of High-Ploidy Breast Cancer.

    PubMed

    Choudhary, Alka; Zachek, Brittany; Lera, Robert F; Zasadil, Lauren M; Lasek, Amber; Denu, Ryan A; Kim, Hyunjung; Kanugh, Craig; Laffin, Jennifer J; Harter, Josephine M; Wisinski, Kari B; Saha, Sandeep; Weaver, Beth A; Burkard, Mark E

    2016-01-01

    Increased ploidy is common in tumors but treatments for tumors with excess chromosome sets are not available. Here, we characterize high-ploidy breast cancers and identify potential anticancer compounds selective for the high-ploidy state. Among 354 human breast cancers, 10% have mean chromosome copy number exceeding 3, and this is most common in triple-negative and HER2-positive types. Women with high-ploidy breast cancers have higher risk of recurrence and death in two patient cohorts, demonstrating that it represents an important group for improved treatment. Because high-ploidy cancers are aneuploid, rather than triploid or tetraploid, we devised a two-step screen to identify selective compounds. The screen was designed to assure both external validity on diverse karyotypic backgrounds and specificity for high-ploidy cell types. This screen identified novel therapies specific to high-ploidy cells. First, we discovered 8-azaguanine, an antimetabolite that is activated by hypoxanthine phosphoribosyltransferase 1 (HPRT1), suggesting an elevated gene-dosage of HPRT1 in high-ploidy tumors can control sensitivity to this drug. Second, we discovered a novel compound, 2,3-diphenylbenzo[g]quinoxaline-5,10-dione (DPBQ). DPBQ activates p53 and triggers apoptosis in a polyploid-specific manner, but does not inhibit topoisomerase or bind DNA. Mechanistic analysis demonstrates that DPBQ elicits a hypoxia gene signature and its effect is replicated, in part, by enhancing oxidative stress. Structure-function analysis defines the core benzo[g]quinoxaline-5,10 dione as being necessary for the polyploid-specific effects of DPBQ. We conclude that polyploid breast cancers represent a high-risk subgroup and that DPBQ provides a functional core to develop polyploid-selective therapy. Mol Cancer Ther; 15(1); 48-59. ©2015 AACR.

  4. Carboxylated Short Single-Walled Carbon Nanotubes But Not Plain and Multi-walled Short Carbon Nanotubes Show in vitro Genotoxicity

    PubMed Central

    Mrakovcic, Maria; Meindl, Claudia; Leitinger, Gerd; Roblegg, Eva; Fröhlich, Eleonore

    2015-01-01

    Long carbon nanotubes (CNTs) resemble asbestos fibers due to their high length to diameter ratio and they thus have genotoxic effects. Another parameter that might explain their genotoxic effects is contamination with heavy metal ions. On the other hand, short (1–2 μm) CNTs do not resemble asbestos fibers, and, once purified from contaminations, they might be suitable for medical applications. To identify the role of fiber thickness and surface properties on genotoxicity, well-characterized short pristine and carboxylated single-walled (SCNTs) and multi-walled (MCNTs) CNTs of different diameters were studied for cytotoxicity, the cell’s response to oxidative stress (immunoreactivity against hemoxygenase 1 and glutathione levels), and in a hypoxanthine guanine phosphoribosyltransferase (HPRT) assay using V79 chinese hamster fibroblasts and human lung adenocarcinoma A549 cells. DNA repair was demonstrated by measuring immunoreactivity against activated histone H2AX protein. The number of micronuclei as well as the number of multinucleated cells was determined. CNTs acted more cytotoxic in V79 than in A549 cells. Plain and carboxylated thin (<8 nm) SCNTs and MCNTs showed greater cytotoxic potential and carboxylated CNTs showed indication for generating oxidative stress. Multi-walled CNTs did not cause HPRT mutation, micronucleus formation, DNA damage, interference with cell division, and oxidative stress. Carboxylated, but not plain, SCNTs showed indication for in vitro DNA damage according to increase of H2AX-immunoreactive cells and HPRT mutation. Although short CNTs presented a low in vitro genotoxicity, functionalization of short SCNTs can render these particles genotoxic. PMID:25505129

  5. Charged-particle mutagenesis 2. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Technical Reports Server (NTRS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-01-01

    The biological effects of high Linear Energy Transfer (LET) charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 sq micrometer and 0.09 to 5.56 x 10(exp -3) sq micrometer respectively. The maximum values were obtained by Fe-56 with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(exp -5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  6. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Astrophysics Data System (ADS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-10-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/μm to 975 KeV/gmm with particle energy (on the cells) between 94 - 603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/μm. The inactivation cross-section (αi) and the action-section for mutant induction (αm) ranged from 2.2 to 92.0 μm2 and 0.09 to 5.56 × 10-3 μm2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/μm. The mutagenicity (αm/αi) ranged from 2.05 to 7.99 × 10-5 with the maximum value at 150 keV/μm. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  7. Glyoxylate lowers metabolic ATP in human platelets without altering adenylate energy charge or aggregation.

    PubMed

    Dangelmaier, Carol A; Holmsen, Holm

    2014-01-01

    Human blood platelets adhere to exposed collagen at the site of vascular injury, initiating a signaling cascade leading to fibrinogen activation, secretion of granules and aggregation, thus producing a stable thrombus. All these steps require metabolic ATP. In this study we have labeled the metabolic pool of ATP with nucleotides, treated platelets with various inhibitors and have monitored their ability to be activated. Incubating platelets with glyoxylate dramatically reduced the ATP level without a change in the adenylate energy charge (AEC). This reduction of ATP did not affect ADP-induced primary or secondary aggregation, whereas glyoxal, methyl glyoxal, or the combination of antimycin plus deoxyglucose reduced both ATP and AEC and inhibited aggregation. The reduction of ATP by glyoxylate was almost quantitatively matched by an increase in hypoxanthine without elevation of ADP. AMP, IMP or inosine, acetoacetate, aspartate, or glutamate had no effect on glyoxylate-induced breakdown of ATP, while pyruvate stopped the ATP reduction fast and efficiently. Glyoxylate also lowered the citrate content. The glyoxylate-induced breakdown of ATP coincided with an increase in fructose-1,6-bisphosphate, indicating that the phosphofructokinase reaction was the main ATP-consuming step. Glyoxylate was a substrate for lactate dehydrogenase although with a Km almost 100 times higher than pyruvate. We suggest that glyoxylate primarily competes with pyruvate in the pyruvate dehydrogenase reaction, thus lowering the citrate concentration, which in turn activates phosphofructokinase. Clearly, lowering of ATP in the cytosol by more than 50% does not affect platelet aggregation provided that the AEC is not reduced.

  8. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Technical Reports Server (NTRS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-01-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 micrometer2 and 0.09 to 5.56 x 10(-3) micrometer2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(-5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  9. Detection of deletion mutations in pSV2gpt-transformed cells

    SciTech Connect

    Tindall, K.R.; Stankowski, L.F. Jr.; Machanoff, R.; Hsie, A.W.

    1984-07-01

    The authors have developed a system to study mutations that affect xanthine-guanine phosphoribosyltransferase gene (gpt) expression in hypoxanthine-guanine phosphoribosyltransferase-deficient CHO cells that have been transformed by the plasmid vector pSV2gpt. One isolated transformant, designated AS52, carries a single copy of the Escherichia coli gpt gene stably integrated into the high-molecular-weight DNA and expresses the bacterial gene for the enzyme xanthine-guanine phosphoribosyltransferase. Mutants deficient in this enzyme can be induced in the AS52 cell line by a variety of mutagens, and spontaneous or induced mutants can be selected for resistance to 6-thioguanine (Tg/sup r/). Two Tg/sup r/ clones derived from the AS52 line were analyzed by Southern blot hybridization and were found to contain deletions involving at least a portion of the gpt gene. Because of the small size and stability of the integrated pSV2gpt plasmid, and the well-defined selection protocol for mutant isolation, the AS52 line offers promise as a system suitable for the study of mutation at the molecular level in CHO cells.

  10. Different mechanisms of radiation-induced loss of heterozygosity in two human lymphoid cell lines from a single donor

    NASA Technical Reports Server (NTRS)

    Wiese, C.; Gauny, S. S.; Liu, W. C.; Cherbonnel-Lasserre, C. L.; Kronenberg, A.

    2001-01-01

    Allelic loss is an important mutational mechanism in human carcinogenesis. Loss of heterozygosity (LOH) at an autosomal locus is one outcome of the repair of DNA double-strand breaks (DSBs) and can occur by deletion or by mitotic recombination. We report that mitotic recombination between homologous chromosomes occurred in human lymphoid cells exposed to densely ionizing radiation. We used cells derived from the same donor that express either normal TP53 (TK6 cells) or homozygous mutant TP53 (WTK1 cells) to assess the influence of TP53 on radiation-induced mutagenesis. Expression of mutant TP53 (Met 237 Ile) was associated with a small increase in mutation frequencies at the hemizygous HPRT (hypoxanthine phosphoribosyl transferase) locus, but the mutation spectra were unaffected at this locus. In contrast, WTK1 cells (mutant TP53) were 30-fold more susceptible than TK6 cells (wild-type TP53) to radiation-induced mutagenesis at the TK1 (thymidine kinase) locus. Gene dosage analysis combined with microsatellite marker analysis showed that the increase in TK1 mutagenesis in WTK1 cells could be attributed, in part, to mitotic recombination. The microsatellite marker analysis over a 64-cM region on chromosome 17q indicated that the recombinational events could initiate at different positions between the TK1 locus and the centromere. Virtually all of the recombinational LOH events extended beyond the TK1 locus to the most telomeric marker. In general, longer LOH tracts were observed in mutants from WTK1 cells than in mutants from TK6 cells. Taken together, the results demonstrate that the incidence of radi-ation-induced mutations is dependent on the genetic background of the cell at risk, on the locus examined, and on the mechanisms for mutation available at the locus of interest.

  11. Relative photomutagenicity of furocoumarins and limettin in the hypoxanthine phosphoribosyl transferase assay in V79 cells.

    PubMed

    Raquet, Nicole; Schrenk, Dieter

    2009-09-01

    Furocoumarins are phototoxic and photomutagenic natural plant constituents found in many medicinal plants and food items. Because plants contain mixtures of several furocoumarins, there is a need for a comparative risk assessment of a large number of furocoumarins. Little is known about the photomutagenicity of the structurally related family of coumarins, which are also abundant in many plant species. In this study, we analyzed the photomutagenic potency of the linear furocoumarins 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP), the angular furocoumarin angelicin, and the coumarin limettin. Above certain concentrations, all test compounds were more or less phototoxic in the presence of UVA doses between 50 and 200 mJ/cm(2), 5-MOP being the most phototoxic compound. At nonphototoxic concentrations, linear correlations were found between concentration and mutagenicity at a UVA dose of 125 mJ/cm(2) for all test compounds including limettin. For 5-MOP, strictly linear correlations were also found for the relationships of mutagenicity vs concentration at various UVA doses or vs UVA dose at given concentrations, respectively. These data indicate that the photomutagenicity of 5-MOP is proportional to the UVA dose x concentration product for noncytotoxic combinations of both factors. They also suggest that the slope of the concentration-photomutagenicity correlation at a given UVA dose may provide a basis for comparison between individual compounds. Applying this concept, in vitro photomutagenicity equivalency factors at 125 mJ/cm(2) were as follows: 1.0 (5-MOP, reference compound), 0.25 (8-MOP), and 0.02 (angelicin and limettin, respectively). These findings provide a new concept for the description of the relative photomutagenic potency of coumarins and furocoumarins and indicate that, in V79 cells, 8-MOP is less photomutagenic and limettin and angelicin are much less photomutagenic than 5-MOP.

  12. Human Trafficking

    MedlinePlus

    ... TRAFFICKING (English) Listen < Back to Search FACT SHEET: HUMAN TRAFFICKING (English) Published: August 2, 2012 Topics: Public Awareness , ... organizations that protect and serve trafficking victims. National Human Trafficking Resource Center at 1.888.373.7888 Last ...

  13. Human Rights/Human Needs.

    ERIC Educational Resources Information Center

    Canning, Cynthia

    1978-01-01

    The faculty of Holy Names High School developed an interdisciplinary human rights program with school-wide activities focusing on three selected themes: the United Nations Universal Declaration of Human Rights, in conjunction with Human Rights Week; Food; and Women. This article outlines major program activities. (SJL)

  14. Germ Line Variants of Human N-Methylpurine DNA Glycosylase Show Impaired DNA Repair Activity and Facilitate 1,N6-Ethenoadenine-induced Mutations*

    PubMed Central

    Adhikari, Sanjay; Chetram, Mahandranauth A.; Woodrick, Jordan; Mitra, Partha S.; Manthena, Praveen V.; Khatkar, Pooja; Dakshanamurthy, Sivanesan; Dixon, Monica; Karmahapatra, Soumendra K.; Nuthalapati, Nikhil K.; Gupta, Suhani; Narasimhan, Ganga; Mazumder, Raja; Loffredo, Christopher A.; Üren, Aykut; Roy, Rabindra

    2015-01-01

    Human N-methylpurine DNA glycosylase (hMPG) initiates base excision repair of a number of structurally diverse purine bases including 1,N6-ethenoadenine, hypoxanthine, and alkylation adducts in DNA. Genetic studies discovered at least eight validated non-synonymous single nucleotide polymorphisms (nsSNPs) of the hMPG gene in human populations that result in specific single amino acid substitutions. In this study, we tested the functional consequences of these nsSNPs of hMPG. Our results showed that two specific arginine residues, Arg-141 and Arg-120, are important for the activity of hMPG as the germ line variants R120C and R141Q had reduced enzymatic activity in vitro as well as in mammalian cells. Expression of these two variants in mammalian cells lacking endogenous MPG also showed an increase in mutations and sensitivity to an alkylating agent compared with the WT hMPG. Real time binding experiments by surface plasmon resonance spectroscopy suggested that these variants have substantial reduction in the equilibrium dissociation constant of binding (KD) of hMPG toward 1,N6-ethenoadenine-containing oligonucleotide (ϵA-DNA). Pre-steady-state kinetic studies showed that the substitutions at arginine residues affected the turnover of the enzyme significantly under multiple turnover condition. Surface plasmon resonance spectroscopy further showed that both variants had significantly decreased nonspecific (undamaged) DNA binding. Molecular modeling suggested that R141Q substitution may have resulted in a direct loss of the salt bridge between ϵA-DNA and hMPG, whereas R120C substitution redistributed, at a distance, the interactions among residues in the catalytic pocket. Together our results suggest that individuals carrying R120C and R141Q MPG variants may be at risk for genomic instability and associated diseases as a consequence. PMID:25538240

  15. Mechanism of cytotoxicity of 5,10-dideazatetrahydrofolic acid in human ovarian carcinoma cells in vitro and modulation of the drug activity by folic or folinic acid.

    PubMed Central

    Erba, E.; Sen, S.; Sessa, C.; Vikhanskaya, F. L.; D'Incalci, M.

    1994-01-01

    Inhibition of clonogenic potential by the glycinamideribonucleosyl transformylase inhibitor 5,10-dideazatetrahydrofolic acid (DDATHF, Lometrexol) was evaluated in vitro in a human ovarian carcinoma cell line, SW626. Drug-induced inhibition of clonogenic potential is a function of the dose and time of exposure and is independent of the formation of DNA single-strand breaks or de novo synthesis of protein. Simultaneous treatment with 100 microM hypoxanthine completely prevented the inhibition of clonogenic potential caused by 0.5 microM DDATHF. DDATHF blocked cells in the early-middle S-phases of the cell cycle, and there was a corresponding marked reduction in the rate of DNA synthesis after drug withdrawal. The cytotoxic potential of DDATHF was modulated by the folic acid concentration present in the medium. In a medium containing 0.22 microM folic acid, DDATHF cytotoxicity was at least 100 times that in a regular medium containing 2.22 microM folic acid, levels which, however, are about 100 times those found in human plasma. DDATHF cytotoxicity differed moderately when folic acid concentrations varied between 0.22 and 0 microM, suggesting that folic acid does not necessarily antagonise DDATHF anti-tumour activity. Folinic acid at a concentration as low as 0.1 microM can completely rescue cells when given simultaneously with 0.5 microM DDATHF. When folinic acid was given 24 h after DDATHF, a reversal of cytotoxicity was observed at 0.5 and 1 microM, but to a much lesser extent than simultaneous treatment. When folinic acid was added after 48 or 72 h of DDATHF washout, even at a high concentration and for a long time, no reduction in DDATHF cytotoxicity was found. In conclusion, the study highlights the modulation of DDATHF cytotoxicity by folic acid or by folinic acid and provides further rationale for in vivo clinical investigation with these combinations. PMID:8297715

  16. Teaching humanism.

    PubMed

    Stern, David T; Cohen, Jordan J; Bruder, Ann; Packer, Barbara; Sole, Allison

    2008-01-01

    As the "passion that animates authentic professionalism," humanism must be infused into medical education and clinical care as a central feature of medicine's professionalism movement. In this article, we discuss a current definition of humanism in medicine. We will also provide detailed descriptions of educational programs intended to promote humanism at a number of medical schools in the United States (and beyond) and identify the key factors that make these programs effective. Common elements of programs that effectively teach humanism include: (1) opportunities for students to gain perspective in the lives of patients; (2) structured time for reflection on those experiences; and (3) focused mentoring to ensure that these events convert to positive, formative learning experiences. By describing educational experiences that both promote and sustain humanism in doctors, we hope to stimulate the thinking of other medical educators and to disseminate the impact of these innovative educational programs to help the profession meet its obligation to provide the public with humanistic physicians.

  17. Human Issues in Human Rights

    ERIC Educational Resources Information Center

    Kates, Robert W.

    1978-01-01

    Presents the report of the National Academy of Sciences' Committee in Human Rights which seeks to ease the plight of individual scientists, engineers, and medical personnel suffering severe repression. Case studies of instances of negligence of human rights are provided. (CP)

  18. Human rights

    PubMed Central

    Powell, J Enoch

    1977-01-01

    What are human rights? In this article Enoch Powell, MP (a former Conservative Minister of Health), approaches this question through a critical discussion of Article 25 (I) of the United Nations Universal Declaration of Human Rights. Professor R S Downie in his accompanying commentary analyses Mr Powell's statements and takes up in particular Mr Powell's argument that claiming rights for one person entails compulsion on another person. In Professor Downie's view there is nothing in Article 25 (I) that cannot embody acceptable moral rights, the commonly accepted interpretation of that Article of the UN Universal Declaration of Human Rights which many people think is wholly acceptable. PMID:604483

  19. Transient induction of a nuclear antigen unrelated to Epstein-Barr nuclear antigen in cells of two human B-lymphoma lines converted by Epstein-Barr virus.

    PubMed

    Fresen, K O; zur Hausen, H

    1977-01-01

    Infection of cells of the Epstein-Barr virus (EBV)-negative human B-lymphoma lines BJAB and Ramos with EBV preparations from P3HR-1 or B 95-8 cells converted these cells to EBV genome carriers expressing Epstein-Barr nuclear antigen (EBNA) in almost 100% of these cells. Induction of these cells as well as of clones from P3HR-1 EBV-converted BJAB cells with iododeoxyuridine, aminopterin, and hypoxanthine resulted in the appearance of a nuclear antigen in about 1-6% of the cells 1-4 days after induction. The antigen is different from known EBV-induced antigens like EBNA, viral capsid antigen (VCA) or the D- and R-subspecificities of the early antigen (EA) complex. It is demonstrated by indirect immunofluorescence and inactivated after acetone fixation. The antigen was not detectable after induction of uninfected BJAB and Ramos cells nor has it been found in noninduced or induced P3HR-1 and Raji cells. Thus, it appears that EBV-infection mediates the expression of this antigen, for which the name TINA (transiently induced nuclear antigen) is suggested. Sera reacting against TINA generally contained high antibody titers against EBV-induced EA. Only a limited number of highly EA-reactive sera, however, were also positive for TINA. Among 200 sera tested thus far, TINA reactivity was most frequently observed in sera of patients with nasopharyngeal carcinoma (7 out of 28), in sera of the only two patients with immunoblastoma tested and occasionally in sera from patients with Hodgkin's disease and chronic lymphatic leukemia. Among 70 sera from nontumor patients, TINA reactivity was observed three times: two patients suffered from "chronic" infectious mononucleosis, the other revealed persistent splenomegaly. PMID:189313

  20. Novel assay for simultaneous measurement of pyridine mononucleotides synthesizing activities allows dissection of the NAD(+) biosynthetic machinery in mammalian cells.

    PubMed

    Zamporlini, Federica; Ruggieri, Silverio; Mazzola, Francesca; Amici, Adolfo; Orsomando, Giuseppe; Raffaelli, Nadia

    2014-11-01

    The redox coenzyme NAD(+) is also a rate-limiting co-substrate for several enzymes that consume the molecule, thus rendering its continuous re-synthesis indispensable. NAD(+) biosynthesis has emerged as a therapeutic target due to the relevance of NAD(+) -consuming reactions in complex intracellular signaling networks whose alteration leads to many neurologic and metabolic disorders. Distinct metabolic routes, starting from various precursors, are known to support NAD(+) biosynthesis with tissue/cell-specific efficiencies, probably reflecting differential expression of the corresponding rate-limiting enzymes, i.e. nicotinamide phosphoribosyltransferase, quinolinate phosphoribosyltransferase, nicotinate phosphoribosyltransferase and nicotinamide riboside kinase. Understanding the contribution of these enzymes to NAD(+) levels depending on the tissue/cell type and metabolic status is necessary for the rational design of therapeutic strategies aimed at modulating NAD(+) availability. Here we report a simple, fast and sensitive coupled fluorometric assay that enables simultaneous determination of the four activities in whole-cell extracts and biological fluids. Its application to extracts from various mouse tissues, human cell lines and plasma yielded for the first time an overall picture of the tissue/cell-specific distribution of the activities of the various enzymes. The screening enabled us to gather novel findings, including (a) the presence of quinolinate phosphoribosyltransferase and nicotinamide riboside kinase in all examined tissues/cell lines, indicating that quinolinate and nicotinamide riboside are relevant NAD(+) precursors, and (b) the unexpected occurrence of nicotinate phosphoribosyltransferase in human plasma. PMID:25223558

  1. [Human monkeypox].

    PubMed

    Chastel, C

    2009-03-01

    Unlike other recent viral emergences, which were in majority caused by RNA viruses, the monkeypox results from infection by a DNA virus, an orthopoxvirus closely related to both vaccine and smallpox viruses and whose two genomic variants are known. Unexpectedly isolated from captive Asiatic monkeys and first considered as an laboratory curiosity, this virus was recognised in 1970 as an human pathogen in tropical Africa. Here it was responsible for sporadic cases following intrusions (for hunting) into tropical rain forests or rare outbreak with human-to-human transmission as observed in 1996 in Democratic Republic of Congo. As monkeypox in humans is not distinguishable from smallpox (a disease globally eradicated in 1977) it was only subjected to vigilant epidemiological surveillance and not considered as a potential threat outside Africa. This point of view radically changed in 2003 when monkeypox was introduced in the USA by African wild rodents and spread to 11 different states of this country. Responsible for 82 infections in American children and adults, this outbreak led to realize the sanitary hazards resulting from international trade of exotic animals and scientific investigations increasing extensively our knowledge of this zoonosis. PMID:18394820

  2. Humanizing Calculus

    ERIC Educational Resources Information Center

    Cirillo, Michelle

    2007-01-01

    In this article, the author explores the history and the mathematics used by Newton and Leibniz in their invention of calculus. The exploration of this topic is intended to show students that mathematics is a human invention. Suggestions are made to help teachers incorporate the mathematics and the history into their own lessons. (Contains 3…

  3. Human Trafficking

    ERIC Educational Resources Information Center

    Wilson, David McKay

    2011-01-01

    The shadowy, criminal nature of human trafficking makes evaluating its nature and scope difficult. The U.S. State Department and anti-trafficking groups estimate that worldwide some 27 million people are caught in a form of forced servitude today. Public awareness of modern-day slavery is gaining momentum thanks to new abolitionist efforts. Among…

  4. Nothing Human

    ERIC Educational Resources Information Center

    Wharram, C. C.

    2014-01-01

    In this essay C. C. Wharram argues that Terence's concept of translation as a form of "contamination" anticipates recent developments in philosophy, ecology, and translation studies. Placing these divergent fields of inquiry into dialogue enables us read Terence's well-known statement "I am a human being--I deem nothing…

  5. Provisional mapping of the gene for a cell surface marker, GA-1, in the red-necked wallaby Macropus rufogriseus.

    PubMed

    Sykes, P J; Hope, R M

    1985-01-01

    A series of M. rufogriseus-mouse somatic cell hybrids was constructed and analysed cytologically, enzymatically and immunologically. A monoclonal antibody, GA-1, was prepared against an M. rufogriseus cell surface antigen on an M. rufogriseus-mouse somatic cell hybrid. A gene determining the expression of this antigen was provisionally assigned to the long arm of the M. rufogriseus chromosome 3. The monoclonal antibody also reacted with an M. rufus (red kangaroo)-mouse somatic cell hybrid containing only the M. rufus chromosome 5, the G-banded chromosome identical to M. rufogriseus 3q. The results also suggest synteny of the genes for the marsupial enzymes hypoxanthine phosphoribosyltransferase and phosphoglycerate kinase-A.

  6. Repeated doses of gamma rays induce resistance to N-methyl-N'-nitro-N-nitrosoguanidine in Chinese hamster cells

    SciTech Connect

    Osmak, M.

    1988-09-01

    Chinese hamster V79 cells were preirradiated repeatedly with gamma rays and then exposed to ultraviolet (uv) light or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The cell killing and induction of mutation at the hypoxanthine-guanine phosphoribosyltransferase locus were examined following these treatments. Cells preirradiated with multiple fractions of gamma rays exhibit the same sensitivity to uv light as the control cells with respect to cell survival and mutation induction. Following treatment with MNNG, resistance to cell killing was observed along with a decreased frequency of mutations induced. These results indicate that the progeny of cells irradiated with multiple fractions of gamma rays could display subsequent changes in sensitivity to lethal and mutagenic effects of additional treatment with DNA-damaging agents.

