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Sample records for elevated dopa decarboxylase

  1. DOPA Decarboxylase Modulates Tau Toxicity.

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    Kow, Rebecca L; Sikkema, Carl; Wheeler, Jeanna M; Wilkinson, Charles W; Kraemer, Brian C

    2018-03-01

    The microtubule-associated protein tau accumulates into toxic aggregates in multiple neurodegenerative diseases. We found previously that loss of D 2 -family dopamine receptors ameliorated tauopathy in multiple models including a Caenorhabditis elegans model of tauopathy. To better understand how loss of D 2 -family dopamine receptors can ameliorate tau toxicity, we screened a collection of C. elegans mutations in dopamine-related genes (n = 45) for changes in tau transgene-induced behavioral defects. These included many genes responsible for dopamine synthesis, metabolism, and signaling downstream of the D 2 receptors. We identified one dopamine synthesis gene, DOPA decarboxylase (DDC), as a suppressor of tau toxicity in tau transgenic worms. Loss of the C. elegans DDC gene, bas-1, ameliorated the behavioral deficits of tau transgenic worms, reduced phosphorylated and detergent-insoluble tau accumulation, and reduced tau-mediated neuron loss. Loss of function in other genes in the dopamine and serotonin synthesis pathways did not alter tau-induced toxicity; however, their function is required for the suppression of tau toxicity by bas-1. Additional loss of D 2 -family dopamine receptors did not synergize with bas-1 suppression of tauopathy phenotypes. Loss of the DDC bas-1 reduced tau-induced toxicity in a C. elegans model of tauopathy, while loss of no other dopamine or serotonin synthesis genes tested had this effect. Because loss of activity upstream of DDC could reduce suppression of tau by DDC, this suggests the possibility that loss of DDC suppresses tau via the combined accumulation of dopamine precursor levodopa and serotonin precursor 5-hydroxytryptophan. Published by Elsevier Inc.

  2. L-Dopa decarboxylase expression profile in human cancer cells.

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    Chalatsa, Ioanna; Nikolouzou, Eleftheria; Fragoulis, Emmanuel G; Vassilacopoulou, Dido

    2011-02-01

    L-Dopa decarboxylase (DDC) catalyses the decarboxylation of L-Dopa. It has been shown that the DDC gene undergoes alternative splicing within its 5'-untranslated region (UTR), in a tissue-specific manner, generating identical protein products. The employment of two alternative 5'UTRs is thought to be responsible for tissue-specific expression of the human DDC mRNA. In this study, we focused on the investigation of the nature of the mRNA expression in human cell lines of neural and non-neural origin. Our results show the expression of a neural-type DDC mRNA splice variant, lacking exon 3 in all cell lines studied. Co-expression of the full length non-neural DDC mRNA and the neural-type DDC splice variant lacking exon 3 was detected in all cell lines. The alternative DDC protein isoform, Alt-DDC, was detected in SH-SY5Y and HeLa cells. Our findings suggest that the human DDC gene undergoes complex processing, leading to the formation of multiple mRNA isoforms. The study of the significance of this phenomenon of multiple DDC mRNA isoforms could provide us with new information leading to the elucidation of the complex biological pathways that the human enzyme is involved in.

  3. The DOPA decarboxylase (DDC) gene is associated with alerting attention.

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    Zhu, Bi; Chen, Chuansheng; Moyzis, Robert K; Dong, Qi; Chen, Chunhui; He, Qinghua; Li, Jin; Li, Jun; Lei, Xuemei; Lin, Chongde

    2013-06-03

    DOPA decarboxylase (DDC) is involved in the synthesis of dopamine, norepinephrine and serotonin. It has been suggested that genes involved in the dopamine, norepinephrine, and cholinergic systems play an essential role in the efficiency of human attention networks. Attention refers to the cognitive process of obtaining and maintaining the alert state, orienting to sensory events, and regulating the conflicts of thoughts and behavior. The present study tested seven single nucleotide polymorphisms (SNPs) within the DDC gene for association with attention, which was assessed by the Attention Network Test to detect three networks of attention, including alerting, orienting, and executive attention, in a healthy Han Chinese sample (N=451). Association analysis for individual SNPs indicated that four of the seven SNPs (rs3887825, rs7786398, rs10499695, and rs6969081) were significantly associated with alerting attention. Haplotype-based association analysis revealed that alerting was associated with the haplotype G-A-T for SNPs rs7786398-rs10499695-rs6969081. These associations remained significant after correcting for multiple testing by max(T) permutation. No association was found for orienting and executive attention. This study provides the first evidence for the involvement of the DDC gene in alerting attention. A better understanding of the genetic basis of distinct attention networks would allow us to develop more effective diagnosis, treatment, and prevention of deficient or underdeveloped alerting attention as well as its related prevalent neuropsychiatric disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Dopa decarboxylase (Ddc) affects variation in Drosophila longevity.

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    De Luca, Maria; Roshina, Nataliya V; Geiger-Thornsberry, Gretchen L; Lyman, Richard F; Pasyukova, Elena G; Mackay, Trudy F C

    2003-08-01

    Mutational analyses in model organisms have shown that genes affecting metabolism and stress resistance regulate life span, but the genes responsible for variation in longevity in natural populations are largely unidentified. Previously, we mapped quantitative trait loci (QTLs) affecting variation in longevity between two Drosophila melanogaster strains. Here, we show that the longevity QTL in the 36E;38B cytogenetic interval on chromosome 2 contains multiple closely linked QTLs, including the Dopa decarboxylase (Ddc) locus. Complementation tests to mutations show that Ddc is a positional candidate gene for life span in these strains. Linkage disequilibrium (LD) mapping in a sample of 173 alleles from a single population shows that three common molecular polymorphisms in Ddc account for 15.5% of the genetic contribution to variance in life span from chromosome 2. The polymorphisms are in strong LD, and the effects of the haplotypes on longevity suggest that the polymorphisms are maintained by balancing selection. DDC catalyzes the final step in the synthesis of the neurotransmitters, dopamine and serotonin. Thus, these data implicate variation in the synthesis of bioamines as a factor contributing to natural variation in individual life span.

  5. Interaction of Human Dopa Decarboxylase with L-Dopa: Spectroscopic and Kinetic Studies as a Function of pH

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    Riccardo Montioli

    2013-01-01

    Full Text Available Human Dopa decarboxylase (hDDC, a pyridoxal 5′-phosphate (PLP enzyme, displays maxima at 420 and 335 nm and emits fluorescence at 384 and 504 nm upon excitation at 335 nm and at 504 nm when excited at 420 nm. Absorbance and fluorescence titrations of hDDC-bound coenzyme identify a single pKspec of ~7.2. This pKspec could not represent the ionization of a functional group on the Schiff base but that of an enzymic residue governing the equilibrium between the low- and the high-pH forms of the internal aldimine. During the reaction of hDDC with L-Dopa, monitored by stopped-flow spectrophotometry, a 420 nm band attributed to the 4′-N-protonated external aldimine first appears, and its decrease parallels the emergence of a 390 nm peak, assigned to the 4′-N-unprotonated external aldimine. The pH profile of the spectral change at 390 nm displays a pK of 6.4, a value similar to that (~6.3 observed in both kcat and kcat/Km profiles. This suggests that this pK represents the ESH+ → ES catalytic step. The assignment of the pKs of 7.9 and 8.3 observed on the basic side of kcat and the PLP binding affinity profiles, respectively, is also analyzed and discussed.

  6. A Dopa Decarboxylase Modulating the Immune Response of Scallop Chlamys farreri

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    Zhou, Zhi; Yang, Jialong; Wang, Lingling; Zhang, Huan; Gao, Yang; Shi, Xiaowei; Wang, Mengqiang; Kong, Pengfei; Qiu, Limei; Song, Linsheng

    2011-01-01

    Background Dopa decarboxylase (DDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. Methodology The full-length cDNA encoding DDC (designated CfDDC) was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, PDDC inhibitor methyldopa, the ROS level in haemocytes of scallops was decreased significantly to 0.41-fold (PDDC in scallop, modulated the immune responses such as haemocytes encapsulation as well as the ROS level through its catalytic activity, functioning as an indispensable immunomodulating enzyme in the neuroendocrine-immune regulatory network of mollusc. PMID:21533240

  7. Identification by virtual screening and in vitro testing of human DOPA decarboxylase inhibitors.

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    Frederick Daidone

    Full Text Available Dopa decarboxylase (DDC, a pyridoxal 5'-phosphate (PLP enzyme responsible for the biosynthesis of dopamine and serotonin, is involved in Parkinson's disease (PD. PD is a neurodegenerative disease mainly due to a progressive loss of dopamine-producing cells in the midbrain. Co-administration of L-Dopa with peripheral DDC inhibitors (carbidopa or benserazide is the most effective symptomatic treatment for PD. Although carbidopa and trihydroxybenzylhydrazine (the in vivo hydrolysis product of benserazide are both powerful irreversible DDC inhibitors, they are not selective because they irreversibly bind to free PLP and PLP-enzymes, thus inducing diverse side effects. Therefore, the main goals of this study were (a to use virtual screening to identify potential human DDC inhibitors and (b to evaluate the reliability of our virtual-screening (VS protocol by experimentally testing the "in vitro" activity of selected molecules. Starting from the crystal structure of the DDC-carbidopa complex, a new VS protocol, integrating pharmacophore searches and molecular docking, was developed. Analysis of 15 selected compounds, obtained by filtering the public ZINC database, yielded two molecules that bind to the active site of human DDC and behave as competitive inhibitors with K(i values ≥10 µM. By performing in silico similarity search on the latter compounds followed by a substructure search using the core of the most active compound we identified several competitive inhibitors of human DDC with K(i values in the low micromolar range, unable to bind free PLP, and predicted to not cross the blood-brain barrier. The most potent inhibitor with a K(i value of 500 nM represents a new lead compound, targeting human DDC, that may be the basis for lead optimization in the development of new DDC inhibitors. To our knowledge, a similar approach has not been reported yet in the field of DDC inhibitors discovery.

  8. L-dopa decarboxylase (DDC) gene expression is related to outcome in patients with prostate cancer.

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    Koutalellis, Georgios; Stravodimos, Konstantinos; Avgeris, Margaritis; Mavridis, Konstantinos; Scorilas, Andreas; Lazaris, Andreas; Constantinides, Constantinos

    2012-09-01

    What's known on the subject? and What does the study add? L-dopa decarboxylase (DDC) has been documented as a novel co-activator of androgen receptor transcriptional activity. Recently, it was shown that DDC gene expression is significantly higher in patients with PCa than in those with BPH. In the present study, there was a significant association between the DDC gene expression levels and the pathological stage and Gleason score of patients with prostate cancer (PCa). Moreover, DDC expression was shown to be an unfavourable prognostic marker of biochemical recurrence and disease-free survival in patients with PCa treated by radical prostatectomy. To determine whether L-dopa decarboxylase gene (DDC) expression levels in patients with prostate cancer (PCa) correlate to biochemical recurrence and disease prognosis after radical prostatectomy (RP). The present study consisted of 56 samples with confirmed malignancy from patients with PCa who had undergone RP at a single tertiary academic centre. Total RNA was isolated from tissue specimens and a SYBR Green fluorescence-based quantitative real-time polymerase chain reaction methodology was developed for the determination of DDC mRNA expression levels of the tested tissues. Follow-up time ranged between 1.0 and 62.0 months (mean ± SE, 28.6 ± 2.1 month; median, 31.5 months). Time to biochemical recurrence was defined as the interval between the surgery and the measurement of two consecutive values of prostate-specific antigen (PSA) ≥0.2 ng/mL. DDC expression levels were found to be positively correlated with the tumour-node-metastasis stage (P = 0.021) and Gleason score (P = 0.036) of the patients with PCa. Patients with PCa with raised DDC expression levels run a significantly higher risk of biochemical recurrence after RP, as indicated by Cox proportional regression analysis (P = 0.021). Multivariate Cox proportional regression models revealed the preoperative PSA-, age- and digital rectal examination

  9. Haplotype analysis indicates an association between the DOPA decarboxylase (DDC) gene and nicotine dependence.

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    Ma, Jennie Z; Beuten, Joke; Payne, Thomas J; Dupont, Randolph T; Elston, Robert C; Li, Ming D

    2005-06-15

    DOPA decarboxylase (DDC; also known as L-amino acid decarboxylase; AADC) is involved in the synthesis of dopamine, norepinephrine and serotonin. Because the mesolimbic dopaminergic system is implicated in the reinforcing effects of many drugs, including nicotine, the DDC gene is considered a plausible candidate for involvement in the development of vulnerability to nicotine dependence (ND). Further, this gene is located within the 7p11 region that showed a 'suggestive linkage' to ND in our previous genome-wide scan in the Framingham Heart Study population. In the present study, we tested eight single nucleotide polymorphisms (SNPs) within DDC for association with ND, which was assessed by smoking quantity (SQ), the heaviness of smoking index (HSI) and the Fagerstrom test for ND (FTND) score, in a total of 2037 smokers and non-smokers from 602 nuclear families of African- or European-American (AA or EA, respectively) ancestry. Association analysis for individual SNPs using the PBAT-GEE program indicated that SNP rs921451 was significantly associated with two of the three adjusted ND measures in the EA sample (P=0.01-0.04). Haplotype-based association analysis revealed a protective T-G-T-G haplotype for rs921451-rs3735273-rs1451371-rs2060762 in the AA sample, which was significantly associated with all three adjusted ND measures after correction for multiple testing (min Z=-2.78, P=0.006 for HSI). In contrast, we found a high-risk T-G-T-G haplotype for a different SNP combination in the EA sample, rs921451-rs3735273-rs1451371-rs3757472, which showed a significant association after Bonferroni correction with the SQ and FTND score (max Z=2.73, P=0.005 for FTND). In summary, our findings provide the first evidence for the involvement of DDC in the susceptibility to ND and, further, reveal the racial specificity of its impact.

  10. Nucleotide variation at the dopa decarboxylase (Ddc) gene in natural populations of Drosophila melanogaster.

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    Tatarenkov, Andrey; Ayala, Francisco J

    2007-08-01

    We studied nucleotide sequence variation at the gene coding for dopa decarboxylase (Ddc) in seven populations of Drosophila melanogaster. Strength and pattern of linkage disequilibrium are somewhat distinct in the extensively sampled Spanish and Raleigh populations. In the Spanish population, a few sites are in strong positive association, whereas a large number of sites in the Raleigh population are associated nonrandomly but the association is not strong. Linkage disequilibrium analysis shows presence of two groups of haplotypes in the populations, each of which is fairly diverged, suggesting epistasis or inversion polymorphism. There is evidence of two forms of natural selection acting on Ddc. The McDonald-Kreitman test indicates a deficit of fixed amino acid differences between D. melanogaster and D. simulans, which may be due to negative selection. An excess of derived alleles at high frequency, significant according to the H-test, is consistent with the effect of hitchhiking. The hitchhiking may have been caused by directional selection downstream of the locus studied, as suggested by a gradual decrease of the polymorphism-to-divergence ratio. Altogether, the Ddc locus exhibits a complicated pattern of variation apparently due to several evolutionary forces. Such a complex pattern may be a result of an unusually high density of functionally important genes.

  11. Common Variation in the DOPA Decarboxylase (DDC) Gene and Human Striatal DDC Activity In Vivo.

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    Eisenberg, Daniel P; Kohn, Philip D; Hegarty, Catherine E; Ianni, Angela M; Kolachana, Bhaskar; Gregory, Michael D; Masdeu, Joseph C; Berman, Karen F

    2016-08-01

    The synthesis of multiple amine neurotransmitters, such as dopamine, norepinephrine, serotonin, and trace amines, relies in part on DOPA decarboxylase (DDC, AADC), an enzyme that is required for normative neural operations. Because rare, loss-of-function mutations in the DDC gene result in severe enzymatic deficiency and devastating autonomic, motor, and cognitive impairment, DDC common genetic polymorphisms have been proposed as a source of more moderate, but clinically important, alterations in DDC function that may contribute to risk, course, or treatment response in complex, heritable neuropsychiatric illnesses. However, a direct link between common genetic variation in DDC and DDC activity in the living human brain has never been established. We therefore tested for this association by conducting extensive genotyping across the DDC gene in a large cohort of 120 healthy individuals, for whom DDC activity was then quantified with [(18)F]-FDOPA positron emission tomography (PET). The specific uptake constant, Ki, a measure of DDC activity, was estimated for striatal regions of interest and found to be predicted by one of five tested haplotypes, particularly in the ventral striatum. These data provide evidence for cis-acting, functional common polymorphisms in the DDC gene and support future work to determine whether such variation might meaningfully contribute to DDC-mediated neural processes relevant to neuropsychiatric illness and treatment.

  12. Expression analysis and clinical utility of L-Dopa decarboxylase (DDC) in prostate cancer.

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    Avgeris, Margaritis; Koutalellis, Georgios; Fragoulis, Emmanuel G; Scorilas, Andreas

    2008-10-01

    L-Dopa decarboxylase (DDC) is a pyridoxal 5'-phosphate-dependent enzyme that was found to be involved in many malignancies. The aim of this study was to investigate the mRNA expression levels of DDC in prostate tissues and to evaluate its clinical utility in prostate cancer (CaP). Total RNA was isolated from 118 tissue specimens from benign prostate hyperplasia (BPH) and CaP patients and a highly sensitive quantitative real-time RT-PCR (qRT-PCR) method for DDC mRNA quantification has been developed using the SYBR Green chemistry. LNCaP prostate cancer cell line was used as a calibrator and GAPDH as a housekeeping gene. DDC was found to be overexpressed, at the mRNA level, in the specimens from prostate cancer patients, in comparison to those from benign prostate hyperplasia patients (pDDC expression has significant discriminatory value between CaP and BPH (pDDC expression status was compared with other established prognostic factors, in prostate cancer. High expression levels of DDC were found more frequently in high Gleason's score tumors (p=0.022) as well as in advanced stage patients (p=0.032). Our data reveal the potential of DDC expression, at the mRNA level, as a novel biomarker in prostate cancer.

  13. A dopa decarboxylase modulating the immune response of scallop Chlamys farreri.

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    Zhi Zhou

    Full Text Available BACKGROUND: Dopa decarboxylase (DDC is a pyridoxal 5-phosphate (PLP-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. METHODOLOGY: The full-length cDNA encoding DDC (designated CfDDC was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, P<0.05 at 3 h and reached the peak at 12 h (9.8-fold, P<0.05, and then recovered to the baseline level. The recombinant protein of CfDDC (rCfDDC was expressed in Escherichia coli BL21 (DE3-Transetta, and 1 mg rCfDDC could catalyze the production of 1.651±0.22 ng dopamine within 1 h in vitro. When the haemocytes were incubated with rCfDDC-coated agarose beads, the haemocyte encapsulation to the beads was increased significantly from 70% at 6 h to 93% at 24 h in vitro in comparison with that in the control (23% at 6 h to 25% at 24 h, and the increased haemocyte encapsulation was repressed by the addition of rCfDDC antibody (which is acquired via immunization 6-week old rats with rCfDDC. After the injection of DDC inhibitor methyldopa, the ROS level in haemocytes of scallops was decreased significantly to 0.41-fold (P<0.05 of blank group at 12 h and 0.47-fold (P<0.05 at 24 h, respectively. CONCLUSIONS: These results collectively suggested that CfDDC, as a homologue of DDC in scallop, modulated the immune responses such as haemocytes encapsulation as well as the ROS level through its catalytic activity, functioning as an indispensable immunomodulating enzyme in the neuroendocrine-immune regulatory network of mollusc.

  14. L-Dopa decarboxylase (DDC) constitutes an emerging biomarker in predicting patients' survival with stomach adenocarcinomas.

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    Florou, Dimitra; Papadopoulos, Iordanis N; Fragoulis, Emmanuel G; Scorilas, Andreas

    2013-02-01

    Stomach adenocarcinoma represents a major health problem and is regarded as the second commonest cause of cancer-associated mortality, universally, since it is still difficult to be perceived at a curable stage. Several lines of evidence have pointed out that the expression of L-Dopa decarboxylase (DDC) gene and/or protein becomes distinctively modulated in several human neuroendocrine neoplasms as well as adenocarcinomas. In order to elucidate the clinical role of DDC on primary gastric adenocarcinomas, we determined qualitatively and quantitatively the mRNA levels of the gene with regular PCR and real-time PCR by using the comparative threshold cycle method, correspondingly, and detected the expression of DDC protein by immunoblotting in cancerous and normal stomach tissue specimens. A statistically significant association was disclosed between DDC expression and gastric intestinal histotype as well as tumor localization at the distal third part of the stomach (p = 0.025 and p = 0.029, respectively). Univariate and multivariate analyses highlighted the powerful prognostic importance of DDC in relation to disease-free survival and overall survival of gastric cancer patients. According to Kaplan-Meier curves, the relative risk of relapse was found to be decreased in DDC-positive (p = 0.031) patients who, also, exhibited higher overall survival rates (p = 0.016) than those with DDC-negative tumors. This work is the first to shed light on the potential clinical usefulness of DDC, as an efficient tumor biomarker in gastric cancer. The provided evidence underlines the propitious predictive value of DDC expression in the survival of stomach adenocarcinoma patients.

  15. In silico screening of potent natural inhibitor compounds against Human DOPA Decarboxylase for management of Parkinson’s Disease

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    Surya Narayan Rath

    2017-12-01

    Full Text Available Loss of dopaminergic neurons of the substantia nigra of the mid brain is a well studied pathophysiology of Parkinson’s disease (PD, is the second most common neurodegenerative disorder. To compensate dopamine levels at the Central Nervous System (CNS exogenous L-Dopa is generally administered. But the major part of the L-Dopa is metabolized by Dopa decarboxylase (DDC, E.C. 4.1.1.28, a pyridoxal 5’ –phosphate (PLP enzyme, which is abundant in CNS and hence, only 1-5% of L-Dopa reaches to dopaminergic neurons. In this context, co-administration of peripheral DDC inhibitors (carbidopa or benserazide has been successfully used for the symptomatic treatment of PD patients. But, due to use of synthetic drugs many adverse effects have been reported during treatment. Therefore, the current study is planned to discover some plant based potent natural inhibitors against human DDC as an alternative way for the management of PD. This study was conducted through virtual screening and molecular docking of DDC enzyme with phytochemicals like withania somnifera (ashwagandha, glycine max (soybean, vicia faba (broad bean, and marsilea quadrifolia (sunsunia etc to evaluate their inhibition properties. In silico study results shown a good binding affinity and predicted some of the phytochemicals as potent natural inhibitors against human DDC. This work could be validated further through experimental procedures.

  16. Positron emission tomographic studies on aromatic L-amino acid decarboxylase activity in vivo for L-dopa and 5-hydroxy-L-tryptophan in the monkey brain

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    Hartvig, P; Tedroff, J; Lindner, K J; Bjurling, P; Chang, C W; Laangstroem, B [Uppsala Univ. (Sweden); Tsukada, H [Central Research Lab., Hamamatsu Photonics Shizuoka, Osaka (Japan); Watanabe, Y [Dept. of Neuroscience, Osaka Bioscience Inst., Osaka (Japan)

    1993-01-01

    The regional brain kinetics following 5-hydroxy-L-([beta]-11 C)tryptophan and L-([beta]-11 C)DOPA intravenous injection was measured in twelve Rhesus monkeys using positron emission tomography (PET). The radiolabelled compounds were also injected together with various doses of unlabelled 5-hydroxy-L-tryptophan or L-DOPA. The radioactivity accumulated in the striatal region and the rate of increased utilization with time was calculated using a graphical method with back of the brain as a reference region. The rate constants for decarboxylation were 0.0070 [+-] 0.0007 (S. D) and 0.0121 [+-] 0.0010 min[sup -1] for 5-hydroxy-L-([beta]-11 C)tryptophan and L-([beta]-11 C)DOPA, respectively. After concomitant injection with unlabelled 5-hydroxy-L-tryptophan, the rate constant of 5-hydroxy-L-([beta]-11 C)tryptophan decreased dose-dependently and a 50 percent reduction was seen with a dose of about 4 mg/kg of unlabelled compound. A decreased utilization rate of L-([beta]-11 C)DOPA was seen only after simultaneous injection of 30 mg/kg of either L-DOPA or 5-hydroxy-L-tryptophan. This capacity limitation was most likely interpreted as different affinity of the striatal aromatic amino acid decarboxylase for L-DOPA and 5-hydroxy-L-tryptophan, respectively.

  17. Lack of Association Between Polymorphisms in Dopa Decarboxylase and Dopamine Receptor-1 Genes With Childhood Autism in Chinese Han Population.

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    Yu, Hong; Liu, Jun; Yang, Aiping; Yang, Guohui; Yang, Wenjun; Lei, Heyue; Quan, Jianjun; Zhang, Zengyu

    2016-04-01

    Genetic factors play an important role in childhood autism. This study is to determine the association of single-nucleotide polymorphisms in dopa decarboxylase (DDC) and dopamine receptor-1 (DRD1) genes with childhood autism, in a Chinese Han population. A total of 211 autistic children and 250 age- and gender-matched healthy controls were recruited. The severity of disease was determined by Children Autism Rating Scale scores. TaqMan Probe by real-time polymerase chain reaction was used to determine genotypes and allele frequencies of single-nucleotide polymorphism rs6592961 in DDC and rs251937 in DRD1. Case-control and case-only studies were respectively performed, to determine the contribution of both single-nucleotide polymorphisms to the predisposition of disease and its severity. Our results showed that there was no significant association of the genotypes and allele frequencies of both single-nucleotide polymorphisms concerning childhood autism and its severity. More studies with larger samples are needed to corroborate their predicting roles. © The Author(s) 2015.

  18. Construction of an Unstable Ring-X Chromosome Bearing the Autosomal Dopa Decarboxylase Gene in Drosophila melanogaster and Analysis of Ddc Mosaics

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    Gailey, Donald A.; Bordne, Deborah L.; Vallés, Ana Maria; Hall, Jeffrey C.; White, Kalpana

    1987-01-01

    An unstable Ring-X chromosome, Ddc+- Ring-X carrying a cloned Dopa decarboxylase (Ddc) encoding segment was constructed. The construction involved a double recombination event between the unstable Ring-X, R(1)wvC and a Rod-X chromosome which contained a P-element mediated Ddc + insert. The resulting Ddc+-Ring-X chromosome behaves similarly to the parent chromosome with respect to somatic instability. The Ddc+-Ring-X chromosome was used to generate Ddc mosaics. Analyses of Ddc mosaics reveal...

  19. L-DOPA decarboxylase mRNA expression is associated with tumor stage and size in head and neck squamous cell carcinoma: a retrospective cohort study

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    Geomela Panagiota-Aikaterini

    2012-10-01

    Full Text Available Abstract Background Head and neck squamous cell carcinoma (HNSCC represents one of the most commonly diagnosed malignancies worldwide. The DDC gene encodes L-DOPA decarboxylase, an enzyme catalyzing the decarboxylation of L-DOPA to dopamine. We have recently shown that DDC mRNA is a significant predictor of patients’ prognosis in colorectal adenocarcinoma and prostate cancer. The aim of the current study was to analyze the DDC mRNA expression in HNSCC patients. Methods 53 malignant tumors were resected from the larynx, pharynx, tongue, buccal mucosa, parotid glands, and nasal cavity, as well as from 34 adjacent non-cancerous tissues of HNSCC patients, and were homogenized. Total RNA was isolated and converted into first-strand cDNA. An ultrasensitive real-time PCR method based on the SYBR Green chemistry was used for DDC mRNA quantification in head and neck tissue specimens. Relative quantification was performed using the comparative Ct (2-ddCt method. Results DDC mRNA levels were lower in squamous cell carcinomas (SCCs of the larynx and tongue than in adjacent non-cancerous tissue specimens. Furthermore, low DDC mRNA expression was noticed in laryngeal and tongue tumors of advanced TNM stage or bigger size, compared to early-stage or smaller tumors, respectively. No statistically significant differences were observed between SCCs resected from pharynx, buccal mucosa, or nasal cavity, and their normal counterparts. Conclusion This is the first study examining the DDC mRNA expression in HNSCC. According to our results, DDC mRNA expression may constitute a potential prognostic biomarker in tongue and/or larynx SCCs, which principally represent the overwhelming majority of HNSCC cases.

  20. L-DOPA decarboxylase mRNA expression is associated with tumor stage and size in head and neck squamous cell carcinoma: a retrospective cohort study

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    Geomela, Panagiota-Aikaterini; Kontos, Christos K; Yiotakis, Ioannis; Fragoulis, Emmanuel G; Scorilas, Andreas

    2012-01-01

    Head and neck squamous cell carcinoma (HNSCC) represents one of the most commonly diagnosed malignancies worldwide. The DDC gene encodes L-DOPA decarboxylase, an enzyme catalyzing the decarboxylation of L-DOPA to dopamine. We have recently shown that DDC mRNA is a significant predictor of patients’ prognosis in colorectal adenocarcinoma and prostate cancer. The aim of the current study was to analyze the DDC mRNA expression in HNSCC patients. 53 malignant tumors were resected from the larynx, pharynx, tongue, buccal mucosa, parotid glands, and nasal cavity, as well as from 34 adjacent non-cancerous tissues of HNSCC patients, and were homogenized. Total RNA was isolated and converted into first-strand cDNA. An ultrasensitive real-time PCR method based on the SYBR Green chemistry was used for DDC mRNA quantification in head and neck tissue specimens. Relative quantification was performed using the comparative Ct (2 -ddCt ) method. DDC mRNA levels were lower in squamous cell carcinomas (SCCs) of the larynx and tongue than in adjacent non-cancerous tissue specimens. Furthermore, low DDC mRNA expression was noticed in laryngeal and tongue tumors of advanced TNM stage or bigger size, compared to early-stage or smaller tumors, respectively. No statistically significant differences were observed between SCCs resected from pharynx, buccal mucosa, or nasal cavity, and their normal counterparts. This is the first study examining the DDC mRNA expression in HNSCC. According to our results, DDC mRNA expression may constitute a potential prognostic biomarker in tongue and/or larynx SCCs, which principally represent the overwhelming majority of HNSCC cases

  1. Intronic variants in the dopa decarboxylase (DDC) gene are associated with smoking behavior in European-Americans and African-Americans.

    Science.gov (United States)

    Yu, Yi; Panhuysen, Carolien; Kranzler, Henry R; Hesselbrock, Victor; Rounsaville, Bruce; Weiss, Roger; Brady, Kathleen; Farrer, Lindsay A; Gelernter, Joel

    2006-07-15

    We report here a study considering association of alleles and haplotypes at the DOPA decarboxylase (DDC) locus with the DSM-IV diagnosis of nicotine dependence (ND) or a quantitative measure for ND using the Fagerstrom Test for Nicotine Dependence (FTND). We genotyped 18 single nucleotide polymorphisms (SNPs) spanning a region of approximately 210 kb that includes DDC and the genes immediately flanking DDC in 1,590 individuals from 621 families of African-American (AA) or European-American (EA) ancestry. Evidence of association (family-based tests) was observed with several SNPs for both traits (0.0002DDC lacking exons 10-15. Haplotype analysis did not reveal any SNP combination with stronger evidence for association than rs12718541 alone. Although sequence analysis suggests that rs12718541 may be an intronic splicing enhancer, further studies are needed to determine whether a direct link exists between an alternatively spliced form of DDC and predisposition to ND. These findings confirm a previous report of association of DDC with ND, localize the causative variants to the 3' end of the coding region and extend the association to multiple population groups.

  2. l-DOPA Decarboxylase (DDC) Expression Status as a Novel Molecular Tumor Marker for Diagnostic and Prognostic Purposes in Laryngeal Cancer.

    Science.gov (United States)

    Patsis, Christos; Glyka, Vasiliki; Yiotakis, Ioannis; Fragoulis, Emmanuel G; Scorilas, Andreas

    2012-08-01

    l-DOPA decarboxylase (DDC) plays an essential role in the enzymatic synthesis of dopamine and alterations in its gene expression have been reported in several malignancies. Our objective was to analyze DDC messenger RNA (mRNA) and protein expression in laryngeal tissues and to evaluate the clinical implication of this molecule in laryngeal cancer. In this study, total RNA was isolated from 157 tissue samples surgically removed from 100 laryngeal cancer patients. A highly sensitive real-time polymerase chain reaction methodology based on SYBR Green I fluorescent dye was developed for the quantification of DDC mRNA levels. In addition, Western blot analysis was performed for the detection of DDC protein. DDC mRNA expression was revealed to be significantly downregulated in primary laryngeal cancer samples compared with their nonmalignant counterparts (P = .001). A significant negative association was also disclosed between DDC mRNA levels and TNM staging (P = .034). Univariate analysis showed that patients bearing DDC-positive tumors had a significantly decreased risk of death (hazard ratio = 0.23, P = .012) and local recurrence (hazard ratio = 0.32, P =.006), whereas DDC expression retained its favorable prognostic significance in the multivariate analysis. Kaplan-Meier curves further demonstrated that DDC-positive patients experienced longer overall and disease-free survival periods (P = .006 and P = .004, respectively). Moreover, DDC protein was detected in both neoplastic and noncancerous tissues. Therefore, our results suggest that DDC expression status could qualify as a promising biomarker for the future clinical management of laryngeal cancer patients.

  3. l-DOPA Decarboxylase (DDC) Expression Status as a Novel Molecular Tumor Marker for Diagnostic and Prognostic Purposes in Laryngeal Cancer1

    Science.gov (United States)

    Patsis, Christos; Glyka, Vasiliki; Yiotakis, Ioannis; Fragoulis, Emmanuel G; Scorilas, Andreas

    2012-01-01

    l-DOPA decarboxylase (DDC) plays an essential role in the enzymatic synthesis of dopamine and alterations in its gene expression have been reported in several malignancies. Our objective was to analyze DDC messenger RNA (mRNA) and protein expression in laryngeal tissues and to evaluate the clinical implication of this molecule in laryngeal cancer. In this study, total RNA was isolated from 157 tissue samples surgically removed from 100 laryngeal cancer patients. A highly sensitive real-time polymerase chain reaction methodology based on SYBR Green I fluorescent dye was developed for the quantification of DDC mRNA levels. In addition, Western blot analysis was performed for the detection of DDC protein. DDC mRNA expression was revealed to be significantly downregulated in primary laryngeal cancer samples compared with their nonmalignant counterparts (P = .001). A significant negative association was also disclosed between DDC mRNA levels and TNM staging (P = .034). Univariate analysis showed that patients bearing DDC-positive tumors had a significantly decreased risk of death (hazard ratio = 0.23, P = .012) and local recurrence (hazard ratio = 0.32, P =.006), whereas DDC expression retained its favorable prognostic significance in the multivariate analysis. Kaplan-Meier curves further demonstrated that DDC-positive patients experienced longer overall and disease-free survival periods (P = .006 and P = .004, respectively). Moreover, DDC protein was detected in both neoplastic and noncancerous tissues. Therefore, our results suggest that DDC expression status could qualify as a promising biomarker for the future clinical management of laryngeal cancer patients. PMID:22937181

  4. Induction of dopamine biosynthesis by l-DOPA in PC12 cells: implications of L-DOPA influx and cyclic AMP.

    Science.gov (United States)

    Jin, Chun Mei; Yang, Yoo Jung; Huang, Hai Shan; Lim, Sung Cil; Kai, Masaaki; Lee, Myung Koo

    2008-09-04

    The effects of 3,4-dihydroxyphenylalanine (l-DOPA) on dopamine biosynthesis and cytotoxicity were investigated in PC12 cells. l-DOPA treatment (20-200 microM) increased the levels of dopamine by 226%-504% after 3-6 h of treatment and enhanced the activities of tyrosine hydroxylase (TH) and aromatic l-amino acid decarboxylase (AADC). l-DOPA (20-200 muM) treatment led to a 562%-937% increase in l-DOPA influx at 1 h, which inhibited the activity of TH, but not AADC, during the same period. The extracellular releases of dopamine were also increased by 231%-570% after treatment with 20 and 200 microM l-DOPA for 0.5-3 h. l-DOPA at a concentration of 100-200 microM, but not 20 microM, exerted apoptotic cytotoxicity towards PC12 cells for 24-48 h. l-DOPA (20-200 microM) increased the intracellular cyclic AMP levels by 318%-557% after 0.5-1 h in a concentration-dependent manner. However, the elevated cyclic AMP levels by l-DOPA could not protect against l-DOPA (100-200 microM)-induced cytotoxicity after 24-48 h. In addition, l-DOPA (20-200 microM)-induced increases in cyclic AMP and dopamine were significantly reduced by treatment with SCH23390 (dopamine D(1) receptor antagonist). The increased levels of dopamine by l-DOPA were also reduced by H89 (protein kinase A, PKA, inhibitor) and GF109203X (protein kinase C inhibitor); however, the reduction by GF109203X was not significant. l-DOPA at 20-200 microM stimulated the phosphorylation of PKA and cyclic AMP-response element binding protein and induced the biosynthesis of the TH protein. These results indicate that 20-200 microM l-DOPA induces dopamine biosynthesis by two pathways. One pathway involves l-DOPA directly entering the cells to convert dopamine through AADC activity (l-DOPA decarboxylation). The other pathway involves l-DOPA and/or released dopamine activating TH to enhance dopamine biosynthesis by the dopamine D(1) receptor-cyclic AMP-PKA signaling system (dopamine biosynthesis by TH).

  5. L-DOPA reverses the elevated density of D/sub 2/ dopamine receptors in Parkinson's diseased striatum

    Energy Technology Data Exchange (ETDEWEB)

    Guttman, M; Seeman, P

    1985-01-01

    Striatal dopamine receptors werde studied using (/sup 3/H)-spiperone in postmortem tissues of thirty-six patients with Parkinson's Disease. Each tissue was analyzed by the receptor saturation method. In non-treated patients, the D/sub 2/ dopamine receptor density was elevated in the caudate nucleus and putamen compared to controls. In L-DOPA-treated patients, the receptor density was the same as controls. The dissociation constant for (/sup 3/H)-spiperone was similar in all groups. The elevated density of D/sub 2/ receptors in non-treated patients may indicate dopaminergic supersensitivity in this disease. The elevated density was reversed with dopamine agonist therapy, but the density was not lower than control tissues.

  6. A Member of the p38 Mitogen-Activated Protein Kinase Family Is Responsible for Transcriptional Induction of Dopa decarboxylase in the Epidermis of Drosophila melanogaster during the Innate Immune Response▿ †

    Science.gov (United States)

    Davis, Monica M.; Primrose, David A.; Hodgetts, Ross B.

    2008-01-01

    Drosophila innate immunity is controlled primarily by the activation of IMD (immune deficiency) or Toll signaling leading to the production of antimicrobial peptides (AMPs). IMD signaling also activates the JUN N-terminal kinase (JNK) cascade, which is responsible for immune induction of non-antimicrobial peptide immune gene transcription though the transcription factor AP-1. Transcription of the Dopa decarboxylase (Ddc) gene is induced in response to gram-negative and gram-positive septic injury, but not aseptic wounding. Transcription is induced throughout the epidermis and not specifically at the site of infection. Ddc transcripts are detectible within 2 h and remain high for several hours following infection with either gram-negative or gram-positive bacteria. Using Ddc-green fluorescent protein (GFP) reporter gene constructs, we show that a conserved consensus AP-1 binding site upstream of the Ddc transcription start site is required for induction. However, neither the Toll, IMD, nor JNK pathway is involved. Rather, Ddc transcription depends on a previously uncharacterized member of the p38 mitogen-activated protein kinase family, p38c. We propose that the involvement of DDC in a new pathway involved in Drosophila immunity increases the levels of dopamine, which is metabolized to produce reactive quinones that exert an antimicrobial effect on invading bacteria. PMID:18519585

  7. [18F]DOPA PET/ceCT in diagnosis and staging of primary medullary thyroid carcinoma prior to surgery.

    Science.gov (United States)

    Rasul, Sazan; Hartenbach, Sabrina; Rebhan, Katharina; Göllner, Adelina; Karanikas, Georgios; Mayerhoefer, Marius; Mazal, Peter; Hacker, Marcus; Hartenbach, Markus

    2018-05-15

    Medullary thyroid carcinoma (MTC) is characterized by a high rate of metastasis. In this study we evaluated the ability of [ 18 F]DOPA PET/ceCT to stage MTC in patients with suspicious thyroid nodules and pathologically elevated serum calcitonin (Ctn) levels prior to total thyroidectomy and lymph node (LN) dissection. A group of 32 patients with sonographically suspicious thyroid nodules and pathologically elevated basal Ctn (bCtn) and stimulated Ctn (sCtn) levels underwent DOPA PET/ceCT prior to surgery. Postoperative histology served as the standard of reference for ultrasonography and DOPA PET/ceCT region-based LN staging. Univariate and multivariate regression analyses as well as receiver operating characteristic analysis were used to evaluate the correlations between preoperative and histological parameters and postoperative tumour persistence or relapse. Primary MTC was histologically verified in all patients. Of the 32 patients, 28 showed increased DOPA decarboxylase activity in the primary tumour (sensitivity 88%, mean SUVmax 10.5). Undetected tumours were exclusively staged pT1a. The sensitivities of DOPA PET in the detection of central and lateral metastatic neck LN were 53% and 73%, in contrast to 20% and 39%, respectively, for neck ultrasonography. Preoperative bCtn and carcinoembryonic antigen levels as well as cN1b status and the number of involved neck regions on DOPA PET/ceCT were predictive of postoperative tumour persistence/relapse in the univariate regression analysis (P PET/ceCT cN1b status remained significant in the multivariate analysis (P = 0.016, relative risk 4.02). This study revealed that DOPA PET/ceCT has high sensitivity in the detection of primary MTC and superior sensitivity in the detection of LN metastases compared to ultrasonography. DOPA PET/ceCT identification of N1b status predicts postoperative tumour persistence. Thus, implementation of a DOPA-guided LN dissection might improve surgical success.