  7. Genetic background of uric acid metabolism in a patient with severe chronic tophaceous gout.

    PubMed

    Petru, Lenka; Pavelcova, Katerina; Sebesta, Ivan; Stiburkova, Blanka

    2016-09-01

    Hyperuricemia depends on the balance of endogenous production and renal excretion of uric acid. Transporters for urate are located in the proximal tubule where uric acid is secreted and extensively reabsorbed: secretion is principally ensured by the highly variable ABCG2 gene. Enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) plays a central role in purine metabolism and its deficiency is an X-linked inherited metabolic disorder associated with clinical manifestations of purine overproduction. Here we report the case of a middle-aged man with severe chronic tophaceous gout with a poor response to allopurinol and requiring repeated surgical intervention. We identified the causal mutations in the HPRT1 gene, variant c.481G>T (p.A161S), and in the crucial urate transporter ABCG2, a heterozygous variant c.421C>A (p.Q141K). This case shows the value of an analysis of the genetic background of serum uric acid. PMID:27288985

  8. From genotype to phenotype; clinical variability in Lesch-Nyhan disease. The role of epigenetics.

    PubMed

    Trigueros Genao, M; Torres, R J

    2014-11-01

    Lesch-Nyhan disease is a rare genetic disease characterized by a deficiency in the function of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). Patients affected by this disease experience hyperuricemia, motor disorders, mental retardation and, in the most severe cases, self-mutilation. Its clinical manifestations depend on the enzymatic activity of HGPRT, which is classically linked to the type of alteration in the HGPRT gene. More than 400 mutations of this gene have been found. At present, one of the controversial aspects of the disease is the relationship between the genotype and phenotype; cases have been described lacking a mutation, such as the patient presented in this article, as well as families who despite sharing the same genetic defect show disorders with differing severity. Epigenetic processes, which modify the genetic expression without changing the sequence of the deoxyribonucleic acid (DNA), could explain the clinical variability observed in this disease.

  9. Investigation of coelectroporation as a method for introducing small mutations into embryonic stem cells.

    PubMed

    Davis, A C; Wims, M; Bradley, A

    1992-06-01

    We have investigated coelectroporation as a method for introducing minor genetic changes into specific genes in embryonic stem cells. A selectable marker (neo) and a targeting replacement vector designed to insert a 4-bp insertion into exon 3 of the mouse hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene were coelectroporated into embryonic stem cells and selected in G418 and 6-thioguanine (6-TG). HPRT-negative clones were obtained at a frequency of approximately 1 per 520 G418r clones. Southern analysis and the polymerase chain reaction were used to demonstrate that 3 of 36 of the 6-TG-resistant clones had the desired 4-bp insertion without any other disruption of the HPRT locus. Initial studies indicated that the other 33 6-TG-resistant clones probably resulted from the targeted integration of a concatemer containing both the targeting construct and the selectable neo gene.

  10. Characterization of hybrids between bovine (MDBK) and mouse (L-cell) cell lines.

    PubMed

    Chinchar, V G; Floyd, A D; Chinchar, G D; Taylor, M W

    1979-02-01

    Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)-deficient mutants of a bovine kidney cell line (MDBK) were selected following mutagenesis with ethylmethane sulfonate or ICR-170G. MDBK mutants were hybridized to thymidine kinase-deficient L cells and selected in HAT medium. Parental and hybrid cells were characterized for isozyme patterns of lactic dehydrogenase malate dehydrogenase, glucose-6-phosphate dehydrogenase, and glutamate oxalate transaminase. Chromosomes of MDBK can be distinguished from mouse L cells by configuration and by fluorescent staining with Hoechst 33-258 stain. Hybrid cells contained both MDBK and L-cell chromosomes and had elevated DNA content. MDBK cells are normally restrictive for mengovirus replication. Both permissive and restrictive hybrids were found. Our data indicate that there was preferential loss of MDBK chromosomes in the hybrid cell lines.

  11. Human Rights in the Humanities

    ERIC Educational Resources Information Center

    Harpham, Geoffrey

    2012-01-01

    Human rights are rapidly entering the academic curriculum, with programs appearing all over the country--including at Duke, Harvard, Northeastern, and Stanford Universities; the Massachusetts Institute of Technology; the Universities of Chicago, of Connecticut, of California at Berkeley, and of Minnesota; and Trinity College. Most of these…

  12. Human genetics

    SciTech Connect

    Carlson, E.A.

    1984-01-01

    This text provides full and balanced coverage of the concepts requisite for a thorough understanding of human genetics. Applications to both the individual and society are integrated throughout the lively and personal narrative, and the essential principles of heredity are clearly presented to prepare students for informed participation in public controversies. High-interest, controversial topics, including recombinant DNA technology, oncogenes, embryo transfer, environmental mutagens and carcinogens, IQ testing, and eugenics encourage understanding of important social issues.

  13. Human evolution.

    PubMed

    Wood, B

    1996-12-01

    The common ancestor of modern humans and the great apes is estimated to have lived between 5 and 8 Myrs ago, but the earliest evidence in the human, or hominid, fossil record is Ardipithecus ramidus, from a 4.5 Myr Ethiopian site. This genus was succeeded by Australopithecus, within which four species are presently recognised. All combine a relatively primitive postcranial skeleton, a dentition with expanded chewing teeth and a small brain. The most primitive species in our own genus, Homo habilis and Homo rudolfensis, are little advanced over the australopithecines and with hindsight their inclusion in Homo may not be appropriate. The first species to share a substantial number of features with later Homo is Homo ergaster, or 'early African Homo erectus', which appears in the fossil record around 2.0 Myr. Outside Africa, fossil hominids appear as Homo erectus-like hominids, in mainland Asia and in Indonesia close to 2 Myr ago; the earliest good evidence of 'archaic Homo' in Europe is dated at between 600-700 Kyr before the present. Anatomically modern human, or Homo sapiens, fossils are seen first in the fossil record in Africa around 150 Kyr ago. Taken together with molecular evidence on the extent of DNA variation, this suggests that the transition from 'archaic' to 'modern' Homo may have taken place in Africa. PMID:8976151

  14. Human evolution.

    PubMed

    Wood, B

    1996-12-01

    The common ancestor of modern humans and the great apes is estimated to have lived between 5 and 8 Myrs ago, but the earliest evidence in the human, or hominid, fossil record is Ardipithecus ramidus, from a 4.5 Myr Ethiopian site. This genus was succeeded by Australopithecus, within which four species are presently recognised. All combine a relatively primitive postcranial skeleton, a dentition with expanded chewing teeth and a small brain. The most primitive species in our own genus, Homo habilis and Homo rudolfensis, are little advanced over the australopithecines and with hindsight their inclusion in Homo may not be appropriate. The first species to share a substantial number of features with later Homo is Homo ergaster, or 'early African Homo erectus', which appears in the fossil record around 2.0 Myr. Outside Africa, fossil hominids appear as Homo erectus-like hominids, in mainland Asia and in Indonesia close to 2 Myr ago; the earliest good evidence of 'archaic Homo' in Europe is dated at between 600-700 Kyr before the present. Anatomically modern human, or Homo sapiens, fossils are seen first in the fossil record in Africa around 150 Kyr ago. Taken together with molecular evidence on the extent of DNA variation, this suggests that the transition from 'archaic' to 'modern' Homo may have taken place in Africa.

  15. The Use of Perinatal 6-Hydroxydopamine to Produce a Rodent Model of Lesch-Nyhan Disease.

    PubMed

    Knapp, Darin J; Breese, George R

    2016-01-01

    Lesch-Nyhan disease is a neurologically, metabolically, and behaviorally devastating condition that has eluded complete characterization and adequate treatment. While it is known that the disease is intimately associated with dysfunction of the hypoxanthine phosphoribosyltransferase 1 (HPRT1) gene that codes for an enzyme of purine metabolism (hypoxanthine-guanine phosphoribosyltransferase) and is associated with neurological, behavioral, as well as metabolic dysfunction, the mechanisms of the neurobehavioral manifestations are as yet unclear. However, discoveries over the past few decades not only have created useful novel animal models (e.g., the HPRT-deficient mouse and the serendipitously discovered perinatal 6-hydroxydopamine (6-OHDA lesion model), but also have expanded into epigenetic, genomic, and proteomic approaches to better understand the mechanisms underlying this disease. The perinatal 6-OHDA model, in addition to modeling self-injury and dopamine depletion in the clinical condition, also underscores the profound importance of development in the differential course of maladaptive progression in the face of a common/single neurotoxic insult at different ages. Recent developments from clinical and basic science efforts attest to the fact that while the disease would seem to have a simple single gene defect at its core, the manifestations of this defect are profound and unexpectedly diverse. Future efforts employing the 6-OHDA model and others in the context of the novel technologies of genome editing, chemo- and opto-genetics, epigenetics, and further studies on the mechanisms of stress-induced maladaptations in brain all hold promise in taking our understanding of this disease to the next level. PMID:27029809

  16. Human Capital, (Human) Capabilities and Higher Education

    ERIC Educational Resources Information Center

    Le Grange, L.

    2011-01-01

    In this article I initiate a debate into the (de)merits of human capital theory and human capability theory and discuss implications of the debate for higher education. Human capital theory holds that economic growth depends on investment in education and that economic growth is the basis for improving the quality of human life. Human capable…

  17. Human Heredity: Genetic Mechanisms in Humans.

    ERIC Educational Resources Information Center

    Blank, C. E.

    1988-01-01

    Discussed are some of the uncertainties in human genetic mechanisms that are often presented as dogma in Biology textbooks. Presented is a brief historical background and illustrations involving chromosome abnormality in humans and linkage studies in humans. (CW)

  18. Human Astroviruses

    PubMed Central

    Pintó, Rosa M.; Guix, Susana

    2014-01-01

    SUMMARY Human astroviruses (HAtVs) are positive-sense single-stranded RNA viruses that were discovered in 1975. Astroviruses infecting other species, particularly mammalian and avian, were identified and classified into the genera Mamastrovirus and Avastrovirus. Through next-generation sequencing, many new astroviruses infecting different species, including humans, have been described, and the Astroviridae family shows a high diversity and zoonotic potential. Three divergent groups of HAstVs are recognized: the classic (MAstV 1), HAstV-MLB (MAstV 6), and HAstV-VA/HMO (MAstV 8 and MAstV 9) groups. Classic HAstVs contain 8 serotypes and account for 2 to 9% of all acute nonbacterial gastroenteritis in children worldwide. Infections are usually self-limiting but can also spread systemically and cause severe infections in immunocompromised patients. The other groups have also been identified in children with gastroenteritis, but extraintestinal pathologies have been suggested for them as well. Classic HAstVs may be grown in cells, allowing the study of their cell cycle, which is similar to that of caliciviruses. The continuous emergence of new astroviruses with a potential zoonotic transmission highlights the need to gain insights on their biology in order to prevent future health threats. This review focuses on the basic virology, pathogenesis, host response, epidemiology, diagnostic assays, and prevention strategies for HAstVs. PMID:25278582

  19. Human schistosomiasis

    PubMed Central

    Colley, Daniel G; Bustinduy, Amaya L; Secor, W Evan; King, Charles H

    2015-01-01

    Human schistosomiasis—or bilharzia—is a parasitic disease caused by trematode flukes of the genus Schistosoma. By conservative estimates, at least 230 million people worldwide are infected with Schistosoma spp. Adult schistosome worms colonise human blood vessels for years, successfully evading the immune system while excreting hundreds to thousands of eggs daily, which must either leave the body in excreta or become trapped in nearby tissues. Trapped eggs induce a distinct immune-mediated granulomatous response that causes local and systemic pathological effects ranging from anaemia, growth stunting, impaired cognition, and decreased physical fitness, to organ-specific effects such as severe hepatosplenism, periportal fibrosis with portal hypertension, and urogenital inflammation and scarring. At present, preventive public health measures in endemic regions consist of treatment once every 1 or 2 years with the isoquinolinone drug, praziquantel, to suppress morbidity. In some locations, elimination of transmission is now the goal; however, more sensitive diagnostics are needed in both the field and clinics, and integrated environmental and health-care management will be needed to ensure elimination. PMID:24698483

  20. Queuine, a tRNA anticodon wobble base, maintains the proliferative and pluripotent potential of HL-60 cells in the presence of the differentiating agent 6-thioguanine.

    PubMed Central

    French, B T; Patrick, D E; Grever, M R; Trewyn, R W

    1991-01-01

    6-Thioguanine (6-TG)-induced differentiation of hypoxanthine phosphoribosyltransferase (IMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.8)-deficient HL-60 cells is characterized by 2 days of growth, after which morphological differentiation proceeds. Addition of the tRNA wobble base queuine, in the presence of 6-TG, maintains the proliferative capability of the cells. The ability of 6-TG to induce differentiation correlates with c-myc mRNA down-regulation, but queuine has no effect on this parameter. Treatment with 6-TG for 2-3 days commits HL-60 cells to granulocytic differentiation, and, once committed, these cells do not respond to the monocytic inducer phorbol 12-myristate 13-acetate. Nonetheless, when cells are treated with queuine and 6-TG, they maintain the promyelocytic morphology and are capable of being induced down the monocytic pathway by phorbol 12-myristate 13-acetate as indicated by stabilization of c-fms mRNA and cell adherence. In the absence of queuine, phorbol 12-myristate 13-acetate is incapable of inducing monocytic markers in the 6-TG-treated cells. The data presented indicate that 6-TG-induced differentiation of HL-60 cells is a tRNA-facilitated event and that the tRNA wobble base queuine is capable of maintaining both the proliferative and pluripotent potential of the cells. Images PMID:1988936

  1. Folate deficiency-induced oxidative stress and apoptosis are mediated via homocysteine-dependent overproduction of hydrogen peroxide and enhanced activation of NF-kappaB in human Hep G2 cells.

    PubMed

    Chern, C L; Huang, R F; Chen, Y H; Cheng, J T; Liu, T Z

    2001-10-01

    Folate coenzymes are critical for de novo synthesis of purine and thymidine, and for interconversion of amino acids. Folate deficiency inhibits cellular proliferation, disturbs cell cycling, causes genetic damage and eventually results in cell death. Previously, we demonstrated that the demise of human hepatoma Hep G2 cells mediated by folate deficiency proceeded via a p53-independent apoptosis, and the perturbation of intracellular calcium homeostasis was also shown to be involved. To further delineate the mechanism associated with this observed phenomenon, Hep G2 cells were cultivated in the control or folate-deficient media (control media lacking folate, glycine, thymidine and hypoxanthine) for 4 weeks. At the end of this cultivation period, we found that TBARS (an index of lipid peroxidation) concentrations in the folate-deficient cells were drastically increased as compared to the control cells (0.04 vs 0.01 nmole/10(6) cells), indicating that a severe oxidative stress of the former cells had occurred. This phenomenon was also shown to coincide with the ability of these folate-deficient cells to elaborate increased amounts of H2O2 as compared to its folate-supplemented cells (2.87 vs 0.98 nmole/10(5) cells/h). Furthermore, the accelerated production of H2O2 by the folate-deficient cells was also closely correlated with the elevated homocysteine concentrations released in the culture medium (15.37 +/- 2.4 vs 3.58 +/- 2.4 micromole/L; P< 0.001). Finally, we demonstrated that folate deficiency was indeed capable of activating a redox-sensitive transcription factor, NF-kappaB, which is crucial in the control of a reactive oxygen species-mediated apoptosis. In summary, we show that folate deficiency-induced apoptosis is proceeded via the enhanced activation of NF-kappaB, which is the resulting form of the homocysteine-mediated overproduction of hydrogen peroxide.

  2. NATO Human View Architecture and Human Networks

    NASA Technical Reports Server (NTRS)

    Handley, Holly A. H.; Houston, Nancy P.

    2010-01-01

    The NATO Human View is a system architectural viewpoint that focuses on the human as part of a system. Its purpose is to capture the human requirements and to inform on how the human impacts the system design. The viewpoint contains seven static models that include different aspects of the human element, such as roles, tasks, constraints, training and metrics. It also includes a Human Dynamics component to perform simulations of the human system under design. One of the static models, termed Human Networks, focuses on the human-to-human communication patterns that occur as a result of ad hoc or deliberate team formation, especially teams distributed across space and time. Parameters of human teams that effect system performance can be captured in this model. Human centered aspects of networks, such as differences in operational tempo (sense of urgency), priorities (common goal), and team history (knowledge of the other team members), can be incorporated. The information captured in the Human Network static model can then be included in the Human Dynamics component so that the impact of distributed teams is represented in the simulation. As the NATO militaries transform to a more networked force, the Human View architecture is an important tool that can be used to make recommendations on the proper mix of technological innovations and human interactions.

  3. The Digital Humanities as a Humanities Project

    ERIC Educational Resources Information Center

    Svensson, Patrik

    2012-01-01

    This article argues that the digital humanities can be seen as a humanities project in a time of significant change in the academy. The background is a number of scholarly, educational and technical challenges, the multiple epistemic traditions linked to the digital humanities, the potential reach of the field across and outside the humanities,…

  4. Cytokinesis-block micronucleus assay in WIL2-NS cells: a sensitive system to detect chromosomal damage induced by reactive oxygen species and activated human neutrophils.

    PubMed

    Umegaki, K; Fenech, M

    2000-05-01

    We have developed a method that can detect the DNA-damaging and cytotoxic effects of physiological levels of reactive oxygen species (ROS) and activated human neutrophils. This was achieved using WIL2-NS cells, a human B lymphoblastoid cell line, as target cells and the cytokinesis-block micronucleus (CBMN) assay. With this method, we observed a 4- and a 30-fold increase in the frequency of micronucleated binucleated cells (MNed BNC) when cells were exposed to 10 and 30 microM hydrogen peroxide, for 1 h, respectively. A dose-dependent increase in the frequency of MNed BNC was also detected when cells were exposed to hypoxanthine (HX)/xanthine oxidase (XO), a superoxide generating system: a 50-fold increase in the frequency of MNed BNC was observed at the highest XO dose (12.5 mU/ml). In this CBMN assay, nucleoplasmic bridges (NPB) in BNC and necrotic cells were also readily detected, especially at the higher exposure doses of hydrogen peroxide or HX/XO. When WIL2-NS cells were exposed to neutrophils stimulated with phorbol 12-myristate acetate (PMA) for 1 h, the frequencies of MNed BNC in WIL2-NS cells increased in a dose-dependent manner (30-fold increase at 100 nM PMA) and with an increasing neutrophil:WIL2-NS co-culture ratio. The frequencies of MNed BNC were closely related to the production of ROS, especially hydrogen peroxide, by the neutrophils. Differentiated HL60 cells (DMSO-treated HL60) also produced ROS in response to PMA. In this case, we used a 'Transwell' system to expose WIL2-NS cells to DMSO-treated HL60 cells, because direct contact with DMSO-treated HL60 cells impaired cell division in WIL2-NS target cells. Exposure to PMA-stimulated DMSO-treated HL60 cells resulted in a PMA dose-dependent increase in the frequency of MNed BNC in WIL2-NS cells. MNed BNC frequencies were positively correlated with NPB (r = 0.61-0.93) and necrosis (r = 0.55-0.86) and negatively correlated with nuclear division index (r = -0.72 to -0. 91) in all of the above

  5. Human Rhinoviruses

    PubMed Central

    Lamson, Daryl M.; St. George, Kirsten; Walsh, Thomas J.

    2013-01-01

    Human rhinoviruses (HRVs), first discovered in the 1950s, are responsible for more than one-half of cold-like illnesses and cost billions of dollars annually in medical visits and missed days of work. Advances in molecular methods have enhanced our understanding of the genomic structure of HRV and have led to the characterization of three genetically distinct HRV groups, designated groups A, B, and C, within the genus Enterovirus and the family Picornaviridae. HRVs are traditionally associated with upper respiratory tract infection, otitis media, and sinusitis. In recent years, the increasing implementation of PCR assays for respiratory virus detection in clinical laboratories has facilitated the recognition of HRV as a lower respiratory tract pathogen, particularly in patients with asthma, infants, elderly patients, and immunocompromised hosts. Cultured isolates of HRV remain important for studies of viral characteristics and disease pathogenesis. Indeed, whether the clinical manifestations of HRV are related directly to viral pathogenicity or secondary to the host immune response is the subject of ongoing research. There are currently no approved antiviral therapies for HRVs, and treatment remains primarily supportive. This review provides a comprehensive, up-to-date assessment of the basic virology, pathogenesis, clinical epidemiology, and laboratory features of and treatment and prevention strategies for HRVs. PMID:23297263

  6. Human oestrus

    PubMed Central

    Gangestad, Steven W; Thornhill, Randy

    2008-01-01

    For several decades, scholars of human sexuality have almost uniformly assumed that women evolutionarily lost oestrus—a phase of female sexuality occurring near ovulation and distinct from other phases of the ovarian cycle in terms of female sexual motivations and attractivity. In fact, we argue, this long-standing assumption is wrong. We review evidence that women's fertile-phase sexuality differs in a variety of ways from their sexuality during infertile phases of their cycles. In particular, when fertile in their cycles, women are particularly sexually attracted to a variety of features that likely are (or, ancestrally, were) indicators of genetic quality. As women's fertile-phase sexuality shares with other vertebrate females' fertile-phase sexuality a variety of functional and physiological features, we propose that the term oestrus appropriately applies to this phase in women. We discuss the function of women's non-fertile or extended sexuality and, based on empirical findings, suggest ways that fertile-phase sexuality in women has been shaped to partly function in the context of extra-pair mating. Men are particularly attracted to some features of fertile-phase women, but probably based on by-products of physiological changes males have been selected to detect, not because women signal their cycle-based fertility status. PMID:18252670

  7. dGTP Starvation in Escherichia coli Provides New Insights into the Thymineless-Death Phenomenon

    PubMed Central

    Itsko, Mark; Schaaper, Roel M.

    2014-01-01

    Starvation of cells for the DNA building block dTTP is strikingly lethal (thymineless death, TLD), and this effect is observed in all organisms. The phenomenon, discovered some 60 years ago, is widely used to kill cells in anticancer therapies, but many questions regarding the precise underlying mechanisms have remained. Here, we show for the first time that starvation for the DNA precursor dGTP can kill E. coli cells in a manner sharing many features with TLD. dGTP starvation is accomplished by combining up-regulation of a cellular dGTPase with a deficiency of the guanine salvage enzyme guanine-(hypoxanthine)-phosphoribosyltransferase. These cells, when grown in medium without an exogenous purine source like hypoxanthine or adenine, display a specific collapse of the dGTP pool, slow-down of chromosomal replication, the generation of multi-branched nucleoids, induction of the SOS system, and cell death. We conclude that starvation for a single DNA building block is sufficient to bring about cell death. PMID:24810600

  8. Quantitative expression proteomics and phosphoproteomics profile of brain from PINK1 knockout mice: insights into mechanisms of familial Parkinson's disease.

    PubMed

    Triplett, Judy C; Zhang, Zhaoshu; Sultana, Rukhsana; Cai, Jian; Klein, Jon B; Büeler, Hansruedi; Butterfield, David Allan

    2015-06-01

    Parkinson's disease (PD) is an age-related, neurodegenerative motor disorder characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta and presence of α-synuclein-containing protein aggregates. Mutations in the mitochondrial Ser/Thr kinase PTEN-induced kinase 1 (PINK1) are associated with an autosomal recessive familial form of early-onset PD. Recent studies have suggested that PINK1 plays important neuroprotective roles against mitochondrial dysfunction by phosphorylating and recruiting Parkin, a cytosolic E3 ubiquitin ligase, to facilitate elimination of damaged mitochondria via autophagy-lysosomal pathways. Loss of PINK1 in cells and animals leads to various mitochondrial impairments and oxidative stress, culminating in dopaminergic neuronal death in humans. Using a 2-D polyacrylamide gel electrophoresis proteomics approach, the differences in expressed brain proteome and phosphoproteome between 6-month-old PINK1-deficient mice and wild-type mice were identified. The observed changes in the brain proteome and phosphoproteome of mice lacking PINK1 suggest that defects in signaling networks, energy metabolism, cellular proteostasis, and neuronal structure and plasticity are involved in the pathogenesis of familial PD. Mutations in PINK1 are associated with an early-onset form of Parkinson's disease (PD). This study examines changes in the proteome and phosphoproteome of the PINK1 knockout mouse brain. Alterations were noted in several key proteins associated with: increased oxidative stress, aberrant cellular signaling, altered neuronal structure, decreased synaptic plasticity, reduced neurotransmission, diminished proteostasis networks, and altered metabolism. 14-3-3ε, 14-3-3 protein epsilon; 3-PGDH, phosphoglycerate dehydrogenase; ALDOA, aldolase A; APT1, acyl-protein thioesterase 1; CaM, calmodulin; CBR3, carbonyl reductase [NADPH] 3; ENO2, gamma-enolase; HPRT, hypoxanthine-guanine phosphoribosyltransferase; HSP70

  9. Biological effectiveness of nuclear fragments produced by high-energy protons interacting in tissues near the bone- soft tissue interface

    NASA Astrophysics Data System (ADS)

    Shavers, Mark Randall

    1999-12-01

    High-energy protons in the galactic cosmic rays (GCR)-or generated by nuclear interactions of GCR heavy-ions with material-are capable of penetrating great thicknesses of shielding to irradiate humans in spacecraft or in lunar or Martian habitats. As protons interact with the nuclei of the elemental constituents of soft tissue and bone, low energy nuclei-target fragments-are emitted into the cells responsible for bone development and maintenance and for hematopoiesis. Leukemogenesis is the principal endpoint of concern because it is the most likely deleterious effect, and it has a short latency period and comparatively low survival rate, although other myelo- proliferative disorders and osteosarcoma also may be induced. A one-dimensional proton-target fragment transport model was used to calculate the energy spectra of fragments produced in bone and soft tissue, and present in marrow cavities at distances from a bone interface. In terms of dose equivalent, the target fragments are as significant as the incident protons. An average radiation quality factor was found to be between 1.8 and 2.6. Biological response to the highly non- uniform energy deposition of the target fragments is such that an alternative approach to conventional predictive risk assessment is needed. Alternative procedures are presented. In vitro cell response and relative biological effectiveness were calculated from the radial dose distribution of each fragment produced by 1-GeV protons using parameters of a modified Ion-Gamma- Kill (IGK) model of radiation action. The modelled endpoints were survival of C3H10t 1/2 and V79 cells, neoplastic transformation of C3H10t1/2 cells, and mutation of the X-linked hypoxanthine phosphoribosyltransferase (HPRT) locus in V79 cells. The dose equivalent and cell responses increased by 10% or less near the interface. Since RBE increases with decreasing dose in the IGK model, comparisons with quality factors were made at dose levels 0.01 <= D [Gy] <= 2. Applying

  10. Human Factors in Human-Systems Integration

    NASA Technical Reports Server (NTRS)

    Fitts, David J.; Sandor, Aniko; Litaker, Harry L., Jr.; Tillman, Barry

    2008-01-01

    Any large organization whose mission is to design and develop systems for humans, and train humans needs a well-developed integration and process plan to deal with the challenges that arise from managing multiple subsystems. Human capabilities, skills, and needs must be considered early in the design and development process, and must be continuously considered throughout the development lifecycle. This integration of human needs within system design is typically formalized through a Human-Systems Integration (HSI) program. By having an HSI program, an institution or organization can reduce lifecycle costs and increase the efficiency, usability, and quality of its products because human needs have been considered from the beginning.