  8. Imaging mass spectrometry reveals elevated nigral levels of dynorphin neuropeptides in L-DOPA-induced dyskinesia in rat model of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Anna Ljungdahl

    Full Text Available L-DOPA-induced dyskinesia is a troublesome complication of L-DOPA pharmacotherapy of Parkinson's disease and has been associated with disturbed brain opioid transmission. However, so far the results of clinical and preclinical studies on the effects of opioids agonists and antagonists have been contradictory at best. Prodynorphin mRNA levels correlate well with the severity of dyskinesia in animal models of Parkinson's disease; however the identities of the actual neuroactive opioid effectors in their target basal ganglia output structures have not yet been determined. For the first time MALDI-TOF imaging mass spectrometry (IMS was used for unbiased assessment and topographical elucidation of prodynorphin-derived peptides in the substantia nigra of a unilateral rat model of Parkinson's disease and L-DOPA induced dyskinesia. Nigral levels of dynorphin B and alpha-neoendorphin strongly correlated with the severity of dyskinesia. Even if dynorphin peptide levels were elevated in both the medial and lateral part of the substantia nigra, MALDI IMS analysis revealed that the most prominent changes were localized to the lateral part of the substantia nigra. MALDI IMS is advantageous compared with traditional molecular methods, such as radioimmunoassay, in that neither the molecular identity analyzed, nor the specific localization needs to be predetermined. Indeed, MALDI IMS revealed that the bioconverted metabolite leu-enkephalin-arg also correlated positively with severity of dyskinesia. Multiplexing DynB and leu-enkephalin-arg ion images revealed small (0.25 by 0.5 mm nigral subregions with complementing ion intensities, indicating localized peptide release followed by bioconversion. The nigral dynorphins associated with L-DOPA-induced dyskinesia were not those with high affinity to kappa opioid receptors, but consisted of shorter peptides, mainly dynorphin B and alpha-neoendorphin that are known to bind and activate mu and delta opioid receptors

  9. Radioenzymatic assay of DOPA (3,4-dihydroxyphenylalanine)

    International Nuclear Information System (INIS)

    Johnson, G.A.; Gren, J.M.; Kupiecki, R.

    1978-01-01

    We modified the single-isotope radioenzymatic assay for catecholamines [Life Sci. 21, 625(1977)] to assay 3,4-dihydroxyphenylalanine (DOPA). DOPA decarboxylase is used to convert DOPA to dopamine, which concurrently is converted to [ 3 H]-3-O-methyldopamine in the presence of catechol-O-methyltransferase and [methyl- 3 H]-S-adenosylmethionine and assayed radioenzymatically. For assay of plasma DOPA, 50 μl of untreated plasma is added directly into the incubation mixture. A duplicate mixture containing an internal standard requires a second 50-μl aliquot of plasma. Because the assay measures both DOPA and endogenous dopamine, two additional aliquots of plasma must be assayed for dopamine in the absence of the decarboxylase by the differential assay; DOPA is estimated by difference. The assay is sensitive to 25 pg (500 ng/liter of plasma). Analysis of DOPA (DOPA plus dopamine) and the concurrent differential assay of catecholamines in at least 10 samples can be done in a single working day. Plasma DOPA concentrations for 42 normotensive adults were 1430 +- 19 ng/liter (mean +- SEM). In contrast, dopamine concentrations for these same subjects averaged 23 +- 20 ng/liter. Values for the 24 women subjects (1510 +- 62 ng/liter) significantly (P = 0.04) exceeded those for the men

  10. A specific radioenzymatic assay for dihydroxyphenylalanine (DOPA). Plasma DOPA may be the precursor of urine free dopamine

    International Nuclear Information System (INIS)

    Brown, M.J.; Dollery, C.T.

    1981-01-01

    A sensitive radioenzymatic assay was developed, in which DOPA is enzymatically decarboxylated to dopamine and the latter converted to [ 3 H]-methoxytryamine in the presence of [ 3 H]-S-adenosyl-L-methionine and catechol-o-methyltransferase. The assay was specific for DOPA, and was sensitive to 50 pg/ml. Endogenous DOPA was found to be present in the plasma of eight human volunteers at a concentration of 10.46 +- 2.42 nmol/l. Simultaneous urine collections in the same subjects showed a free dopamine excretion of 68.88 +- 17.70 nmol/h. There was a significant correlation (P < 0.01) between plasma DOPA concentration and urine free dopamine excretion (r = 0.84). After the oral administration of 250 mg levodopa, plasma DOPA and urine dopamine both increased by a similar proportion (98 +- 8.4-fold, and 93.4 +- 6.9-fold respectively). These compare with an increase in plasma dopamine of only 26 +- 15-fold (P<0.01). Following the oral dose of DOPA, the increase in plasma DOPA, but not plasma dopamine, could account for the increase in urine dopamine. The calculated clearance of plasma DOPA by renal decarboxylation to dopamine was 114 +- 20 ml/min. This is not significantly different from the apparent clearance of endogenous DOPA by renal decarboxylation to dopamine, and suggests that there is adequate renal decarboxylase activity for DOPA to be the precursor for renal dopamine formation. (author)

  11. Nucleotide variation at the dopa decarboxylase (Ddc) gene in ...

    Indian Academy of Sciences (India)

    rates and genetic polymorphism (Begun and Aquadro 1992), balancing selection ... as a neurotransmitter, affecting mating behaviour, fertility, circadian rhythms .... standard DNA polymorphism analyses were carried out us- ing either DNAsp ...

  12. On the use of [18F]DOPA as an imaging biomarker for transplanted islet mass

    International Nuclear Information System (INIS)

    Eriksson, Olof; Mintz, Akiva; Liu, Chengyang; Yu, Ming; Naji, Ali; Alavi, Abass

    2014-01-01

    Islet transplantation is being developed as a potential cure for patients with type 1 diabetes. There is a need for non-invasive imaging techniques for the quantification of transplanted islets, as current transplantation sites are associated with a substantial loss of islet viability. The dopaminergic metabolic pathway is present in the islets; therefore, we propose Fluorine-18 labeled L-3,4-dihydroxyphenylalanine ([ 18 F]DOPA) as a biomarker for transplanted islet mass. The expression of enzymes involved in the dopaminergic metabolic pathway was investigated in both native and transplanted human islets. The specific uptake of [ 18 F]DOPA in islets and immortalized beta cells was studied in vitro by selective blocking of dopa decarboxylase (DDC). Initial in vivo positron emission tomography (PET) imaging of viable subcutaneous human islets was performed using [ 18 F]DOPA. DDC and vesicular monoamine transporter 2 are co-localized with insulin in the native human pancreas, and the expression is retained after transplantation. Islet uptake of the [ 18 F]DOPA could be modulated by inhibiting DDC, indicating that the uptake followed the normal dopaminergic metabolic pathway. In vivo imaging revealed [ 18 F]DOPA uptake at the site of the functional islet graft. Based on the in vitro and in vivo results presented in this study, we propose to further validate [ 18 F]DOPA-PET as a sensitive imaging modality for imaging extrahepatically transplanted islets. (author)

  13. Estimation of in vitro activity of tuberoinfundibular dopaminergic neurons by measurement of DOPA synthesis in the median eminence of hypothalamic slices.

    Science.gov (United States)

    Arita, J; Kimura, F

    1984-12-01

    A new method for estimation of in vitro neurosecretory activity of tuberoinfundibular dopaminergic (TIDA) neurons was developed by measuring the rate of synthesis of dihydroxyphenylalanine (DOPA) in the median eminence of hypothalamic slices. Sagittal hypothalamic slices of ovariectomized rats were incubated in a medium containing 3-hydroxybenzylhydrazine (NSD 1015), an inhibitor of DOPA decarboxylase. DOPA accumulated in the median eminence following incubation with NSD 1015 was determined by high-performance liquid chromatography with electro-chemical detection. The amount of DOPA accumulated in vitro in the median eminence was maximal in a medium containing 10 mM NSD 1015 and linear up to 120 min at 37 degrees C. Increasing the concentration of tyrosine in medium stimulated the synthesis of DOPA in the median eminence. The synthesis of DOPA was blocked by 1 mM alpha-methyltyrosine, an inhibitor of tyrosine hydroxylase. The rate of in vitro synthesis of DOPA in the median eminence was 33% of that of in vivo synthesis. Incubation in a medium containing 50 mM K+ to depolarize neurons caused a 2.4-fold increase in DOPA synthesis in the median eminence. The high K+-induced increase in DOPA synthesis was blocked by omission of Ca2+ and addition of 1 mM EGTA into the medium, suggesting Ca2+ dependency of depolarization-activated DOPA synthesis. These results indicate that this in vitro assay is a useful means to study the regulatory mechanisms of TIDA neurons.

  14. Dopa-responsive dystonia

    Directory of Open Access Journals (Sweden)

    Đurić Gordana

    2009-01-01

    Full Text Available Backgrround/Aim. Dystonia is considered to be a prolonged involuntary contractions of the muscles leading to twisting, repetitive movements or irregular postures. Etiologically, it could be classified as primary and secondary dystonia. Dopa-responsive dystonia (DRD belongs to a group of primary dystonia. The aim of this study was to detect the presence of gene GCH-I mutation in our population in patients with dopa-responsive dystonic dyskinesia and to analyze clinical specificity of the affected. Methods. Out of the group of patients with dystonia of different distribution four patients were separated whose clinical picture indicated the diagnosis of DRD. Two patients had a positive family anamnesis while the other two were sporadic. Genetic analysis was performed by the use of a standard protocol, which included PCR amplification and DNK sequencing according to the method of Senger and autoradiografy. Results. In the patients from the family DRD-1 new hetaerazygote point mutation 520G→A in 4-m exson gene GCH-I was revealed. First symptoms of the disease showed in the age of seven by the torsion of the left foot, progressively advanced and got into the evolution of numbness in the legs, aggravated gait, tending to worsen in the evening, and the therapy with levodopa (500 mg produced a dramatic effect. The second mutation in the female patient from the family DRD-2 was homozygote deletion in1-m intron gene GCH-I (IVS1-85delA. Unwilling torsion of the foot, feeling of weakness in the lower extremities (that caused falling without loss of the consciousness were clinical demonstrations of the disease. The application of levodopa (300 mg caused regression of the symptoms of the disease. Hetaerazygote deletion of adenine in the position 209 in the first exon (209del A was identificated in the patient DRD-3 with negative family anamnesis, in who in the age of ten the torsion of the foot inside occurred for the first time following by trembling of

  15. Modulatory effects of L-DOPA on D2 dopamine receptors in rat striatum, measured using in vivo microdialysis and PET

    International Nuclear Information System (INIS)

    Opacka-Juffry, J.; Hume, S. P.; Ashworth, S.; Ahier, R. G.

    1997-01-01

    Putative modulatory effects of L-3,4-dihydroxyphenylalanine (L-DOPA) on D2 dopamine receptor function in the striatum of anaesthetized rats were investigated using both in vivo microdialysis and positron emission tomography (PET) with carbon-11 labelled raclopride as a selective D2 receptor ligand. A single dose of L-DOPA (20 or 100 mg/kg i.p.) resulted in an increase in [ 11 C]raclopride binding potential which was also observed in the presence of the central aromatic decarboxylase inhibitor NSD 1015, confirming that the effect was independent of dopamine. This L-DOPA evoked D2 receptor sensitization was abolished by a prior, long-term administration of L-DOPA in drinking water (5 weeks, 170 mg/kg/day). In the course of acute L-DOPA treatment (20 mg/kg), extracellular GABA levels were reduced by ∼20 % in the globus pallidus. It is likely that L-DOPA sensitising effect on striatal D2 receptors, as confirmed by PET, may implicate striato-pallidal neurones, hence a reduced GABA-ergic output in the projection area. Since the L-DOPA evoked striatal D2 receptor supersensitivity habituates during long-term treatment, the effects reported here may contribute to the fluctuations observed during chronic L-DOPA therapy in Parkinson's disease. (author)

  16. A selective phosphodiesterase 10A inhibitor reduces l-dopa-induced dyskinesias in parkinsonian monkeys.

    Science.gov (United States)

    Beck, Goichi; Maehara, Shunsuke; Chang, Phat Ly; Papa, Stella M

    2018-03-06

    Phosphodiesterase 10A is a member of the phosphodiesterase family whose brain expression is restricted to the striatum. Phosphodiesterase 10A regulates cyclic adenosine monophosphate and cyclic guanosine monophosphate, which mediate responses to dopamine receptor activation, and the levels of these cyclic nucleotides are decreased in experimental models of l-dopa-induced dyskinesia. The elevation of cyclic adenosine monophosphate/cyclic guanosine monophosphate levels by phosphodiesterase 10A inhibition may thus be targeted to reduce l-dopa-induced dyskinesia. The present study was aimed at determining the potential antidyskinetic effects of phosphodiesterase 10A inhibitors in a primate model of Parkinson's disease (PD). The experiments performed in this model were also intended to provide translational data for the design of future clinical trials. Five MPTP-treated macaques with advanced parkinsonism and reproducible l-dopa-induced dyskinesia were used. MR1916, a selective phosphodiesterase 10A inhibitor, at doses 0.0015 to 0.05 mg/kg, subcutaneously, or its vehicle (control test) was coadministered with l-dopa methyl ester acutely (predetermined optimal and suboptimal subcutaneous doses) and oral l-dopa chronically as daily treatment for 5 weeks. Standardized scales were used to assess motor disability and l-dopa-induced dyskinesia by blinded examiners. Pharmacokinetics was also examined. MR1916 consistently reduced l-dopa-induced dyskinesia in acute tests of l-dopa optimal and suboptimal doses. Significant effects were present with every MR1916 dose tested, but the most effective was 0.015 mg/kg. None of the MR1916 doses tested affected the antiparkinsonian action of l-dopa at the optimal dose. The anti-l-dopa-induced dyskinesia effect of MR1916 (0.015 mg/kg, subcutaneously) was sustained with chronic administration, indicating that tolerance did not develop over the 5-week treatment. No adverse effects were observed after MR1916 administration acutely or

  17. Radiometric microassay for ornithine decarboxylase

    Energy Technology Data Exchange (ETDEWEB)

    Maderdrut, J L; Oppenheim, R W [North Carolina Univ., Chapel Hill (USA). School of Medicine

    1978-01-01

    A simple method for purifying (/sup 3/H)L-ornithine and incubation conditions suitable for estimating L-ornithine decarboxylase activity are described. Routine and recycle cation exchange procedures for separating putrescine from ornithine are outlined. Blanks using the routine cation exchange method average approx. 0.04% of the radioactivity contained in the substrate; product recovery is approx. 94%. The L-ornithine decarboxylase assay is proportional to time for at least 8 h. The relationship between substrate purity and the sensitivity of the cation exchange procedures is assessed. Radiochemical purity is the critical determinant of sensitivity for recycled assays. The cation exchange method is compared with the commonly used CO/sub 2/-trapping method. The cation exchange method is more specific and approximately three orders of magnitude more sensitive than the CO/sub 2/-trapping method. L-ornithine decarboxylase activity can be measured reliably in samples of embryonic neural tissues having wet-weights of approx. 1 ..mu..g. L-ornithine decarboxylase activity in the lumbar spinal cord of the chick embryo decreases 25-30 fold from day 5 to day 18 of embryonic development. A cation exchange procedure for estimating L-lysine decarboxylase activity is also described. Failure to detect L-lysine decarboxylase activity in the chick embryo lumbar spinal cord is contrasted with the previous report of high cadaverine levels in chick embryos.

  18. Effects of L-DOPA on aggressive behavior and central monoaminergic activity in the lizard Anolis carolinensis, using a new method for drug delivery.

    Science.gov (United States)

    Höglund, Erik; Korzan, Wayne J; Watt, Michael J; Forster, Gina L; Summers, Tangi R; Johannessen, Helga Falch; Renner, Kenneth J; Summers, Cliff H

    2005-01-06

    The dopamine (DA) precursor, L-DOPA (500 microg), was injected into living crickets, which were ingested (one each) by adult male Anolis carolinensis. This method of delivery elevated plasma L-DOPA and DA concentrations by approximately 1000-fold. In contrast, plasma epinephrine (Epi) and norepinephrine (NE) were not influenced by L-DOPA treatment, although they were elevated following the consumption of the cricket. Lizards that ingested L-DOPA treated crickets had elevated L-DOPA in all brain regions measured, with DA and/or DOPAC also increased significantly in most brain regions studied. Despite increased DA levels in the striatum and nucleus accumbens as a response to L-DOPA, the treatment had no influence on general motor activity. Central serotonin, NE, and Epi systems were not affected in any brain region by oral L-DOPA treatment. In addition, aggression was inhibited by this dose of L-DOPA, even though there was no effect on serotonergic systems. This is surprising because controlling aggressive behavior is usually considered the province of serotonergic activity. Aggression was measured before and after treatment, and while saline-treated lizards retained the full vigor of aggressive activity, those fed a cricket injected with L-DOPA were only one-third as aggressive after treatment. As L-DOPA treatment did not affect general motor activity, the effect appears to be directly associated with aggression. This is supported by the observation that L-DOPA treatment delayed latency to eyespot darkening, which predicts the latency to aggression.

  19. Carbidopa and physiological distribution of the 6-L-[{sup 18}F]-fluoro-dihydroxy-phenylalanine ({sup 18}F-DOPA); Carbidopa et biodistribution physiologique de la 6-L-[{sup 18}F]-fluorodihydroxyphenylalanine ({sup 18}F-DOPA)

    Energy Technology Data Exchange (ETDEWEB)

    Detour, J.; Hammer, C.; Lucas, A. [Hopitaux universitaires de Strasbourg, Service de radiopharmacie, 67 (France); Imperiale, A.; Constantinesco, A. [Hopitaux universitaires de Strasbourg, Service de biophysique et medecine nucleaire, 67 (France); Beretz, L. [Hopitaux universitaires de Strasbourg, pole de pharmacie-pharmacologie, 67 (France)

    2010-07-01

    Purpose: The administration of carbidopa, an peripheral inhibitor of decarboxylase DOPA, may be performed prior to a full body PET scan {sup 18}F-DOPA. There is currently no consensus regarding the routine use of this metabolic preparation (200 mg, 100 mg, 2 mg / kg, no pre-medication). Conclusions: The absence of pre-medication clearly increases pancreatic uptake of {sup 18}F-D.O.P.A.. These results suggest to reconsider the metabolic preparation based on carbidopa, particularly in cases of suspected clinico biological forms of diffuse hyper-insulinism (nesidioblastosis). Pre-medication in cases of digestive neuroendocrine tumors should be reconsidered. The dose-dependent effect of pre-medication on the tumor uptake remains to be explored. (N.C.)

  20. DOPA, norepinephrine, and dopamine in rat tissues

    DEFF Research Database (Denmark)

    Eldrup, E; Richter, Erik; Christensen, N J

    1989-01-01

    We studied the effect of unilateral sympathectomy on rat quadriceps and gastrocnemius muscle concentrations of endogenous dihydroxyphenylalanine (DOPA), dopamine (DA), and norepinephrine (NE) and assessed the relationships between these catecholamines in several rat tissues. Catecholamines were...

  1. Herbs containing L- Dopa: An update.

    Science.gov (United States)

    Ramya, Kuber B; Thaakur, Santhrani

    2007-07-01

    L-Dopa is the drug of choice in the treatment of Parkinson's disease but it has dose related adverse effects such as nausea, vomiting, orthostatic hypotension, end of dose deterioration, on off phenomena and on chronic therapy motor complications synonymous to parkinsonism. Mucuna pruriens (M.P) commonly known as velvet beans or cowitch are used in case of spasms associated with Parkins onism. Clinical efficacy of seeds of this plant was confirmed and the efficacy was contributed to its L-Dopa content. M.P extract showed twice the antiparkinsonism activity compared with synthetic L-Dopa. There is sufficient L-Dopa in broad bean (Vicia faba) pods. One study proved its efficacy in Parkinsonism. Ginkgo biloba extract showed protective effect in vivo and invitro. 50% ethanolic extract of Plumbago zeylanica was effective in rats. The following plants were reported to have L-Dopa but their protective effect is yet to be established in animal models. Vigna aconitifolia, Vigna unguiculata, Vigna vexillata, Prosopis chilensis, Pileostigma malabarica, Phanera vahlis, Parkinsonia acculeata, Macuna urens, Canvavalia glandiata, Cassia floribanda, Casia hirsute and Dalbergia retusa etc.

  2. Aspergillus niger PA2: a novel strain for extracellular biotransformation of L-tyrosine into L-DOPA.

    Science.gov (United States)

    Agarwal, Pragati; Pareek, Nidhi; Dubey, Swati; Singh, Jyoti; Singh, R P

    2016-05-01

    L-DOPA (3,4-dihydroxyphenyl-L-alanine), an amino acid derivative is the most widely used drug of choice for the treatment of Parkinson's disease and other neurologic injuries. The present study deals with the elevated biochemical transformation of L-tyrosine to L-DOPA by Aspergillus niger PA2, a potent tyrosinase producer, isolated from decomposed food wastes. This appears to be the first report on A. niger as a notable extracellular tyrosinase producer. The extracellular tyrosinase activity produced remarkably higher levels of L-DOPA, i.e. 2.44 mg mL(-1) when the media was supplemented with 5 mg mL(-1) L-tyrosine. The optimum pH for tyrosinase production was 6.0, with the maximal L-DOPA production at the same pH. The product thus produced was analyzed by thin-layer chromatography, UV spectroscopy, high-performance liquid chromatography and Fourier transform infrared spectroscopy, that had denoted this to be L-DOPA. Kinetic parameters viz. Y p/s, Q s and Q p had further indicated the notable levels of production. Thus, Aspergillus niger PA2 could be a promising resource and may be further exploited for large-scale production of L-DOPA.

  3. Oxidation of DNA, proteins and lipids by DOPA, protein-bound DOPA, and related catechol(amine)s

    DEFF Research Database (Denmark)

    Pattison, David I; Dean, Roger T; Davies, Michael Jonathan

    2002-01-01

    Incubation of free 3,4-dihydroxyphenylalanine (DOPA), protein-bound DOPA (PB-DOPA) and related catechols with DNA, proteins and lipids has been shown to result in oxidative damage to the target molecule. This article reviews these reactions with particular emphasis on those that occur in the pres......Incubation of free 3,4-dihydroxyphenylalanine (DOPA), protein-bound DOPA (PB-DOPA) and related catechols with DNA, proteins and lipids has been shown to result in oxidative damage to the target molecule. This article reviews these reactions with particular emphasis on those that occur...... in the presence of molecular O(2) and redox-active metal ions (e.g. Fe(3+), Cu(2+), Cr(6+)), which are known to increase the rate of DOPA oxidation. The majority of oxidative damage appears to be mediated by reactive oxygen species (ROS) such as superoxide and HO(.) radicals, though other DOPA oxidation products...