  11. Humane Education: An Overview.

    ERIC Educational Resources Information Center

    Whitlock, Eileen S.; Westerlund, Stuart R.

    This booklet traces the historical development of human education as it has been instilled into the young people of America from colonial times to the present and provides a future prognosis of humaneness in the schools. Humane education promotes humane behavior and is an important part of the humane movement in the United States, although until…

  12. Human Research Risk Management

    NASA Video Gallery

    Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and per...

  13. Investigation of vital pathogenic target orotate phosphoribosyltransferases (OPRTase) from Thermus thermophilus HB8: Phylogenetic and molecular modeling approach.

    PubMed

    Surekha, Kanagarajan; Prabhu, Damodharan; Richard, Mariadasse; Nachiappan, Mutharasappan; Biswal, Jayashree; Jeyakanthan, Jeyaraman

    2016-06-01

    Biosynthesis pathways of pyrimidine and purine are shown to play an important role in regular cellular activities. The biosynthesis can occur either through de novo or salvage pathways based on the requirement of the cell. The pyrimidine biosynthesis pathway has been linked to several disorders and various autoimmune diseases. Orotate phosphoribosyl transferase (OPRTase) is an important enzyme which catalyzes the conversion of orotate to orotate monophosphate in the fifth step of pyrimidine biosynthesis. Phylogenetic analysis of 228 OPRTase sequences shows the distribution of proteins across different living forms of life. High structural similarities between Thermusthermophilus and other organisms kindled us to concentrate on OPRTase as an anti-pathogenic target. In this study, a homology model of OPRTase was constructed using 2P1Z as a template. About 100 ns molecular dynamics simulation was performed to investigate the conformational stability and dynamic patterns of the protein. The amino acid residues (Met1, Asp2, Glu43, Ala44, Glu47, Lys51, Ala157 and Leu158) lining in the binding site were predicted using SiteMap. Further, structure based virtual screening was performed on the predicted binding site using ChemBridge, Asinex, Binding, NCI, TosLab and Zinc databases. Compounds retrieved from the screening collections were manually clustered. The resultant protein-ligand complexes were subjected to molecular dynamics simulations, which further validates the binding modes of the hits. The study may provide better insight for designing potent anti-pathogenic agent. PMID:26861612

  14. Human-machine interactions

    DOEpatents

    Forsythe, J. Chris; Xavier, Patrick G.; Abbott, Robert G.; Brannon, Nathan G.; Bernard, Michael L.; Speed, Ann E.

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  15. Engineered human vaccines

    SciTech Connect

    Sandhu, J.S. . Div. of Immunology and Neurobiology)

    1994-01-01

    The limitations of human vaccines in use at present and the design requirements for a new generation of human vaccines are discussed. The progress in engineering of human vaccines for bacteria, viruses, parasites, and cancer is reviewed, and the data from human studies with the engineered vaccines are discussed, especially for cancer and AIDS vaccines. The final section of the review deals with the possible future developments in the field of engineered human vaccines and the requirement for effective new human adjuvants.

  16. Visualizing Humans by Computer.

    ERIC Educational Resources Information Center

    Magnenat-Thalmann, Nadia

    1992-01-01

    Presents an overview of the problems and techniques involved in visualizing humans in a three-dimensional scene. Topics discussed include human shape modeling, including shape creation and deformation; human motion control, including facial animation and interaction with synthetic actors; and human rendering and clothing, including textures and…

  17. Special Section: Human Rights

    ERIC Educational Resources Information Center

    Frydenlund, Knut; And Others

    1978-01-01

    Eleven articles examine human rights in Europe. Topics include unemployment, human rights legislation, role of the Council of Europe in promoting human rights, labor unions, migrant workers, human dignity in industralized societies, and international violence. Journal available from Council of Europe, Directorate of Press and Information, 67006…

  18. Human Research Program Opportunities

    NASA Technical Reports Server (NTRS)

    Kundrot, Craig E.

    2014-01-01

    The goal of HRP is to provide human health and performance countermeasures, knowledge, technologies, and tools to enable safe, reliable, and productive human space exploration. The Human Research Program was designed to meet the needs of human space exploration, and understand and reduce the risk to crew health and performance in exploration missions.

  19. The Humanities: Interconnections.

    ERIC Educational Resources Information Center

    Salomone, Ronald E., Ed.

    1985-01-01

    Focusing on a wide range of interdisciplinary themes and ideas for humanities instruction, the 17 articles in this journal issue discuss the following topics: (1) literature, humanities, and the adult learner; (2) the role of the humanities in educating for a democracy; (3) humanities in the marketplace; (4) literature versus "great books" in high…

  20. ISS Payload Human Factors

    NASA Technical Reports Server (NTRS)

    Ellenberger, Richard; Duvall, Laura; Dory, Jonathan

    2016-01-01

    The ISS Payload Human Factors Implementation Team (HFIT) is the Payload Developer's resource for Human Factors. HFIT is the interface between Payload Developers and ISS Payload Human Factors requirements in SSP 57000. ? HFIT provides recommendations on how to meet the Human Factors requirements and guidelines early in the design process. HFIT coordinates with the Payload Developer and Astronaut Office to find low cost solutions to Human Factors challenges for hardware operability issues.

  1. Economics of human trafficking.

    PubMed

    Wheaton, Elizabeth M; Schauer, Edward J; Galli, Thomas V

    2010-01-01

    Because freedom of choice and economic gain are at the heart of productivity, human trafficking impedes national and international economic growth. Within the next 10 years, crime experts expect human trafficking to surpass drug and arms trafficking in its incidence, cost to human well-being, and profitability to criminals (Schauer and Wheaton, 2006: 164-165). The loss of agency from human trafficking as well as from modern slavery is the result of human vulnerability (Bales, 2000: 15). As people become vulnerable to exploitation and businesses continually seek the lowest-cost labour sources, trafficking human beings generates profit and a market for human trafficking is created. This paper presents an economic model of human trafficking that encompasses all known economic factors that affect human trafficking both across and within national borders. We envision human trafficking as a monopolistically competitive industry in which traffickers act as intermediaries between vulnerable individuals and employers by supplying differentiated products to employers. In the human trafficking market, the consumers are employers of trafficked labour and the products are human beings. Using a rational-choice framework of human trafficking we explain the social situations that shape relocation and working decisions of vulnerable populations leading to human trafficking, the impetus for being a trafficker, and the decisions by employers of trafficked individuals. The goal of this paper is to provide a common ground upon which policymakers and researchers can collaborate to decrease the incidence of trafficking in humans.

  2. Economics of human trafficking.

    PubMed

    Wheaton, Elizabeth M; Schauer, Edward J; Galli, Thomas V

    2010-01-01

    Because freedom of choice and economic gain are at the heart of productivity, human trafficking impedes national and international economic growth. Within the next 10 years, crime experts expect human trafficking to surpass drug and arms trafficking in its incidence, cost to human well-being, and profitability to criminals (Schauer and Wheaton, 2006: 164-165). The loss of agency from human trafficking as well as from modern slavery is the result of human vulnerability (Bales, 2000: 15). As people become vulnerable to exploitation and businesses continually seek the lowest-cost labour sources, trafficking human beings generates profit and a market for human trafficking is created. This paper presents an economic model of human trafficking that encompasses all known economic factors that affect human trafficking both across and within national borders. We envision human trafficking as a monopolistically competitive industry in which traffickers act as intermediaries between vulnerable individuals and employers by supplying differentiated products to employers. In the human trafficking market, the consumers are employers of trafficked labour and the products are human beings. Using a rational-choice framework of human trafficking we explain the social situations that shape relocation and working decisions of vulnerable populations leading to human trafficking, the impetus for being a trafficker, and the decisions by employers of trafficked individuals. The goal of this paper is to provide a common ground upon which policymakers and researchers can collaborate to decrease the incidence of trafficking in humans. PMID:20645472

  3. Mice with human livers.

    PubMed

    Grompe, Markus; Strom, Stephen

    2013-12-01

    Animal models are used to study many aspects of human disease and to test therapeutic interventions. However, some very important features of human biology cannot be replicated in animals, even in nonhuman primates or transgenic rodents engineered with human genes. Most human microbial pathogens do not infect animals and the metabolism of many xenobiotics is different between human beings and animals. The advent of transgenic immune-deficient mice has made it possible to generate chimeric animals harboring human tissues and cells, including hepatocytes. The liver plays a central role in many human-specific biological processes and mice with humanized livers can be used to model human metabolism, liver injury, gene regulation, drug toxicity, and hepatotropic infections.

  4. Virtual Human Project

    SciTech Connect

    Ward, RD

    2001-06-12

    This paper describes the development of a comprehensive human modeling environment, the Virtual Human, which will be used initially to model the human respiratory system for purposes of predicting pulmonary disease or injury using lung sounds. The details of the computational environment, including the development of a Virtual Human Thorax, a database for storing models, model parameters, and experimental data, and a Virtual Human web interface are outlined. Preliminary progress in developing this environment will be presented. A separate paper at the conference describes the modeling of sound generation using computational fluid dynamics and the modeling of sound propagation in the human respiratory system.

  5. Mining human antibody repertoires

    PubMed Central

    2010-01-01

    Human monoclonal antibodies (mAbs) have become drugs of choice for the management of an increasing number of human diseases. Human antibody repertoires provide a rich source for human mAbs. Here we review the characteristics of natural and non-natural human antibody repertoires and their mining with non-combinatorial and combinatorial strategies. In particular, we discuss the selection of human mAbs from naïve, immune, transgenic and synthetic human antibody repertoires using methods based on hybridoma technology, clonal expansion of peripheral B cells, single-cell PCR, phage display, yeast display and mammalian cell display. Our reliance on different strategies is shifting as we gain experience and refine methods to the efficient generation of human mAbs with superior pharmacokinetic and pharmacodynamic properties. PMID:20505349

  6. Pathfinder: Humans in space

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1988-01-01

    Viewgraphs are presented on the Pathfinder program. Information is given on human exploration of the solar system, technical requirements interfaces, program objectives, space suits, human performance, man-machine systems, space habitats, life support systems, and artificial gravity

  7. Human bites (image)

    MedlinePlus

    Human bites present a high risk of infection. Besides the bacteria which can cause infection, there is ... the wound extends below the skin. Anytime a human bite has broken the skin, seek medical attention.

  8. Telling the Human Story.

    ERIC Educational Resources Information Center

    Richardson, Miles

    1987-01-01

    Proposes that one of the fundamental human attributes is telling stories. Explores the debate on whether Neanderthals possessed language ability. Discusses the role of the "human story" in teaching anthropology. (DH)

  9. Human assisted robotic exploration

    NASA Astrophysics Data System (ADS)

    Files, B. T.; Canady, J.; Warnell, G.; Stump, E.; Nothwang, W. D.; Marathe, A. R.

    2016-05-01

    In support of achieving better performance on autonomous mapping and exploration tasks by incorporating human input, we seek here to first characterize humans' ability to recognize locations from limited visual information. Such a characterization is critical to the design of a human-in-the-loop system faced with deciding whether and when human input is useful. In this work, we develop a novel and practical place-recognition task that presents humans with video clips captured by a navigating ground robot. Using this task, we find experimentally that human performance does not seem to depend on factors such as clip length or familiarity with the scene and also that there is significant variability across subjects. Moreover, we find that humans significantly outperform a state-of-the-art computational solution to this problem, suggesting the utility of incorporating human input in autonomous mapping and exploration techniques.

  10. Human productivity program definition

    NASA Technical Reports Server (NTRS)

    Cramer, D. B.

    1985-01-01

    The optimization of human productivity on the space station within the existing resources and operational constraints is the aim of the Human Productivity Program. The conceptual objectives of the program are as follows: (1) to identify long lead technology; (2) to identify responsibility for work elements; (3) to coordinate the development of crew facilities and activities; and (4) to lay the foundation for a cost effective approach to improving human productivity. Human productivity work elements are also described and examples are presented.

  11. Some Criteria for Humanizing.

    ERIC Educational Resources Information Center

    Read, Charlotte S.

    Patterns for humanizing the information sciences include recognizing essential "humanness," taking a holistic approach to the subject field, and being aware of the epistemological nature of how people communicate and relate to others and themselves. The complete inclusion of the human factor in information theory researches can only amplify the…

  12. A Human Rights Glossary.

    ERIC Educational Resources Information Center

    Flowers, Nancy

    1998-01-01

    Presents a human rights glossary that includes definitions of basic terms, treaties, charters, and groups/organizations that have been featured in previous articles in this edition of "Update on Law-Related Education"; the human rights terms have been compiled as part of the celebration of the Universal Declaration of Human Rights (UDHR). (CMK)

  13. Human Resource Development.

    ERIC Educational Resources Information Center

    Mensel, R. Frank

    The contradictions of campus management are examined in this speech and applied to the problems of human resource development. The author suggests that human resource development cannot be considered fully without taking into account the state of the institution and institutional development. Since human resources represents 75 percent or more of…

  14. Demystifying the Humanities.

    ERIC Educational Resources Information Center

    Bonham, George

    1980-01-01

    The new Rockefeller Foundation's Commission on the Humanities' report is discussed. Some of the commission's recommendations include: improved quality of elementary and secondary schools, strengthening of humanities research, reaffirmation within education of the values of the humanities, and closer collaboration of educational and cultural…

  15. Visible Human Project

    MedlinePlus

    ... Mobile Gallery Site Navigation Home The Visible Human Project ® Overview The Visible Human Project ® is an outgrowth of the NLM's 1986 Long- ... The long-term goal of the Visible Human Project ® is to produce a system of knowledge structures ...

  16. Whose Human Rights?

    ERIC Educational Resources Information Center

    Rendel, Margherita

    During the last 50 years, principles, institutions, and policies of human rights have been developed worldwide. This book brings together European and international conventions on human rights, the rights of women, and the users and uses of education, and places them in their wider context. It examines issues in how human rights work, the ways in…

  17. Human nature and enhancement.

    PubMed

    Buchanan, Allen

    2009-03-01

    Appeals to the idea of human nature are frequent in the voluminous literature on the ethics of enhancing human beings through biotechnology. Two chief concerns about the impact of enhancements on human nature have been voiced. The first is that enhancement may alter or destroy human nature. The second is that if enhancement alters or destroys human nature, this will undercut our ability to ascertain the good because, for us, the good is determined by our nature. The first concern assumes that altering or destroying human nature is in itself a bad thing. The second concern assumes that human nature provides a standard without which we cannot make coherent, defensible judgments about what is good. I will argue (1) that there is nothing wrong, per se, with altering or destroying human nature, because, on a plausible understanding of what human nature is, it contains bad as well as good characteristics and there is no reason to believe that eliminating some of the bad would so imperil the good as to make the elimination of the bad impermissible, and (2) that altering or destroying human nature need not result in the loss of our ability to make judgments about the good, because we possess a conception of the good by which we can and do evaluate human nature. I will argue that appeals to human nature tend to obscure rather than illuminate the debate over the ethics of enhancement and can be eliminated in favor of more cogent considerations.

  18. Production Of Human Antibodies

    NASA Technical Reports Server (NTRS)

    Sammons, David W.; Neil, Garry A.

    1993-01-01

    Process for making human monoclonal antibodies based on combination of techniques. Antibodies made active against specific antigen. Process involves in vivo immunization of human B lymphocyte cells in mice. B cells of interest enriched in vitro before fusion. Method potentially applicable to any antigen. Does not rely on use of Epstein-Barr virus at any step. Human lymphocytes taken from any source.

  19. Has Human Evolution Stopped?

    PubMed Central

    Templeton, Alan R.

    2010-01-01

    It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences. PMID:23908778

  20. Financing Human Capital.

    ERIC Educational Resources Information Center

    Juffras, Jason; Sawhill, Isabel V.

    This paper examines the government's role in financing human capital investments. It first examines why private investments in education, training, and other forms of human capital are likely to fall short of socially desirable levels. It then reviews past trends in public support for human resource investments. Finally, it discusses current…

  1. Human Mitochondrial Protein Database

    National Institute of Standards and Technology Data Gateway

    SRD 131 Human Mitochondrial Protein Database (Web, free access)   The Human Mitochondrial Protein Database (HMPDb) provides comprehensive data on mitochondrial and human nuclear encoded proteins involved in mitochondrial biogenesis and function. This database consolidates information from SwissProt, LocusLink, Protein Data Bank (PDB), GenBank, Genome Database (GDB), Online Mendelian Inheritance in Man (OMIM), Human Mitochondrial Genome Database (mtDB), MITOMAP, Neuromuscular Disease Center and Human 2-D PAGE Databases. This database is intended as a tool not only to aid in studying the mitochondrion but in studying the associated diseases.

  2. Human-technology Integration

    NASA Astrophysics Data System (ADS)

    Mullen, Katharine M.

    Human-technology integration is the replacement of human parts and extension of human capabilities with engineered devices and substrates. Its result is hybrid biological-artificial systems. We discuss here four categories of products furthering human-technology integration: wearable computers, pervasive computing environments, engineered tissues and organs, and prosthetics, and introduce examples of currently realized systems in each category. We then note that realization of a completely artificial sytem via the path of human-technology integration presents the prospect of empirical confirmation of an aware artificially embodied system.

  3. Biological Races in Humans

    PubMed Central

    Templeton, Alan R.

    2013-01-01

    Races may exist in humans in a cultural sense, but biological concepts of race are needed to access their reality in a non-species-specific manner and to see if cultural categories correspond to biological categories within humans. Modern biological concepts of race can be implemented objectively with molecular genetic data through hypothesis-testing. Genetic data sets are used to see if biological races exist in humans and in our closest evolutionary relative, the chimpanzee. Using the two most commonly used biological concepts of race, chimpanzees are indeed subdivided into races but humans are not. Adaptive traits, such as skin color, have frequently been used to define races in humans, but such adaptive traits reflect the underlying environmental factor to which they are adaptive and not overall genetic differentiation, and different adaptive traits define discordant groups. There are no objective criteria for choosing one adaptive trait over another to define race. As a consequence, adaptive traits do not define races in humans. Much of the recent scientific literature on human evolution portrays human populations as separate branches on an evolutionary tree. A tree-like structure among humans has been falsified whenever tested, so this practice is scientifically indefensible. It is also socially irresponsible as these pictorial representations of human evolution have more impact on the general public than nuanced phrases in the text of a scientific paper. Humans have much genetic diversity, but the vast majority of this diversity reflects individual uniqueness and not race. PMID:23684745

  4. Mapping human genetic ancestry.

    PubMed

    Ebersberger, Ingo; Galgoczy, Petra; Taudien, Stefan; Taenzer, Simone; Platzer, Matthias; von Haeseler, Arndt

    2007-10-01

    The human genome is a mosaic with respect to its evolutionary history. Based on a phylogenetic analysis of 23,210 DNA sequence alignments from human, chimpanzee, gorilla, orangutan, and rhesus, we present a map of human genetic ancestry. For about 23% of our genome, we share no immediate genetic ancestry with our closest living relative, the chimpanzee. This encompasses genes and exons to the same extent as intergenic regions. We conclude that about 1/3 of our genes started to evolve as human-specific lineages before the differentiation of human, chimps, and gorillas took place. This explains recurrent findings of very old human-specific morphological traits in the fossils record, which predate the recent emergence of the human species about 5-6 MYA. Furthermore, the sorting of such ancestral phenotypic polymorphisms in subsequent speciation events provides a parsimonious explanation why evolutionary derived characteristics are shared among species that are not each other's closest relatives.

  5. Human rights and bioethics.

    PubMed

    Barilan, Y M; Brusa, M

    2008-05-01

    In the first part of this article we survey the concept of human rights from a philosophical perspective and especially in relation to the "right to healthcare". It is argued that regardless of meta-ethical debates on the nature of rights, the ethos and language of moral deliberation associated with human rights is indispensable to any ethics that places the victim and the sufferer in its centre. In the second part we discuss the rise of the "right to privacy", particularly in the USA, as an attempt to make the element of personal free will dominate over the element of basic human interest within the structure of rights and when different rights seem to conflict. We conclude by discussing the relationship of human rights with moral values beyond the realm of rights, mainly human dignity, free will, human rationality and response to basic human needs.

  6. Office for Human Research Protections

    MedlinePlus

    ... Office for Human Research Protections The Office for Human Research Protections (OHRP) provides leadership in the protection of the rights, welfare, and wellbeing of human subjects involved in ...

  7. Human research subjects as human research workers.

    PubMed

    Lynch, Holly Fernandez

    2014-01-01

    Biomedical research involving human subjects has traditionally been treated as a unique endeavor, presenting special risks and demanding special protections. But in several ways, the regulatory scheme governing human subjects research is counter-intuitively less protective than the labor and employment laws applicable to many workers. This Article relies on analogical and legal reasoning to demonstrate that this should not be the case; in a number of ways, human research subjects ought to be fundamentally recast as human research workers. Like other workers protected under worklaw, biomedical research subjects often have interests that diverge from those in positions of control but little bargaining power for change. Bearing these important similarities in mind, the question becomes whether there is any good reason to treat subjects and protected workers differently as a matter of law. With regard to unrestricted payment, eligibility for a minimum wage, compensation for injury, and rights to engage in concerted activity, the answer is no and human subjects regulations ought to be revised accordingly. PMID:25051653

  8. Integrated Environmental Modelling: human decisions, human challenges

    USGS Publications Warehouse

    Glynn, Pierre D.

    2015-01-01

    Integrated Environmental Modelling (IEM) is an invaluable tool for understanding the complex, dynamic ecosystems that house our natural resources and control our environments. Human behaviour affects the ways in which the science of IEM is assembled and used for meaningful societal applications. In particular, human biases and heuristics reflect adaptation and experiential learning to issues with frequent, sharply distinguished, feedbacks. Unfortunately, human behaviour is not adapted to the more diffusely experienced problems that IEM typically seeks to address. Twelve biases are identified that affect IEM (and science in general). These biases are supported by personal observations and by the findings of behavioural scientists. A process for critical analysis is proposed that addresses some human challenges of IEM and solicits explicit description of (1) represented processes and information, (2) unrepresented processes and information, and (3) accounting for, and cognizance of, potential human biases. Several other suggestions are also made that generally complement maintaining attitudes of watchful humility, open-mindedness, honesty and transparent accountability. These suggestions include (1) creating a new area of study in the behavioural biogeosciences, (2) using structured processes for engaging the modelling and stakeholder communities in IEM, and (3) using ‘red teams’ to increase resilience of IEM constructs and use.

  9. Human organ markets and inherent human dignity.

    PubMed

    MacKellar, Calum

    2014-01-01

    It has been suggested that human organs should be bought and sold on a regulated market as any other material property belongingto an individual. This would have the advantage of both addressing the grave shortage of organs available for transplantation and respecting the freedom of individuals to choose to do whatever they want with their body parts. The old arguments against such a market in human organs are, therefore, being brought back into question. The article examines the different arguments both in favour and against the sale of human organs. It concludes that the body and any of its elements is a full expression of the whole person. As such, they cannot have a price if the individual is to retain his or her full inherent dignity and if society is to retain and protect this very important concept.

  10. [The embryo, the human and the humanized].

    PubMed

    Roa, A

    1992-03-01

    Since the moment of fecundation the human embryo is endowed with the properties of unity and uniqueness and its existence is therefore inviolable. Disputing arguments against this thesis are analyzed. Recent views of some biologists negate the human character to the embryo since the essence of a human being would be its cultural nature and ability to communicate. However, the embryo contains all the genetic information that will allow him to develop the ability to communicate. Any attempt to separate the 3 moments of time, past present and future is a definitive violation of ethics. A basic foundation of ethics is that present and future are implicit in the past and vice-versa. Finally, the idea that the unwanted child is not a cultural being should be discarded.

  11. Human organ markets and inherent human dignity.

    PubMed

    MacKellar, Calum

    2014-01-01

    It has been suggested that human organs should be bought and sold on a regulated market as any other material property belongingto an individual. This would have the advantage of both addressing the grave shortage of organs available for transplantation and respecting the freedom of individuals to choose to do whatever they want with their body parts. The old arguments against such a market in human organs are, therefore, being brought back into question. The article examines the different arguments both in favour and against the sale of human organs. It concludes that the body and any of its elements is a full expression of the whole person. As such, they cannot have a price if the individual is to retain his or her full inherent dignity and if society is to retain and protect this very important concept. PMID:24979876

  12. Human Performance in Space

    NASA Technical Reports Server (NTRS)

    Jones, Patricia M.; Fiedler, Edna

    2010-01-01

    Human factors is a critical discipline for human spaceflight. Nearly every human factors research area is relevant to space exploration -- from the ergonomics of hand tools used by astronauts, to the displays and controls of a spacecraft cockpit or mission control workstation, to levels of automation designed into rovers on Mars, to organizational issues of communication between crew and ground. This chapter focuses more on the ways in which the space environment (especially altered gravity and the isolated and confined nature of long-duration spaceflight) affects crew performance, and thus has specific novel implications for human factors research and practice. We focus on four aspects of human performance: neurovestibular integration, motor control and musculo-skeletal effects, cognitive effects, and behavioral health. We also provide a sampler of recent human factors studies from NASA.

  13. Chimeras and human dignity.

    PubMed

    de Melo-Martín, Inmaculada

    2008-12-01

    Discussions about whether new biomedical technologies threaten or violate human dignity are now common. Indeed, appeals to human dignity have played a central role in national and international debates about whether to allow particular kinds of biomedical investigations. The focus of this paper is on chimera research. I argue here that both those who claim that particular types of human-nonhuman chimera research threaten human dignity and those who argue that such threat does not exist fail to make their case. I first introduce some of the arguments that have been offered supporting the claim that the creation of certain sorts of chimeras threatens or violates human dignity. I next present opponents' assessments of such arguments. Finally I critically analyze both the critics' and the supporters' claims about whether chimera research threatens human dignity.

  14. [Humanization and nursing work].

    PubMed

    Collet, Neusa; Rozendo, Célia Alves

    2003-01-01

    In this work we have as our objective to reflect on the theme of the 63rd. Annual Nursing Week "Humanization and Work: reason and meaning in Nursing". We discuss the relationship between humanization/work in nursing, differentiating the aspects related to the humanization of nursing work to those of the humanized work in nursing. The challenges of the process of humanization of assistance and of work relationships imply on the overcoming of the relevance given to the technical scientific competence, routine patterns which are crystallized, conventional models of management, corporativism of the different professional categories in favor of interdependence and the complementarity in health actions; construction of an utopia of the humanization as collective process which can be reached and implemented.

  15. Human reliability analysis

    SciTech Connect

    Dougherty, E.M.; Fragola, J.R.

    1988-01-01

    The authors present a treatment of human reliability analysis incorporating an introduction to probabilistic risk assessment for nuclear power generating stations. They treat the subject according to the framework established for general systems theory. Draws upon reliability analysis, psychology, human factors engineering, and statistics, integrating elements of these fields within a systems framework. Provides a history of human reliability analysis, and includes examples of the application of the systems approach.

  16. Robotics for Human Exploration

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Deans, Mathew; Bualat, Maria

    2013-01-01

    Robots can do a variety of work to increase the productivity of human explorers. Robots can perform tasks that are tedious, highly repetitive or long-duration. Robots can perform precursor tasks, such as reconnaissance, which help prepare for future human activity. Robots can work in support of astronauts, assisting or performing tasks in parallel. Robots can also perform "follow-up" work, completing tasks designated or started by humans. In this paper, we summarize the development and testing of robots designed to improve future human exploration of space.

  17. Human cloning 2001.

    PubMed

    Healy, David L; Weston, Gareth; Pera, Martin F; Rombauts, Luk; Trounson, Alan O

    2002-05-01

    This review summaries human cloning from a clinical perspective. Natural human clones, that is, monozygotic twins, are increasing in the general community. Iatrogenic human clones have been produced for decades in infertile couples given fertility treatment such as ovulation induction. A clear distinction must be made between therapeutic cloning using embryonic stem cells and reproductive cloning attempts. Unlike the early clinical years of in vitro fertilization, with cloning there is no animal model that is safe and dependable. Until there is such a model, 'Dolly'-style human cloning is medically unacceptable.

  18. Artificial human vision camera

    NASA Astrophysics Data System (ADS)

    Goudou, J.-F.; Maggio, S.; Fagno, M.

    2014-10-01

    In this paper we present a real-time vision system modeling the human vision system. Our purpose is to inspire from human vision bio-mechanics to improve robotic capabilities for tasks such as objects detection and tracking. This work describes first the bio-mechanical discrepancies between human vision and classic cameras and the retinal processing stage that takes place in the eye, before the optic nerve. The second part describes our implementation of these principles on a 3-camera optical, mechanical and software model of the human eyes and associated bio-inspired attention model.

  19. Developing Human Resources through Actualizing Human Potential

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    2012-01-01

    The key to human resource development is in actualizing individual and collective thinking, feeling and choosing potentials related to our minds, hearts and wills respectively. These capacities and faculties must be balanced and regulated according to the standards of truth, love and justice for individual, community and institutional development,…

  20. Interactions of human cytomegalovirus with human fibroblasts.

    PubMed

    Vonka, V; Benyesh-Melnick, M

    1966-01-01

    Vonka, Vladimir (Baylor University College of Medicine, Houston, Tex.), and Matilda Benyesh-Melnick. Interactions of human cytomegalovirus with human fibroblasts. J. Bacteriol. 91:213-220. 1966.-Virus attachment of human cytomegalovirus to human embryo lung fibroblasts was found to be temperature-independent, from 4 to 37 C. Prolonged incubation at 4 C, however, resulted in inactivation of a high proportion of attached virus. Virus penetration seemed to be temperature-dependent, occurring at 37 C but not at 4 C. Detailed studies of the growth curve of the virus were made. Cell-associated virus preceded the appearance of virus in the fluid phase by 2 to 5 days. Complement-fixing antigen could be detected, but only when the cytopathic effect was advanced, and it was demonstrable only in the cell-associated fraction. Under methyl cellulose, decreasing the bicarbonate concentration in the overlay from 0.225 to 0.15% resulted in marked increase in plating efficiency with all strains tested. However, varying the concentration of bicarbonate from 0.3 to 0.15% in fluid medium did not influence the growth of virus.

  1. Human Pythiosis, Brazil

    PubMed Central

    Bosco, Sandra de Moraes Gimenes; Araújo, João Pessoa; Candeias, João Manuel Grisi; Fabiano de Franco, Marcello; Marques, Mariangela Esther Alencar; Mendoza, Leonel; Pires de Camargo, Rosangela; Marques, Silvio Alencar

    2005-01-01

    Pythiosis, caused by Pythium insidiosum, occurs in humans and animals and is acquired from aquatic environments that harbor the emerging pathogen. Diagnosis is difficult because clinical and histopathologic features are not pathognomonic. We report the first human case of pythiosis from Brazil, diagnosed by using culture and rDNA sequencing. PMID:15890126

  2. Assessment of Human Factors

    NASA Technical Reports Server (NTRS)

    Mount, Frances; Foley, Tico

    1999-01-01

    Human Factors Engineering, often referred to as Ergonomics, is a science that applies a detailed understanding of human characteristics, capabilities, and limitations to the design, evaluation, and operation of environments, tools, and systems for work and daily living. Human Factors is the investigation, design, and evaluation of equipment, techniques, procedures, facilities, and human interfaces, and encompasses all aspects of human activity from manual labor to mental processing and leisure time enjoyments. In spaceflight applications, human factors engineering seeks to: (1) ensure that a task can be accomplished, (2) maintain productivity during spaceflight, and (3) ensure the habitability of the pressurized living areas. DSO 904 served as a vehicle for the verification and elucidation of human factors principles and tools in the microgravity environment. Over six flights, twelve topics were investigated. This study documented the strengths and limitations of human operators in a complex, multifaceted, and unique environment. By focusing on the man-machine interface in space flight activities, it was determined which designs allow astronauts to be optimally productive during valuable and costly space flights. Among the most promising areas of inquiry were procedures, tools, habitat, environmental conditions, tasking, work load, flexibility, and individual control over work.

  3. HUMAN HEALTH RESEARCH STRATEGY

    EPA Science Inventory

    The mission of the U.S. Environmental Protection Agency (EPA) is to protect public health and safeguard the environment. Risk assessment is an integral part of this mission in that it identifies and characterizes environmentally related human health problems. The Human Health Re...

  4. HSI in Human Spaceflight

    NASA Technical Reports Server (NTRS)

    Baggerman, Susan D.

    2007-01-01

    This viewgraph document examines the scope of Human Systems Integration (HSI) at NASA, and the implementation of HSI in the human space flight programs. Two areas of interest are the Responsibilities and the lessons learned from the International Space Station and the strategy and approach for the Crew Exploration Vehicle.

  5. Being Human in Sport.

    ERIC Educational Resources Information Center

    Allen, Dorothy J.; Fahey, Brian W.

    The structure of humanness as the unique and essential being of the individual, constantly emerging through experience and the actualization of human potential within the sports environment, is the central theme of this book. Sport is defined broadly to include all forms of physical activity experiences. Each chapter represents an inquiry unique…

  6. Quantifying Human Performance Reliability.

    ERIC Educational Resources Information Center

    Askren, William B.; Regulinski, Thaddeus L.

    Human performance reliability for tasks in the time-space continuous domain is defined and a general mathematical model presented. The human performance measurement terms time-to-error and time-to-error-correction are defined. The model and measurement terms are tested using laboratory vigilance and manual control tasks. Error and error-correction…

  7. Human Powered Centrifuge

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald M. (Inventor); Vernikos, Joan (Inventor)

    1997-01-01

    A human powered centrifuge has independently established turntable angular velocity and human power input. A control system allows excess input power to be stored as electric energy in a battery or dissipated as heat through a resistors. In a mechanical embodiment, the excess power is dissipated in a friction brake.

  8. Human Mind Maps

    ERIC Educational Resources Information Center

    Glass, Tom

    2016-01-01

    When students generate mind maps, or concept maps, the maps are usually on paper, computer screens, or a blackboard. Human Mind Maps require few resources and little preparation. The main requirements are space where students can move around and a little creativity and imagination. Mind maps can be used for a variety of purposes, and Human Mind…

  9. Introduction to human factors

    SciTech Connect

    Winters, J.M.

    1988-03-01

    Some background is given on the field of human factors. The nature of problems with current human/computer interfaces is discussed, some costs are identified, ideal attributes of graceful system interfaces are outlined, and some reasons are indicated why it's not easy to fix the problems. (LEW)

  10. Toward a Humane Curriculum.

    ERIC Educational Resources Information Center

    Foshay, Arthur W.

    In this paper, an integrated view is presented of the direction that education must take if it is to become the creative, effective, joyful enterprise that many educators long for. Educational institutions are not humane because they fail to deal with the human condition in all its variety and meaning. They continue to affirm the intellectual part…

  11. IMMUNOASSAY HUMAN EXPOSURE STUDIES

    EPA Science Inventory

    The Human Exposure Research Branch has developed several enzyme-linked immunosorbent assay (ELISA) methods to support human exposure assessment studies. Immunoassays to detect low levels (<10 ng/mL) of chlorpyrifos in food, track-in dirt and house dust have been applied to sam...

  12. Manage "Human Capital" Strategically

    ERIC Educational Resources Information Center

    Odden, Allan

    2011-01-01

    To strategically manage human capital in education means restructuring the entire human resource system so that schools not only recruit and retain smart and capable individuals, but also manage them in ways that support the strategic directions of the organization. These management practices must be aligned with a district's education improvement…

  13. Hooking Kids with Humanities.

    ERIC Educational Resources Information Center

    Anstead, Neil L.

    1993-01-01

    Humanitas is part of Collaboratives for Humanities and Arts Teaching (CHART), a nationwide network funded primarily by the Rockefeller Foundation. In 11 large school districts and numerous rural districts, high school teachers, academics, artists, and business and community leaders are cooperating to promote teaching of the arts and humanities.…

  14. Human Dignity Through History.

    ERIC Educational Resources Information Center

    Satterlie, Arthur L.

    A major educational need, as assessed by a committee of teachers, students, and community members, is to recognize acceptance of human dignity as the ultimate value in decision making. This concept provides a basis for the elementary and secondary social studies program. Although the concept of human dignity was promoted with the signing of the…

  15. Humanities in Engineering Education.

    ERIC Educational Resources Information Center

    Ruprecht, Robert

    1997-01-01

    States that engineers contribute tremendously to the changing face of the earth, and the ever more urgent call for languages, management, and law competencies for engineers is an expression of the need for a grounding in humanities. Discusses the role of humanities in engineering education in the context of world economics and the role of…

  16. The Humanities' Value

    ERIC Educational Resources Information Center

    Harpham, Geoffrey Galt

    2009-01-01

    Why should society support the humanities when so many people are suffering from the effects of the economic crisis? What claim do the humanities, or scholarship generally, have on increasingly limited resources? Shouldn't such pursuits be considered luxuries at a time when people should be focusing on essentials? The alleviation of human…

  17. Evaluating the Humanities

    ERIC Educational Resources Information Center

    Brody, Howard

    2013-01-01

    How can one measure the value of teaching the humanities? The problem of assessment and accountability is prominent today, of course, in secondary and higher education. It is perhaps even more acute for those who teach the humanities in nontraditional settings, such as medical and other professional schools. The public assumes that academes can…

  18. Human Simulated Diving Experiments.

    ERIC Educational Resources Information Center

    Bruce, David S.; Speck, Dexter F.

    1979-01-01

    This report details several simulated divinq experiments on the human. These are suitable for undergraduate or graduate laboratories in human or environmental physiology. The experiment demonstrates that a diving reflex is precipitated by both facial cooling and apnea. (Author/RE)

  19. Methods in human cytogenetics

    SciTech Connect

    1993-12-31

    Chapter 4, discusses the various techniques used in the study human cytogenetics. The methods are discussed in historical order, from direct methods to tissue culture techniques, prenatal studies, meiotic studies, sex chromatin techniques, banding techniques, prophase banding and replication studies. Nomenclature of human chromosomes and quantitative methods are also mentioned. 60 refs., 3 figs.

  20. Humanism within Globalization

    ERIC Educational Resources Information Center

    Weber, Jennifer E.

    2014-01-01

    The complexity of adult learning connects it to almost all other facets of human endeavor. Consequently, the future of adult education depends, to a large extent on who participates and the quality of such participation. Quality participation, when teamed with environments committed to a concern for humanity, launches opportunities for varied…

  1. Quantification of human responses

    NASA Technical Reports Server (NTRS)

    Steinlage, R. C.; Gantner, T. E.; Lim, P. Y. W.

    1992-01-01

    Human perception is a complex phenomenon which is difficult to quantify with instruments. For this reason, large panels of people are often used to elicit and aggregate subjective judgments. Print quality, taste, smell, sound quality of a stereo system, softness, and grading Olympic divers and skaters are some examples of situations where subjective measurements or judgments are paramount. We usually express what is in our mind through language as a medium but languages are limited in available choices of vocabularies, and as a result, our verbalizations are only approximate expressions of what we really have in mind. For lack of better methods to quantify subjective judgments, it is customary to set up a numerical scale such as 1, 2, 3, 4, 5 or 1, 2, 3, ..., 9, 10 for characterizing human responses and subjective judgments with no valid justification except that these scales are easy to understand and convenient to use. But these numerical scales are arbitrary simplifications of the complex human mind; the human mind is not restricted to such simple numerical variations. In fact, human responses and subjective judgments are psychophysical phenomena that are fuzzy entities and therefore difficult to handle by conventional mathematics and probability theory. The fuzzy mathematical approach provides a more realistic insight into understanding and quantifying human responses. This paper presents a method for quantifying human responses and subjective judgments without assuming a pattern of linear or numerical variation for human responses. In particular, quantification and evaluation of linguistic judgments was investigated.

  2. Humane Education Projects Handbook.

    ERIC Educational Resources Information Center

    Junior League of Ogden, UT.

    This handbook was developed to promote interest in humane education and to encourage the adoption of humane education projects. Although specifically designed to assist Junior Leagues in developing such projects, the content should prove valuable to animal welfare organizations, zoos, aquariums, nature centers, and other project-oriented groups…

  3. Environment and the Humanities.

    ERIC Educational Resources Information Center

    Allen, Rodney F., Ed.; And Others

    As a conference report, the booklet is primarily devoted to abstracts of papers presented at a Conference on Environment and Humanities held in Tallahassee, Florida, April 25-27, 1976. Dr. Huston Smith of Syracuse University, the main speaker, addressed the issue of "Humanities and Environmental Awareness." Other topics discussed included: (1)…

  4. Ecology and Human Values.

    ERIC Educational Resources Information Center

    1970

    "Ecology and Human Values" is an interdisciplinary course designed for senior year high school students in social studies and/or science. Its main thrust is the investigation of human values as they relate to the environment, although rooted in the natural sciences as a means of understanding the complexities inherent in the environment. Use is…

  5. Human Space Flight

    NASA Technical Reports Server (NTRS)

    Woolford, Barbara; Mount, Frances

    2004-01-01

    The first human space flight, in the early 1960s, was aimed primarily at determining whether humans could indeed survive and function in micro-gravity. Would eating and sleeping be possible? What mental and physical tasks could be performed? Subsequent programs increased the complexity of the tasks the crew performed. Table 1 summarizes the history of U.S. space flight, showing the projects, their dates, crew sizes, and mission durations. With over forty years of experience with human space flight, the emphasis now is on how to design space vehicles, habitats, and missions to produce the greatest returns to human knowledge. What are the roles of the humans in space flight in low earth orbit, on the moon, and in exploring Mars?

  6. Mars Human Exploration Objectives

    NASA Technical Reports Server (NTRS)

    Briggs, Geoff

    1998-01-01

    This paper reviews the objectives and other considerations of Human exploration of Mars. The objectives of human exploration of Mars are: (1) to learn how Mars is similar to, and different from, Earth; (2) to explore possible life, past and present; (3) to discover what Mars is like now from the perspective of Geoscience and geologic history; and (4) how did Mars form and how did its formation differ from Earth. Considerations of human Martian exploration involve: (1) having a capable base laboratory; (2) having long range transportation; (3) having operational autonomy of the crew, and the requirement of the crew to possess a range of new cognitive processes along with easy communications with terrestrial colleagues; and finally (4) creating the human habitat along with human factors which involve more than just survivability.

  7. Helminths in human carcinogenesis.

    PubMed

    Fried, Bernard; Reddy, Aditya; Mayer, David

    2011-06-28

    This review examines the salient literature on selected helminths involved in carcinogenicity in humans and updates information in an earlier review on cancer and helminths by Mayer and Fried (2007, Advances in Parasitology 65, 239-296). The earlier review was concerned with various helminths, i.e., trematodes, cestodes, and nematodes, that are definitely implicated as being carcinogenic. This review examines only those helminths, all of which turn out to be trematodes, that are definitely implicated as being carcinogenic. These trematodes are the blood flukes Schistosoma haematobium, associated with inducing human carcinoma of the urinary bladder and the liver flukes Opisthorchis viverrini and Clonorchis sinensis, associated with inducing cancer of the bile duct (cholangiocarcinoma) and cancer of the liver (hepatocarcinoma) in humans. The review examines mainly the epidemiology and pathology of these helminthic infections in humans and considers what we know about the mechanisms associated with the carcinogenicity of these three trematodes in humans.

  8. Beliefs about Human Extinction

    SciTech Connect

    Tonn, Bruce Edward

    2009-11-01

    This paper presents the results of a web-based survey about futures issues. Among many questions, respondents were asked whether they believe humans will become extinct. Forty-five percent of the almost 600 respondents believe that humans will become extinct. Many of those holding this believe felt that humans could become extinct within 500-1000 years. Others estimated extinction 5000 or more years into the future. A logistic regression model was estimated to explore the bases for this belief. It was found that people who describe themselves a secular are more likely to hold this belief than people who describe themselves as being Protestant. Older respondents and those who believe that humans have little control over their future also hold this belief. In addition, people who are more apt to think about the future and are better able to imagine potential futures tend to also believe that humans will become extinct.

  9. Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Antony

    2014-01-01

    The Mars probe, launched by India a few months ago, is on its way to Mars. At this juncture, it is appropriate to talk about the opportunities presented to us for the Human Exploration of Mars. I am planning to highlight some of the challenges to take humans to Mars, descend, land, stay, ascend and return home safely. The logistics of carrying the necessary accessories to stay at Mars will be delivered in multiple stages using robotic missions. The primary ingredients for human survival is air, water, food and shelter and the necessity to recycle the primary ingredients will be articulated. Humans have to travel beyond the van Allen radiation belt under microgravity condition during this inter-planetary travel for about 6 months minimum one way. The deconditioning of human system under microgravity conditions and protection of humans from Galactic cosmic radiation during the travel should be taken into consideration. The multi-disciplinary effort to keep the humans safe and functional during this journey will be addressed.

  10. Archaea on human skin.

    PubMed

    Probst, Alexander J; Auerbach, Anna K; Moissl-Eichinger, Christine

    2013-01-01

    The recent era of exploring the human microbiome has provided valuable information on microbial inhabitants, beneficials and pathogens. Screening efforts based on DNA sequencing identified thousands of bacterial lineages associated with human skin but provided only incomplete and crude information on Archaea. Here, we report for the first time the quantification and visualization of Archaea from human skin. Based on 16 S rRNA gene copies Archaea comprised up to 4.2% of the prokaryotic skin microbiome. Most of the gene signatures analyzed belonged to the Thaumarchaeota, a group of Archaea we also found in hospitals and clean room facilities. The metabolic potential for ammonia oxidation of the skin-associated Archaea was supported by the successful detection of thaumarchaeal amoA genes in human skin samples. However, the activity and possible interaction with human epithelial cells of these associated Archaea remains an open question. Nevertheless, in this study we provide evidence that Archaea are part of the human skin microbiome and discuss their potential for ammonia turnover on human skin.

  11. Human Plasma Protein C

    PubMed Central

    Kisiel, Walter

    1979-01-01

    Protein C is a vitamin K-dependent protein, which exists in bovine plasma as a precursor of a serine protease. In this study, protein C was isolated to homogeneity from human plasma by barium citrate adsorption and elution, ammonium sulfate fractionation, DEAE-Sephadex chromatography, dextran sulfate agarose chromatography, and preparative polyacrylamide gel electrophoresis. Human protein C (Mr = 62,000) contains 23% carbohydrate and is composed of a light chain (Mr = 21,000) and a heavy chain (Mr = 41,000) held together by a disulfide bond(s). The light chain has an amino-terminal sequence of Ala-Asn-Ser-Phe-Leu- and the heavy chain has an aminoterminal sequence of Asp-Pro-Glu-Asp-Gln. The residues that are identical to bovine protein C are underlined. Incubation of human protein C with human α-thrombin at an enzyme to substrate weight ratio of 1:50 resulted in the formation of activated protein C, an enzyme with serine amidase activity. In the activation reaction, the apparent molecular weight of the heavy chain decreased from 41,000 to 40,000 as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. No apparent change in the molecular weight of the light chain was observed in the activation process. The heavy chain of human activated protein C also contains the active-site serine residue as evidenced by its ability to react with radiolabeled diisopropyl fluorophosphate. Human activated protein C markedly prolongs the kaolin-cephalin clotting time of human plasma, but not that of bovine plasma. The amidolytic and anticoagulant activities of human activated protein C were completely obviated by prior incubation of the enzyme with diisopropyl fluorophosphate. These results indicate that human protein C, like its bovine counterpart, exists in plasma as a zymogen and is converted to a serine protease by limited proteolysis with attendant anticoagulant activity. Images PMID:468991

  12. Human exposure to aluminium.

    PubMed

    Exley, Christopher

    2013-10-01

    Human activities have circumvented the efficient geochemical cycling of aluminium within the lithosphere and therewith opened a door, which was previously only ajar, onto the biotic cycle to instigate and promote the accumulation of aluminium in biota and especially humans. Neither these relatively recent activities nor the entry of aluminium into the living cycle are showing any signs of abating and it is thus now imperative that we understand as fully as possible how humans are exposed to aluminium and the future consequences of a burgeoning exposure and body burden. The aluminium age is upon us and there is now an urgent need to understand how to live safely and effectively with aluminium.

  13. Aluminium in human sweat.

    PubMed

    Minshall, Clare; Nadal, Jodie; Exley, Christopher

    2014-01-01

    It is of burgeoning importance that the human body burden of aluminium is understood and is measured. There are surprisingly few data to describe human excretion of systemic aluminium and almost no reliable data which relate to aluminium in sweat. We have measured the aluminium content of sweat in 20 healthy volunteers following mild exercise. The concentration of aluminium ranged from 329 to 5329μg/L. These data equate to a daily excretion of between 234 and 7192μg aluminium and they strongly suggest that perspiration is the major route of excretion of systemic aluminium in humans.

  14. Human pancreas development.

    PubMed

    Jennings, Rachel E; Berry, Andrew A; Strutt, James P; Gerrard, David T; Hanley, Neil A

    2015-09-15

    A wealth of data and comprehensive reviews exist on pancreas development in mammals, primarily mice, and other vertebrates. By contrast, human pancreatic development has been less comprehensively reviewed. Here, we draw together those studies conducted directly in human embryonic and fetal tissue to provide an overview of what is known about human pancreatic development. We discuss the relevance of this work to manufacturing insulin-secreting β-cells from pluripotent stem cells and to different aspects of diabetes, especially permanent neonatal diabetes, and its underlying causes.

  15. Human Genome Project

    SciTech Connect

    Block, S.; Cornwall, J.; Dally, W.; Dyson, F.; Fortson, N.; Joyce, G.; Kimble, H. J.; Lewis, N.; Max, C.; Prince, T.; Schwitters, R.; Weinberger, P.; Woodin, W. H.

    1998-01-04

    The study reviews Department of Energy supported aspects of the United States Human Genome Project, the joint National Institutes of Health/Department of Energy program to characterize all human genetic material, to discover the set of human genes, and to render them accessible for further biological study. The study concentrates on issues of technology, quality assurance/control, and informatics relevant to current effort on the genome project and needs beyond it. Recommendations are presented on areas of the genome program that are of particular interest to and supported by the Department of Energy.

  16. Human Computer Interaction

    NASA Astrophysics Data System (ADS)

    Bhagwani, Akhilesh; Sengar, Chitransh; Talwaniper, Jyotsna; Sharma, Shaan

    2012-08-01

    The paper basically deals with the study of HCI (Human computer interaction) or BCI(Brain-Computer-Interfaces) Technology that can be used for capturing brain signals and translating them into commands that allow humans to control (just by thinking) devices such as computers, robots, rehabilitation technology and virtual reality environments. The HCI is based as a direct communication pathway between the brain and an external device. BCIs are often aimed at assisting, augmenting, or repairing human cognitive or sensory-motor functions.The paper also deals with many advantages of BCI Technology along with some of its applications and some major drawbacks.

  17. The human genome project

    SciTech Connect

    Bell, G.I.

    1991-06-01

    The Human Genome Project will obtain high-resolution genetic and physical maps of each human chromosome and, somewhat later, of the complete nucleotide sequence of the deoxyribonucleic acid (DNA) in a human cell. The talk will begin with an extended introduction to explain the Project to nonbiologists and to show that map construction and sequence determination require extensive computation in order to determine the correct order of the mapped entities and to provide estimates of uncertainty. Computational analysis of the sequence data will become an increasingly important part of the project, and some computational challenges are described. 5 refs.

  18. ESA Human Exploration Activities

    NASA Astrophysics Data System (ADS)

    Hovland, Scott

    The long term goal of the Aurora Exploration Programme is Human exploration of Mars. In preparation for this, exploration of the Moon is a necessary step to provide demonstration of capabilities, mandatory for long duration human spaceflight. With the European Columbus module attached to the ISS, Europe has access to a world class laboratory in space for microgravity research, technology demonstration and preparation for future human exploration missions. The ongoing phase of the exploration programme has been focused on defining the overall European strategy and exploration architecture within the global exploration environment. System studies as well as focused technology developments are in progress (e.g. development of regenerative life support).

  19. [Human dying has changed].

    PubMed

    Llano Escobar, A

    1990-01-01

    In the modern era, the act of dying, at least in the West, presents a series of new characteristics resulting from scientific and technological progress and social changes. More and more frequently, humans die in the strange surroundings of medical establishments without the support of their loved ones and without the opportunity of taking part in decisions related to their own deaths. In the light of the serious personal and social problems caused by this transformation of human death, bioethics emerges as an attempt to uncover options that are more humane.

  20. The Concept of Being Human.

    ERIC Educational Resources Information Center

    Purcell, Royal

    This analysis of the relationship between humanism and humanitarianism outlines educational goals that should lead to a more humane world. Section 1, an outline of human life examines six substructures--human life, individuality, amenity, contact, actualization, and problems. A definition and examples of humanism in section 2 are elaborated into a…

  1. Plants as Sources of Antimalarial Drugs Part. 1. In vitro Test Method for the Evaluation of Crude Extracts from Plants.