  4. New PET tracers for cerebral dopamine: Should 6-[18f]fluoro-dopa be replaced?

    International Nuclear Information System (INIS)

    Firnau, G.; Chirakal, R.; Chen, J.J.; Murthy, D.; Nahmias, C.; Garnett, E.S.

    1993-01-01

    The visualization with PET of dopaminergic terminals in the human brain has been accomplished by a variety of approaches using β + -labelled substrates 1. for Aromatic L-Amino acid Decarboxylase, AADC, (6-[ 18 F]fluoro-L-dopa, FD; 6-[ 18 F]fluoro-L-meta-tyrosine, FmT; L-[ 11 C]Dopa); and β + -labelled inhibitors 2. for reuptake transporter ([ 11 C]Cocain, [ 11 C]WIN 35,428); 3. for Monoamine Oxidase-B ([ 11 C]deprenyl); 4. for the Vesicular uptake site ([ 11 C]tetrabenzamine). The enzyme approach with FD has been particularly successful in providing important insights into Parkinson's disease and dystonias. The extraction of quantitative data from FD/PET studies in humans is complicated by the formation of O-methylFD in the periphery, which, like FD, also enters the brain. Following the suggestion by deJesus (1988) to use a labelled meta-tyrosine (substrate for AADC but not COMT) the authors have synthesized FmT, developed it into a radiopharmaceutical (toxicology and radiation dose in humans) and studied the intracerebral distribution in man and the metabolites in monkeys. They found that FmT's peripheral metabolite does not enter the brain. Unlike FD, FmT delineates with greater clarity the dopaminergic terminals and cells including those in the substantia nigra that, so far, could not be investigated with any other PET tracer. Thus, FmT appears to be superior to FD

  5. Intraindividual comparison of 68Ga-DOTA-TATE and 18F-DOPA PET in patients with well-differentiated metastatic neuroendocrine tumours

    International Nuclear Information System (INIS)

    Haug, Alexander; Auernhammer, Christoph J.; Goeke, Burkhard; Waengler, Bjoern; Tiling, Reinhold; Bartenstein, Peter; Poepperl, Gabriele; Schmidt, Gerwin

    2009-01-01

    To compare the diagnostic impact of 68 Ga-DOTA-TATE and 18 F-DOPA PET in the diagnosis of well-differentiated metastatic neuroendocrine tumours (NET). PET/CT using both 68 Ga-DOTA-TATE and 18 F-DOPA was performed in 25 patients with histologically proven metastatic NET (nine gut, five pancreas, six lung, one paranasal sinus, four with unknown primary). Analyses of PET examinations were patient-based (pathological uptake: yes/no), and based on tumour regions (primary tumour if present and metastases of liver, lung, bones and lymph nodes). The results were compared with the results of contrast enhanced CT, and with plasma serotonin levels, which were available in 24 of the 25 patients. Patient-based sensitivities were 96% for 68 Ga-DOTA-TATE PET and 56% for 18 F-DOPA PET. 68 Ga-DOTA-TATE PET delineated metastases in 54 of 55 positive metastatic tumour regions in contrast to 29 of 55 delineated by 18 F-DOPA PET. Overall, 68 Ga-DOTA-TATE was superior to 18 F-DOPA in 13 patients (two patients showed fewer positive tumour regions with 18 F-DOPA PET). The results were comparable in 12 patients. In 13 of 24 patients, plasma serotonin levels were elevated, and 11 of these 13 patients showed pathological uptake of 18 F-DOPA. Of the 11 patients with normal levels of serotonin, 3 also showed positive 18 F-DOPA uptake. In patients positive for 18 F-DOPA uptake the maximum tumour SUVs were correlated with the levels of serotonin (r=0.66, p=0.01). In this study 68 Ga-DOTA-TATE PET proved clearly superior to 18 F-DOPA PET for detection and staging of NET. 18 F-DOPA uptake tended to be increased in those patients with elevated plasma serotonin. We conclude that 18 F-DOPA PET should be employed in patients with NET with negative 68 Ga-DOTA-TATE PET and elevated plasma serotonin. (orig.)

  6. From L-dopa to dihydroxyphenylacetaldehyde: a toxic biochemical pathway plays a vital physiological function in insects.

    Directory of Open Access Journals (Sweden)

    Christopher Vavricka

    2011-01-01

    Full Text Available One protein in Aedes aegypti, classified into the aromatic amino acid decarboxylase (AAAD family based on extremely high sequence homology (∼70% with dopa decarboxylase (Ddc, was biochemically investigated. Our data revealed that this predicted AAAD protein use L-dopa as a substrate, as does Ddc, but it catalyzes the production of 3,4-dihydroxylphenylacetaldehyde (DHPAA directly from L-dopa and apparently has nothing to do with the production of any aromatic amine. The protein is therefore named DHPAA synthase. This subsequently led to the identification of the same enzyme in Drosophila melanogaster, Anopheles gambiae and Culex quinquefasciatus by an initial prediction of putative DHPAA synthase based on sequence homology and subsequent verification of DHPAA synthase identity through protein expression and activity assays. DHPAA is highly toxic because its aldehyde group readily reacts with the primary amino groups of proteins, leading to protein crosslinking and inactivation. It has previously been demonstrated by several research groups that Drosophila DHPAA synthase was expressed in tissues that produce cuticle materials and apparent defects in regions of colorless, flexible cuticular structures have been observed in its gene mutants. The presence of free amino groups in proteins, the high reactivity of DHPAA with the free amino groups, and the genetically ascertained function of the Drosophila DHPAA synthase in the formation of colorless, flexible cuticle, when taken together, suggest that mosquito and Drosophila DHPAA synthases are involved in the formation of flexible cuticle through their reactive DHPAA-mediated protein crosslinking reactions. Our data illustrate how a seemingly highly toxic pathway can serve for an important physiological function in insects.

  7. The value of 18F-DOPA PET-CT in patients with medullary thyroid carcinoma: comparison with 18F-FDG PET-CT

    International Nuclear Information System (INIS)

    Beheshti, Mohsen; Poecher, Sigrid; Vali, Reza; Nader, Michael; Langsteger, Werner; Waldenberger, Peter; Broinger, Gabriele; Kohlfuerst, Susanne; Pirich, Christian; Dralle, Henning

    2009-01-01

    The purpose of this prospective study was to compare the value of DOPA PET-CT with FDG PET-CT in the detection of malignant lesions in patients with medullary thyroid carcinoma (MTC). Twenty-six consecutive patients (10 men, 16 women, mean age 59 ± 14 years) with elevated calcitonin levels were evaluated in this prospective study. DOPA and FDG PET-CT modalities were performed within a maximum of 4 weeks (median 7 days) in all patients. The data were evaluated on a patient- and lesion-based analysis. The final diagnosis of positive PET lesions was based on histopathological findings and/or imaging follow-up studies (i.e., DOPA and/or FDG PET-CT) for at least 6 months (range 6-24 months). In 21 (21/26) patients at least one malignant lesion was detected by DOPA PET, while only 15 (15/26) patients showed abnormal FDG uptake. DOPA PET provided important additional information in the follow-up assessment in seven (27%) patients which changed the therapeutic management. The patient-based analysis of our data demonstrated a sensitivity of 81% for DOPA PET versus 58% for FDG PET, respectively. In four (4/26) postoperative patients DOPA and FDG PET-CT studies were negative in spite of elevated serum calcitonin and CEA levels as well as abnormal pentagastrin tests. Overall 59 pathological lesions with abnormal tracer uptake were seen on DOPA and/or FDG PET studies. In the final diagnosis 53 lesions proved to be malignant. DOPA PET correctly detected 94% (50/53) of malignant lesions, whereas only 62% (33/53) of malignant lesions were detected with FDG PET. DOPA PET-CT showed superior results to FDG PET-CT in the preoperative and follow-up assessment of MTC patients. Therefore, we recommend DOPA PET-CT as a one-stop diagnostic procedure to provide both functional and morphological data in order to select those patients who may benefit from (re-)operation with curative intent as well as guiding further surgical procedures. (orig.)

  8. Chemical labeling of gluatmate decarboxylase in vivo

    International Nuclear Information System (INIS)

    Rando, R.R.

    1981-01-01

    Mouse brain glutamate decarboxylase(s) was specifically titrated in vivo and in crude brain homogenates by a combination of gabaculine and [alpha-3H]acetylenic gamma-aminobutyric acid. This specific titration is based on the differential spectra of action of these two mechanism-based enzyme inactivators. The specificity of the titration in vitro was demonstrated by showing that the time course of radioactivity incorporation exactly paralleled the time course for glutamate of decarboxylase inactivation. This means that there is approximately 0.66 nmol of glutamate decarboxylase/0.5 g of mouse brain, assuming the stoichiometry of inactivator bound to enzyme is one. This value is similar to the one obtained from a calculation based on the enzyme purification data

  9. Biochemical evaluation of a parsley tyrosine decarboxylase results in a novel 4-hydroxyphenylacetaldehyde synthase enzyme.

    Science.gov (United States)

    Torrens-Spence, Michael P; Gillaspy, Glenda; Zhao, Bingyu; Harich, Kim; White, Robert H; Li, Jianyong

    2012-02-10

    Plant aromatic amino acid decarboxylases (AAADs) are effectively indistinguishable from plant aromatic acetaldehyde syntheses (AASs) through primary sequence comparison. Spectroscopic analyses of several characterized AASs and AAADs were performed to look for absorbance spectral identifiers. Although this limited survey proved inconclusive, the resulting work enabled the reevaluation of several characterized plant AAS and AAAD enzymes. Upon completion, a previously reported parsley AAAD protein was demonstrated to have AAS activity. Substrate specificity tests demonstrate that this novel AAS enzyme has a unique substrate specificity towards tyrosine (km 0.46mM) and dopa (km 1.40mM). Metabolite analysis established the abundance of tyrosine and absence of dopa in parsley extracts. Such analysis indicates that tyrosine is likely to be the sole physiological substrate. The resulting information suggests that this gene is responsible for the in vivo production of 4-hydroxyphenylacetaldehyde (4-HPAA). This is the first reported case of an AAS enzyme utilizing tyrosine as a primary substrate and the first report of a single enzyme capable of producing 4-HPAA from tyrosine. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Aromatic L-amino acid decarboxylase (AADC) is crucial for brain development and motor functions.

    Science.gov (United States)

    Shih, De-Fen; Hsiao, Chung-Der; Min, Ming-Yuan; Lai, Wen-Sung; Yang, Chianne-Wen; Lee, Wang-Tso; Lee, Shyh-Jye

    2013-01-01

    Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare pediatric neuro-metabolic disease in children. Due to the lack of an animal model, its pathogenetic mechanism is poorly understood. To study the role of AADC in brain development, a zebrafish model of AADC deficiency was generated. We identified an aadc gene homolog, dopa decarboxylase (ddc), in the zebrafish genome. Whole-mount in situ hybridization analysis showed that the ddc gene is expressed in the epiphysis, locus caeruleus, diencephalic catecholaminergic clusters, and raphe nuclei of 36-h post-fertilization (hpf) zebrafish embryos. Inhibition of Ddc by AADC inhibitor NSD-1015 or anti-sense morpholino oligonucleotides (MO) reduced brain volume and body length. We observed increased brain cell apoptosis and loss of dipencephalic catecholaminergic cluster neurons in ddc morphants (ddc MO-injected embryos). Seizure-like activity was also detected in ddc morphants in a dose-dependent manner. ddc morphants had less sensitive touch response and impaired swimming activity that could be rescued by injection of ddc plasmids. In addition, eye movement was also significantly impaired in ddc morphants. Collectively, loss of Ddc appears to result in similar phenotypes as that of ADCC deficiency, thus zebrafish could be a good model for investigating pathogenetic mechanisms of AADC deficiency in children.

  11. Aromatic L-amino acid decarboxylase (AADC is crucial for brain development and motor functions.

    Directory of Open Access Journals (Sweden)

    De-Fen Shih

    Full Text Available Aromatic L-amino acid decarboxylase (AADC deficiency is a rare pediatric neuro-metabolic disease in children. Due to the lack of an animal model, its pathogenetic mechanism is poorly understood. To study the role of AADC in brain development, a zebrafish model of AADC deficiency was generated. We identified an aadc gene homolog, dopa decarboxylase (ddc, in the zebrafish genome. Whole-mount in situ hybridization analysis showed that the ddc gene is expressed in the epiphysis, locus caeruleus, diencephalic catecholaminergic clusters, and raphe nuclei of 36-h post-fertilization (hpf zebrafish embryos. Inhibition of Ddc by AADC inhibitor NSD-1015 or anti-sense morpholino oligonucleotides (MO reduced brain volume and body length. We observed increased brain cell apoptosis and loss of dipencephalic catecholaminergic cluster neurons in ddc morphants (ddc MO-injected embryos. Seizure-like activity was also detected in ddc morphants in a dose-dependent manner. ddc morphants had less sensitive touch response and impaired swimming activity that could be rescued by injection of ddc plasmids. In addition, eye movement was also significantly impaired in ddc morphants. Collectively, loss of Ddc appears to result in similar phenotypes as that of ADCC deficiency, thus zebrafish could be a good model for investigating pathogenetic mechanisms of AADC deficiency in children.

  12. Tratamento do parkinsonismo com L-Dopa

    Directory of Open Access Journals (Sweden)

    Nilton Luís Latuf

    1972-06-01

    Full Text Available São apresentados os resultados obtidos no tratamento de 54 pacientes parkinsonianos com L-Dopa. A intensidade dos sintomas foi avaliada mediante a escala NUDS (Northwestern University Disability Scales antes e após o tratamento. Os autores ressaltam a obtenção de melhores resultados no que respeita à rigidez e à discinesia, em comparação com o tremor. São apontados os efeitos colaterais, quase sempre de pequena intensidade e corrigíveis com a diminuição ou suspensão da administração medicamentosa.

  13. Impact of L-DOPA treatment on regional cerebral blood flow and metabolism in the basal ganglia in a rat model of Parkinson's disease.

    Science.gov (United States)

    Ohlin, K Elisabet; Sebastianutto, Irene; Adkins, Chris E; Lundblad, Cornelia; Lockman, Paul R; Cenci, M Angela

    2012-05-15

    Large increases in regional cerebral blood flow (rCBF) have been measured in patients with Parkinson's disease (PD) following the administration of L-DOPA, but the underlying mechanisms have remained unknown. In this study, rats with unilateral 6-hydroxydopamine (6-OHDA) lesions were used to compare patterns of rCBF and regional cerebral glucose utilisation (rCGU) in chronically L-DOPA-treated subjects following a final injection of L-DOPA or saline. The same animal model was used to the leakage of a blood-brain barrier (BBB) tracer molecule at 60 min vs. 24h following the last L-DOPA injection of a chronic treatment. All the parameters under investigation were examined with brain autoradiography following intravenous injections of specific radiotracers in awake animals ([14C]-iodoantipyrine for rCBF, [14C]-2-deoxyglucose for rCGU, and [14C]-α-aminoisobutyric acid for BBB leakage). Significant changes in rCBF and rCGU on the side ipsilateral to the 6-OHDA lesion relative to the non-lesioned side were seen at 60 min ("ON") but not 24h ("OFF") following L-DOPA administration. These changes were not seen in sham-operated rats. In the output nuclei of the basal ganglia (the entopeduncular nucleus and the substantia nigra pars reticulata) both rCBF and rCGU were elevated both in acutely L-DOPA-treated rats and chronically L-DOPA-treated rats displaying dyskinesia, but did not change significantly in chronically L-DOPA-treated non-dyskinetic cases. Acutely and chronically L-DOPA-treated rats with dyskinesia exhibited increases in rCBF "ON L-DOPA" also in the motor cortex, the striatum, and the globus pallidus, but the corresponding changes in rCGU did not show the same direction, magnitude, and/or relative group differences. The uptake of a BBB tracer (studied in the striatum and the substantia nigra reticulata in chronically L-DOPA treated rats) was significantly higher ON vs. OFF L-DOPA. The present results are the first to show that the administration of L-DOPA is

  14. Dysphagia Causes Symptom Fluctuations after Oral L-DOPA Treatment in a Patient with Parkinson Disease.

    Science.gov (United States)

    Sato, Hiromasa; Yamamoto, Toshiyuki; Sato, Masako; Furusawa, Yoshihiko; Murata, Miho

    2018-01-01

    The causes of "delayed-on" and "no-on" phenomena in Parkinson disease (PD) are thought to have some impact on the progress of L-DOPA from the time of ingestion until it reaches the brain and is converted to dopamine. Dysphagia can cause fluctuating symptom expression in L-DOPA therapy for PD. A 69-year-old man with PD presented with "delayed-on" and "no-on" phenomena. The patient developed a gait disorder at age 60 years, and he began coughing on his food during breakfast at age 64 years. Even though he was independent in daily life, he could not eat because of dysphagia in an "off" state. Videofluoroscopic examination of swallowing in an "off" state revealed bradykinesia of the tongue and the retention of tablets in the epiglottic vallecula. We trained him to keep his tongue in strong contact with the upper incisors before swallowing. After rehabilitation of dysphagia, the frequency of "delayed-on" and "no-on" phenomena decreased, and his peak L-DOPA plasma concentration was elevated. Additionally, transdermal rotigotine (RTG) was initiated at a maintenance dose of 9.0 mg. The patient reported improvement in swallowing, and the frequency of "no-on" phenomena decreased. In PD patients, the "no-on" phenomenon can be caused by posterior contractile dysfunction of the tongue, and it can be improved with training of the tongue and transdermal RTG administration.

  15. A radiometric microassay for glutamic acid decarboxylase

    International Nuclear Information System (INIS)

    Maderdrut, J.L.; North Carolina Univ., Chapel Hill

    1979-01-01

    A simple method for purifying L-[ 3 H] glutamic acid and incubation conditions suitable for estimating L-glutamic acid decarboxylase activity are described. Routine and recycled cation-exchange procedure for separating γ-aminobutyric acid from L-glutamate are outlined and compared. Recycling increases the sensitivity of the cation-exchange method by 6-7 fold. L-Glutamate decarboxylase activity can be measured reliably in samples of embryonic neural tissue having wet-weights of approximately 1 μg. The cation-exchange method is compared with the anion-exchange and CO 2 -trapping methods. L-Glutamate decarboxylase activity has been detected in the lumbar spinal cord of the chick embryo at Day 21/4 (stage 14) using the cation-exchange method. This is 5-6 days earlier than L-glutamate decarboxylase activity has been detected in embryonic neural tissue by previous investigators. L-Glutamate decarboxylase is present in the lumbar spinal cord at least as early as the birth of the first lumbar spinal cord neurons and at least 1-2 days before the initiation of synaptogenesis. (author)

  16. Radiometric microassay for glutamic acid decarboxylase

    Energy Technology Data Exchange (ETDEWEB)

    Maderdrut, J L [North Carolina Dept. of Mental Health, Raleigh (USA); North Carolina Univ., Chapel Hill (USA). School of Medicine)

    1979-01-01

    A simple method for purifying L-(/sup 3/H) glutamic acid and incubation conditions suitable for estimating L-glutamic acid decarboxylase activity are described. Routine and recycled cation-exchange procedure for separating ..gamma..-aminobutyric acid from L-glutamate are outlined and compared. Recycling increases the sensitivity of the cation-exchange method by 6-7 fold. L-Glutamate decarboxylase activity can be measured reliably in samples of embryonic neural tissue having wet-weights of approximately 1 ..mu..g. The cation-exchange method is compared with the anion-exchange and CO/sub 2/-trapping methods. L-Glutamate decarboxylase activity has been detected in the lumbar spinal cord of the chick embryo at Day 21/4 (stage 14) using the cation-exchange method. This is 5-6 days earlier than L-glutamate decarboxylase activity has been detected in embryonic neural tissue by previous investigators. L-Glutamate decarboxylase is present in the lumbar spinal cord at least as early as the birth of the first lumbar spinal cord neurons and at least 1-2 days before the initiation of synaptogenesis.

  17. L-DOPA is an endogenous ligand for OA1.

    Directory of Open Access Journals (Sweden)

    Vanessa M Lopez

    2008-09-01

    Full Text Available Albinism is a genetic defect characterized by a loss of pigmentation. The neurosensory retina, which is not pigmented, exhibits pathologic changes secondary to the loss of pigmentation in the retina pigment epithelium (RPE. How the loss of pigmentation in the RPE causes developmental defects in the adjacent neurosensory retina has not been determined, but offers a unique opportunity to investigate the interactions between these two important tissues. One of the genes that causes albinism encodes for an orphan GPCR (OA1 expressed only in pigmented cells, including the RPE. We investigated the function and signaling of OA1 in RPE and transfected cell lines. Our results indicate that OA1 is a selective L-DOPA receptor, with no measurable second messenger activity from two closely related compounds, tyrosine and dopamine. Radiolabeled ligand binding confirmed that OA1 exhibited a single, saturable binding site for L-DOPA. Dopamine competed with L-DOPA for the single OA1 binding site, suggesting it could function as an OA1 antagonist. OA1 response to L-DOPA was defined by several common measures of G-protein coupled receptor (GPCR activation, including influx of intracellular calcium and recruitment of beta-arrestin. Further, inhibition of tyrosinase, the enzyme that makes L-DOPA, resulted in decreased PEDF secretion by RPE. Further, stimulation of OA1 in RPE with L-DOPA resulted in increased PEDF secretion. Taken together, our results illustrate an autocrine loop between OA1 and tyrosinase linked through L-DOPA, and this loop includes the secretion of at least one very potent retinal neurotrophic factor. OA1 is a selective L-DOPA receptor whose downstream effects govern spatial patterning of the developing retina. Our results suggest that the retinal consequences of albinism caused by changes in melanin synthetic machinery may be treated by L-DOPA supplementation.