    PubMed

    O'neill, M J; Bray, D H; Boardman, P; Phillipson, J D; Warhurst, D C

    1985-10-01

    An IN VITRO antimalarial test, utilising the inhibition of uptake of [G- (3)H]-hypoxanthine into PLASMODIUM FALCIPARUM cultured in human blood, has been used to assess the activity of crude extracts of ARTEMISIA ANNUA and A. VULGARIS (Compositae) and of BRUCEA JAVANICA, AILANTHUS ALTISSIMA, and SIMABA CEDRON (Simaroubaceae).

  2. Pesticides and Human Health

    MedlinePlus

    ... Control a pest Integrated Pest Management What are pesticides? Herbicides Disinfectants Fungicides Insecticides Natural and Biological Pesticides ... Rodenticides Other types of pesticides Disponible en español Pesticides and Human Health Pesticides have a specific purpose ...

  3. Approaches to Human Communication.

    ERIC Educational Resources Information Center

    Budd, Richard W., Ed.; Ruben, Brent D., Ed.

    This anthology of essays approaches human communication from the points of view of: anthropology, art biology, economics, encounter groups, semantics, general system theory, history, information theory, international behavior, journalism, linguistics, mass media, neurophysiology, nonverbal behavior, organizational behavior, philosophy, political…

  4. Statement on Human Cloning

    MedlinePlus

    ... form Search American Association for the Advancement of Science Statement on Human Cloning Print Email Tweet The American Association for the Advancement of Science (AAAS) recognizes the intense debates within our society ...

  5. Viruses and human cancer

    SciTech Connect

    Gallo, R.C.; Haseltine, W.; Klein, G.; Zur Hausen, H.

    1987-01-01

    This book contains papers on the following topics: Immunology and Epidemiology, Biology and Pathogenesis, Models of Pathogenesis and Treatment, Simian and Bovine Retroviruses, Human Papilloma Viruses, EBV and Herpesvirus, and Hepatitis B Virus.

  6. Creativity: The Human Resource.

    ERIC Educational Resources Information Center

    Lewis, Richard W.

    1979-01-01

    The author discusses an exhibition entitled "Creativity--The Human Resource." The exhibition examines the work of 15 Americans, such as designer Buckminster Fuller and artist Judy Chicago, who have contributed in special ways to the arts and sciences. (PHR)

  7. Aerospace Human Factors

    NASA Technical Reports Server (NTRS)

    Jordan, Kevin

    1999-01-01

    The following contains the final report on the activities related to the Cooperative Agreement between the human factors research group at NASA Ames Research Center and the Psychology Department at San Jose State University. The participating NASA Ames division has been, as the organization has changed, the Aerospace Human Factors Research Division (ASHFRD and Code FL), the Flight Management and Human Factors Research Division (Code AF), and the Human Factors Research and Technology Division (Code IH). The inclusive dates for the report are November 1, 1984 to January 31, 1999. Throughout the years, approximately 170 persons worked on the cooperative agreements in one capacity or another. The Cooperative Agreement provided for research personnel to collaborate with senior scientists in ongoing NASA ARC research. Finally, many post-MA/MS and post-doctoral personnel contributed to the projects. It is worth noting that 10 former cooperative agreement personnel were hired into civil service positions directly from the agreements.

  8. Humanism vs. Behaviorism

    ERIC Educational Resources Information Center

    Hunter, Madeline

    1977-01-01

    Author argues that humanism and behaviorism are not necessarily exclusive of one another, and that principles of behaviorism, when thoughtfully applied, can lead to the achievement of humanistic goals. (RW)

  9. Bridging Humanism and Behaviorism.

    ERIC Educational Resources Information Center

    Chu, Lily

    1980-01-01

    Humanistic behaviorism may provide the necessary bridge between behaviorism and humanism. Perhaps the most humanistic approach to teaching is to learn how certain changes will help students and how these changes can be accomplished. (Author/MLF)

  10. Teaching about Human Geography.

    ERIC Educational Resources Information Center

    Schlene, Vickie J.

    1991-01-01

    Presents a sampling of items from the ERIC database concerning the teaching of human geography. Includes documents dealing with Africa, Asia, the United States, Canada, Antarctica, and geographic concepts. Explains how to obtain ERIC documents. (SG)

  11. Human Reliability Program Overview

    SciTech Connect

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  12. Human Resource Planning

    ERIC Educational Resources Information Center

    Hoffman, W. H.; Wyatt, L. L.

    1977-01-01

    By using the total resource approach, we have focused attention on the need to integrate human resource planning with other business plans and highlighted the importance of a productivity strategy. (Author)

  13. HPV (Human Papillomavirus)

    MedlinePlus

    ... Health Topics Mammography Women and Diabetes HPV, HIV, Birth Control Heart Health for Women Pregnancy Menopause More Women's Health Topics Resources for You Human Papillomavirus Vaccine HPV Information in Other Languages Women ...

  14. Human Biomass Consumption

    NASA Video Gallery

    Humans are using an increasing amount of Earth’s annual production of plants. Research shows that, from 1995 to 2005, consumption rose from 20 to 25 percent of the planet's annual production. Wha...

  15. Human Systems Integration Introduction

    NASA Video Gallery

    This lecture provides an overview of Human Systems Integration (HSI), its implementation cost and return on investment, HSI domains, how HSI fits into the NASA organization structure, HSI roles and...

  16. The Human Hazard.

    ERIC Educational Resources Information Center

    Tickell, Crispin

    1995-01-01

    Examines the plight of environmental refugees and the adequacy of political responses to the situation. Discusses the consequences of accelerated environmental change, particularly the impact of global warming on human migration. (LZ)

  17. Elitism in the Humanities

    ERIC Educational Resources Information Center

    Bloomfield, Morton W.

    1974-01-01

    A justification and explication of the existence of elites in the academic world, but especially in the humanities where they perform a practical and necessary function for the enrichment of the mankind, is presented. (JH)

  18. Pushing Human Frontiers

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert

    2005-01-01

    With human colonization of Mars, I think you will see a higher standard of civilization, just as America set a higher standard of civilization which then promulgated back into Europe. I think that if you want to maximize human potential, you need a higher standard of civilization, and that becomes an example that benefits everyone. Without an open frontier, closed world ideologies, such as the Malthus Theory, tend to come to the forefront. It is that there are limited resources; therefore, we are all in deadly competition with each other for the limited pot. The result is tyrannical and potentially genocidal regimes, and we've already seen this in the twentieth century. There s no truth in the Malthus Theory, because human beings are the creators of their resources. With every mouth comes a pair of hands and a brain. But if it seems to be true, you have a vector in this direction, and it is extremely unfortunate. It is only in a universe of infinite resources that all humans can be brothers and sisters. The fundamental question which affects humanity s sense of itself is whether the world is changeable or fixed. Are we the makers of our world or just its inhabitants? Some people have a view that they re living at the end of history within a world that s already defined, and there is no fundamental purpose to human life because there is nothing humans can do that matters. On the other hand, if humans understand their own role as the creators of their world, that s a much more healthy point of view. It raises the dignity of humans. Indeed, if we do establish a new branch of human civilization on Mars that grows in time and potency to the point where it cannot really settle Mars, but transforms Mars, and brings life to Mars, we will prove to everyone and for all time the precious and positive nature of the human species and every member of it.

  19. Human Assisted Assembly Processes

    SciTech Connect

    CALTON,TERRI L.; PETERS,RALPH R.

    2000-01-01

    Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative

  20. Habitability and Human Factors Contributions to Human Space Flight

    NASA Technical Reports Server (NTRS)

    Sumaya, Jennifer Boyer

    2011-01-01

    This slide presentation reviews the work of the Habitability and Human Factors Branch in support of human space flight in two main areas: Applied support to major space programs, and Space research. The field of Human Factors applies knowledge of human characteristics for the design of safer, more effective, and more efficient systems. This work is in several areas of the human space program: (1) Human-System Integration (HSI), (2) Orion Crew Exploration Vehicle, (3) Extravehicular Activity (EVA), (4) Lunar Surface Systems, (5) International Space Station (ISS), and (6) Human Research Program (HRP). After detailing the work done in these areas, the facilities that are available for human factors work are shown.

  1. Human ocular anatomy.

    PubMed

    Kels, Barry D; Grzybowski, Andrzej; Grant-Kels, Jane M

    2015-01-01

    We review the normal anatomy of the human globe, eyelids, and lacrimal system. This contribution explores both the form and function of numerous anatomic features of the human ocular system, which are vital to a comprehensive understanding of the pathophysiology of many oculocutaneous diseases. The review concludes with a reference glossary of selective ophthalmologic terms that are relevant to a thorough understanding of many oculocutaneous disease processes.

  2. Humans in space.

    PubMed

    White, R J; Averner, M

    2001-02-22

    Many successful space missions over the past 40 years have highlighted the advantages and necessity of humans in the exploration of space. But as space travel becomes ever more feasible in the twenty-first century, the health and safety of future space explorers will be paramount. In particular, understanding the risks posed by exposure to radiation and extended weightlessness will be crucial if humans are to travel far from Earth.

  3. Evolution and human sexuality.

    PubMed

    Gray, Peter B

    2013-12-01

    The aim of this review is to put core features of human sexuality in an evolutionary light. Toward that end, I address five topics concerning the evolution of human sexuality. First, I address theoretical foundations, including recent critiques and developments. While much traces back to Darwin and his view of sexual selection, more recent work helps refine the theoretical bases to sex differences and life history allocations to mating effort. Second, I consider central models attempting to specify the phylogenetic details regarding how hominin sexuality might have changed, with most of those models honing in on transitions from a possible chimpanzee-like ancestor to the slightly polygynous and long-term bonded sociosexual partnerships observed among most recently studied hunter-gatherers. Third, I address recent genetic and physiological data contributing to a refined understanding of human sexuality. As examples, the availability of rapidly increasing genomic information aids comparative approaches to discern signals of selection in sexuality-related phenotypes, and neuroendocrine studies of human responses to sexual stimuli provide insight into homologous and derived mechanisms. Fourth, I consider some of the most recent, large, and rigorous studies of human sexuality. These provide insights into sexual behavior across other national samples and on the Internet. Fifth, I discuss the relevance of a life course perspective to understanding the evolution of human sexuality. Most research on the evolution of human sexuality focuses on young adults. Yet humans are sexual beings from gestation to death, albeit in different ways across the life course, and in ways that can be theoretically couched within life history theory.

  4. Quality and human society

    NASA Astrophysics Data System (ADS)

    Stoll, W.

    1991-02-01

    Quality of products and services is seen as a necessity in our modern world. Quality also has important cross-links to safety in our society. It is however suggested, that human beings are living in their industrial environment under the stress of a fractured personality with anxieties and frustrations. Some cultural comparisons with other industrial nations are given. Quality control tailored to human nature is recommended.

  5. Mapping the human genome

    SciTech Connect

    Annas, G.C.; Elias, S.

    1992-01-01

    This article is a review of the book Mapping the Human Genome: Using Law and Ethics as Guides, edited by George C. Annas and Sherman Elias. The book is a collection of essays on the subject of using ethics and laws as guides to justify human gene mapping. It addresses specific issues such problems related to eugenics, patents, insurance as well as broad issues such as the societal definitions of normality.

  6. Human exploration mission studies

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    1990-01-01

    This paper describes several case studies of human space exploration, considered by the NASA's Office of Exploration in 1988. Special attention is given to the mission scenarios, the critical technology required in these expeditions, and the extraterrestrial power requirements of significant system elements. The cases examined include a manned expedition to Phobos, the inner Martian moon; a human expedition to Mars; the Lunar Observatory; and a lunar outpost to early Mars evolution.

  7. Meeting human needs

    NASA Technical Reports Server (NTRS)

    Nicogossian, Arnauld E.

    1992-01-01

    The degree of autonomy of future long duration manned missions will emphasize interactions between human operators and automated systems aimed at the most effective allocations of tasks between humans and machines. Knowledge of crewmembers' physical status, encompassing both capabilities and limitations, will also be critical during EVA and planetary roving missions; psychological evaluation and support, with a view to both individual health and group cohesion and productivity, may become a critical consideration. Attention is here given to crewmembers' medical and psychological vulnerabilities.

  8. The human oncogenic viruses

    SciTech Connect

    Luderer, A.A.; Weetall, H.H

    1986-01-01

    This book contains eight selections. The titles are: Cytogenetics of the Leukemias and Lymphomas; Cytogenetics of Solid Tumors: Renal Cell Carcinoma, Malignant Melanoma, Retinoblastoma, and Wilms' Tumor; Elucidation of a Normal Function for a Human Proto-Oncogene; Detection of HSV-2 Genes and Gene Products in Cervical Neoplasia; Papillomaviruses in Anogennital Neoplasms; Human Epstein-Barr Virus and Cancer; Hepatitis B Virus and Hepatocellular Carcinoma; and Kaposi's Sarcoma: Acquired Immunodeficiency Syndrome (AIDS) and Associated Viruses.

  9. Human Factors Review Plan

    SciTech Connect

    Paramore, B.; Peterson, L.R.

    1985-12-01

    ''Human Factors'' is concerned with the incorporation of human user considerations into a system in order to maximize human reliability and reduce errors. This Review Plan is intended to assist in the assessment of human factors conditions in existing DOE facilities. In addition to specifying assessment methodologies, the plan describes techniques for improving conditions which are found to not adequately support reliable human performance. The following topics are addressed: (1) selection of areas for review describes techniques for needs assessment to assist in selecting and prioritizing areas for review; (2) human factors engineering review is concerned with optimizing the interfaces between people and equipment and people and their work environment; (3) procedures review evaluates completeness and accuracy of procedures, as well as their usability and management; (4) organizational interface review is concerned with communication and coordination between all levels of an organization; and (5) training review evaluates training program criteria such as those involving: trainee selection, qualification of training staff, content and conduct of training, requalification training, and program management.

  10. Glycobiology of human milk.

    PubMed

    Newburg, D S

    2013-07-01

    Glycans are characteristic components of milk, and each species has unique patterns of specific carbohydrates. Human milk is unusually rich in glycans, with the major components being lactose and oligosaccharides, representing approximately 6.8 and 1% of the milk, respectively. Other sources of glycans in human milk include monosaccharides, mucins, glycosaminoglycans, glycoproteins, glycopeptides, and glycolipids. In human milk, the presence and patterns of these glycans vary depending upon the stage of lactation and the maternal genes and their genetic polymorphisms that control glycosyl transferases. The synthesis of milk glycans utilizes a significant portion of the metabolic energy that the mother expends when producing her milk, but other than lactose, these glycans contribute little to the nutritional needs of the infant. The data herein support several functions. 1) Many human milk glycans inhibit pathogens from binding to the intestinal mucosa. 2) Human milk glycans attenuate inflammation. 3) Glycans also directly stimulate the growth of beneficial (mutualist) bacteria of the microbiota (formerly considered commensal microflora of the intestine); these mutualists and their fermentation products can, in turn, (a) inhibit pathogens, (b) modulate signaling and inflammation, and (c) the fermentation products can be absorbed and utilized as a source of dietary calories. These functions can help direct and support intestinal postnatal growth, development, and ontogeny of colonization. The many functions of the milk glycans may synergistically protect infants from disease. Hence, human milk glycans and their homologs may serve as novel prophylactic or therapeutic agents for a diverse range of deleterious conditions.

  11. Genomics of human longevity.

    PubMed

    Slagboom, P E; Beekman, M; Passtoors, W M; Deelen, J; Vaarhorst, A A M; Boer, J M; van den Akker, E B; van Heemst, D; de Craen, A J M; Maier, A B; Rozing, M; Mooijaart, S P; Heijmans, B T; Westendorp, R G J

    2011-01-12

    In animal models, single-gene mutations in genes involved in insulin/IGF and target of rapamycin signalling pathways extend lifespan to a considerable extent. The genetic, genomic and epigenetic influences on human longevity are expected to be much more complex. Strikingly however, beneficial metabolic and cellular features of long-lived families resemble those in animals for whom the lifespan is extended by applying genetic manipulation and, especially, dietary restriction. Candidate gene studies in humans support the notion that human orthologues from longevity genes identified in lower species do contribute to longevity but that the influence of the genetic variants involved is small. Here we discuss how an integration of novel study designs, labour-intensive biobanking, deep phenotyping and genomic research may provide insights into the mechanisms that drive human longevity and healthy ageing, beyond the associations usually provided by molecular and genetic epidemiology. Although prospective studies of humans from the cradle to the grave have never been performed, it is feasible to extract life histories from different cohorts jointly covering the molecular changes that occur with age from early development all the way up to the age at death. By the integration of research in different study cohorts, and with research in animal models, biological research into human longevity is thus making considerable progress.

  12. The human telomere

    SciTech Connect

    Moyzis, R.K.

    1989-01-01

    An ultimate goal of human genetics is the generation of a complete physical and ''functional'' map of the human genome. Twenty-five percent of human DNA, however, consists of repetitive DNA sequences. These repetitive DNA sequences are thought to arise by many mechanisms, from direct sequence amplification by the unequal recombination of homologous DNA regions to the reverse flow of genetic information. A general outline of the chromosomal organization of these repetitive sequences will be discussed. Our working hypothesis is that certain classes of human repetitive DNA sequences ''encode'' the information necessary for defining long-range genomic structure. Evidence will be presented that the first goal of this research, the identification and cloning of the human telomere, has been achieved. A human repetitive DNA library was constructed from randomly sheared, reassociated, and oligo(G/center dot/C)-tailed DNA, a method that minimizes the potential loss of sequences devoid of a given restriction enzyme site. Sequences too large to clone efficiently in cosmid or /lambda/ vectors, such as centromeric repeats, or telomeric sequences with an end incompatible for cloning, should be present in this library. In order to isolate highly conserved repetitive DNA sequences, this library was screened with radiolabeled hamster Cot50 repetitive DNA. Two clones, containing tandem arrays of the sequence (TTAGGG), were isolated by this method. 30 refs., 1 fig., 2 tabs.

  13. Human bites - self-care

    MedlinePlus

    Bites - human - self-care ... Human bites can occur in 2 ways: If someone bites you If your hand comes into contact ... bite to express anger or other negative feelings. Human bites may be more dangerous than animal bites. ...

  14. Human behavior and human performance: Psychomotor demands

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The results of several experiments are presented in abstract form. These studies are critical for the interpretation and acceptance of flight based science to be conducted by the Behavior and Performance project. Some representative titles are as follow: External audio for IBM/PC compatible computers; A comparative assessment of psychomotor performance (target prediction by humans and macaques); Response path (a dependent measure for computer maze solving and other tasks); Behavioral asymmetries of psychomotor performance in Rhesus monkey (a dissociation between hand preference and skill); Testing primates with joystick based automated apparatus; and Environmental enrichment and performance assessment for ground or flight based research with primates;

  15. Meeting human needs

    NASA Technical Reports Server (NTRS)

    Nicogossian, Arnauld E.

    1992-01-01

    Manned space flight can be viewed as an interaction of three general elements: the human crewmember, spacecraft systems, and the environment. While the human crewmember is a crucial element in the system, certain physiological, psychological, environ- mental and spacecraft systems factors can compromise human performance in space. These factors include atmospheric pressure, physiology, uncertainties associated with space radiation, the potential for exposure to toxic materials in the closed environment, and spacecraft habitability. Health protection in space, for current and future missions, relies on a philosophy of risk reduction, which in the space program is achieved in four ways-through health maintenance, health care, design criteria, an selection and training. Emphasis is place upon prevention, through selection criteria and careful screening. Spacecraft health care systems must be absolutely reliable, and they will be automated and computerized to the maximum extent possible, but still designed with the human crewmember's capabilities in mind. The autonomy and technological sophistication of future missions will require a greater emphasis on high-level interaction between the human operator and automated systems, with effective allocation of tasks between humans and machines. Performance in space will include complex tasks during extravehicular activity (EVA) and on planetary surfaces, and knowledge of crewmembers' capability and limitations during such operations will be critical to mission success. Psychological support will become increasingly important on space missions, as crews spend long periods in remote and potentially hazardous environments. The success of future missions will depend on both individual psychological health and group cohesion and productivity, particularly as crew profiles become more heterogeneous. Thus, further human factors are needed in the area of small-group dynamics and performance.

  16. Human Milk Fortification.

    PubMed

    Simmer, Karen

    2015-01-01

    Human milk is the feed of choice for preterm infants. However, human milk does not provide enough nutrition, especially protein, for preterm infants to achieve target growth rates similar to those in utero (15-20 g/kg per day). Fortifiers for human milk, manufactured from bovine milk, are commercially available and routinely used for patients born <32 weeks' gestation prior to discharge home. Recent recommended dietary intakes (RDI) have been revised. Up to 4.2 g of protein and 135 kcal/kg per day is recommended for infants born very preterm. Additional supplements are needed to current commercial fortifiers to achieve these RDI and reduce the incidence of ex-uterine growth failure. A human milk fortifier that is manufactured from donor human milk is available in some developed countries and may confer some clinical benefits, including a reduction in necrotizing enterocolitis. Fortification can be added in a standardized protocol as per manufacturers' instructions. Human milk composition can be analyzed and fortification individualized to take into account the large variation from mother to mother. Alternatively, fortification can be increased in a stepwise manner based on assumed composition while monitoring blood urea levels for safety. The current aim is to prevent preterm infants dropping percentiles and falling below the 10th percentile at 36 weeks' corrected gestational age or discharge home. More data are required on how best to fortify human milk for preterm infants to achieve optimal growth, development and health outcomes in the long term. There is an urgent need for well-designed and informed randomized clinical trials in this vulnerable preterm population. PMID:26111568

  17. Human Milk Fortification.

    PubMed

    Simmer, Karen

    2015-01-01

    Human milk is the feed of choice for preterm infants. However, human milk does not provide enough nutrition, especially protein, for preterm infants to achieve target growth rates similar to those in utero (15-20 g/kg per day). Fortifiers for human milk, manufactured from bovine milk, are commercially available and routinely used for patients born <32 weeks' gestation prior to discharge home. Recent recommended dietary intakes (RDI) have been revised. Up to 4.2 g of protein and 135 kcal/kg per day is recommended for infants born very preterm. Additional supplements are needed to current commercial fortifiers to achieve these RDI and reduce the incidence of ex-uterine growth failure. A human milk fortifier that is manufactured from donor human milk is available in some developed countries and may confer some clinical benefits, including a reduction in necrotizing enterocolitis. Fortification can be added in a standardized protocol as per manufacturers' instructions. Human milk composition can be analyzed and fortification individualized to take into account the large variation from mother to mother. Alternatively, fortification can be increased in a stepwise manner based on assumed composition while monitoring blood urea levels for safety. The current aim is to prevent preterm infants dropping percentiles and falling below the 10th percentile at 36 weeks' corrected gestational age or discharge home. More data are required on how best to fortify human milk for preterm infants to achieve optimal growth, development and health outcomes in the long term. There is an urgent need for well-designed and informed randomized clinical trials in this vulnerable preterm population.

  18. Spaceflight Human System Standards

    NASA Technical Reports Server (NTRS)

    Holubec, Keith; Tillman, Barry; Connolly, Jan

    2009-01-01

    NASA created a new approach for human system integration and human performance standards. NASA created two documents a standard and a reference handbook. The standard is titled NASA Space Flight Human-System Standard (SFHSS) and consists of two-volumes: Volume 1- Crew Health This volume covers standards needed to support astronaut health (medical care, nutrition, sleep, exercise, etc.) Volume 2 Human Factors, Habitability and Environmental Health This volume covers the standards for system design that will maintain astronaut performance (ie., environmental factors, design of facilities, layout of workstations, and lighting requirements). It includes classic human factors requirements. The new standards document is written in terms so that it is applicable to a broad range of present and future NASA systems. The document states that all new programs prepare system-specific requirements that will meet the general standards. For example, the new standard does not specify a design should accommodate specific percentiles of a defined population. Rather, NASA-STD-3001, Volume 2 states that all programs shall prepare program-specific requirements that define the user population and their size ranges. The design shall then accommodate the full size range of those users. The companion reference handbook, Human Integration Design Handbook (HIDH), was developed to capture the design consideration information from NASA-STD-3000, and adds spaceflight lessons learned, gaps in knowledge, example solutions, and suggests research to further mature specific disciplines. The HIDH serves two major purposes: HIDH is the reference document for writing human factors requirements for specific systems. HIDH contains design guidance information that helps insure that designers create systems which safely and effectively accommodate the capabilities and limitations of space flight crews.

  19. Why Geo-Humanities

    NASA Astrophysics Data System (ADS)

    Graells, Robert Casals i.; Sibilla, Anna; Bohle, Martin

    2016-04-01

    Anthropogenic global change is a composite process. It consists of societal processes (in the 'noosphere') and natural processes (in the 'bio-geosphere'). The 'noosphere' is the ensemble of social, cultural or political insights ('shared subjective mental concepts') of people. Understanding the composite of societal and natural processes ('human geo-biosphere intersections'), which shapes the features of anthropogenic global change, would benefit from a description that draws equally on natural sciences, social sciences and humanities. To that end it is suggested to develop a concept of 'geo-humanities': This essay presents some aspects of its scope, discussing "knowledge that is to manage", "intentions that are to shape", "choices that are to justify" and "complexity that is to handle". Managing knowledge: That people understand anthropogenic global change requires their insights into how 'human geosphere intersections' function. Insights are formed ('processed') in the noosphere by means of interactions between people. Understanding how 'human geosphere intersections' functions combines scientific, engineering and economic studies with studies of the dynamics of the noosphere. Shaping intentions: During the last century anthropogenic global change developed as the collateral outcome of humankind's accumulated actions. It is caused by the number of people, the patterns of their consumption of resources, and the alterations of their environments. Nowadays, anthropogenic global chance is either an intentional negligence or a conscious act. Justifying choices: Humanity has alternatives how to alter Earth at planetary scale consciously. For example, there is a choice to alter the geo-biosphere or to adjust the noosphere. Whatever the choice, it will depend on people's world-views, cultures and preferences. Thus beyond issues whether science and technology are 'sound' overarching societal issues are to tackle, such as: (i) how to appropriate and distribute natural

  20. Methodology and Application of Flow Cytometry for Investigation of Human Malaria Parasites

    PubMed Central

    Grimberg, Brian T.