  18. Gypenosides ameliorate memory deficits in MPTP-lesioned mouse model of Parkinson's disease treated with L-DOPA.

    Science.gov (United States)

    Zhao, Ting Ting; Kim, Kyung Sook; Shin, Keon Sung; Park, Hyun Jin; Kim, Hyun Jeong; Lee, Kyung Eun; Lee, Myung Koo

    2017-09-06

    Previous studies have revealed that gypenosides (GPS) improve the symptoms of anxiety disorders in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned rat model of Parkinson's disease (PD). The present study aimed to investigate the effects of GPS on memory deficits in an MPTP-lesioned mouse model of PD treated with L-3,4-dihydroxyphenylalanine (L-DOPA). MPTP (30 mg/kg/day, 5 days)-lesioned mice were treated with GPS (50 mg/kg) and/or L-DOPA (10 and 25 mg/kg) for 21 days. After the final treatments, behavioral changes were assessed in all mice using passive avoidance and elevated plus-maze tests. We then evaluated the biochemical influences of GPS treatment on levels of tyrosine hydroxylase (TH), dopamine, N-methyl-D-aspartate (NMDA) receptors, extracellular signal-regulated kinase (ERK1/2), and cyclic AMP-response element binding protein (CREB) phosphorylation. MPTP-lesioned mice exhibited deficits associated with habit learning and spatial memory, which were further aggravated by treatment with L-DOPA (25 mg/kg). However, treatment with GPS (50 mg/kg) ameliorated memory deficits. Treatment with GPS (50 mg/kg) also improved L-DOPA (25 mg/kg)-treated MPTP lesion-induced decreases in retention latency on the passive avoidance test, as well as levels of TH-immunopositive cells and dopamine in the substantia nigra and striatum. GPS treatment also attenuated increases in retention transfer latency on the elevated plus-maze test and in NMDA receptor expression, as well as decreases in the phosphorylation of ERK1/2 and CREB in the hippocampus. Treatment with L-DOPA (10 mg/kg) also ameliorated deficits in habit learning and spatial memory in MPTP-lesioned mice, and this effect was further enhanced by treatment with GPS (50 mg/kg). GPS ameliorate deficits in habit learning and spatial memory by modulating the dopaminergic neuronal and N-methyl-D-aspartate receptor-mediated signaling systems in MPTP-lesioned mice treated with L-DOPA. GPS may serve as an adjuvant

  19. Plasma dihydroxyphenylalanine (DOPA) is independent of sympathetic activity in humans

    DEFF Research Database (Denmark)

    Eldrup, E; Christensen, N J; Andreasen, J

    1989-01-01

    in diabetic patients with autonomic neuropathy compared to diabetics without neuropathy, whereas baseline plasma DOPA concentrations were similar in the three groups investigated: 6.55 (5.03-7.26, median [interquartile range], n = 8) nmol l-1 in diabetics with neuropathy, 7.41 (5.79-7.97, n = 8) nmol l-1...... in diabetics without neuropathy, and 6.85 (5.58-7.36, n = 8) nmol l-1 in controls. No relationship was obtained between baseline values of plasma NE and plasma DOPA. Plasma DOPA did not change in the upright position, whereas plasma NE increased significantly. Our results indicate that plasma DOPA...... is not related to sympathetic activity and may be of non-neuronal origin....

  20. [Deep brain stimulation in parkinsonian patients with dopa intolerance].

    Science.gov (United States)

    García-Ruiz, Pedro J; Feliz-Feliz, Cici; Ayerbe Gracia, Joaquín; Matías Arbelo, José; Salvador, Carlos; Val Fernández, Javier Del; García-Caldentey, Juan

    2017-10-28

    Deep brain stimulation (DBS) is at present, a useful treatment for patients with advanced Parkinson's disease and motor complications. The crucial step toward consistent DBS outcomes remains careful patient selection; several conditions must be fulfilled including excellent levo dopa response. We report two cases of early onset Parkinson's disease with severe intolerance to levo dopa but excellent and sustained response to DBS. DBS can be a useful alternative for parkinsonian patients with severe intolerance to levo dopa, provided a positive acute response to levo dopa or apomorphine is obtained. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Corticostriatal Plastic Changes in Experimental L-DOPA-Induced Dyskinesia

    Directory of Open Access Journals (Sweden)

    Veronica Ghiglieri

    2012-01-01

    Full Text Available In Parkinson’s disease (PD, alteration of dopamine- (DA- dependent striatal functions and pulsatile stimulation of DA receptors caused by the discontinuous administration of levodopa (L-DOPA lead to a complex cascade of events affecting the postsynaptic striatal neurons that might account for the appearance of L-DOPA-induced dyskinesia (LID. Experimental models of LID have been widely used and extensively characterized in rodents and electrophysiological studies provided remarkable insights into the inner mechanisms underlying L-DOPA-induced corticostriatal plastic changes. Here we provide an overview of recent findings that represent a further step into the comprehension of mechanisms underlying maladaptive changes of basal ganglia functions in response to L-DOPA and associated to development of LID.

  2. Overview on the biotechnological production of L-DOPA.

    Science.gov (United States)

    Min, Kyoungseon; Park, Kyungmoon; Park, Don-Hee; Yoo, Young Je

    2015-01-01

    L-DOPA (3,4-dihydroxyphenyl-L-alanine) has been widely used as a drug for Parkinson's disease caused by deficiency of the neurotransmitter dopamine. Since Monsanto developed the commercial process for L-DOPA synthesis for the first time, most of currently supplied L-DOPA has been produced by the asymmetric method, especially asymmetric hydrogenation. However, the asymmetric synthesis shows critical limitations such as a poor conversion rate and a low enantioselectivity. Accordingly, alternative biotechnological approaches have been researched for overcoming the shortcomings: microbial fermentation using microorganisms with tyrosinase, tyrosine phenol-lyase, or p-hydroxyphenylacetate 3-hydroxylase activity and enzymatic conversion by immobilized tyrosinase. Actually, Ajinomoto Co. Ltd commercialized Erwinia herbicola fermentation to produce L-DOPA from catechol. In addition, the electroenzymatic conversion system was recently introduced as a newly emerging scheme. In this review, we aim to not only overview the biotechnological L-DOPA production methods, but also to briefly compare and analyze their advantages and drawbacks. Furthermore, we suggest the future potential of biotechnological L-DOPA production as an industrial process.

  3. S-adenosylmethionine decarboxylase from baker's yeast.

    Science.gov (United States)

    Pösö, H; Sinervirta, R; Jänne, J

    1975-01-01

    1. S-Adenosyl-L-methionine decarboxylase (S-adenosyl-L-methionine carboxy-lyase, EC 4.1.1.50) was purified more than 1100-fold from extracts of Saccharomyces cerevisiae by affinity chromatography on columns of Sepharose containing covalently bound methylglyoxal bis(guanylhydrazone) (1,1'[(methylethanediylidene)dinitrilo]diguanidine) [Pegg, (1974) Biochem J. 141, 581-583]. The final preparation appeared to be homogeneous on polyacrylamide-gel electrophoresis at pH 8.4. 2. S-Adenosylmethionine decarboxylase activity was completely separated from spermidine synthase activity [5'-deoxyadenosyl-(5'),3-aminopropyl-(1),methylsulphonium-salt-putrescine 3-aminopropyltransferase, EC 2.5.1.16] during the purification procedure. 3. Adenosylmethionine decarboxylase activity from crude extracts of baker's yeast was stimulated by putrescine, 1,3-diamino-propane, cadaverine (1,5-diaminopentane) and spermidine; however, the purified enzyme, although still stimulated by the diamines, was completely insensitive to spermidine. 4. Adenosylmethionine decarboxylase has an apparent Km value of 0.09 mM for adenosylmethionine in the presence of saturating concentrations of putrescine. The omission of putrescine resulted in a five-fold increase in the apparent Km value for adenosylmethionine. 5. The apparent Ka value for putrescine, as the activator of the reaction, was 0.012 mM. 6. Methylglyoxal bis(guanylhydrazone) and S-methyladenosylhomocysteamine (decarboxylated adenosylmethionine) were powerful inhibitors of the enzyme. 7. Adenosylmethionine decarboxylase from baker's yeast was inhibited by a number of conventional carbonyl reagents, but in no case could the inhibition be reversed with exogenous pyridoxal 5'-phosphate. PMID:1108876

  4. Dysphagia Causes Symptom Fluctuations after Oral L-DOPA Treatment in a Patient with Parkinson Disease

    Directory of Open Access Journals (Sweden)

    Hiromasa Sato

    2018-03-01

    Full Text Available Objective: The causes of “delayed-on” and “no-on” phenomena in Parkinson disease (PD are thought to have some impact on the progress of L-DOPA from the time of ingestion until it reaches the brain and is converted to dopamine. Dysphagia can cause fluctuating symptom expression in L-DOPA therapy for PD. Case Description: A 69-year-old man with PD presented with “delayed-on” and “no-on” phenomena. The patient developed a gait disorder at age 60 years, and he began coughing on his food during breakfast at age 64 years. Even though he was independent in daily life, he could not eat because of dysphagia in an “off” state. Videofluoroscopic examination of swallowing in an “off” state revealed bradykinesia of the tongue and the retention of tablets in the epiglottic vallecula. We trained him to keep his tongue in strong contact with the upper incisors before swallowing. After rehabilitation of dysphagia, the frequency of “delayed-on” and “no-on” phenomena decreased, and his peak L-DOPA plasma concentration was elevated. Additionally, transdermal rotigotine (RTG was initiated at a maintenance dose of 9.0 mg. The patient reported improvement in swallowing, and the frequency of “no-on” phenomena decreased. Conclusion: In PD patients, the “no-on” phenomenon can be caused by posterior contractile dysfunction of the tongue, and it can be improved with training of the tongue and transdermal RTG administration.

  5. Ability of 18F-DOPA PET/CT and fused 18F-DOPA PET/MRI to assess striatal involvement in paediatric glioma

    International Nuclear Information System (INIS)

    Morana, Giovanni; Severino, Mariasavina; Tortora, Domenico; Rossi, Andrea; Puntoni, Matteo; Garre, Maria Luisa; Massollo, Michela; Naseri, Merhdad; Piccardo, Arnoldo; Lopci, Egesta

    2016-01-01

    To assess the diagnostic performance of 18 F-DOPA PET/CT and fused 18 F-DOPA PET/MRI in detecting striatal involvement in children with gliomas. This retrospective study included 28 paediatric patients referred to our institution for the presence of primary, residual or recurrent glioma (12 boys, 16 girls; mean age 10.7 years) and investigated with 18 F-DOPA PET/CT and brain MRI. Fused 18 F-DOPA PET/MR images were obtained and compared with PET/CT and MRI images. Accuracy, sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for striatal involvement were calculated for each diagnostic tool. Univariate and multivariate logistic analyses were applied to evaluate the associations between 18 F-DOPA PET/CT and fused 18 F-DOPA PET/MRI diagnostic results and tumour uptake outside the striatum, grade, dimension and site of striatal involvement (ventral and/or dorsal). Accuracy, sensitivity, specificity, PPV, and NPV were 100 % for MRI, 93 %, 89 %, 100 %, 100 % and 82 % for 18 F-DOPA PET/MRI, and 75 %, 74 %, 78 %, 88 % and 58 % for 18 F-DOPA PET/CT, respectively. 18 F-DOPA PET/MRI showed a trend towards higher accuracy compared with 18 F-DOPA PET/CT (p = 0.06). MRI showed significantly higher accuracy compared with 18 F-DOPA PET/CT (p = 0.01), but there was no significant difference between MRI and 18 F-DOPA PET/MRI. Both univariate and multivariate logistic analyses showed a significant association (OR 8.0 and 7.7, respectively) between the tumour-to-normal striatal uptake (T/S) ratio and the diagnostic ability of 18 F-DOPA PET/CT (p = 0.03). A strong significant association was also found between involvement of the dorsal striatum and the 18 F-DOPA PET/CT results (p = 0.001), with a perfect prediction of involvement of the dorsal striatum by 18 F-DOPA PET/MRI. Physiological striatal 18 F-DOPA uptake does not appear to be a main limitation in the evaluation of basal ganglia involvement. 18 F-DOPA PET/CT correctly detected

  6. The role of L-DOPA in plants

    Science.gov (United States)

    Soares, Anderson Ricardo; Marchiosi, Rogério; Siqueira-Soares, Rita de Cássia; Barbosa de Lima, Rogério; Dantas dos Santos, Wanderley; Ferrarese-Filho, Osvaldo

    2014-01-01

    Since higher plants regularly release organic compounds into the environment, their decay products are often added to the soil matrix and a few have been reported as agents of plant-plant interactions. These compounds, active against higher plants, typically suppress seed germination, cause injury to root growth and other meristems, and inhibit seedling growth. Mucuna pruriens is an example of a successful cover crop with several highly active secondary chemical agents that are produced by its seeds, leaves and roots. The main phytotoxic compound encountered is the non-protein amino acid L-3,4-dihydroxyphenylalanine (L-DOPA), which is used in treating the symptoms of Parkinson disease. In plants, L-DOPA is a precursor of many alkaloids, catecholamines, and melanin and is released from Mucuna into soils, inhibiting the growth of nearby plant species. This review summarizes knowledge regarding L-DOPA in plants, providing a brief overview about its metabolic actions. PMID:24598311

  7. Blood-brain transfer and metabolism of 6-[18F]fluoro-L-dopa in rat

    International Nuclear Information System (INIS)

    Reith, J.; Dyve, S.; Kuwabara, H.; Guttman, M.; Diksic, M.; Gjedde, A.

    1990-01-01

    In a study designed to reveal the rates of blood-brain transfer and decarboxylation of fluoro-L-3,4-dihydroxyphenylalanine (FDOPA), we discovered a major discrepancy between the DOPA decarboxylase activity reported in the literature and the rate of FDOPA decarboxylation measured in the study. Donor rats received intravenous injections of 6 mCi fluorine-18-labeled FDOPA. The donor rats synthesized methyl-FDOPA. Arterial plasma, containing both FDOPA and methyl-FDOPA, was sampled from the donor rats at different times and reinjected into recipient rats in which it circulated for 20 s. The blood-brain clearance of the mixture of labeled tracers in the plasma was determined by an integral method. The individual permeabilities were determined by linear regression analysis, according to which the average methyl-FDOPA permeability in the blood-brain barrier was twice that of FDOPA, which averaged 0.037 ml g-1 min-1. The permeability ratio was used to determine the fractional clearance from the brain of FDOPA (and hence of methyl-FDOPA), which averaged 0.081 min-1. In the striatum, the measured average FDOPA decarboxylation rate constant (kD3) was 0.010 min-1, or no more than 1% of the rate of striatal decarboxylation of DOPA measured in vitro and in vivo. We interpreted this finding as further evidence in favor of the hypothesis that striatum has two dopamine (DA) pools, of which only DA in the large pool is protected from metabolism. Hence, no more than 1% of the quantity of fluoro-DA theoretically synthesized was actually retained in striatum

  8. l-Histidine Decarboxylase and Tourette's Syndrome

    Science.gov (United States)

    Ercan-Sencicek, A. Gulhan; Stillman, Althea A.; Ghosh, Ananda K.; Bilguvar, Kaya; O'Roak, Brian J.; Mason, Christopher E.; Abbott, Thomas; Gupta, Abha; King, Robert A.; Pauls, David L.; Tischfield, Jay A.; Heiman, Gary A.; Singer, Harvey S.; Gilbert, Donald L.; Hoekstra, Pieter J.; Morgan, Thomas M.; Loring, Erin; Yasuno, Katsuhito; Fernandez, Thomas; Sanders, Stephan; Louvi, Angeliki; Cho, Judy H.; Mane, Shrikant; Colangelo, Christopher M.; Biederer, Thomas; Lifton, Richard P.; Gunel, Murat; State, Matthew W.

    2010-01-01

    Summary Tourette's syndrome is a common developmental neuropsychiatric disorder characterized by chronic motor and vocal tics. Despite a strong genetic contribution, inheritance is complex, and risk alleles have proven difficult to identify. Here, we describe an analysis of linkage in a two-generation pedigree leading to the identification of a rare functional mutation in the HDC gene encoding l-histidine decarboxylase, the rate-limiting enzyme in histamine biosynthesis. Our findings, together with previously published data from model systems, point to a role for histaminergic neurotransmission in the mechanism and modulation of Tourette's syndrome and tics. PMID:20445167

  9. Discriminative sensing of DOPA enantiomers by cyclodextrin anchored graphene nanohybrids.

    Science.gov (United States)

    Ates, Salih; Zor, Erhan; Akin, Ilker; Bingol, Haluk; Alpaydin, Sabri; Akgemci, Emine G

    2017-06-01

    Discriminative sensing of chiral species with a convenient and robust system is a challenge in chemistry, pharmaceutics and particularly in biomedical science. Advanced nanohybrid materials for discrimination of these biologically active molecules can be developed by combination of individual obvious advantages of different molecular scaffolds. Herein, we report on the comparison of the performance of cyclodextrin functionalized graphene derivatives (x-CD/rGO, x: α-, β-, γ-) for discrimination of DOPA enantiomers. Within this respect, electrochemical measurements were conducted and the experimental results were compared to molecular docking method. Thanks to cavity size of γ-CD and the unique properties of graphene, rGO/γ-CD nanohybrid is capable of selective recognition of DOPA enantiomers. Limit of detection (LOD) value and sensitivity were determined as 15.9 μM and 0.2525 μA μM -1 for D-DOPA, and 14.9 μM and 0.6894 μA μM -1 for L-DOPA. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Plasma dihydroxyphenylalanine (DOPA) is independent of sympathetic activity in humans

    DEFF Research Database (Denmark)

    Eldrup, E; Christensen, N J; Andreasen, J

    1989-01-01

    in diabetic patients with autonomic neuropathy compared to diabetics without neuropathy, whereas baseline plasma DOPA concentrations were similar in the three groups investigated: 6.55 (5.03-7.26, median [interquartile range], n = 8) nmol l-1 in diabetics with neuropathy, 7.41 (5.79-7.97, n = 8) nmol l-1...

  11. Activities of arginine and ornithine decarboxylases in various plant species.

    Science.gov (United States)

    Birecka, H; Bitonti, A J; McCann, P P

    1985-10-01

    In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to V(max), ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. alpha-Difluoromethylornithine and alpha-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species.No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed.In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum.

  12. Changes in kynurenine pathway metabolism in Parkinson patients with L-DOPA-induced dyskinesia.

    Science.gov (United States)

    Havelund, Jesper F; Andersen, Andreas D; Binzer, Michael; Blaabjerg, Morten; Heegaard, Niels H H; Stenager, Egon; Faergeman, Nils J; Gramsbergen, Jan Bert

    2017-09-01

    L-3,4-Dihydroxyphenylalanine (L-DOPA) is the most effective drug in the symptomatic treatment of Parkinson's disease, but chronic use is associated with L-DOPA-induced dyskinesia in more than half the patients after 10 years of treatment. L-DOPA treatment may affect tryptophan metabolism via the kynurenine pathway. Altered levels of kynurenine metabolites can affect glutamatergic transmission and may play a role in the development of L-DOPA-induced dyskinesia. In this study, we assessed kynurenine metabolites in plasma and cerebrospinal fluid of Parkinson's disease patients and controls. Parkinson patients (n = 26) were clinically assessed for severity of motor symptoms (UPDRS) and L-DOPA-induced dyskinesia (UDysRS). Plasma and cerebrospinal fluid samples were collected after overnight fasting and 1-2 h after intake of L-DOPA or other anti-Parkinson medication. Metabolites were analyzed in plasma and cerebrospinal fluid of controls (n = 14), Parkinson patients receiving no L-DOPA (n = 8), patients treated with L-DOPA without dyskinesia (n = 8), and patients with L-DOPA-induced dyskinesia (n = 10) using liquid chromatography-mass spectrometry. We observed approximately fourfold increase in the 3-hydroxykynurenine/kynurenic acid ratio in plasma of Parkinson's patients with L-DOPA-induced dyskinesia. Anthranilic acid levels were decreased in plasma and cerebrospinal fluid of this patient group. 5-Hydroxytryptophan levels were twofold increased in all L-DOPA-treated Parkinson's patients. We conclude that a higher 3-hydroxykynurenine/kynurenic acid ratio in plasma may serve as a biomarker for L-DOPA-induced dyskinesia. Longitudinal studies including larger patients cohorts are needed to verify whether the changes observed here may serve as a prognostic marker for L-DOPA-induced dyskinesia. © 2017 International Society for Neurochemistry.