    2011-01-01

    Historically, examinations of the inhibition of malaria parasite growth/invasion, whether using drugs or antibodies, have relied on the use of microscopy or radioactive hypoxanthine uptake. These are considered gold standards for measuring the effectiveness of antimalarial treatments, however, these methods have well known shortcomings. With the advent of flow cytometry coupled with the use of fluorescent DNA stains allowed for increased speed, reproducibility, and qualitative estimates of the effectiveness of antibodies and drugs to limit malaria parasite growth which addresses the challenges of traditional techniques. Because materials and machines available to research facilities are so varied, different methods have been developed to investigate malaria parasites by flow cytometry. This review is intended to serve as a reference guide for advanced users and importantly, as a primer for new users, to support expanded use and improvements to malaria flow cytometry, particularly in endemic countries. PMID:21296083

  1. Methodology and application of flow cytometry for investigation of human malaria parasites.

    PubMed

    Grimberg, Brian T

    2011-03-31

    Historically, examinations of the inhibition of malaria parasite growth/invasion, whether using drugs or antibodies, have relied on the use of microscopy or radioactive hypoxanthine uptake. These are considered gold standards for measuring the effectiveness of antimalarial treatments, however, these methods have well known shortcomings. With the advent of flow cytometry coupled with the use of fluorescent DNA stains allowed for increased speed, reproducibility, and qualitative estimates of the effectiveness of antibodies and drugs to limit malaria parasite growth which addresses the challenges of traditional techniques. Because materials and machines available to research facilities are so varied, different methods have been developed to investigate malaria parasites by flow cytometry. This review is intended to serve as a reference guide for advanced users and importantly, as a primer for new users, to support expanded use and improvements to malaria flow cytometry, particularly in endemic countries.

  2. Infants' Responses to Real Humans and Representations of Humans

    ERIC Educational Resources Information Center

    Heron, Michelle; Slaughter, Virginia

    2010-01-01

    Infants' responses to typical and scrambled human body shapes were assessed in relation to the realism of the human body stimuli presented. In four separate experiments, infants were familiarized to typical human bodies and then shown a series of scrambled human bodies on the test. Looking behaviour was assessed in response to a range of different…

  3. [Human ehrlichiosis. Review].

    PubMed

    Arraga-Alvarado, C

    1994-12-01

    Human ehrlichiosis is a newly recognized tick-borne disease. Since 1935 Ehrlichia canis has been known as a cause of illness in dogs and other canine species, and for a few years it was related with human disease. In 1990, Ehrlichia chaffeensis was isolated from a man suspected of having ehrlichiosis. Partial sequencing of the rRNAS from the human isolate and E. canis, indicated that they are 98.7% related. More recently (May 1994) an "human granulocytic ehrlichiosis" have been reported in USA. PCR amplification and sequence of 16S rDNA, showed that the human isolate was virtually identical to those reported for E. phagocytophila y E. equi, organisms that cause ehrlichiosis in rumiant and in horses. Most patients shows fever, headache, malaise, nausea or vomiting, anorexia and in a minority of cases rash is present. Some of them have complications such as pulmonary infiltrates, gastrointestinal problems, renal dysfunction or failure, hepatoesplenomegaly, neurologic abnormalities, DIC and some times death. Leucopenia, thrombocytopenia and elevated liver enzyme values have been common findings. Tetracycline and cloramphenicol have been using in adults and children as especific theraphy.

  4. Healthy human gut phageome.

    PubMed

    Manrique, Pilar; Bolduc, Benjamin; Walk, Seth T; van der Oost, John; de Vos, Willem M; Young, Mark J

    2016-09-13

    The role of bacteriophages in influencing the structure and function of the healthy human gut microbiome is unknown. With few exceptions, previous studies have found a high level of heterogeneity in bacteriophages from healthy individuals. To better estimate and identify the shared phageome of humans, we analyzed a deep DNA sequence dataset of active bacteriophages and available metagenomic datasets of the gut bacteriophage community from healthy individuals. We found 23 shared bacteriophages in more than one-half of 64 healthy individuals from around the world. These shared bacteriophages were found in a significantly smaller percentage of individuals with gastrointestinal/irritable bowel disease. A network analysis identified 44 bacteriophage groups of which 9 (20%) were shared in more than one-half of all 64 individuals. These results provide strong evidence of a healthy gut phageome (HGP) in humans. The bacteriophage community in the human gut is a mixture of three classes: a set of core bacteriophages shared among more than one-half of all people, a common set of bacteriophages found in 20-50% of individuals, and a set of bacteriophages that are either rarely shared or unique to a person. We propose that the core and common bacteriophage communities are globally distributed and comprise the HGP, which plays an important role in maintaining gut microbiome structure/function and thereby contributes significantly to human health. PMID:27573828

  5. The Human Serum Metabolome

    PubMed Central

    Psychogios, Nikolaos; Hau, David D.; Peng, Jun; Guo, An Chi; Mandal, Rupasri; Bouatra, Souhaila; Sinelnikov, Igor; Krishnamurthy, Ramanarayan; Eisner, Roman; Gautam, Bijaya; Young, Nelson; Xia, Jianguo; Knox, Craig; Dong, Edison; Huang, Paul; Hollander, Zsuzsanna; Pedersen, Theresa L.; Smith, Steven R.; Bamforth, Fiona; Greiner, Russ; McManus, Bruce; Newman, John W.; Goodfriend, Theodore; Wishart, David S.

    2011-01-01

    Continuing improvements in analytical technology along with an increased interest in performing comprehensive, quantitative metabolic profiling, is leading to increased interest pressures within the metabolomics community to develop centralized metabolite reference resources for certain clinically important biofluids, such as cerebrospinal fluid, urine and blood. As part of an ongoing effort to systematically characterize the human metabolome through the Human Metabolome Project, we have undertaken the task of characterizing the human serum metabolome. In doing so, we have combined targeted and non-targeted NMR, GC-MS and LC-MS methods with computer-aided literature mining to identify and quantify a comprehensive, if not absolutely complete, set of metabolites commonly detected and quantified (with today's technology) in the human serum metabolome. Our use of multiple metabolomics platforms and technologies allowed us to substantially enhance the level of metabolome coverage while critically assessing the relative strengths and weaknesses of these platforms or technologies. Tables containing the complete set of 4229 confirmed and highly probable human serum compounds, their concentrations, related literature references and links to their known disease associations are freely available at http://www.serummetabolome.ca. PMID:21359215

  6. The Human Genome Program

    SciTech Connect

    Bell, G.I.

    1989-01-01

    Early in 1986, Charles DeLisi, then head of the Office of Health and Environmental Research at the Department of Energy (DOE) requested the Los Alamos National Laboratory (LANL) to organize a workshop charged with inquiring whether the state of technology and potential payoffs in biological knowledge and medical practice were such as to justify an organized program to map and sequence the human genome. The DOE's interest arose from its mission to assess the effects of radiation and other products of energy generation on human health in general and genetic material in particular. The workshop concluded that the technology was ripe, the benefits would be great, and a national program should be promptly initiated. Later committees, reporting to DOE, to the NIH, to the Office of Technology Assessment of the US Congress, and to the National Academy of Science have reviewed these issues more deliberately and come to the same conclusion. As a consequence, there has been established in the United States, a Human Genome Program, with funding largely from the NIH and the DOE, as indicated in Table 1. Moreover, the Program has attracted international interest, and Great Britain, France, Italy, and the Soviet Union, among other countries, have been reported to be starting human genome initiatives. Coordination of these programs, clearly in the interests of each, remains to be worked out, although an international Human Genome Organization (HUGO) is considering such coordination. 5 refs., 1 fig., 2 tabs.

  7. Human HOX gene disorders.

    PubMed

    Quinonez, Shane C; Innis, Jeffrey W

    2014-01-01

    The Hox genes are an evolutionarily conserved family of genes, which encode a class of important transcription factors that function in numerous developmental processes. Following their initial discovery, a substantial amount of information has been gained regarding the roles Hox genes play in various physiologic and pathologic processes. These processes range from a central role in anterior-posterior patterning of the developing embryo to roles in oncogenesis that are yet to be fully elucidated. In vertebrates there are a total of 39 Hox genes divided into 4 separate clusters. Of these, mutations in 10 Hox genes have been found to cause human disorders with significant variation in their inheritance patterns, penetrance, expressivity and mechanism of pathogenesis. This review aims to describe the various phenotypes caused by germline mutation in these 10 Hox genes that cause a human phenotype, with specific emphasis paid to the genotypic and phenotypic differences between allelic disorders. As clinical whole exome and genome sequencing is increasingly utilized in the future, we predict that additional Hox gene mutations will likely be identified to cause distinct human phenotypes. As the known human phenotypes closely resemble gene-specific murine models, we also review the homozygous loss-of-function mouse phenotypes for the 29 Hox genes without a known human disease. This review will aid clinicians in identifying and caring for patients affected with a known Hox gene disorder and help recognize the potential for novel mutations in patients with phenotypes informed by mouse knockout studies.

  8. Human herpesvirus 6.

    PubMed Central

    Braun, D K; Dominguez, G; Pellett, P E

    1997-01-01

    Human herpesvirus 6 variant A (HHV-6A) and human herpesvirus 6 variant B (HHV-6B) are two closely related yet distinct viruses. These visuses belong to the Roseolovirus genus of the betaherpesvirus subfamily; they are most closely related to human herpesvirus 7 and then to human cytomegalovirus. Over 95% of people older than 2 years of age are seropositive for either or both HHV-6 variants, and current serologic methods are incapable of discriminating infection with one variant from infection with the other. HHV-6A has not been etiologically linked to any human disease, but such an association will probably be found soon. HHV-6B is the etiologic agent of the common childhood illness exanthem subitum (roseola infantum or sixth disease) and related febrile illnesses. These viruses are frequently active and associated with illness in immunocompromised patients and may play a role in the etiology of Hodgkin's disease and other malignancies. HHV-6 is a commensal inhabitant of brains; various neurologic manifestations, including convulsions and encephalitis, can occur during primary HHV-6 infection or in immunocompromised patients. HHV-6 and distribution in the central nervous system are altered in patients with multiple sclerosis; the significance of this is under investigation. PMID:9227865

  9. Human occupancy detection

    NASA Astrophysics Data System (ADS)

    Brown, David A.

    1994-10-01

    In the area of security and surveillance technologies, the problem of the arrival in Canada of illegal and undesirable ship and truck cargo loads is steadily increasing. As the volumes of cargo arrivals increase so do the Immigration and Customs problems related to the determination of the validity of those cargo contents. Of special concern to Immigration Control Authorities around the world is the emerging and increasing trend of illegal smuggling of human beings hidden inside of shipping containers. Beginning in 1992, Immigration Control Authorities in Canada observed an escalation of alien people smuggling through the use of cargo shipping containers arriving in the Port of Montreal. This paper will present to the audience the recently completed Immigration Canada Human Occupancy Detection project by explaining the design, development and testing of human occupancy detectors. The devices are designed to electronically detect the presence of persons hiding inside of shipping containers, without the requirement of opening the container doors. The human occupancy detection concepts are based upon the presence of carbon dioxide or other human waste characteristics commonly found inside of shipping containers.

  10. Humanized Mice for Studying Human Leukocyte Integrins In Vivo

    PubMed Central

    Kim, Sang-Soo; Kumar, Priti; Ye, Chunting; Shankar, Premlata

    2015-01-01

    Humanized mice have recently emerged as powerful translational animal models for studying human hematopoiesis, immune interactions, and diseases of the human immune system. Several important advances in the humanized mouse technology have been reported over the last few years, thereby resulting in improved engraftment, high levels of human chimerism, and sustained human hematopoiesis. This chapter describes the detailed procedures for generating various humanized mouse models including hu-PBL, hu-HSC, and BLT models and discusses considerations for choosing the appropriate model system. PMID:21909931

  11. Teleoperator Human Factors Study

    NASA Technical Reports Server (NTRS)

    1986-01-01

    An investigation of the spectrum of space teleoperation activities likely in the 1985 to 1995 decade focused on the resolution of critical human engineering issues and characterization of the technology effect on performance of remote human operators. The study began with the identification and documentation of a set of representative reference teleoperator tasks. For each task, technology, development, and design options, issues, and alternatives that bear on human operator performance were defined and categorized. A literature survey identified existing studies of man/machine issues. For each teleoperations category, an assessment was made of the state of knowledge on a scale from adequate to void. The tests, experiments, and analyses necessary to provide the missing elements of knowledge were then defined. A limited set of tests were actually performed, including operator selection, baseline task definition, control mode study, lighting study, camera study, and preliminary time delay study.

  12. Human factors in aviation

    NASA Technical Reports Server (NTRS)

    Wiener, Earl L. (Editor); Nagel, David C. (Editor)

    1988-01-01

    The fundamental principles of human-factors (HF) analysis for aviation applications are examined in a collection of reviews by leading experts, with an emphasis on recent developments. The aim is to provide information and guidance to the aviation community outside the HF field itself. Topics addressed include the systems approach to HF, system safety considerations, the human senses in flight, information processing, aviation workloads, group interaction and crew performance, flight training and simulation, human error in aviation operations, and aircrew fatigue and circadian rhythms. Also discussed are pilot control; aviation displays; cockpit automation; HF aspects of software interfaces; the design and integration of cockpit-crew systems; and HF issues for airline pilots, general aviation, helicopters, and ATC.

  13. Seaweed and human health.

    PubMed

    Brown, Emma S; Allsopp, Philip J; Magee, Pamela J; Gill, Chris I R; Nitecki, Sonja; Strain, Conall R; McSorley, Emeir M

    2014-03-01

    Seaweeds may have an important role in modulating chronic disease. Rich in unique bioactive compounds not present in terrestrial food sources, including different proteins (lectins, phycobiliproteins, peptides, and amino acids), polyphenols, and polysaccharides, seaweeds are a novel source of compounds with potential to be exploited in human health applications. Purported benefits include antiviral, anticancer, and anticoagulant properties as well as the ability to modulate gut health and risk factors for obesity and diabetes. Though the majority of studies have been performed in cell and animal models, there is evidence of the beneficial effect of seaweed and seaweed components on markers of human health and disease status. This review is the first to critically evaluate these human studies, aiming to draw attention to gaps in current knowledge, which will aid the planning and implementation of future studies.

  14. Human trichromacy revisited.

    PubMed

    Horiguchi, Hiroshi; Winawer, Jonathan; Dougherty, Robert F; Wandell, Brian A

    2013-01-15

    The presence of a photopigment (melanopsin) within certain retinal ganglion cells was a surprising and significant discovery. This pigment is routinely described as "nonvisual" to highlight its signaling role in pupil dilation and circadian rhythms. Here we asked whether light absorbed by melanopsin can be seen by healthy human subjects. To answer this requires delivering intense (above rod saturation), well-controlled lights using four independent primaries. We collected detection thresholds to many four-primary stimuli. Threshold measurements in the fovea are explained by trichromatic theory, with no need to invoke a fourth photopigment. In the periphery, where melanopsin is present, threshold measurements deviate from trichromatic theory; at high photopic levels, sensitivity is explained by absorptions in four, not three, photopigment classes. We consider a series of hypotheses to explain the tetrasensitivity at high photopic levels in the human peripheral field. The most likely hypothesis is that in healthy human subjects melanopsin absorptions influence visibility. PMID:23256158

  15. Abortion and human rights.

    PubMed

    Shaw, Dorothy

    2010-10-01

    Abortion has been a reality in women's lives since the beginning of recorded history, typically with a high risk of fatal consequences, until the last century when evolutions in the field of medicine, including techniques of safe abortion and effective methods of family planning, could have ended the need to seek unsafe abortion. The context of women's lives globally is an important but often ignored variable, increasingly recognised in evolving human rights especially related to gender and reproduction. International and regional human rights instruments are being invoked where national laws result in violations of human rights such as health and life. The individual right to conscientious objection must be respected and better understood, and is not absolute. Health professional organisations have a role to play in clarifying responsibilities consistent with national laws and respecting reproductive rights. Seeking common ground using evidence rather than polarised opinion can assist the future focus. PMID:20303830

  16. Highest permanent human habitation.

    PubMed

    West, John B

    2002-01-01

    The aim of this analysis was to determine the altitude of the highest permanent human habitation in the hope that this will throw some light on what determines the highest altitude that a community can tolerate indefinitely. A number of places where people have lived at very high altitudes for long periods of time are reviewed. Individuals have lived for as long as 2 yr at an altitude of 5950 m, and there was a miner's camp at 5300 m for several years. The highest permanently inhabited town in the world at the present time appears to be La Rinconada, a mining village of over 7000 people in southern Peru at an altitude of up to 5100 m, which has been in existence for over 40 yr. The altitude of the highest permanent human habitation is determined partly by economic factors, rather than solely by human tolerance to hypoxia. PMID:12631426

  17. [Human rights and procreation].

    PubMed

    Leroy, F

    1990-04-01

    The impact of procreation on freedom, health and welfare of human beings, is considerable. This relationship, however, is not mirrored in texts devoted to Human Rights. This omission obviously implies a neglect of women's and children's rights. The history of anticonceptive methods exemplifies the struggle for these rights. This conquest, which has lasted two hundred years, is far from completed. Because of the demographic outbreak in Third World countries, an ideological conflict has appeared between first generation Human Rights concerned with individual freedom ("rights of") and those of second generation aiming at social fairness ("rights to"). Adequate political and economic adjustment between North and South is a prerequisite to any balanced compromise that would resolve this conflict through democratic, albeit intensive, birth control.

  18. Is humanity suicidal?

    PubMed

    Wilson, E O

    1993-01-01

    The world's fauna and flora has entered a crisis unparalleled since the end of the Mesozoic Era, with the extinction rate of species now elevated to more than a thousand times that existing before the coming of humanity. Scientists and policy makers are ill-prepared to moderate this hemorrhaging, because so little is known of the biology of the Earth's millions of species and because so little effort has been directed toward conservation thus far. With the vanished species will go great potential wealth in scientific knowledge, new products, ecosystems services, and part of the natural world in which the human species originated. The need for new research and improved management is thus urgent. If it is not met, humanity will likely survive, but in a world biologically impoverished for all time.

  19. Human nutrition: evolutionary perspectives.

    PubMed

    Barnicot, N A

    2005-01-01

    In recent decades, much new evidence relating to the ape forerunners of modern humans has come to hand and diet appears to be an important factor. At some stage, there must have been a transition from a largely vegetarian ape diet to a modern human hunting economy providing significant amounts of meat. On an even longer evolutionary time scale the change was more complex. The mechanisms of evolutionary change are now better understood than they were in Darwin's time, thanks largely to great advances in genetics, both experimental and theoretical. It is virtually certain that diet, as a major component of the human environment, must have exerted evolutionary effects, but researchers still have little good evidence. PMID:17393680

  20. Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Rochlis-Zumbado, Jennifer; Sandor, Aniko; Ezer, Neta

    2012-01-01

    Risk of Inadequate Design of Human and Automation/Robotic Integration (HARI) is a new Human Research Program (HRP) risk. HRI is a research area that seeks to understand the complex relationship among variables that affect the way humans and robots work together to accomplish goals. The DRP addresses three major HRI study areas that will provide appropriate information for navigation guidance to a teleoperator of a robot system, and contribute to the closure of currently identified HRP gaps: (1) Overlays -- Use of overlays for teleoperation to augment the information available on the video feed (2) Camera views -- Type and arrangement of camera views for better task performance and awareness of surroundings (3) Command modalities -- Development of gesture and voice command vocabularies

  1. Helicopter human factors

    NASA Technical Reports Server (NTRS)

    Hart, Sandra G.

    1988-01-01

    The state-of-the-art helicopter and its pilot are examined using the tools of human-factors analysis. The significant role of human error in helicopter accidents is discussed; the history of human-factors research on helicopters is briefly traced; the typical flight tasks are described; and the noise, vibration, and temperature conditions typical of modern military helicopters are characterized. Also considered are helicopter controls, cockpit instruments and displays, and the impact of cockpit design on pilot workload. Particular attention is given to possible advanced-technology improvements, such as control stabilization and augmentation, FBW and fly-by-light systems, multifunction displays, night-vision goggles, pilot night-vision systems, night-vision displays with superimposed symbols, target acquisition and designation systems, and aural displays. Diagrams, drawings, and photographs are provided.

  2. Preparing for Human Exploration

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.; Joosten, B. Kent

    1998-01-01

    NASA's Human Exploration and Development of Space (HEDS) Enterprise is defining architectures and requirements for human exploration that radically reduce the costs of such missions through the use of advanced technologies, commercial partnerships and innovative systems strategies. In addition, the HEDS Enterprise is collaborating with the Space Science Enterprise to acquire needed early knowledge about Mars and to demonstrate critical technologies via robotic missions. This paper provides an overview of the technological challenges facing NASA as it prepares for human exploration. Emphasis is placed on identifying the key technologies including those which will provide the most return in terms of reducing total mission cost and/or reducing potential risk to the mission crew. Top-level requirements are provided for those critical enabling technology options currently under consideration.

  3. Scientists and Human Rights

    NASA Astrophysics Data System (ADS)

    Makdisi, Yousef

    2012-02-01

    The American Physical Society has a long history of involvement in defense of human rights. The Committee on International Freedom of Scientists was formed in the mid seventies as a subcommittee within the Panel On Public Affairs ``to deal with matters of an international nature that endangers the abilities of scientists to function as scientists'' and by 1980 it was established as an independent committee. In this presentation I will describe some aspects of the early history and the impetus that led to such an advocacy, the methods employed then and how they evolved to the present CIFS responsibility ``for monitoring concerns regarding human rights for scientists throughout the world''. I will also describe the current approach and some sample cases the committee has pursued recently, the interaction with other human rights organizations, and touch upon some venues through which the community can engage to help in this noble cause.

  4. Cardiovascular Deconditioning in Humans: Human Studies Core

    NASA Technical Reports Server (NTRS)

    Williams, Gordon

    1999-01-01

    Major cardiovascular problems, secondary to cardiovascular deconditioning, may occur on extended space missions. While it is generally assumed that the microgravity state is the primary cause of cardiovascular deconditioning, sleep deprivation and disruption of diurnal rhythms may also play an important role. Factors that could be modified by either or both of these perturbations include: autonomic function and short-term cardiovascular reflexes, vasoreactivity, circadian rhythm of cardiovascular hormones (specifically the renin-angiotensin system) and renal sodium handling and hormonal influences on that process, venous compliance, cardiac mass, and cardiac conduction processes. The purpose of the Human Studies Core is to provide the infrastructure to conduct human experiments which will allow for the assessment of the likely role of such factors in the space travel associated cardiovascular deconditioning process and to develop appropriate countermeasures. The Core takes advantage of a newly-created Intensive Physiologic Monitoring (IPM) Unit at the Brigham and Women's Hospital, Boston, MA, to perform these studies. The Core includes two general experimental protocols. The first protocol involves a head down tilt bed-rest study to simulate microgravity. The second protocol includes the addition of a disruption of circadian rhythms to the simulated microgravity environment. Before and after each of these environmental manipulations, the subjects will undergo acute stressors simulating changes in volume and/or stress, which could occur in space and on return to Earth. The subjects are maintained in a rigidly controlled environment with fixed light/dark cycles, activity pattern, and dietary intake of nutrients, fluids, ions and calories.

  5. Human Modeling for Ground Processing Human Factors Engineering Analysis

    NASA Technical Reports Server (NTRS)

    Stambolian, Damon B.; Lawrence, Brad A.; Stelges, Katrine S.; Steady, Marie-Jeanne O.; Ridgwell, Lora C.; Mills, Robert E.; Henderson, Gena; Tran, Donald; Barth, Tim

    2011-01-01

    There have been many advancements and accomplishments over the last few years using human modeling for human factors engineering analysis for design of spacecraft. The key methods used for this are motion capture and computer generated human models. The focus of this paper is to explain the human modeling currently used at Kennedy Space Center (KSC), and to explain the future plans for human modeling for future spacecraft designs

  6. The Exploration of Mars by Humans: Why Mars? Why Humans?

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    2011-01-01

    As we commemorate the 50th anniversary of Yuri Gagarin's historic flight in 1961, the first flight of a human in space, plans are underway for another historic human mission. Plans are being developed for a human mission to Mars. Once we reach Mars, the human species will become the first two-planet species. Both the Bush Administration (in 2004) and the Obama Administration (in 2010) proposed a human mission to Mars as a national goal of the United States.

  7. Disorders of Human Hemoglobin

    NASA Astrophysics Data System (ADS)

    Bank, Arthur; Mears, J. Gregory; Ramirez, Francesco

    1980-02-01

    Studies of the human hemoglobin system have provided new insights into the regulation of expression of a group of linked human genes, the γ -δ -β globin gene complex in man. In particular, the thalassemia syndromes and related disorders of man are inherited anemias that provide mutations for the study of the regulation of globin gene expression. New methods, including restriction enzyme analysis and cloning of cellular DNA, have made it feasible to define more precisely the structure and organization of the globin genes in cellular DNA. Deletions of specific globin gene fragments have already been found in certain of these disorders and have been applied in prenatal diagnosis.

  8. Artificial human vision.

    PubMed

    Dowling, Jason

    2005-01-01

    Can vision be restored to the blind? As early as 1929 it was discovered that stimulating the visual cortex of an individual led to the perception of spots of light, known as phosphenes [1] . The aim of artificial human vision systems is to attempt to utilize the perception of phosphenes to provide a useful substitute for normal vision. Currently, four locations for electrical stimulation are being investigated; behind the retina (subretinal), in front of the retina (epiretinal), the optic nerve and the visual cortex (using intra- and surface electrodes). This review discusses artificial human vision technology and requirements, and reviews the current development projects.

  9. Human Factors Model

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Jack is an advanced human factors software package that provides a three dimensional model for predicting how a human will interact with a given system or environment. It can be used for a broad range of computer-aided design applications. Jack was developed by the computer Graphics Research Laboratory of the University of Pennsylvania with assistance from NASA's Johnson Space Center, Ames Research Center and the Army. It is the University's first commercial product. Jack is still used for academic purposes at the University of Pennsylvania. Commercial rights were given to Transom Technologies, Inc.

  10. We Are Human Beings.

    PubMed

    McGee, Andrew

    2016-04-01

    In this paper, I examine Jeff McMahan's arguments for his claim that we are not human organisms, and the arguments of Derek Parfit to the same effect in a recent paper. McMahan uses these arguments to derive conclusions concerning the moral status of embryos and permanent vegetative state (PVS) patients. My claim will be that neither thinker has successfully shown that we are not human beings, and therefore these arguments do not establish the ethical conclusions that McMahan has sought to draw from the arguments in respect of the moral status of embryos and PVS patients.

  11. Human exploration mission studies

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    1989-01-01

    The nation's efforts to expand human presence and activity beyond Earth orbit into the solar system was given renewed emphasis in January of 1988 when the Presidential Directive on National Space Policy was signed into effect. The expansion of human presence into the solar system has particular significance, in that it defines long-range goals for NASA's future missions. To embark and achieve such ambitious ventures is a significant undertaking, particularly compared to past space activities. Missions to Mars, the Moon, and Phobos, as well as an observatory based on the dark side of the Moon are discussed.

  12. Defining the Human Microbiome

    PubMed Central

    Ursell, Luke K; Metcalf, Jessica L; Parfrey, Laura Wegener; Knight, Rob

    2012-01-01

    Rapidly developing sequencing methods and analytical techniques are enhancing our ability to understand the human microbiome, and, indeed, how we define the microbiome and its constituents. In this review we highlight recent research that expands our ability to understand the human microbiome on different spatial and temporal scales, including daily timeseries datasets spanning months. Furthermore, we discuss emerging concepts related to defining operational taxonomic units, diversity indices, core versus transient microbiomes and the possibility of enterotypes. Additional advances in sequencing technology and in our understanding of the microbiome will provide exciting prospects for exploiting the microbiota for personalized medicine. PMID:22861806

  13. Human push capability.

    PubMed

    Barnett, Ralph L; Liber, Theodore

    2006-02-22

    Use of unassisted human push capability arises from time to time in the areas of crowd and animal control, the security of locked doors, the integrity of railings, the removal of tree stumps and entrenched vehicles, the manoeuvering of furniture, and athletic pursuits such as US football or wrestling. Depending on the scenario, human push capability involves strength, weight, weight distribution, push angle, footwear/floor friction, and the friction between the upper body and the pushed object. Simple models are used to establish the relationships among these factors.

  14. Mapping Human Epigenomes

    PubMed Central

    Rivera, Chloe M.; Ren, Bing

    2013-01-01

    As the second dimension to the genome, the epigenome contains key information specific to every type of cells. Thousands of human epigenome maps have been produced in recent years thanks to rapid development of high throughput epigenome mapping technologies. In this review, we discuss the current epigenome mapping toolkit and utilities of epigenome maps. We focus particularly on mapping of DNA methylation, chromatin modification state and chromatin structures, and emphasize the use of epigenome maps to delineate human gene regulatory sequences and developmental programs. We also provide a perspective on the progress of the epigenomics field and challenges ahead. PMID:24074860

  15. Microsporidia and human infections.

    PubMed Central

    Shadduck, J A; Greeley, E

    1989-01-01

    Protozoa of the phylum Microspora are obligate intracellular pathogens that are being detected with increasing frequency in humans, especially in patients with acquired immunodeficiency syndrome. Organisms from four genera have been reported to date, and serological data suggest the occurrence of latent infections. Sources of human infections are not known, but microsporidia are widespread in lower vertebrates and invertebrates. There is no known treatment. Study of the disease in mammals suggests that infection often will be clinically silent, that intact T-cell-mediated host defenses are required for resistance, and that serious clinical disease may occur under circumstances in which extensive parasite replication can occur. Images PMID:2650860

  16. Human disease genes.

    PubMed

    Jimenez-Sanchez, G; Childs, B; Valle, D

    2001-02-15

    The complete human genome sequence will facilitate the identification of all genes that contribute to disease. We propose that the functional classification of disease genes and their products will reveal general principles of human disease. We have determined functional categories for nearly 1,000 documented disease genes, and found striking correlations between the function of the gene product and features of disease, such as age of onset and mode of inheritance. As knowledge of disease genes grows, including those contributing to complex traits, more sophisticated analyses will be possible; their results will yield a deeper understanding of disease and an enhanced integration of medicine with biology.

  17. Human MSH2 protein

    DOEpatents

    Chapelle, A. de la; Vogelstein, B.; Kinzler, K.W.

    1997-01-07

    The human MSH2 gene, responsible for hereditary non-polyposis colorectal cancer, was identified by virtue of its homology to the MutS class of genes, which are involved in DNA mismatch repair. The sequence of cDNA clones of the human gene are provided, and the sequence of the gene can be used to demonstrate the existence of germ line mutations in hereditary non-polyposis colorectal cancer (HNPCC) kindreds, as well as in replication error{sup +} (RER{sup +}) tumor cells. 19 figs.

  18. Human MSH2 protein

    DOEpatents

    de la Chapelle, Albert; Vogelstein, Bert; Kinzler, Kenneth W.

    1997-01-01

    The human MSH2 gene, responsible for hereditary non-polyposis colorectal cancer, was identified by virtue of its homology to the MutS class of genes, which are involved in DNA mismatch repair. The sequence of cDNA clones of the human gene are provided, and the sequence of the gene can be used to demonstrate the existence of germ line mutations in hereditary non-polyposis colorectal cancer (HNPCC) kindreds, as well as in replication error.sup.+ (RER.sup.+) tumor cells.

  19. Biodemography of human ageing

    PubMed Central

    Vaupel, James W.

    2014-01-01

    Human senescence has been delayed by a decade. This finding, documented in 1994 and bolstered since, is a fundamental discovery about the biology of human ageing, and one with profound implications for individuals, society and the economy. Remarkably, the rate of deterioration with age seems to be constant across individuals and over time: it seems that death is being delayed because people are reaching old age in better health. Research by demographers, epidemiologists and other biomedical researchers suggests that further progress is likely to be made in advancing the frontier of survival — and healthy survival — to even greater ages. PMID:20336136

  20. We Are Human Beings.

    PubMed

    McGee, Andrew

    2016-04-01

    In this paper, I examine Jeff McMahan's arguments for his claim that we are not human organisms, and the arguments of Derek Parfit to the same effect in a recent paper. McMahan uses these arguments to derive conclusions concerning the moral status of embryos and permanent vegetative state (PVS) patients. My claim will be that neither thinker has successfully shown that we are not human beings, and therefore these arguments do not establish the ethical conclusions that McMahan has sought to draw from the arguments in respect of the moral status of embryos and PVS patients. PMID:26810918

  1. Human dignity and human tissue: a meaningful ethical relationship?

    PubMed

    Kirchhoffer, David G; Dierickx, Kris

    2011-09-01

    Human dignity has long been used as a foundational principle in policy documents and ethical guidelines intended to govern various forms of biomedical research. Despite the vast amount of literature concerning human dignity and embryonic tissues, the majority of biomedical research uses non-embryonic human tissue. Therefore, this contribution addresses a notable lacuna in the literature: the relationship, if any, between human dignity and human tissue. This paper first elaborates a multidimensional understanding of human dignity that overcomes many of the shortcomings associated with the use of human dignity in other ethical debates. Second, it discusses the relationship between such an understanding of human dignity and 'non-embryonic' human tissue. Finally, it considers the implications of this relationship for biomedical research and practice involving human tissue. The contribution demonstrates that while human tissue cannot be said to have human dignity, human dignity is nevertheless implicated by human tissue, making what is done with human tissue and how it is done worthy of moral consideration.

  2. Human Rights: The Essential Reference.

    ERIC Educational Resources Information Center

    Devine, Carol; Hansen, Carol Rae; Wilde, Ralph; Bronkhorst, Daan; Moritz, Frederic A.; Rolle, Baptiste; Sherman, Rebecca; Southard, Jo Lynn; Wilkinson, Robert; Poole, Hilary, Ed.

    This reference work documents the history of human rights theory, explains each article of the Universal Declaration of Human Rights, explores the contemporary human rights movement, and examines the major human rights issues facing the world today. This book is the first to combine historical and contemporary perspectives on these critical…

  3. Making IBM's Computer, Watson, Human

    ERIC Educational Resources Information Center

    Rachlin, Howard

    2012-01-01

    This essay uses the recent victory of an IBM computer (Watson) in the TV game, "Jeopardy," to speculate on the abilities Watson would need, in addition to those it has, to be human. The essay's basic premise is that to be human is to behave as humans behave and to function in society as humans function. Alternatives to this premise are considered…

  4. Human Challenges in Exploration Missions

    NASA Technical Reports Server (NTRS)

    Lloyd, Charles W.

    2007-01-01

    This viewgraph presents an overview using pictures some of the history of human exploration of the new frontiers of Earth and then examines some of the challenges to human exploration of space. Particular attention is given to the environmental factors and to the social and human factors that effect humans in space environments.

  5. Sacred Sounds in the Humanities.

    ERIC Educational Resources Information Center

    Kelly, Robert A.

    To see literature as a sign and a symbol simply reasserts the view of the humanities as the embodiment of the highest aspirations of human nature. Human beings are sign givers and symbol makers as they look for the sacred meaning in their lives. Through a college humanities course, some of the symbols that artists employ in fiction, poetry, drama,…

  6. Humanizing the Earth

    ERIC Educational Resources Information Center

    Dubos, Rene J.

    1973-01-01

    By using scientific knowledge and ecological wisdom, new ecosystems can be created which will be more stable, profitable, and favorable to the continued growth of civilization. Nature by itself has not taken care of many problems of ecological interest in past and human intervention is necessary. (PS)

  7. Animal and human influenzas.

    PubMed

    Peiris, M; Yen, H-L

    2014-08-01

    Influenza type A viruses affect humans and other animals and cause significant morbidity, mortality and economic impact. Influenza A viruses are well adapted to cross species barriers and evade host immunity. Viruses that cause no clinical signs in wild aquatic birds may adapt in domestic poultry to become highly pathogenic avian influenza viruses which decimate poultry flocks. Viruses that cause asymptomatic infection in poultry (e.g. the recently emerged A/H7N9 virus) may cause severe zoonotic disease and pose a major pandemic threat. Pandemic influenza arises at unpredictable intervals from animal viruses and, in its global spread, outpaces current technologies for making vaccines against such novel viruses. Confronting the threat of influenza in humans and other animals is an excellent example of a task that requires a One Health approach. Changes in travel, trade in livestock and pets, changes in animal husbandry practices, wet markets and complex marketing chains all contribute to an increased risk of the emergence of novel influenza viruses with the ability to cross species barriers, leading to epizootics or pandemics. Coordinated surveillance at the animal- human interface for pandemic preparedness, risk assessment, risk reduction and prevention at source requires coordinated action among practitioners in human and animal health and the environmental sciences. Implementation of One Health in the field can be challenging because of divergent short-term objectives. Successful implementation requires effort, mutual trust, respect and understanding to ensure that long-term goals are achieved without adverse impacts on agricultural production and food security.

  8. Futures of Human Communication.

    ERIC Educational Resources Information Center

    Harms, L. S.

    There are several research areas basic to the long-range future of human communications. Telecommunication and transportation offer the possiblity of two worldwide communications networks whose interrelationships need to be explored in terms of the needs of the individual, the community, and the world at large. Expanding possibilities of…

  9. Human Resource Information System

    ERIC Educational Resources Information Center

    Swinford, Paul

    1978-01-01

    A computer at Valley View Schools, Illinois, is used to collect, store, maintain, and retrieve information about a school district's human resources. The system was designed to increase the efficiency and thoroughness of personnel and payroll record keeping, and reporting functions. (Author/MLF)

  10. Toward a Technical Humanism

    ERIC Educational Resources Information Center

    Malassis, Louis

    1977-01-01

    Examines the relationship between education and development in developing nations. Advocates the fostering of a technical humanism--the development of knowledge in all its forms as a basis for action. In this system, technical education is as highly valued as general education. The system, and its applications to rural education is discussed. (CP)

  11. Humane Treatment of Animals.

    ERIC Educational Resources Information Center

    Dawson, Joan Smithey

    This booklet is designed to give teachers resource information about the humane treatment of and care for animals. The topics are presented as springboards for discussion and class activity. Topics include the care of dogs, cats, birds, horses, and fish; wildlife and ecological relationships; and careers with animals. Illustrations on some pages…

  12. The Human Potential Movement.

    ERIC Educational Resources Information Center

    Tamashiro, Roy T.

    The advent of the human potential movement has generated the expectation that educators unleash the intellectual, emotional, physical, and spiritual talents of students. This movement is characterized by its focus on (1) the person as a total being, (2) the needs and concerns of students, (3) phenomenology, (4) personal values and goals, and (5)…

  13. "Healthy" Human Development Indices

    ERIC Educational Resources Information Center

    Engineer, Merwan; Roy, Nilanjana; Fink, Sari

    2010-01-01

    In the Human Development Index (HDI), life expectancy is the only indicator used in modeling the dimension "a long and healthy life". Whereas life expectancy is a direct measure of quantity of life, it is only an indirect measure of healthy years lived. In this paper we attempt to remedy this omission by introducing into the HDI the morbidity…

  14. Designers of Human Settlements

    ERIC Educational Resources Information Center

    Cliff, Ursula

    1976-01-01

    Reviewed herein are the ideas of nine men who have addressed themselves to the problems of human settlements in this century. The ideas reviewed include those of Arnold Toynbee, Lewis Mumford, Hassan Fathy, Buckminster Fuller, Constantinos Doxiadis, Charles Correa, Paul Mwaluko, Robert McNamara and John F. C. Turner. (BT)

  15. Who Hung the Humanities?

    ERIC Educational Resources Information Center

    Lambert, David

    2013-01-01

    This paper is partly based on a lecture given at the AGTA conference in Perth in January 2013. It argues for a progressive subject based curriculum in which geography plays an essential part. This is based on an analysis of why and how subjects like geography, as part of the humanities, have been undermined and diminished in recent times. In a way…

  16. Human grasp point selection.

    PubMed

    Kleinholdermann, Urs; Franz, Volker H; Gegenfurtner, Karl R

    2013-07-25

    When we grasp an object, our visuomotor system has to solve an intricate problem: how to find the best out of an infinity of possible contact points of the fingers with the object? The contact point selection model (CoPS) we present here solves this problem and predicts human grasp point selection in precision grip grasping by combining a few basic rules that have been identified in human and robotic grasping. Usually, not all of the rules can be perfectly satisfied. Therefore, we assessed their relative importance by creating simple stimuli that put them into conflict with each other in pairs. Based on these conflict experiments we made model-based grasp point predictions for another experiment with a novel set of complexly shaped objects. The results show that our model predicts the human choice of grasp points very well, and that observers' preferences for their natural grasp angles is as important as physical stability constraints. Incorporating a human grasp point selection model like the one presented here could markedly improve current approaches to cortically guided arm and hand prostheses by making movements more natural while also allowing for a more efficient use of the available information.

  17. Parasites and human evolution.

    PubMed

    Perry, George H

    2014-01-01

    Our understanding of human evolutionary and population history can be advanced by ecological and evolutionary studies of our parasites. Many parasites flourish only in the presence of very specific human behaviors and in specific habitats, are wholly dependent on us, and have evolved with us for thousands or millions of years. Therefore, by asking when and how we first acquired those parasites, under which environmental and cultural conditions we are the most susceptible, and how the parasites have evolved and adapted to us and we in response to them, we can gain considerable insight into our own evolutionary history. As examples, the tapeworm life cycle is dependent on our consumption of meat, the divergence of body and head lice may have been subsequent to the development of clothing, and malaria hyperendemicity may be associated with agriculture. Thus, the evolutionary and population histories of these parasites are likely intertwined with critical aspects of human biology and culture. Here I review the mechanics of these and multiple other parasite proxies for human evolutionary history and discuss how they currently complement our fossil, archeological, molecular, linguistic, historical, and ethnographic records. I also highlight potential future applications of this promising model for the field of evolutionary anthropology.

  18. "HUMANITIES" AS A SUBJECT.

    ERIC Educational Resources Information Center

    KUHNS, RICHARD

    SINCE MOST OF THE SCHOOL CURRICULUM IS DEVOTED TO SPECIALIZED DISCIPLINES, HUMANITIES COURSES PROVIDE THE OPPORTUNITY FOR CREATING IN STUDENTS AN AWARENESS OF THE UNITY WHICH EXISTS AMONG PHILOSOPHY, HISTORY, AND THE ARTS. INTENSIVE STUDY AND CLASS DISCUSSION OF INDIVIDUAL WORKS BECOMES IMPOSSIBLE, HOWEVER, WHEN TOO MANY BOOKS ARE CROWDED INTO A…

  19. Antihumanism in the Humanities.

    ERIC Educational Resources Information Center

    Schwartz, Joel

    1990-01-01

    Analyzes the antihumanistic elements of Jacques Derrida's theory of deconstruction. Argues that the modern French intellectuals, including Foucault, Derrida, and Lacan, have had an antihumanistic effect on the American social sciences and humanities by rejecting the existence of truth, morality, and rationality. (FMW)

  20. Reconsidering Human Performance Technology

    ERIC Educational Resources Information Center

    Jang, Hwan Young

    2008-01-01

    This article discusses three perceived challenges in the field of human performance technology: a missing link from training to performance, limitations in gap analysis and cause analysis, and a lack of attention to business and organization performance. It then provides possible alternatives for each issue, such as instructional system…

  1. Occupying the Digital Humanities

    ERIC Educational Resources Information Center

    Rice, Jeff

    2013-01-01

    This essay questions the digital humanities' dependence on interpretation and critique as strategies for reading and responding to texts. Instead, the essay proposes suggestion as a digital rhetorical practice, one that does not replace hermeneutics, but instead offers alternative ways to respond to texts. The essay uses the Occupy movement as an…

  2. Human Biology: Experimental.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Bureau of Curriculum Development.

    Education is a process of adapting to change, and the rate of change is especially rapid in science today. This curriculum in human biology is an alternative to the New York State courses in general and Regents biology, and it has been designed to focus on change from the standpoint of the urban student. It is designed to provide students with…

  3. Biotechnologies and Human Dignity

    ERIC Educational Resources Information Center

    Sweet, William; Masciulli, Joseph

    2011-01-01

    In this article, the authors review some contemporary cases where biotechnologies have been employed, where they have had global implications, and where there has been considerable debate. The authors argue that the concept of dignity, which lies at the center of such documents as the 2005 Universal Declaration on Bioethics and Human Rights, the…

  4. Human Memory: The Basics

    ERIC Educational Resources Information Center

    Martinez, Michael E.

    2010-01-01

    The human mind has two types of memory: short-term and long-term. In all types of learning, it is best to use that structure rather than to fight against it. One way to do that is to ensure that learners can fit new information into patterns that can be stored in and more easily retrieved from long-term memory.

  5. Human Learning and Memory

    ERIC Educational Resources Information Center

    Lieberman, David A.

    2012-01-01

    This innovative textbook is the first to integrate learning and memory, behaviour, and cognition. It focuses on fascinating human research in both memory and learning (while also bringing in important animal studies) and brings the reader up to date with the latest developments in the subject. Students are encouraged to think critically: key…

  6. Marketing Human Resource Development.

    ERIC Educational Resources Information Center

    Frank, Eric, Ed.

    1994-01-01

    Describes three human resource development activities: training, education, and development. Explains marketing from the practitioners's viewpoint in terms of customer orientation; external and internal marketing; and market analysis, research, strategy, and mix. Shows how to design, develop, and implement strategic marketing plans and identify…

  7. Humanizing the Workplace.

    ERIC Educational Resources Information Center

    Fairfield, Roy P., Ed.

    A series of essays discussing ideas about humanizing work are presented in the document. Three major sections divide the essays, and each includes a preface with comments suggesting the central focus and questions with which the authors are concerned. The first section deals with the history, philosophy, and issues related to work and contains…

  8. Strengthening Career Human Agency

    ERIC Educational Resources Information Center

    Chen, Charles P.

    2006-01-01

    Rooted in A. Bandura's (1982, 2001b) social cognitive theory, the notion of human agency has received considerable attention in vocational and career psychology for the last 2 decades, especially with the recent emergence of social constructivist thinking in the field. This article continues in the same direction. In reviewing the notion of human…

  9. Sarcocystis in Humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Humans serve as definitive hosts for two known species of Sarcocystis, acquired from eating undercooked pork or beef, and resulting in gastrointestinal infection. Sporocysts excreted from these infected persons are each infectious for pigs and cattle, the intermediate hosts, resulting in the develop...

  10. Human thimet oligopeptidase.

    PubMed Central

    Dando, P M; Brown, M A; Barrett, A J

    1993-01-01

    We have purified human thimet oligopeptidase to homogeneity from erythrocytes, and compared it with the enzyme from rat testis and chicken liver. An antiserum raised against rat thimet oligopeptidase also recognized the human and chicken enzymes, suggesting that the structure of the enzyme has been strongly conserved in evolution. Consistent with this, the properties of the human enzyme were very similar to those for the other species. Thus human thimet oligopeptidase also is a thiol-dependent metallo-oligopeptidase with M(r) about 75,000. Specificity for cleavage of a number of peptides was indistinguishable from that of the rat enzyme, but Ki values for the four potent reversible inhibitors tested were lower. In discussing the results, we consider the determinants of the complex substrate specificity of thimet oligopeptidase. We question whether substrates containing more than 17 amino acid residues are cleaved, as has been suggested. We also point out that the favourable location of a proline residue and a free C-terminus in the substrate may be as important as the hydrophobic residues in the P2, P1 and P3' positions that have been emphasized in the past. Images Figure 1 PMID:8373360

  11. Human Aggression and Suicide

    ERIC Educational Resources Information Center

    Brown, Gerald L.; Goodwin, Frederick K

    1986-01-01

    The central nervous system transmitter serontonin may be altered in aggressive/impulsive and suicidal behaviors in humans. These reports are largely consistent with animal data, and constitute one of the most highly replicated set of findings in biological psychiatry. Suggests that some suicidal behavior may be a special kind of aggressive…

  12. Communicating Humanism Nonverbally.

    ERIC Educational Resources Information Center

    Hillison, John

    1983-01-01

    Discusses the importance of nonverbal communication by counselors in expressing humanistic feeling. Notes that facial expression (i.e., smiling) provides immediate feedback to the observer; use of space (i.e., close proximity) communicates warmth and humaneness; and tone of voice can complement spoken words and give them more meaning. (WAS)

  13. Trends in Humanities Programming.

    ERIC Educational Resources Information Center

    Vavrek, Bernard, Ed.; Whitney, Loralyn, Ed.

    Proceedings from this workshop sponsored by the Center for the Study of Rural Librarianship are intended to disseminate information to assist rural librarians engaged in planning and conducting public programs that explore issues related to the humanities. This report of the proceedings includes the texts of three presented papers, reactions from…

  14. Television's New Humane Collectivity.

    ERIC Educational Resources Information Center

    Schrag, Robert L.; And Others

    1981-01-01

    Analyzes "Taxi,""Barney Miller,""Lou Grant," and "M*A*S*H" in terms of three fantasy themes: the realization of significant others, the alliance in action, and membership into personhood. From these themes emerges a rhetorical vision of the new humane collectivity. (PD)

  15. Structurally abnormal human autosomes

    SciTech Connect

    1993-12-31

    Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

  16. Neurobiology and the Humanities

    PubMed Central

    Zeki, Semir

    2014-01-01

    Can the arts and humanities contribute significantly to the study of the brain? Similar brain processes are involved in humanistic and scientific inference, and in this essay, I argue that conclusions reached by one are relevant to the other. PMID:25277451

  17. Radar: Human Safety Net

    ERIC Educational Resources Information Center

    Ritz, John M.

    2016-01-01

    Radar is a technology that can be used to detect distant objects not visible to the human eye. A predecessor of radar, called the telemobiloscope, was first used to detect ships in the fog in 1904 off the German coast. Many scientists have worked on the development and refinement of radar (Hertz with electromagnetic waves; Popov with determining…

  18. Developing Human Values.

    ERIC Educational Resources Information Center

    Hall, Brian P.; And Others

    The process by which human beings, as they grow toward maturity, develop values is not an automatic one. The process can be fostered by a number of teaching strategies. The strategies include the techniques of self-discovery, the provision of learning environments that encourage growth, and the practice of specific skills. This volume provides a…

  19. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. PMID:27486731

  20. Human Babesiosis, Bolivia, 2013

    PubMed Central

    Gabrielli, Simona; Totino, Valentina; Macchioni, Fabio; Zuñiga, Freddy; Rojas, Patricia; Lara, Yuni; Roselli, Mimmo; Cancrini, Gabriella

    2016-01-01

    To investigate human babesiosis in the Bolivian Chaco, in 2013 we tested blood samples from 271 healthy persons living in 2 rural communities in this region. Microscopy and PCR indicated that 3.3% of persons were positive for Babesia microti parasites (US lineage); seroprevalence was 45.7%. Appropriate screening should mitigate the risk for transfusion-associated babesiosis. PMID:27434696

  1. Human Development Student Modules.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This set of 61 student learning modules deals with various topics pertaining to human development. The modules, which are designed for use in performance-based vocational education programs, each contain the following components: an introduction for the student, a performance objective, a variety of learning activities, content information, a…

  2. Humans as Lie Detectors.

    ERIC Educational Resources Information Center

    DePaulo, Bella; And Others

    1980-01-01

    Discusses several studies of whether and how well humans can detect lies. Examines the accuracy of such persons as well as the process of how they actually detect lies, how they think they detect lies, and whether the actual and perceived processes of lie detection correspond to one another. (JMF)

  3. Food Affects Human Behavior.

    ERIC Educational Resources Information Center

    Kolata, Gina

    1982-01-01

    A conference on whether food and nutrients affect human behavior was held on November 9, 1982 at the Massachusetts Institute of Technology. Various research studies on this topic are reviewed, including the effects of food on brain biochemistry (particularly sleep) and effects of tryptophane as a pain reducer. (JN)

  4. The Humanities, Unraveled

    ERIC Educational Resources Information Center

    Berube, Michael

    2013-01-01

    Graduate education in the humanities is in crisis. Every aspect, from the most specific details of the curriculum to the broadest questions about its purpose, is in crisis. It is a seamless garment of crisis: If one pulls on any one thread, the entire thing unravels. It is therefore exceptionally difficult to discuss any one aspect of graduate…

  5. Conceptualizations of Human Environments

    ERIC Educational Resources Information Center

    Moos, Rudolf H.

    1973-01-01

    Presents six major methods by which characteristics of environments have been related to indexes of human functioning: (1) ecological dimensions; (2) behavior settings; (3) dimensions of organizational structure; and, (4) dimensions identifying the collective personal and/or behavioral characteristics of the milieu inhabitants; and two others.…

  6. Predictors of human rotation.

    PubMed

    Stochl, Jan; Croudace, Tim

    2013-01-01

    Why some humans prefer to rotate clockwise rather than anticlockwise is not well understood. This study aims to identify the predictors of the preferred rotation direction in humans. The variables hypothesised to influence rotation preference include handedness, footedness, sex, brain hemisphere lateralisation, and the Coriolis effect (which results from geospatial location on the Earth). An online questionnaire allowed us to analyse data from 1526 respondents in 97 countries. Factor analysis showed that the direction of rotation should be studied separately for local and global movements. Handedness, footedness, and the item hypothesised to measure brain hemisphere lateralisation are predictors of rotation direction for both global and local movements. Sex is a predictor of the direction of global rotation movements but not local ones, and both sexes tend to rotate clockwise. Geospatial location does not predict the preferred direction of rotation. Our study confirms previous findings concerning the influence of handedness, footedness, and sex on human rotation; our study also provides new insight into the underlying structure of human rotation movements and excludes the Coriolis effect as a predictor of rotation.