  13. Pyruvate decarboxylases from the petite-negative yeast Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Møller, Kasper; Langkjær, Rikke Breinhold; Nielsen, Jens

    2004-01-01

    was controlled by variations in the amount of mRNA. The mRNA level and the pyruvate decarboxylase activity responded to anaerobiosis and growth on different carbon sources in essentially the same fashion as in S. cerevisiae. This indicates that the difference in ethanol formation between these two yeasts...... is not due to differences in the regulation of pyruvate decarboxylase(s), but rather to differences in the regulation of the TCA cycle and the respiratory machinery. However, the PDC genes of Saccharomyces/Kluyveromyces yeasts differ in their genetic organization and phylogenetic origin. While S. cerevisiae...

  14. Effects of (-)-sesamin on motor and memory deficits in an MPTP-lesioned mouse model of Parkinson's disease treated with l-DOPA.

    Science.gov (United States)

    Zhao, T T; Shin, K S; Kim, K S; Park, H J; Kim, H J; Lee, K E; Lee, M K

    2016-12-17

    The present study investigated the effects of (-)-sesamin on motor and memory deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) with l-3,4-dihydroxyphenylalanine (l-DOPA). MPTP-lesioned (30mg/kg/day, 5days) mice showed deficits in memory including habit learning memory and spatial memory, which were further aggravated by daily treatment with 25mg/kg l-DOPA for 21days. However, daily treatment with (-)-sesamin (25 and 50mg/kg) for 21days ameliorated memory deficits in an MPTP-lesioned mouse model of PD treated with l-DOPA (25mg/kg). Both (-)-sesamin doses reduced decreases in the retention latency time in the passive avoidance test, latency to fall of rotarod test and distance traveled in the open field test, and attenuated decreases in tyrosine hydroxylase (TH)-immunopositive cells, dopamine, and its metabolites in the substantia nigra-striatum. (-)-Sesamin reduced increases in the retention transfer latency time in the elevated plus-maze test and N-methyl-d-aspartate receptor (NMDAR) expression and reduced decreases in the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus. In contrast, daily treatment with 10mg/kg l-DOPA for 21days ameliorated memory deficits in MPTP-lesioned mice, and this effect was further improved by treatment with (-)-sesamin (25 and 50mg/kg). These results suggest that (-)-sesamin protects against habit learning memory deficits by activating the dopamine neuronal system, while spatial memory deficits are decreased by its modulatory effects on the NMDAR-ERK1/2-CREB system. Accordingly, (-)-sesamin may act as an adjuvant phytonutrient for motor and memory deficits in patients with PD receiving l-DOPA. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Characterization of arginine decarboxylase from Dianthus caryophyllus.

    Science.gov (United States)

    Ha, Byung Hak; Cho, Ki Joon; Choi, Yu Jin; Park, Ky Young; Kim, Kyung Hyun

    2004-04-01

    Arginine decarboxylase (ADC, EC 4.1.1.9) is a key enzyme in the biosynthesis of polyamines in higher plants, whereas ornithine decarboxylase represents the sole pathway of polyamine biosynthesis in animals. Previously, we characterized a genomic clone from Dianthus caryophyllus, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 78 kDa. In the present study, the ADC gene was subcloned into the pGEX4T1 expression vector in combination with glutathione S-transferase (GST). The fusion protein GST-ADC was water-soluble and thus was purified by sequential GSTrap-arginine affinity chromatography. A thrombin-mediated on-column cleavage reaction was employed to release free ADC from GST. Hiload superdex gel filtration FPLC was then used to obtain a highly purified ADC. The identity of the ADC was confirmed by immunoblot analysis, and its specific activity with respect to (14)C-arginine decarboxylation reaction was determined to be 0.9 CO(2) pkat mg(-1) protein. K(m) and V(max) of the reaction between ADC and the substrate were 0.077 +/- 0.001 mM and 6.0 +/- 0.6 pkat mg(-1) protein, respectively. ADC activity was reduced by 70% in the presence of 0.1 mM Cu(2+) or CO(2+), but was only marginally affected by Mg(2+), or Ca(2+) at the same concentration. Moreover, spermine at 1 mM significantly reduced its activity by 30%.

  16. Changes in kynurenine pathway metabolism in Parkinson patients with L-DOPA-induced dyskinesia

    DEFF Research Database (Denmark)

    Havelund, Jesper F; Dammann Andersen, Andreas; Binzer, Michael

    2017-01-01

    L-DOPA is the most effective drug in the symptomatic treatment of Parkinson's disease, but chronic use is associated with L-DOPA-induced dyskinesia in more than half the patients after 10 years of treatment. L-DOPA treatment may affect tryptophan metabolism via the kynurenine pathway. Altered...... levels of kynurenine metabolites can affect glutamatergic transmission and may play a role in the development of L-DOPA-induced dyskinesia. In this study we assessed kynurenine metabolites in plasma and cerebrospinal fluid of Parkinson's disease patients and controls. Parkinson patients (n=26) were...... clinically assessed for severity of motor symptoms (UPDRS) and L-DOPA-induced dyskinesia (UDysRS). Plasma and cerebrospinal fluid samples were collected after overnight fasting and 1-2 hours after intake of L-DOPA or other anti-Parkinson medication. Metabolites were analyzed in plasma and cerebrospinal fluid...

  17. Maladaptive synaptic plasticity in L-DOPA-induced dyskinesia

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2016-12-01

    Full Text Available The emergence of L-DOPA-induced dyskinesia (LID in patients with Parkinson disease (PD could be due to maladaptive plasticity of corticostriatal synapses in response to L-DOPA treatment. A series of recent studies has revealed that LID is associated with marked morphological plasticity of striatal dendritic spines, particularly cell type-specific structural plasticity of medium spiny neurons (MSNs in the striatum. In addition, evidence demonstrating the occurrence of plastic adaptations, including aberrant morphological and functional features, in multiple components of cortico-basal ganglionic circuitry, such as primary motor cortex (M1 and basal ganglia (BG output nuclei. These adaptations have been implicated in the pathophysiology of LID. Here, we briefly review recent studies that have addressed maladaptive plastic changes within the cortico-BG loop in dyskinetic animal models of PD and patients with PD.

  18. MRI findings in glutamic acid decarboxylase associated autoimmune epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksen, Jason R.; Carr, Carrie M.; Koeller, Kelly K.; Verdoorn, Jared T.; Kotsenas, Amy L. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Gadoth, Avi; Pittock, Sean J. [Mayo Clinic, Department of Neurology, Rochester, MN (United States)

    2018-03-15

    Glutamic acid decarboxylase (GAD65) has been implicated in a number of autoimmune-associated neurologic syndromes, including autoimmune epilepsy. This study categorizes the spectrum of MRI findings in patients with a clinical diagnosis of autoimmune epilepsy and elevated serum GAD65 autoantibodies. An institutional database search identified patients with elevated serum GAD65 antibodies and a clinical diagnosis of autoimmune epilepsy who had undergone brain MRI. Imaging studies were reviewed by three board-certified neuroradiologists and one neuroradiology fellow. Studies were evaluated for cortical/subcortical and hippocampal signal abnormality, cerebellar and cerebral volume loss, mesial temporal sclerosis, and parenchymal/leptomeningeal enhancement. The electronic medical record was reviewed for relevant clinical information and laboratory markers. A study cohort of 19 patients was identified. The majority of patients were female (84%), with a mean age of onset of 27 years. Serum GAD65 titers ranged from 33 to 4415 nmol/L (normal < 0.02 nmol/L). The most common presentation was medically intractable, complex partial seizures with temporal lobe onset. Parenchymal atrophy was the most common imaging finding (47%), with a subset of patients demonstrating cortical/subcortical parenchymal T2 hyperintensity (37%) or abnormal hippocampal signal (26%). No patients demonstrated abnormal parenchymal/leptomeningeal enhancement. The most common MRI finding in GAD65-associated autoimmune epilepsy is disproportionate parenchymal atrophy for age, often associated with abnormal cortical/subcortical T2 hyperintensities. Hippocampal abnormalities are seen in a minority of patients. This constellation of findings in a patient with medically intractable epilepsy should raise the possibility of GAD65 autoimmunity. (orig.)

  19. Keto-isovalerate decarboxylase enzymes and methods of use thereof

    Science.gov (United States)

    McElvain, Jessica; O'Keefe, Daniel P.; Paul, Brian James; Payne, Mark S.; Rothman, Steven Cary; He, Hongxian

    2016-01-19

    Provided herein are polypeptides and polynucleotides encoding such polypeptides which have ketoisovalerate decarboxylase activity. Also provided are recombinant host cells comprising such polypeptides and polynucleotides and methods of use thereof.

  20. Depression of Serotonin Synaptic Transmission by the Dopamine Precursor L-DOPA

    OpenAIRE

    Gantz, Stephanie C.; Levitt, Erica S.; Llamosas Muñozguren, Nerea; Neve, Kim A.; Williams, John T.

    2015-01-01

    Imbalance between the dopamine and serotonin (5-HT) neurotransmitter systems has been implicated in the comorbidity of Parkinson's disease (PD) and psychiatric disorders. L-DOPA, the leading treatment of PD, facilitates the production and release of dopamine. This study assessed the action of L-DOPA on monoamine synaptic transmission in mouse brain slices. Application of L-DOPA augmented the D2-receptor-mediated inhibitory postsynaptic current (IPSC) in dopamine neurons of the substantia nigr...

  1. Overexpression of pyruvate decarboxylase in the yeast Hansenula polymorpha results in increased ethanol yield in high-temperature fermentation of xylose.

    Science.gov (United States)

    Ishchuk, Olena P; Voronovsky, Andriy Y; Stasyk, Oleh V; Gayda, Galina Z; Gonchar, Mykhailo V; Abbas, Charles A; Sibirny, Andriy A

    2008-11-01

    Improvement of xylose fermentation is of great importance to the fuel ethanol industry. The nonconventional thermotolerant yeast Hansenula polymorpha naturally ferments xylose to ethanol at high temperatures (48-50 degrees C). Introduction of a mutation that impairs ethanol reutilization in H. polymorpha led to an increase in ethanol yield from xylose. The native and heterologous (Kluyveromyces lactis) PDC1 genes coding for pyruvate decarboxylase were expressed at high levels in H. polymorpha under the control of the strong constitutive promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH). This resulted in increased pyruvate decarboxylase activity and improved ethanol production from xylose. The introduction of multiple copies of the H. polymorpha PDC1 gene driven by the strong constitutive promoter led to a 20-fold increase in pyruvate decarboxylase activity and up to a threefold elevation of ethanol production.

  2. Synthetic improvement and animal experiment of 6-18F-DOPA

    International Nuclear Information System (INIS)

    Tang Ganghua; Tang Xiaolan; Wang Mingfang; Luo Lei; Li Zhi; Huang Zuhan; Zhang Lan; Wang Yongxian

    2002-01-01

    Objective: To study synthetic improvement and biodistribution of 6- 18 F-DOPA in normal rats and hemi-Parkinsonism rats. Methods: 6- 18 F-DOPA was synthesized from the starting material 6-nitropiperonal via multi-step reaction including the nucleophilic fluorination, reductive iodination with diiodosilane on Sep-Pak column, chiral catalytic phase-transfer alkylation, and hydrolysis reaction. Biodistribution of 6- 18 F-DOPA in normal rats and the brain of hemi-Parkinsonism rats was determined. Results: The total time of synthesis was less than 110 min, the total uncorrected radiochemical yield from potassium 6- 18 F-DOPA was 5%-18%, and the enantiomeric purity and radiochemical purity were above 97% and 98%, respectively. High uptake in the kidney, blood, striatum, and hippocampus, rapid blood clearance in the kidney and blood, long retaining time and high striatum/cerebellum and striatum/cortex 6- 18 F-DOPA uptake ratio were found in normal rats. Compared with the intact side of hemi-Parkinsonism rats and pseudo-operated group, 6- 18 F-DOPA uptake and striatum/cerebellum and striatum/cortex 6- 18 F-DOPA uptake ratio reduced significantly in the lesioned side of hemi-Parkinsonism rats (P 18 F-DOPA. The synthetic 6- 18 F-DOPA is allowed to be used to study the animal and Parkinson's disease with PET imaging

  3. Characterization of dopaminergic dysfunction in familial progressive supranuclear palsy: an 18F-dopa PET study

    International Nuclear Information System (INIS)

    Tai, Y.F.; Ahsan, R.L.; Pavese, N.; Brooks, D.J.; Piccini, P.; Yebenes de, J.G.

    2007-01-01

    We analyzed 18 F-dopa PET data from 11 members of kindreds with familial progressive supranuclear palsy (PSP) to characterize their cerebral dopaminergic dysfunction. Three clinically-affected PSP patients showed reduced 18 F-dopa uptake in the striatum, orbitofrontal cortex and amygdala. One asymptomatic subject exhibited progressive putamen dopaminergic dysfunction. 60 % of subjects with abnormal 18 F-dopa scans developed PSP subsequently. This is the first in vivo documentation of cortical dopaminergic deficiency in PSP. Reduced striatal 18 F-dopa uptake in susceptible relatives may predict later clinical disease. (author)

  4. Evaluation of oxalate decarboxylase and oxalate oxidase for industrial applications.

    Science.gov (United States)

    Cassland, Pierre; Sjöde, Anders; Winestrand, Sandra; Jönsson, Leif J; Nilvebrant, Nils-Olof

    2010-05-01

    Increased recirculation of process water has given rise to problems with formation of calcium oxalate incrusts (scaling) in the pulp and paper industry and in forest biorefineries. The potential in using oxalate decarboxylase from Aspergillus niger for oxalic acid removal in industrial bleaching plant filtrates containing oxalic acid was examined and compared with barley oxalate oxidase. Ten different filtrates from chemical pulping were selected for the evaluation. Oxalate decarboxylase degraded oxalic acid faster than oxalate oxidase in eight of the filtrates, while oxalate oxidase performed better in one filtrate. One of the filtrates inhibited both enzymes. The potential inhibitory effect of selected compounds on the enzymatic activity was tested. Oxalate decarboxylase was more sensitive than oxalate oxidase to hydrogen peroxide. Oxalate decarboxylase was not as sensitive to chlorate and chlorite as oxalate oxidase. Up to 4 mM chlorate ions, the highest concentration tested, had no inhibitory effect on oxalate decarboxylase. Analysis of the filtrates suggests that high concentrations of chlorate present in some of the filtrates were responsible for the higher sensitivity of oxalate oxidase in these filtrates. Oxalate decarboxylase was thus a better choice than oxalate oxidase for treatment of filtrates from chlorine dioxide bleaching.

  5. Diagnostic utility of PET/CT with {sup 18}F-DOPA and {sup 18}F-FDG in persistent or recurrent medullary thyroid carcinoma: the importance of calcitonin and carcinoembryonic antigen cutoff

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Lluch, Ana Reyes; Guerrero-Vazquez, Raquel; Martinez-Ortega, Antonio Jesus; Navarro-Gonzalez, Elena [Hospital Universitario Virgen del Rocio, Unidad de Gestion Clinica de Endocrinologia y Nutricion, Seville (Spain); Cuenca-Cuenca, Juan Ignacio; Tirado-Hospital, Juan Luis; Borrego-Dorado, Isabel [Hospital Universitario Virgen del Rocio, Unidad de Medicina Nuclear, Seville (Spain)

    2017-11-15

    This study sought to evaluate and compare the utility of 18-F-fluorodihydroxyphenylalanine ({sup 18}F-DOPA) and 18-F-fluorodeoxyglucose ({sup 18}F-FDG) positron emission tomography/computed tomography (PET/CT) for identification of lesions in patients with recurrent medullary thyroid carcinoma (MTC). In addition, we analyzed the correlation between the calcitonin (Ct), carcinoembryonic antigen (CEA) levels, each doubling time (DT), and PET positivity. We evaluated the reliability of the 150 pg/mL Ct cutoff set by the American Thyroid Association guidelines for further imaging (including {sup 18}F-DOPA PET/CT). We prospectively recruited 18 patients with recurrent MTC, identified by elevation of Ct or CEA. Each patient underwent a {sup 18}F-FDG PET/CT and a {sup 18}F-DOPA PET/CT. Abnormal uptakes were detected with {sup 18}F-DOPA (n=12) and {sup 18}F-FDG (n=9), (sensitivity of 66.7% vs. 50%; p<0.01). Twenty-eight lesions were detected with {sup 18}F-DOPA vs. 16 lesions with {sup 18}F-FDG (1.56±1.5 vs. 0.89±1.18 lesions per patient; p=0.01). None of our patients showed additional lesions with {sup 18}F-FDG in comparison to {sup 18}F-DOPA. Patient-based detection rate increased significantly with Ct levels ≥150 pg/mL vs. Ct<150 pg/mL for both {sup 18}F-DOPA (sensitivity 90.9% vs. 28.6%; p=0.013) and {sup 18}F-FDG PET/CT (sensitivity 72.7% vs. 14.3%; p=0.025). Using a CEA cutoff of ≥5 ng/mL, detection rates of {sup 18}F-DOPA and {sup 18}F-FDG PET/CT were 81.1% and 72.7%, respectively. No correlation between Ct-DT or CEA-DT and PET positivity was found. Histological confirmation was obtained in eight patients. {sup 18}F-DOPA PET/CT appears to be superior to {sup 18}F-FDG PET/CT in detecting and locating lesions in patients with recurrent MTC. This technique tends to be especially useful in patients with negative results in other imaging modalities and Ct≥150 pg/mL or CEA≥5 ng/mL. (orig.)

  6. Evolutionary Profiling of Group II Pyridoxal-Phosphate-Dependent Decarboxylases Suggests Expansion and Functional Diversification of Histidine Decarboxylases in Tomato

    Directory of Open Access Journals (Sweden)

    Rahul Kumar

    2016-03-01

    Full Text Available Pyridoxal phosphate (PLP-dependent enzymes are one of the most important enzymes involved in plant N metabolism. Here, we explored the evolution of group II PLP-dependent decarboxylases (PLP_deC, including aromatic L-amino acid decarboxylase, glutamate decarboxylase, and histidine decarboxylase in the plant lineage. Gene identification analysis revealed a higher number of genes encoding PLP_deC in higher plants than in lower plants. Expression profiling of PLP_deC orthologs and syntelogs in (L. Heynh., pepper ( L., and tomato ( L. pointed toward conserved as well as distinct roles in developmental processes such as fruit maturation and ripening and abiotic stress responses. We further characterized a putative promoter of tomato ripening-associated gene ( operating in a complex regulatory circuit. Our analysis provides a firm basis for further in-depth exploration of the PLP_deC gene family, particularly in the economically important Solanaceae family.

  7. Motivational Disturbances and Effects of L-dopa Administration in Neurofibromatosis-1 Model Mice

    Science.gov (United States)

    Wozniak, David F.; Diggs-Andrews, Kelly A.; Conyers, Sara; Yuede, Carla M.; Dearborn, Joshua T.; Brown, Jacquelyn A.; Tokuda, Kazuhiro; Izumi, Yukitoshi; Zorumski, Charles F.; Gutmann, David H.

    2013-01-01

    Children with neurofibromatosis type 1 (NF1) frequently have cognitive and behavioral deficits. Some of these deficits have been successfully modeled in Nf1 genetically-engineered mice that develop optic gliomas (Nf1 OPG mice). In the current study, we show that abnormal motivational influences affect the behavior of Nf1 OPG mice, particularly with regard to their response to novel environmental stimuli. For example, Nf1 OPG mice made fewer spontaneous alternations in a Y-maze and fewer arm entries relative to WT controls. However, analysis of normalized alternation data demonstrated that these differences were not due to a spatial working memory deficit. Other reported behavioral results (e.g., open-field test, below) suggest that differential responses to novelty and/or other motivational influences may be more important determinants of these kinds of behavior than simple differences in locomotor activity/spontaneous movements. Importantly, normal long-term depression was observed in hippocampal slices from Nf1 OPG mice. Results from elevated plus maze testing showed that differences in exploratory activity between Nf1 OPG and WT control mice may be dependent on the environmental context (e.g., threatening or non-threatening) under which exploration is being measured. Nf1 OPG mice also exhibited decreased exploratory hole poking in a novel holeboard and showed abnormal olfactory preferences, although L-dopa (50 mg/kg) administration resolved the abnormal olfactory preference behaviors. Nf1 OPG mice displayed an attenuated response to a novel open field in terms of decreased ambulatory activity and rearing but only during the first 10 min of the session. Importantly, Nf1 OPG mice demonstrated investigative rearing deficits with regard to a novel hanging object suspended on one side of the field which were not rescued by L-dopa administration. Collectively, our results provide new data important for evaluating therapeutic treatments aimed at ameliorating NF1

  8. Motivational disturbances and effects of L-dopa administration in neurofibromatosis-1 model mice.

    Directory of Open Access Journals (Sweden)

    David F Wozniak

    Full Text Available Children with neurofibromatosis type 1 (NF1 frequently have cognitive and behavioral deficits. Some of these deficits have been successfully modeled in Nf1 genetically-engineered mice that develop optic gliomas (Nf1 OPG mice. In the current study, we show that abnormal motivational influences affect the behavior of Nf1 OPG mice, particularly with regard to their response to novel environmental stimuli. For example, Nf1 OPG mice made fewer spontaneous alternations in a Y-maze and fewer arm entries relative to WT controls. However, analysis of normalized alternation data demonstrated that these differences were not due to a spatial working memory deficit. Other reported behavioral results (e.g., open-field test, below suggest that differential responses to novelty and/or other motivational influences may be more important determinants of these kinds of behavior than simple differences in locomotor activity/spontaneous movements. Importantly, normal long-term depression was observed in hippocampal slices from Nf1 OPG mice. Results from elevated plus maze testing showed that differences in exploratory activity between Nf1 OPG and WT control mice may be dependent on the environmental context (e.g., threatening or non-threatening under which exploration is being measured. Nf1 OPG mice also exhibited decreased exploratory hole poking in a novel holeboard and showed abnormal olfactory preferences, although L-dopa (50 mg/kg administration resolved the abnormal olfactory preference behaviors. Nf1 OPG mice displayed an attenuated response to a novel open field in terms of decreased ambulatory activity and rearing but only during the first 10 min of the session. Importantly, Nf1 OPG mice demonstrated investigative rearing deficits with regard to a novel hanging object suspended on one side of the field which were not rescued by L-dopa administration. Collectively, our results provide new data important for evaluating therapeutic treatments aimed at

  9. Delayed O-methylation of l-DOPA in MB-COMT-deficient mice after oral administration of l-DOPA and carbidopa.

    Science.gov (United States)

    Tammimäki, Anne; Aonurm-Helm, Anu; Männistö, Pekka T

    2018-04-01

    1. Catechol-O-methyltransferase (COMT) is involved in the O-methylation of l-DOPA, dopamine, and other catechols. The enzyme is expressed in two isoforms: soluble (S-COMT), which resides in the cytoplasm, and membrane-bound (MB-COMT), which is anchored to intracellular membranes. 2. To obtain specific information on the functions of COMT isoforms, we studied how a complete MB-COMT deficiency affects the total COMT activity in the body, peripheral l-DOPA levels, and metabolism after l-DOPA (10 mg kg -1 ) plus carbidopa (30 mg kg -1 ) administration by gastric tube in wild-type (WT) and MB-COMT-deficient mice. l-DOPA and 3-O-methyl-l-DOPA (3-OMD) levels were assayed in plasma, duodenum, and liver. 3. We showed that the selective lack of MB-COMT did not alter the total COMT activity, COMT enzyme kinetics, l-DOPA levels, or the total O-methylation of l-DOPA but delayed production of 3-OMD in plasma and peripheral tissues.

  10. Tratamento da síndrome parkinsoniana pelo L-dopa Parkinsonism's treatment by L-Dopa

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    Roberto Melaragno

    1971-12-01

    Full Text Available O trabalho refere o tratamento com L-Dopa de 33 pacientes internados, sendo 19 homens e 14 mulheres. Os casos foram agrupados, segundo uma classificação esquemática, em leves, moderados, intensos e severos. As idades dos pacientes, previamente operados ou não, variaram de 42 a 78 anos. O esquema de medicação constou de administração de L-Dopa na dose inicial de 500 mg associado a um inibidor da MAO. A dose de L-Dopa era elevada de 500 mg cada 3 ou 4 dias, segundo a tolerância de cada paciente. Todos os sintomas dependentes, direta ou indiretamente, da rigidez tiveram melhoras mais nítidas em relação aos tremores. Durante a administração do medicamento os teores sangüíneos de ácido úrico e uréia, mostraram tendência para se elevar; a reserva alcalina, pelo contrário, tendeu para a diminuição; o hemograma revelou muitas vezes eosinofilia por vezes intensa. Os efeitos colaterais foram catalogados em dois tipos — efeitos adrenérgicos e efeitos dopaminérgicos — correspondentes a duas fases: uma primeira, de pequena duração, na qual foram usados concomitantemente o L-Dopa e um inibidor da MAO, surgindo cefaléia hipertensão arterial paroxística, rubor facial, sudorese, tenesmo vesical e angina pectoris; numa segunda fase surgiram os efeitos colaterais ditos dopaminérgicos, proporcionais à gravidade clínica do caso, cujas manifestações principais foram hipotensão arterial, sudorese fria, arritmia cardíaca e lipotimia. As complicações clínicas gerais eram representados habitualmente por anorexia, obstipação intestinal, náuseas, vômitos, discretas alterações do estado psíquico com depressão e euforia. Dentre as complicações neurológicas foram assinalados o estado parkinsonóide, discinesias e acatisia.The results of the treatment with L-Dopa of 33 patients (19 males and 14 females are reported. The cases were separated, acording to their symptoms and signs, in slight, moderate, intense and severe ones

  11. A porphodimethene chemical inhibitor of uroporphyrinogen decarboxylase.

    Directory of Open Access Journals (Sweden)

    Kenneth W Yip

    Full Text Available Uroporphyrinogen decarboxylase (UROD catalyzes the conversion of uroporphyrinogen to coproporphyrinogen during heme biosynthesis. This enzyme was recently identified as a potential anticancer target; its inhibition leads to an increase in reactive oxygen species, likely mediated by the Fenton reaction, thereby decreasing cancer cell viability and working in cooperation with radiation and/or cisplatin. Because there is no known chemical UROD inhibitor suitable for use in translational studies, we aimed to design, synthesize, and characterize such a compound. Initial in silico-based design and docking analyses identified a potential porphyrin analogue that was subsequently synthesized. This species, a porphodimethene (named PI-16, was found to inhibit UROD in an enzymatic assay (IC50 = 9.9 µM, but did not affect porphobilinogen deaminase (at 62.5 µM, thereby exhibiting specificity. In cellular assays, PI-16 reduced the viability of FaDu and ME-180 cancer cells with half maximal effective concentrations of 22.7 µM and 26.9 µM, respectively, and only minimally affected normal oral epithelial (NOE cells. PI-16 also combined effectively with radiation and cisplatin, with potent synergy being observed in the case of cisplatin in FaDu cells (Chou-Talalay combination index <1. This work presents the first known synthetic UROD inhibitor, and sets the foundation for the design, synthesis, and characterization of higher affinity and more effective UROD inhibitors.

  12. Cysteinesulfinate decarboxylase: Characterization, inhibition, and metabolic role in taurine formation

    International Nuclear Information System (INIS)

    Weinstein, C.L.

    1988-01-01

    Cysteinesulfinate decarboxylase, an enzyme that plays a major role in the formation of taurine from cysteine, has been purified from rat liver to homogeneity and characterized. The physical properties of the enzyme were studied, along with its substrate specificity. Multiple forms of the enzyme were found in rat liver, kidney, and brain with isoelectric points ranging from pH 5.6 to 4.9. These multiple forms did not differ in their substrate specificity. It was found by using gel electrofocusing and polyclonal antibodies raised to the liver enzyme that the different forms of cysteinesulfinate decarboxylase are identical in the various rat tissues studied. Various inhibitors of the enzyme were tested both in vitro and in vivo in order to evaluate the role of cysteinesulfinate decarboxylase in taurine formation in mammalian tissues. In in vitro studies, cysteinesulfinate decarboxylase was irreversibly inhibited by β-ethylidene-DL-aspartate (Ki = 10 mM), and competitive inhibition was found using mercaptomethylsuccinate (Ki = 0.1 mM) and D-cysteinesulfinate (Ki = 0.32 mM) when L-cysteinesulfinate was used as a substrate. In order to be able to test these inhibitors in vivo, L-[1- 14 C]cysteinesulfonate was evaluated as a probe for the in vivo measurement of cysteinesulfinate decarboxylase activity. The metabolism of cysteinesulfonate and the product of its transamination, β-sulfopyruvate, was studied, and it was found that L-[1- 14 C]cysteinesulfonate is an accurate and convenient probe for cysteinesulfinate decarboxylase activity. Using L-[1- 14 C]cysteinesulfonate, it was found that D-cysteinesulfinate inhibits cysteinesulfinate decarboxylase activity by greater than 90% in the intact mouse and that inhibition lasts for up to fifteen hours

  13. Evidence of D-phenylglycine as delivering tool for improving L-dopa absorption.

    Science.gov (United States)

    Wang, Chun-Li; Fan, Yang-Bin; Lu, Hsiao-Hwa; Tsai, Tung-Hu; Tsai, Ming-Cheng; Wang, Hui-Po

    2010-09-06

    L-dopa has been used for Parkinson's disease management for a long time. However, its wide variety in the rate and the extent of absorption remained challenge in designing suitable therapeutic regime. We report here a design of using D-phenylglycine to guard L-dopa for better absorption in the intestine via intestinal peptide transporter I (PepT1). D-phenylglycine was chemically attached on L-dopa to form D-phenylglycine-L-dopa as a dipeptide prodrug of L-dopa. The cross-membrane transport of this dipeptide and L-dopa via PepT1 was compared in brush-boarder membrane vesicle (BBMV) prepared from rat intestine. The intestinal absorption was compared by in situ jejunal perfusion in rats. The pharmacokinetics after i.v. and p.o. administration of both compounds were also compared in Wistar rats. The striatal dopamine released after i.v. administration of D-phenylglycine-L-dopa was collected by brain microdialysis and monitored by HPLC. Anti-Parkinsonism effect was determined by counting the rotation of 6-OHDA-treated unilateral striatal lesioned rats elicited rotation with (+)-methamphetamine (MA). The BBMV uptake of D-phenylglycine-L-dopa was inhibited by Gly-Pro, Gly-Phe and cephradine, the typical PepT1 substrates, but not by amino acids Phe or L-dopa. The cross-membrane permeability (Pm*) determined in rat jejunal perfusion of D-phenylglycine-L-dopa was higher than that of L-dopa (2.58 ± 0.14 vs. 0.94 ± 0.10). The oral bioavailability of D-phenylglycine-L-dopa was 31.7 times higher than that of L-dopa in rats. A sustained releasing profile of striatal dopamine was demonstrated after i. v. injection of D-phenylglycine-L-dopa (50 mg/kg), indicated that D-phenylglycine-L-dopa might be a prodrug of dopamine. D-phenylglycine-L-dopa was more efficient than L-dopa in lowering the rotation of unilateral striatal lesioned rats (19.1 ± 1.7% vs. 9.9 ± 1.4%). The BBMV uptake studies indicated that D-phenylglycine facilitated the transport of L-dopa through the intestinal

  14. Evidence of d-phenylglycine as delivering tool for improving l-dopa absorption

    Directory of Open Access Journals (Sweden)

    Wang Chun-Li

    2010-09-01

    Full Text Available Abstract Background l-Dopa has been used for Parkinson's disease management for a long time. However, its wide variety in the rate and the extent of absorption remained challenge in designing suitable therapeutic regime. We report here a design of using d-phenylglycine to guard l-dopa for better absorption in the intestine via intestinal peptide transporter I (PepT1. Methods d-Phenylglycine was chemically attached on l-dopa to form d-phenylglycine-l-dopa as a dipeptide prodrug of l-dopa. The cross-membrane transport of this dipeptide and l-dopa via PepT1 was compared in brush-boarder membrane vesicle (BBMV prepared from rat intestine. The intestinal absorption was compared by in situ jejunal perfusion in rats. The pharmacokinetics after i.v. and p.o. administration of both compounds were also compared in Wistar rats. The striatal dopamine released after i.v. administration of d-phenylglycine-l-dopa was collected by brain microdialysis and monitored by HPLC. Anti-Parkinsonism effect was determined by counting the rotation of 6-OHDA-treated unilateral striatal lesioned rats elicited rotation with (+-methamphetamine (MA. Results The BBMV uptake of d-phenylglycine-l-dopa was inhibited by Gly-Pro, Gly-Phe and cephradine, the typical PepT1 substrates, but not by amino acids Phe or l-dopa. The cross-membrane permeability (Pm* determined in rat jejunal perfusion of d-phenylglycine-l-dopa was higher than that of l-dopa (2.58 ± 0.14 vs. 0.94 ± 0.10. The oral bioavailability of d-phenylglycine-l-dopa was 31.7 times higher than that of l-dopa in rats. A sustained releasing profile of striatal dopamine was demonstrated after i. v. injection of d-phenylglycine-l-dopa (50 mg/kg, indicated that d-phenylglycine-l-dopa might be a prodrug of dopamine. d-Phenylglycine-l-dopa was more efficient than l-dopa in lowering the rotation of unilateral striatal lesioned rats (19.1 ± 1.7% vs. 9.9 ± 1.4%. Conclusion The BBMV uptake studies indicated that d

  15. A systematic review on aromatic L-amino acid decarboxylase (5-hydroxytryptophan decarboxylase)

    International Nuclear Information System (INIS)

    Rahman, M.K.; Nagatsu, T.

    1988-11-01

    Aromatic L-amino acid decarboxylase (AADC, EC. 4.1.1.28) with L-5-hydroxytryptophan as a substrate (also called L-5-hydroxytryptophan decarboxylase, 5-HTPDC) decarboxylates L-5-hydroxytryptophan to serotonin (5-HT), an important neurotransmitter that involved in the regulation of neuronal functions, behaviour and emotion of higher animals. As it is an important enzyme, many researchers are now working on its physiological functions and properties and also on its isolation, purification and characterization from mammalian tissues. But up to now no systematic review studies have been done on this enzyme. We made systematic studies on this enzyme in tissues and brains of rats, and human subjects. We also developed highly sensitive assay methods of the enzyme. This new method led us to discover the enzyme in the sera of various animals. We examined the developmental changes of 5-HTPDC in the sera of animals. We discovered an endogenous inhibitor of the enzyme in the monkey blood. The purification of the enzyme were performed by us and other researches from the sera, brains, adrenals, liver and kidneys of mammals. These and other results of up to date research papers on 5-HTPDC have been reviewed in this paper. (author). 71 refs, 10 figs, 14 tabs

  16. Impairment of Serotonergic Transmission by the Antiparkinsonian Drug L-DOPA: Mechanisms and Clinical Implications

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    Cristina Miguelez

    2017-09-01

    Full Text Available The link between the anti-Parkinsonian drug L-3,4-dihydroxyphenylalanine (L-DOPA and the serotonergic (5-HT system has been long established and has received increased attention during the last decade. Most studies have focused on the fact that L-DOPA can be transformed into dopamine (DA and released from 5-HT terminals, which is especially important for the management of L-DOPA-induced dyskinesia. In patients, treatment using L-DOPA also impacts 5-HT neurotransmission; however, few studies have investigated the mechanisms of this effect. The purpose of this review is to summarize the electrophysiological and neurochemical data concerning the effects of L-DOPA on 5-HT cell function. This review will argue that L-DOPA disrupts the link between the electrical activity of 5-HT neurons and 5-HT release as well as that between 5-HT release and extracellular 5-HT levels. These effects are caused by the actions of L-DOPA and DA in 5-HT neurons, which affect 5-HT neurotransmission from the biosynthesis of 5-HT to the impairment of the 5-HT transporter. The interaction between L-DOPA and 5-HT transmission is especially relevant in those Parkinson’s disease (PD patients that suffer dyskinesia, comorbid anxiety or depression, since the efficacy of antidepressants or 5-HT compounds may be affected.

  17. New and highly sensitive assay for L-5-hydroxytryptophan decarboxylase activity by high-performance liquid chromatography-voltammetry.

    Science.gov (United States)

    Rahman, M K; Nagatsu, T; Kato, T

    1980-12-12

    This paper describes a new, inexpensive and highly sensitive assay for aromatic L-amino acid decarboxylase (AADC) activity, using L-5-hydroxytryptophan (L-5-HTP) as substrate, in rat and human brains and serum by high-performance liquid chromatography (HPLC) with voltammetric detection. L-5-HTP was used as substrate and D-5-HTP for the blank. After isolating serotonin (5-HT) formed enzymatically from L-5-HTP on a small Amberlite CG-50 column, the 5-HT was eluted with hydrochloric acid and assayed by HPLC with a voltammetric detector. N-Methyldopamine was added to each incubation mixture as an internal standard. This method is sensitive enough to measure 5-HT, formed by the enzyme, 100 fmol to 140 pmol or more. An advantage of this method is that one can incubate the enzyme for longer time (up to 150 min), as compared with AADC assay using L-DOPA as substrate, resulting in a very high sensitivity. By using this new method, AADC activity was discovered in rat serum.

  18. Ornithine decarboxylase, polyamines, and pyrrolizidine alkaloids in senecio and crotalaria.

    Science.gov (United States)

    Birecka, H; Birecki, M; Cohen, E J; Bitonti, A J; McCann, P P

    1988-01-01

    When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high relative to that of ornithine decarboxylase. Unlike Heliotropium angiospermum and Heliotropium indicum, in which endogenous arginine was the only detectable precursor of putrescine channeled into pyrrolizidines, in the species studied here-using difluoromethylornithine and difluoromethylarginine as the enzyme inhibitors-endogenous ornithine was the main if not the only precursor of putrescine converted into the alkaloid aminoalcohol moiety. In S. riddellii and C. retusa at flowering, ornithine decarboxylase activity was present mainly in leaves, especially the young ones. However, other very young organs such as inflorescence and growing roots exhibited much lower or very low activities; the enzyme activity in stems was negligible. There was no correlation between the enzyme activity and polyamine or alkaloid content in either species. In both species only free polyamines were detected except for C. retusa roots and inflorescence-with relatively very high levels of these compounds-in which conjugated putrescine, spermidine, and spermine were also found; agmatine was not identified by HPLC in any plant organ except for C. retusa roots with rhizobial nodules. Organ- or age-dependent differences in the polyamine levels were small or insignificant. The highest alkaloid contents were found in young leaves and inflorescence.

  19. Pengaruh Diameter Partikel Terhadap Konsentrasi L-Dopa, Kc Dan De Pada Ekstraksi L-Dopa Dari Biji Kara Benguk (Mucuna Pruriens Dc.

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    Eni Budiyati

    2013-10-01

    Full Text Available Mucuna pruriens (biji kara benguk merupakan tanaman penghasil bahan obat-obatan karena mengandung senyawa L-Dopa. Senyawa tersebut dapat digunakan untuk pengobatan penyakit gangguan syaraf, anti bisa ular, meningkatkan bobot dan kekuatan otot, vitalitas seksual pria, zat anti-aging dan obat cacing pada manusia. Penelitian ini bertujuan untuk mengekstraksi L- Dopa dari biji kara benguk dengan menggunakan pelarut air. Di samping itu, penelitian ini juga mengevaluasi pengaruh dari diameter partikel terhadap konsentrasi L- dopa hasil ekstraksi, koefisien transfer massa (kC, dan difusivitas efektif (De. Tahapan yang digunakan pada penelitian ini adalah, persiapan bahan baku, proses ekstraksi, dan analisis L-Dopa. Proses ekstraksi dilakukan dalam tangki yang dilengkapi dengan thermometer. Analisis L-Dopa dilakukan dengan dengan High Performance Liquid Chromatography (HPLC. Hasil penelitian menunjukkan bahwa semakin kecil diameter partikel maka konsentrasi L-Dopa terekstrak semakin besar. Konsentrasi tertinggi diperoleh pada diameter partikel 0,5 mm yaitu 1739,56 ppm. Nilai difusivitas efektif (De untuk variabel diameter partikel (0,5; 0,675; 2,18; dan 2,5 mm hampir sama yaitu 2,99.10–5 sampai 3,07.10–5 cm2/menit. Sedangkan nilai koefisien transfer massa (kC berbanding terbalik dengan diameter partikel. Nilai kC berkisar antara 2,83.10-2 sampai 3,98.10-2 g/cm2.menit. 

  20. Role of ornithine decarboxylase in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Wensheng Deng; Xian Jiang; Yu Mei; Jingzhong Sun; Rong Ma; Xianxi Liu; Hui Sun; Hui Tian; Xueying Sun

    2008-01-01

    Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis that decarboxylates ornithine to putrescine, has become a promising target for cancer research. The aim of this study is to investigate the role of ODC in breast cancer. We detected expression of ODC in breast cancer tissues and four breast cancer cell lines, and transfected breast cancer cells with an adenoviral vector carrying antisense ODC (rAd-ODC/Ex3as) and examined their growth and migration.ODC was overexpressed in breast cancer tissues and cell lines compared with non-tumor tissues and normal breast epithelial celis,and there was a positive correlation between the level of ODC mRNA and the staging of tumors.The expression of ODC correlated with cyclin D1,a cell cycle protein,in synchronized breast cancer MDA-MB-231 cells.Gene transfection of rAd-ODC/Ex3as markedly down-regulated expression Of ODC and cyclin D1,resulting in suppression of proliferation and cell cycle arrest at G0-G1 phase,and the inhibifion of colony formation,an anchorage-independent growth pattern,and the migratory ability of MDA-MB-231 cells.rAd-ODC/Ex3as also markedly reduced the concentration of putrescine,but not spermidine or spermine,in MDA-MB-231 cells.The results suggested that the ODC gene might act as aprognostic factor for breast cancer and it could be a promising therapeutic target.

  1. Hypothalamic L-Histidine Decarboxylase Is Up-Regulated During Chronic REM Sleep Deprivation of Rats.

    Directory of Open Access Journals (Sweden)

    Gloria E Hoffman

    Full Text Available A competition of neurobehavioral drives of sleep and wakefulness occurs during sleep deprivation. When enforced chronically, subjects must remain awake. This study examines histaminergic neurons of the tuberomammillary nucleus of the posterior hypothalamus in response to enforced wakefulness in rats. We tested the hypothesis that the rate-limiting enzyme for histamine biosynthesis, L-histidine decarboxylase (HDC, would be up-regulated during chronic rapid eye movement sleep deprivation (REM-SD because histamine plays a major role in maintaining wakefulness. Archived brain tissues of male Sprague Dawley rats from a previous study were used. Rats had been subjected to REM-SD by the flowerpot paradigm for 5, 10, or 15 days. For immunocytochemistry, rats were transcardially perfused with acrolein-paraformaldehyde for immunodetection of L-HDC; separate controls used carbodiimide-paraformaldehyde for immunodetection of histamine. Immunolocalization of histamine within the tuberomammillary nucleus was validated using carbodiimide. Because HDC antiserum has cross-reactivity with other decarboxylases at high antibody concentrations, titrations localized L-HDC to only tuberomammillary nucleus at a dilution of ≥ 1:300,000. REM-SD increased immunoreactive HDC by day 5 and it remained elevated in both dorsal and ventral aspects of the tuberomammillary complex. Our results suggest that up-regulation of L-HDC within the tuberomammillary complex during chronic REM-SD may be responsible for maintaining wakefulness.