  7. Tackling Human Rights

    ERIC Educational Resources Information Center

    McLester, Susan

    2005-01-01

    In 2003, four high school students from the Tashkent International School in the capital city confronted the issue of their nation's human rights problems head on by researching the topic and publishing their findings on the Web. The site, "Uzbekistan: Opaque Reality," was created as an entry for the non-profit Global SchoolNet's Doors to…

  8. Learning to Be Human

    ERIC Educational Resources Information Center

    Macmurray, John

    2012-01-01

    This article presents "Learning to be Human", which John Macmurray delivered on 5 May 1958 as the annual public lecture at Moray House College of Education, now part of Edinburgh University. The key themes of the paper are ones to which Macmurray returned again and again in both his educational and his philosophical writing for over 40 years and…

  9. Communicating with Virtual Humans.

    ERIC Educational Resources Information Center

    Thalmann, Nadia Magnenat

    The face is a small part of a human, but it plays an essential role in communication. An open hybrid system for facial animation is presented. It encapsulates a considerable amount of information regarding facial models, movements, expressions, emotions, and speech. The complex description of facial animation can be handled better by assigning…

  10. Humanism in Education

    ERIC Educational Resources Information Center

    Armstrong, Michael

    2015-01-01

    This is the text of Michael Armstrong's address to the Brian Simon Centenary conference, held at the Institute of Education on 26 March 2015. Michael Armstrong celebrates the humanism that underlay Brian's belief in a common system of education, democratic and non-selective, and finds its counterpart in the creative practice of school children.

  11. Human growth hormone.

    PubMed

    Strobl, J S; Thomas, M J

    1994-03-01

    The study of human growth hormone is a little more than 100 years old. Growth hormone, first identified for its dramatic effect on longitudinal growth, is now known to exert generalized effects on protein, lipid, and carbohydrate metabolism. Additional roles for growth hormone in human physiology are likely to be discovered in the areas of sleep research and reproduction. Furthermore, there is some indication that growth hormone also may be involved in the regulation of immune function, mental well-being, and the aging process. Recombinant DNA technology has provided an abundant and safe, albeit expensive, supply of human growth hormone for human use, but the pharmacological properties of growth hormone are poor. Most growth hormone-deficient individuals exhibit a secretory defect rather than a primary defect in growth hormone production, however, and advances in our understanding of the neuroendocrine regulation of growth hormone secretion have established the basis for the use of drugs to stimulate release of endogenously synthesized growth hormone. This promises to be an important area for future drug development. PMID:8190748

  12. Human Social Genomics

    PubMed Central

    Cole, Steven W.

    2014-01-01

    A growing literature in human social genomics has begun to analyze how everyday life circumstances influence human gene expression. Social-environmental conditions such as urbanity, low socioeconomic status, social isolation, social threat, and low or unstable social status have been found to associate with differential expression of hundreds of gene transcripts in leukocytes and diseased tissues such as metastatic cancers. In leukocytes, diverse types of social adversity evoke a common conserved transcriptional response to adversity (CTRA) characterized by increased expression of proinflammatory genes and decreased expression of genes involved in innate antiviral responses and antibody synthesis. Mechanistic analyses have mapped the neural “social signal transduction” pathways that stimulate CTRA gene expression in response to social threat and may contribute to social gradients in health. Research has also begun to analyze the functional genomics of optimal health and thriving. Two emerging opportunities now stand to revolutionize our understanding of the everyday life of the human genome: network genomics analyses examining how systems-level capabilities emerge from groups of individual socially sensitive genomes and near-real-time transcriptional biofeedback to empirically optimize individual well-being in the context of the unique genetic, geographic, historical, developmental, and social contexts that jointly shape the transcriptional realization of our innate human genomic potential for thriving. PMID:25166010

  13. Human performance measuring device

    NASA Technical Reports Server (NTRS)

    Michael, J.; Scow, J.

    1970-01-01

    Complex coordinator, consisting of operator control console, recorder, subject display panel, and limb controls, measures human performance by testing perceptual and motor skills. Device measures psychophysiological functions in drug and environmental studies, and is applicable to early detection of psychophysiological body changes.

  14. Human chromosome 8.

    PubMed Central

    Wood, S

    1988-01-01

    The role of human chromosome 8 in genetic disease together with the current status of the genetic linkage map for this chromosome is reviewed. Both hereditary genetic disease attributed to mutant alleles at gene loci on chromosome 8 and neoplastic disease owing to somatic mutation, particularly chromosomal translocations, are discussed. PMID:3070042

  15. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection.

  16. The Human Toxome Project

    EPA Science Inventory

    The Human Toxome project, funded as an NIH Transformative Research grant 2011--‐ 2016, is focused on developing the concepts and the means for deducing, validating, and sharing molecular Pathways of Toxicity (PoT). Using the test case of estrogenic endocrine disruption, the respo...

  17. Fighting for the Humanities

    ERIC Educational Resources Information Center

    Nelson, Cary

    2012-01-01

    The question, "Who will bankroll poetry?", succinctly embodies what is now a widespread recognition that the humanities may have more to lose in the current budget wars than either the sciences or a number of technical fields. The only budget war that can unite individuals, rather than divide them, is one arguing that too much is being spent on…

  18. Fighting for Human Rights

    ERIC Educational Resources Information Center

    Ong, Bao

    2011-01-01

    Speak Truth To Power consists of 17 teacher-developed lessons based on the stories of rights advocates from all over the world. The lessons were created for sixth-through 12th-grade students, and have come to New York schools thanks to the Robert F. Kennedy Center for Justice and Human Rights and the New York State United Teachers union. Speak…

  19. Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Sandor, Aniko; Cross, E. Vincent, II; Chang, Mai Lee

    2015-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces affect the human's ability to perform tasks effectively and efficiently when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. For efficient and effective remote navigation of a rover, a human operator needs to be aware of the robot's environment. However, during teleoperation, operators may get information about the environment only through a robot's front-mounted camera causing a keyhole effect. The keyhole effect reduces situation awareness which may manifest in navigation issues such as higher number of collisions, missing critical aspects of the environment, or reduced speed. One way to compensate for the keyhole effect and the ambiguities operators experience when they teleoperate a robot is adding multiple cameras and including the robot chassis in the camera view. Augmented reality, such as overlays, can also enhance the way a person sees objects in the environment or in camera views by making them more visible. Scenes can be augmented with integrated telemetry, procedures, or map information. Furthermore, the addition of an exocentric (i.e., third-person) field of view from a camera placed in the robot's environment may provide operators with the additional information needed to gain spatial awareness of the robot. Two research studies investigated possible mitigation approaches to address the keyhole effect: 1) combining the inclusion of the robot chassis in the camera view with augmented reality overlays, and 2) modifying the camera

  20. Making Human Beings Human: Bioecological Perspectives on Human Development. The SAGE Program on Applied Developmental Science

    ERIC Educational Resources Information Center

    Bronfenbrenner, Urie, Ed.

    2004-01-01

    To a greater extent than any other species, human beings create the environments that, in turn, shape their own development. This book endeavors to demonstrate that human beings can also develop those environments to optimize their most constructive genetic potentials. What makes human beings human, therefore, is both the potential to shape their…

  1. Helicopter Human Factors

    NASA Technical Reports Server (NTRS)

    Hart, Sandra G.; Sridhar, Banavar (Technical Monitor)

    1995-01-01

    Even under optimal conditions, helicopter flight is a most demanding form of human-machine interaction, imposing continuous manual, visual, communications, and mental demands on pilots. It is made even more challenging by small margins for error created by the close proximity of terrain in NOE flight and missions flown at night and in low visibility. Although technology advances have satisfied some current and proposed requirements, hardware solutions alone are not sufficient to ensure acceptable system performance and pilot workload. However, human factors data needed to improve the design and use of helicopters lag behind advances in sensor, display, and control technology. Thus, it is difficult for designers to consider human capabilities and limitations when making design decisions. This results in costly accidents, design mistakes, unrealistic mission requirements, excessive training costs, and challenge human adaptability. NASA, in collaboration with DOD, industry, and academia, has initiated a program of research to develop scientific data bases and design principles to improve the pilot/vehicle interface, optimize training time and cost, and maintain pilot workload and system performance at an acceptable level. Work performed at Ames, and by other research laboratories, will be reviewed to summarize the most critical helicopter human factors problems and the results of research that has been performed to: (1) Quantify/model pilots use of visual cues for vehicle control; (2) Improve pilots' performance with helmet displays of thermal imagery and night vision goggles for situation awareness and vehicle control; (3) Model the processes by which pilots encode maps and compare them to the visual scene to develop perceptually and cognitively compatible electronic map formats; (4) Evaluate the use of spatially localized auditory displays for geographical orientation, target localization, radio frequency separation; (5) Develop and flight test control

  2. [Tuberculosis and human rights].

    PubMed

    Nagai, Hideaki; Inagaki, Tomokazu; Toyoda, Emiko; Kawabe, Yoshiko; Fujiwara, Keiko; Masuyama, Hidenori; Takahashi, Shigeru

    2005-01-01

    Tuberculosis (TB) patients must be hospitalized while the smear of sputum is positive because TB spreads through air. Cooperation of a patient is important in order to complete the treatment of TB. However, a small number of patients are noncooperative for the treatment and may sometimes refuse it. At this symposium, we discussed about whether we could restrict the human rights of noncooperative TB patients. Although the patients' human rights must be protected, we also have to protect the human rights of people who may receive TB infection. The balance of the both people's rights is fully considered in the TB control policy. It is epoch-making that the TB society took up the theme about the human rights' restriction of TB patients. Five speakers presented their papers from each position. There were presentations about the scientific evidence of isolation, the actual cases, the situation of the United States, and the legal view on the human rights' restriction of TB patients. The present situation and the legal problems in Japan became clear at this symposium. We need further discussion about the human rights' restriction of TB patients for the revision of the Tuberculosis Protection Act and have to obtain the national consensus on it. 1. The evidence for isolation: Emiko TOYODA (International Medical Center of Japan) To determine appropriate periods of respiratory isolation, available biological, clinical, and epidemiological issues and data were studied. Although absolute lack of infectiousness requires consecutive culture negative and it takes too long and impractical periods. There seems to be no established evidence for noncontagiousness after 2 to 3 weeks effective treatment. Practically conversion to 3 negative consecutive smear results may used as a surrogate for noninfectiousness, even though a small risk of transmission still be present. Chemical isolation has been more important and administration with DOT should be indicated to keep compliance. 2

  3. The Universal Declaration on the Human Genome and Human Rights.

    PubMed

    Mayor, Federico

    2003-01-01

    Since 1985, UNESCO studies ethical questions arising in genetics. In 1992, I established the International Bioethics Committee at UNESCO with the mission to draft the Universal Declaration on the Human Genome and Human Rights, which was adopted by UNESCO in 1997 and the United Nations in 1998. The Declaration relates the human genome with human dignity, deals with the rights of the persons concerned by human genome research and provides a reference legal framework for both stimulating the ethical debate and the harmonization of the law worldwide, favouring useful developments that respect human dignity. PMID:14744123

  4. The science of unitary human beings and interpretive human science.

    PubMed

    Reeder, F

    1993-01-01

    Natural science and human science are identified as the bases of most nursing theories and research programs. Natural science has been disclaimed by Martha Rogers as the philosophy of science that undergirds her work. The question remains, is the science of unitary human beings an interpretive human science? The author explores the works of Rogers through a dialectic with two human scientists' works. Wilhelm Dilthey's works represent the founding or traditional view, and Jurgen Habermas' works represent a contemporary, reconstructionist view. The ways Rogerian thought contributes to human studies but is distinct from traditional and reconstructionist human sciences are illuminated.

  5. Clay catalysis of oligonucleotide formation: kinetics of the reaction of the 5'-phosphorimidazolides of nucleotides with the non-basic heterocycles uracil and hypoxanthine

    NASA Technical Reports Server (NTRS)

    Kawamura, K.; Ferris, J. P.

    1999-01-01

    The montmorillonite clay catalyzed condensation of activated monocleotides to oligomers of RNA is a possible first step in the formation of the proposed RNA world. The rate constants for the condensation of the phosphorimidazolide of adenosine were measured previously and these studies have been extended to the phosphorimidazolides of inosine and uridine in the present work to determine of substitution of neutral heterocycles for the basic adenine ring changes the reaction rate or regioselectivity. The oligomerization reactions of the 5'-phosphoromidazolides of uridine (ImpU) and inosine (ImpI) on montmorillonite yield oligo(U)s and oligo(I)s as long as heptamers. The rate constants for oligonucleotide formation were determined by measuring the rates of formation of the oligomers by HPLC. Both the apparent rate constants in the reaction mixture and the rate constants on the clay surface were calculated using the partition coefficients of the oligomers between the aqueous and clay phases. The rate constants for trimer formation are much greater than those dimer synthesis but there was little difference in the rate constants for the formation of trimers and higher oligomers. The overall rates of oligomerization of the phosphorimidazolides of purine and pyrimidine nucleosides in the presence of montmorillonite clay are the same suggesting that RNA formed on the primitive Earth could have contained a variety of heterocyclic bases. The rate constants for oligomerization of pyrimidine nucleotides on the clay surface are significantly higher than those of purine nucleotides since the pyrimidine nucleotides bind less strongly to the clay than do the purine nucleotides. The differences in the binding is probably due to Van der Waals interactions between the purine bases and the clay surface. Differences in the basicity of the heterocyclic ring in the nucleotide have little effect on the oligomerization process.

  6. Zygomycetes in Human Disease

    PubMed Central

    Ribes, Julie A.; Vanover-Sams, Carolyn L.; Baker, Doris J.

    2000-01-01

    The Zygomycetes represent relatively uncommon isolates in the clinical laboratory, reflecting either environmental contaminants or, less commonly, a clinical disease called zygomycosis. There are two orders of Zygomycetes containing organisms that cause human disease, the Mucorales and the Entomophthorales. The majority of human illness is caused by the Mucorales. While disease is most commonly linked to Rhizopus spp., other organisms are also associated with human infection, including Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces, and Syncephalastrum spp. Although Mortierella spp. do cause disease in animals, there is no longer sufficient evidence to suggest that they are true human pathogens. The spores from these molds are transmitted by inhalation, via a variety of percutaneous routes, or by ingestion of spores. Human zygomycosis caused by the Mucorales generally occurs in immunocompromised hosts as opportunistic infections. Host risk factors include diabetes mellitus, neutropenia, sustained immunosuppressive therapy, chronic prednisone use, iron chelation therapy, broad-spectrum antibiotic use, severe malnutrition, and primary breakdown in the integrity of the cutaneous barrier such as trauma, surgical wounds, needle sticks, or burns. Zygomycosis occurs only rarely in immunocompetent hosts. The disease manifestations reflect the mode of transmission, with rhinocerebral and pulmonary diseases being the most common manifestations. Cutaneous, gastrointestinal, and allergic diseases are also seen. The Mucorales are associated with angioinvasive disease, often leading to thrombosis, infarction of involved tissues, and tissue destruction mediated by a number of fungal proteases, lipases, and mycotoxins. If the diagnosis is not made early, dissemination often occurs. Therapy, if it is to be effective, must be started early and requires combinations of antifungal drugs, surgical intervention, and reversal of the underlying risk

  7. A focus on human flourishing.

    PubMed

    Bunkers, Sandra Schmidt

    2010-10-01

    In this column the author focuses on the concepts of human vulnerability and human flourishing. A parable is presented highlighting the importance of now, the present, in human flourishing. A bioethical, anthropological perspective and a nursing humanbecoming perspective on human flourishing are offered. Nursing education is challenged to emphasize the nursing theories of the discipline to teach the concept of human flourishing. Parse's concept of true presence, the four postulates of humanbecoming, and the humanbecoming community change concepts illuminate a nursing theoretical understanding of human flourishing. PMID:20870999

  8. Human Capital Accumulation: The Role of Human Resource Development.

    ERIC Educational Resources Information Center

    Garavan, Thomas N.; Morley, Michael; Gunnigle, Patrick; Collins, Eammon

    2001-01-01

    Presents definitions of intellectual and human capital. Examines human capital from the individual perspective (employability, performance, career development) and organization perspective (investment, ownership, knowledge management). Reviews papers in the theme issue. (Contains 117 references.) (SK)

  9. Posthumanism: beyond humanism?

    PubMed

    Valera, Luca

    2014-01-01

    The focal point of posthumanism consists not as such in an a-critical acceptance of the technological promises - like there is for transhumanism - but in a total contamination and hybridization of human beings with other living beings and machines (these are the two main forms of contamination). The change of perspective untaken by posthumanism would be, thus, a paradigmatic shift in anthropology. As with ecologism, posthumanism, in order to obtain total contamination and man's openness to otherness, proposes the elimination and the fluidification of boundaries, thus even denying man's identity, and, with it, the very possibility of openness. However, by denying the identity, one denies the condition of possibility of thought, just as it has been manifested in history until now: hence we understand how, primarily, posthumanism is not configured as an adequate philosophical reflection, but as a narrative that takes origin from certain requirements, which are eminently human, and that discloses its deeply anthropogenic roots.

  10. Fractionating human intelligence.

    PubMed

    Hampshire, Adam; Highfield, Roger R; Parkin, Beth L; Owen, Adrian M

    2012-12-20

    What makes one person more intellectually able than another? Can the entire distribution of human intelligence be accounted for by just one general factor? Is intelligence supported by a single neural system? Here, we provide a perspective on human intelligence that takes into account how general abilities or "factors" reflect the functional organization of the brain. By comparing factor models of individual differences in performance with factor models of brain functional organization, we demonstrate that different components of intelligence have their analogs in distinct brain networks. Using simulations based on neuroimaging data, we show that the higher-order factor "g" is accounted for by cognitive tasks corecruiting multiple networks. Finally, we confirm the independence of these components of intelligence by dissociating them using questionnaire variables. We propose that intelligence is an emergent property of anatomically distinct cognitive systems, each of which has its own capacity.

  11. [Human dignity revisited].

    PubMed

    Pereira-Menaut, Antonio Carlos; Pereira Sáez, Carolina

    2014-01-01

    Since World War II, human dignity has made its way into many constitutions, bills of rights and international treaties. As its roots can be traced easily back to the Judeo-Christian tradition, and, later on, to the influential Kantian vision, dignity cannot be deemed an entirely new concept. For the same token, it cannot be said that dignity has been entirely alien to the legal realm till 1945. On the other hand, the latest philosophical and anthropological trends, as well as the politicisation of the human being, along with some recent advances in biotechnologies, help to explain its growing presence in the legal world. However, these authors suggest that writing down dignity in legal texts does not fully settle its meaning, not even if such texts are constitutions, and the fact remains that its presence in the judicial reasoning does not always imply being the ratio decidendi, as the study of some relevant judicial decisions shows. PMID:25329413

  12. Studying the Human Microbiota.

    PubMed

    Walker, Alan W

    2016-01-01

    There are a range of methodologies available to study the human microbiota, ranging from traditional approaches such as culturing through to state-of-the-art developments in next generation DNA sequencing technologies. The advent of molecular techniques in particular has opened up tremendous new avenues for research, and has galvanised interest in the study of our microbial inhabitants. Given the dazzling array of available options, however, it is important to understand the inherent advantages and limitations of each technique so that the best approach can be employed to address the particular research objective. In this chapter we cover some of the most widely used current techniques in human microbiota research and highlight the particular strengths and caveats associated with each approach. PMID:27161348

  13. Altruistic punishment in humans.

    PubMed

    Fehr, Ernst; Gächter, Simon

    2002-01-10

    Human cooperation is an evolutionary puzzle. Unlike other creatures, people frequently cooperate with genetically unrelated strangers, often in large groups, with people they will never meet again, and when reputation gains are small or absent. These patterns of cooperation cannot be explained by the nepotistic motives associated with the evolutionary theory of kin selection and the selfish motives associated with signalling theory or the theory of reciprocal altruism. Here we show experimentally that the altruistic punishment of defectors is a key motive for the explanation of cooperation. Altruistic punishment means that individuals punish, although the punishment is costly for them and yields no material gain. We show that cooperation flourishes if altruistic punishment is possible, and breaks down if it is ruled out. The evidence indicates that negative emotions towards defectors are the proximate mechanism behind altruistic punishment. These results suggest that future study of the evolution of human cooperation should include a strong focus on explaining altruistic punishment.

  14. Hyaluronan in human malignancies

    SciTech Connect

    Sironen, R.K.; Tammi, M.; Tammi, R.; Auvinen, P.K.; Anttila, M.; Kosma, V-M.

    2011-02-15

    Hyaluronan, a major macropolysaccharide in the extracellular matrix of connective tissues, is intimately involved in the biology of cancer. Hyaluronan accumulates into the stroma of various human tumors and modulates intracellular signaling pathways, cell proliferation, motility and invasive properties of malignant cells. Experimental and clinicopathological evidence highlights the importance of hyaluronan in tumor growth and metastasis. A high stromal hyaluronan content is associated with poorly differentiated tumors and aggressive clinical behavior in human adenocarcinomas. Instead, the squamous cell carcinomas and malignant melanomas tend to have a reduced hyaluronan content. In addition to the stroma-cancer cell interaction, hyaluronan can influence stromal cell recruitment, tumor angiogenesis and epithelial-mesenchymal transition. Hyaluronan receptors, hyaluronan synthases and hyaluronan degrading enzymes, hyaluronidases, are involved in the modulation of cancer progression, depending on the tumor type. Furthermore, intracellular signaling and angiogenesis are affected by the degradation products of hyaluronan. Hyaluronan has also therapeutic implications since it is involved in multidrug resistance.

  15. Ancient human microbiomes

    PubMed Central

    Warinner, Christina; Speller, Camilla; Collins, Matthew J.; Lewis, Cecil M.

    2015-01-01

    Very recently, we discovered a vast new microbial self: the human microbiome. Our native microbiota interface with our biology and culture to influence our health, behavior, and quality of life, and yet we know very little about their origin, evolution, or ecology. With the advent of industrialization, globalization, and modern sanitation, it is intuitive that we have changed our relationship with microbes, but we have little information about the ancestral state of our microbiome, and therefore, we lack a foundation for characterizing this change. High-throughput sequencing has opened up new opportunities in the field of paleomicrobiology, allowing us to investigate the evolution of the complex microbial ecologies that inhabit our bodies. By focusing on recent coprolite and dental calculus research, we explore how emerging research on ancient human microbiomes is changing the way we think about ancient disease and how archaeological studies can contribute to a medical understanding of health and nutrition today. PMID:25559298

  16. Secure Distributed Human Computation

    NASA Astrophysics Data System (ADS)

    Gentry, Craig; Ramzan, Zulfikar; Stubblebine, Stuart

    In Peha’s Financial Cryptography 2004 invited talk, he described the Cyphermint PayCash system (see www.cyphermint.com), which allows people without bank accounts or credit cards (a sizeable segment of the U.S. population) to automatically and instantly cash checks, pay bills, or make Internet transactions through publicly-accessible kiosks. Since PayCash offers automated financial transactions and since the system uses (unprotected) kiosks, security is critical. The kiosk must decide whether a person cashing a check is really the person to whom the check was made out, so it takes a digital picture of the person cashing the check and transmits this picture electronically to a central office, where a human worker compares the kiosk’s picture to one that was taken when the person registered with Cyphermint. If both pictures are of the same person, then the human worker authorizes the transaction.

  17. Recombinant Human Erythropoietin

    PubMed Central

    Bartels, Claudia; Späte, Kira; Krampe, Henning

    2008-01-01

    Treatment of multiple sclerosis (MS) is still unsatisfactory and essentially non-existing for the progressive course of the disease. Recombinant human erythropoietin (EPO) may be a promising neuroprotective/neuroregenerative treatment of MS. In the nervous system, EPO acts anti-apoptotic, antioxidative, anti-inflammatory, neurotrophic and plasticity-modulating. Beneficial effects have been shown in animal models of various neurological and psychiatric diseases, including different models of experimental autoimmune encephalomyelitis. EPO is also effective in human brain disease, as shown in double-blind placebo-controlled clinical studies on ischemic stroke and chronic schizophrenia. An exploratory study on chronic progressive MS yielded lasting improvement in motor and cognitive performance upon high-dose long-term EPO treatment. PMID:21180577

  18. Human-centric sensing.

    PubMed

    Srivastava, Mani; Abdelzaher, Tarek; Szymanski, Boleslaw

    2012-01-13

    The first decade of the century witnessed a proliferation of devices with sensing and communication capabilities in the possession of the average individual. Examples range from camera phones and wireless global positioning system units to sensor-equipped, networked fitness devices and entertainment platforms (such as Wii). Social networking platforms emerged, such as Twitter, that allow sharing information in real time. The unprecedented deployment scale of such sensors and connectivity options ushers in an era of novel data-driven applications that rely on inputs collected by networks of humans or measured by sensors acting on their behalf. These applications will impact domains as diverse as health, transportation, energy, disaster recovery, intelligence and warfare. This paper surveys the important opportunities in human-centric sensing, identifies challenges brought about by such opportunities and describes emerging solutions to these challenges. PMID:22124088

  19. Human DNA repair genes.

    PubMed

    Wood, R D; Mitchell, M; Sgouros, J; Lindahl, T

    2001-02-16

    Cellular DNA is subjected to continual attack, both by reactive species inside cells and by environmental agents. Toxic and mutagenic consequences are minimized by distinct pathways of repair, and 130 known human DNA repair genes are described here. Notable features presently include four enzymes that can remove uracil from DNA, seven recombination genes related to RAD51, and many recently discovered DNA polymerases that bypass damage, but only one system to remove the main DNA lesions induced by ultraviolet light. More human DNA repair genes will be found by comparison with model organisms and as common folds in three-dimensional protein structures are determined. Modulation of DNA repair should lead to clinical applications including improvement of radiotherapy and treatment with anticancer drugs and an advanced understanding of the cellular aging process. PMID:11181991

  20. Epidemiology of human listeriosis.

    PubMed Central

    Schuchat, A; Swaminathan, B; Broome, C V

    1991-01-01

    During the 1980s, investigation of several large epidemics of listeriosis confirmed that transmission of L. monocytogenes in food causes human disease. Progress in laboratory detection and subtyping of the organism has enhanced our ability to compare human and environmental isolates of L. monocytogenes. Transmission by foodborne organisms is now recognized as causing both epidemic and sporadic listeriosis. Continued study of dietary risk factors associated with listeriosis is needed in order to develop dietary recommendations for the expanding population at increased risk of disease. Current research application of new molecular methods to the study of L. monocytogenes may improve the ability to diagnose pregnancy-associated disease and permit the rapid detection and control of L. monocytogenes in the food supply. PMID:1906370