  2. Influence of ornithine decarboxylase antizymes and antizyme inhibitors on agmatine uptake by mammalian cells.

    Science.gov (United States)

    Ramos-Molina, Bruno; López-Contreras, Andrés J; Lambertos, Ana; Dardonville, Christophe; Cremades, Asunción; Peñafiel, Rafael

    2015-05-01

    Agmatine (4-aminobutylguanidine), a dicationic molecule at physiological pH, exerts relevant modulatory actions at many different molecular target sites in mammalian cells, having been suggested that the administration of this compound may have therapeutic interest. Several plasma membrane transporters have been implicated in agmatine uptake by mammalian cells. Here we report that in kidney-derived COS-7 cell line, at physiological agmatine levels, the general polyamine transporter participates in the plasma membrane translocation of agmatine, with an apparent Km of 44 ± 7 µM and Vmax of 17.3 ± 3.3 nmol h(-1) mg(-1) protein, but that at elevated concentrations, agmatine can be also taken up by other transport systems. In the first case, the physiological polyamines (putrescine, spermidine and spermine), several diguanidines and bis(2-aminoimidazolines) and the polyamine transport inhibitor AMXT-1501 markedly decreased agmatine uptake. In cells transfected with any of the three ornithine decarboxylase antizymes (AZ1, AZ2 and AZ3), agmatine uptake was dramatically reduced. On the contrary, transfection with antizyme inhibitors (AZIN1 and AZIN2) markedly increased the transport of agmatine. Furthermore, whereas putrescine uptake was significantly decreased in cells transfected with ornithine decarboxylase (ODC), the accumulation of agmatine was stimulated, suggesting a trans-activating effect of intracellular putrescine on agmatine uptake. All these results indicate that ODC and its regulatory proteins (antizymes and antizyme inhibitors) may influence agmatine homeostasis in mammalian tissues.

  3. Gynostemma pentaphyllum Ethanolic Extract Protects Against Memory Deficits in an MPTP-Lesioned Mouse Model of Parkinson's Disease Treated with L-DOPA.

    Science.gov (United States)

    Kim, Kyung Sook; Zhao, Ting Ting; Shin, Keon Sung; Park, Hyun Jin; Cho, Yoon Jeong; Lee, Kyung Eun; Kim, Seung Hwan; Lee, Myung Koo

    2017-01-01

    This study investigated the effects of ethanol extract from Gynostemma pentaphyllum (GP-EX) on memory deficits in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) (MPTP-lesioned mice). MPTP (30 mg/kg/day, 5 days)-lesioned mice showed deficits of habit learning memory and spatial memory, which were further aggravated by treatment with L-3,4-dihydroxyphenylalanine (L-DOPA) (25 mg/kg, 21 days). However, treatment with GP-EX (50 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice treated with L-DOPA (25 mg/kg): GP-EX prevented the decreases in retention latency time in the passive avoidance test and tyrosine hydroxylase-immunopositive cells and dopamine levels in the nigrostriatum. GP-EX also reduced increases in retention transfer latency time of the elevated plus-maze test and expression of N-methyl-D-aspartate (NMDA) receptor and improved decreases in phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus in the same models. By contrast, L-DOPA treatment (10 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice, which were further improved by GP-EX treatment. These results suggest that GP-EX ameliorates habit learning memory deficits by activating dopaminergic neurons and spatial memory deficits by modulating NMDA receptor-ERK1/2-CREB system in MPTP-lesioned mice treated with L-DOPA. GP-EX may serve as an adjuvant phytonutrient for memory deficits in PD.

  4. Enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens by liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Hasegawa, Takashi; Takahashi, Kazunaga; Fukiwake, Tomohide; Saijo, Masaaki; Motoki, Yuji

    2013-01-01

    We developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens. L- and D-DOPA were ultrasonically extracted with 1% formic acid aqueous solution. The isolated extracts were analyzed by LC/MS using a Crownpak CR (-) column at 30℃. The mass spectrometer was operated in the positive mode of electrospray ionization, and the mobile phase was aqueous formic acid (pH 2.0). L-DOPA-ring-d3 was used as an internal standard. The method was validated for a dietary supplement spiked with L- and D-DOPA at 50 and 500 μg/g, respectively, and the recoveries of the DOPA enantiomers were between 97.5% and 101.3%. Relative standard deviation values of repeatability and intermediate precision were less than 7%. The method was applied to 14 dietary supplements. L-DOPA was detected in these supplements in the range of 0.88-12.8 mg/unit. D-DOPA was not detected.

  5. Striatal proteomic analysis suggests that first L-dopa dose equates to chronic exposure.

    Directory of Open Access Journals (Sweden)

    Birger Scholz

    Full Text Available L-3,4-dihydroxypheylalanine (L-dopa-induced dyskinesia represent a debilitating complication of therapy for Parkinson's disease (PD that result from a progressive sensitization through repeated L-dopa exposures. The MPTP macaque model was used to study the proteome in dopamine-depleted striatum with and without subsequent acute and chronic L-dopa treatment using two-dimensional difference in-gel electrophoresis (2D-DIGE and mass spectrometry. The present data suggest that the dopamine-depleted striatum is so sensitive to de novo L-dopa treatment that the first ever administration alone would be able (i to induce rapid post-translational modification-based proteomic changes that are specific to this first exposure and (ii, possibly, lead to irreversible protein level changes that would be not further modified by chronic L-dopa treatment. The apparent equivalence between first and chronic L-dopa administration suggests that priming would be the direct consequence of dopamine loss, the first L-dopa administrations only exacerbating the sensitization process but not inducing it.

  6. Pupillometry as an indicator of L-DOPA dosages in Parkinson's disease patients.

    Science.gov (United States)

    Bartošová, O; Bonnet, C; Ulmanová, O; Šíma, M; Perlík, F; Růžička, E; Slanař, O

    2018-04-01

    Dopamine was shown to induce mydriasis by excitation of alpha-adrenergic receptors at the dilator pupillae muscle. Pupilla diameter may thus serve as an indirect measure of peripheral pharmacokinetics of L-DOPA and dopamine. The aim of this study is to evaluate the effect of L-DOPA dosage on pupillometric parameters in Parkinson's disease (PD) patients. Sixteen PD patients and 14 healthy control subjects (CS) were studied. The statistical analysis revealed significant differences between CS and PD patients for the mean maximum and minimum pupil diameters (p = 0.017, p = 0.028, respectively), with higher values found in PD. Moreover, a significant dose-response relationship was found between the maximum pupil diameter and both the morning L-DOPA dose (R 2  = 0.78) and the total daily L-DOPA dose (R 2  = 0.93). A sigmoid-shaped curve best describes the dose-response relationship, with a ceiling effect at about 400 mg L-DOPA daily dose. In conclusion, measuring pupillometric parameters represents a sensitive tool for non-invasive evaluation of the peripheral effect of L-DOPA, especially with daily doses below 400 mg L-DOPA.

  7. Depression of Serotonin Synaptic Transmission by the Dopamine Precursor L-DOPA

    Directory of Open Access Journals (Sweden)

    Stephanie C. Gantz

    2015-08-01

    Full Text Available Imbalance between the dopamine and serotonin (5-HT neurotransmitter systems has been implicated in the comorbidity of Parkinson’s disease (PD and psychiatric disorders. L-DOPA, the leading treatment of PD, facilitates the production and release of dopamine. This study assessed the action of L-DOPA on monoamine synaptic transmission in mouse brain slices. Application of L-DOPA augmented the D2-receptor-mediated inhibitory postsynaptic current (IPSC in dopamine neurons of the substantia nigra. This augmentation was largely due to dopamine release from 5-HT terminals. Selective optogenetic stimulation of 5-HT terminals evoked dopamine release, producing D2-receptor-mediated IPSCs following treatment with L-DOPA. In the dorsal raphe, L-DOPA produced a long-lasting depression of the 5-HT1A-receptor-mediated IPSC in 5-HT neurons. When D2 receptors were expressed in the dorsal raphe, application of L-DOPA resulted in a D2-receptor-mediated IPSC. Thus, treatment with L-DOPA caused ectopic dopamine release from 5-HT terminals and a loss of 5-HT-mediated synaptic transmission.

  8. Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

    Science.gov (United States)

    Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

    2012-11-01

    The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Cerebrospinal Fluid Biomarkers For Parkinson's Disease and L-DOPA-induced Dyskinesia

    DEFF Research Database (Denmark)

    Dammann Andersen, Andreas

    -DOPA, 18 patienter blev behandlet med L-DOPA, hvoraf 10 havde LID. Prøverne blev analyseret ved brug af high-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), western blotting, enzyme linked immune-assays (ELISA), Multiplex og fluorescence-assays. Flere mulige......-patienter, som ikke fik L-DOPA. Patienter med LID havde signifikante forandringer i tryptofan- og katekolamin-metabolismen og en øget fosforylering af enzymet extracellular signal-regulated kinase (ERK 1/2). Disse fund kan bidrage til en bedre forståelse af de sygdomsmekanismer, som giver PS og LID...

  10. Altered subcellular localization of ornithine decarboxylase in Alzheimer's disease brain

    DEFF Research Database (Denmark)

    Nilsson, Tatjana; Bogdanovic, Nenad; Volkman, Inga

    2006-01-01

    The amyloid precursor protein can through ligand-mimicking induce expression of ornithine decarboxylase (ODC), the initial and rate-limiting enzyme in polyamine biosynthesis. We report here the regional distribution and cellular localization of ODC immunoreactivity in Alzheimer's disease (AD...

  11. Atypical presentation of dopa-responsive dystonia in Taiwan.

    Science.gov (United States)

    Weng, Yi Ching; Wang, Chun Chieh; Wu, Yih Ru

    2018-02-01

    The typical clinical presentation of dopa-responsive dystonia, which is also called Segawa disease, is a young age of onset, with predominance in females, diurnal fluctuation of lower limb dystonia, and fair response to low-dose levodopa. This disease has both autosomal dominant and autosomal recessive inheritance. Autosomal dominant Segawa disease is caused by GCH1 mutation on chromosome 14q22.1-q22.2. Here, we report the case of a male patient with genetically confirmed Segawa disease and atypical presentations including no diurnal symptom fluctuation and insufficient response to levodopa. The patient's father who had the same mutation presented parkinsonism in old age. We also review the literature to address the broad clinical heterogeneity of Segawa disease and the influence of onset age on clinical presentation.

  12. Elevating your elevator talk

    Science.gov (United States)

    An important and often overlooked item that every early career researcher needs to do is compose an elevator talk. The elevator talk, named because the talk should not last longer than an average elevator ride (30 to 60 seconds), is an effective method to present your research and yourself in a clea...

  13. Brain kinetics of L-[β-11C]DOPA in humans studied by positron emission tomography

    International Nuclear Information System (INIS)

    Hartvig, P.; Agren, H.; Reibring, L.; Tedroff, J.; Bjurling, P.; Kihlberg, T.; Langstroem, B.

    1991-01-01

    The in vivo dopamine precursor L-3,4-dihydroxyphenylalanine (L-DOPA) labelled with 11 C in the β position has been used for positron emission tomography studies of L-DOPA utilization in the brain. The brain uptake and kinetics of L-[ 11 C]DOPA-derived radioactivity were studied in healthy male volunteers, and the specific utilization, i.e. decarboxylation rate of L-[ 11 C]DOPA in different brain areas, was quantified using a brain region devoid of specific L-[ 11 C]DOPA utilization as reference. Total uptake of L-[ 11 C]DOPA-derived radioactivity measured in the brain varied two- to three-fold between subjects, with highest radioactivity in the striatal region. Specific utilization of L-[ 11 C]DOPA radioactivity in the striatal region and in the prefrontal cortex varied twofold between subjects. No specific utilization was observed in other regions of the brain. The uptake of radioactivity in the brain increased dose-dependently with the simultaneous administration of unlabelled L-DOPA up to 10 mg. On the other hand, a decrease in brain radioactivity uptake was measured after pretreatment with 1 mg/kg oral L-DOPA, indicating competition for transport across the blood-brain barrier. Benserazide 0.5mg/kg orally increased somewhat the radioactivity uptake to the brain. None of these pharmacological perturbations demonstrated any clearcut effect on specific utilization of L-[ 11 C]DOPA. Thus, 11 C-labelled L-DOPA is introduced as an alternative to the well-established L-6-[ 18 F]fluoro-DOPA methodology in clinical studies on brain L-DOPA uptake and dopamine synthesis. (authors)

  14. Magnetically Separable Fe3O4@DOPA-Pd: A Heterogeneous Catalyst for Aqueous Heck Reaction

    Science.gov (United States)

    Magnetically separable Fe3O4@DOPA-Pd catalyst has been synthesized via anchoring of palladium over dopamine-coated magnetite via non-covalent interaction and the catalyst is utilized for expeditious Heck coupling in aqueous media.

  15. Enantioselective synthesis of no-carrier added (NCA) 6-[18F]Fluoro-L-Dopa

    International Nuclear Information System (INIS)

    Duanzhi Yin; Lan Zhang; Yongxian Wang; Ganghua Tang; First Military Medical Univ., Guangzhou; Xiaolan Tang

    2003-01-01

    6-[ 18 F]Fluoro-L-Dopa (6-FDOPA) is the analogue of L-Dopa, the biosynthesis precursor for dopamine. As a PET tracer, it was widely applied for the presynaptic dopamine function studies in human brain. The application of a chiral phase-transfer-catalyst (PTC) in enantioselective synthesis of N.C.A. 6-[ 18 F]Fluoro-L-Dopa has been developed recently. An improved procedure was described. The labeling precursor (6-Trimethylammoniumveratraldehyde Triflate) and PTC (O-Allyl-N-(9)-anthracenylcinchonidinium Bromide) were synthesized. A successful synthesis route was developed for the preparation of 6-[ 18 F]Fluoro-L-Dopa with high radiochemical yields (4-9%, decay uncorrected) and short synthesis time(80min). The radiochemical purity was over 99% and no D-isomer was detected by HPLC analysis using a chiral mobile phase. (author)

  16. 18F-DOPA PET/CT Physiological Distribution and Pitfalls: Experience in 215 Patients.

    Science.gov (United States)

    Calabria, Ferdinando F; Chiaravalloti, Agostino; Jaffrain-Rea, Marielise L; Zinzi, Maddalena; Sannino, Pasqualina; Minniti, Giuseppe; Rubello, Domenico; Schillaci, Orazio

    2016-10-01

    F-DOPA PET/CT is potentially helpful in the management of patients with low-grade brain tumors, movement disorders, and somatic neuroendocrine tumors. We describe the whole-body physiological distribution of F-DOPA uptake. We examined 215 patients with F-DOPA PET/CT. Among these, 161 had brain scans and 54 had whole-body scans. Physiological distribution was negligible in the brain, with the exception of basal ganglia, whereas greatest activity was noted in the liver, pancreas, other exocrine glands, and the urinary system. Incidental tracer uptake sites were identified in 5.5% of patients. Some of these findings were due to inflammation, whereas in most cases, uptake was seen in benign tumors of the brain or in the endocrine or exocrine glands. F-DOPA uptake may be seen in inflammatory tissue or benign tumors. Correlations with history, physical examination, laboratory examination, CT, MRI, and histology are necessary for optimal diagnosis.

  17. Management of L-dopa overdose in the competitive inhibition state

    Directory of Open Access Journals (Sweden)

    Hinz M

    2014-07-01

    Full Text Available Marty Hinz,1 Alvin Stein,2 Ted Cole3 1Clinical Research, NeuroResearch Clinics, Inc., Cape Coral, FL, USA; 2Stein Orthopedic Associates, Plantation, FL, USA; 3Cole Center for Healing, Cincinnati, OH, USA Abstract: The amino acid L-3,4-dihydroxyphenylalanine (L-dopa is prescribed for conditions where increased central and/or peripheral dopamine synthesis is desired. Its administration can establish dopamine concentrations higher than can be achieved from an optimal diet. Specific indications include Parkinson's disease and restless leg syndrome. The interaction between serotonin and dopamine exists in one of two distinctly different physiologic states: the endogenous state or the competitive inhibition state. Management with L-dopa in the competitive inhibition state is the focus of this paper. In the past, control of the competitive inhibition state was thought to be so difficult and complex that it was described in the literature as functionally “meaningless”. When administering L-dopa without simultaneous administration of serotonin precursors, the patient is in the endogenous state. Experience gained with patient outcomes during endogenous L-dopa administration does not allow predictability of L-dopa outcomes in the competitive inhibition state. The endogenous approach typically increases the daily L-dopa dosing value in a linear fashion until symptoms of Parkinson's disease are under control. It is the novel observations made during treatment with the competitive inhibition state approach that L-dopa dosing values above or below the optimal therapeutic range are generally associated with the presence of the exact same Parkinson's disease symptoms with identical intensity. This recognition requires a novel approach to optimization of daily L-dopa dosing values from that used in the endogenous state. This paper outlines that novel approach through utilization of a pill stop. This approach enhances patient safety through its ability to

  18. Enantioselective synthesis of 6-[18F] fluoro-L-DOPA

    International Nuclear Information System (INIS)

    Zhang Lan; Tang Ganghua; Zhou Wei; Li Junling; Yin Duanzhi; Wang Yongxian; Tang Xiaolan; Huang Zuhan

    2002-01-01

    Trimethylammonium veratraldehyde triflate was synthesized and used as a precurser for the synthesis of 6-[ 18 F] Fluoro-L-DOPA by using the chiral phase-transfer catalyst, O-Allyl-N-(9)-anthracenylcinchonidinium bromide which was also synthesized in this study. Based on these, 6-[ 18 F] Fluoro-L-DOPA was prepared with acceptable radiochemical yield (10 ± 3)% in short synthesis time (80 min), with high radiochemical purity, specific activity and chemical purity

  19. Statistically optimized biotransformation protocol for continuous production of L-DOPA using Mucuna monosperma callus culture.

    Science.gov (United States)

    Inamdar, Shrirang Appasaheb; Surwase, Shripad Nagnath; Jadhav, Shekhar Bhagwan; Bapat, Vishwas Anant; Jadhav, Jyoti Prafull

    2013-01-01

    L-DOPA (3,4-dihydroxyphenyl-L-alanine), a modified amino acid, is an expansively used drug for the Parkinson's disease treatment. In the present study, optimization of nutritional parameters influencing L-DOPA production was attempted using the response surface methodology (RSM) from Mucuna monosperma callus. Optimization of the four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.894 g l(-1), pH 4.99, ascorbic acid 31.62 mg l(-1)and copper sulphate 23.92 mg l(-1), which resulted in highest L-DOPA yield of 0.309 g l(-1). The optimization of medium using RSM resulted in a 3.45-fold increase in the yield of L-DOPA. The ANOVA analysis showed a significant R (2) value (0.9912), model F-value (112.465) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for continuous production of L-DOPA. Uninterrupted flow column exhibited maximum L-DOPA production rate of 200 mg L(-1) h(-1) which is one of the highest values ever reported using plant as a biotransformation source. L-DOPA production was confirmed by HPTLC and HPLC analysis. This study demonstrates the synthesis of L- DOPA using Mucuna monosperma callus using a laboratory scale column reactor.

  20. Biochemical identification of residues that discriminate between 3,4-dihydroxyphenylalanine decarboxylase and 3,4-dihydroxyphenylacetaldehyde synthase-mediated reactions.

    Science.gov (United States)

    Liang, Jing; Han, Qian; Ding, Haizhen; Li, Jianyong

    2017-12-01

    In available insect genomes, there are several L-3,4-dihydroxyphenylalanine (L-dopa) decarboxylase (DDC)-like or aromatic amino acid decarboxylase (AAAD) sequences. This contrasts to those of mammals whose genomes contain only one DDC. Our previous experiments established that two DDC-like proteins from Drosophila actually mediate a complicated decarboxylation-oxidative deamination process of dopa in the presence of oxygen, leading to the formation of 3,4-dihydroxyphenylacetaldehyde (DHPA), CO 2 , NH 3, and H 2 O 2 . This contrasts to the typical DDC-catalyzed reaction, which produces CO 2 and dopamine. These DDC-like proteins were arbitrarily named DHPA synthases based on their critical role in insect soft cuticle formation. Establishment of reactions catalyzed by these AAAD-like proteins solved a puzzle that perplexed researchers for years, but to tell a true DHPA synthase from a DDC in the insect AAAD family remains problematic due to high sequence similarity. In this study, we performed extensive structural and biochemical comparisons between DHPA synthase and DDC. These comparisons identified several target residues potentially dictating DDC-catalyzed and DHPA synthase-catalyzed reactions, respectively. Comparison of DHPA synthase homology models with crystal structures of typical DDC proteins, particularly residues in the active sites, provided further insights for the roles these identified target residues play. Subsequent site-directed mutagenesis of the tentative target residues and activity evaluations of their corresponding mutants determined that active site His192 and Asn192 are essential signature residues for DDC- and DHPA synthase-catalyzed reactions, respectively. Oxygen is required in DHPA synthase-mediated process and this oxidizing agent is reduced to H 2 O 2 in the process. Biochemical assessment established that H 2 O 2 , formed in DHPA synthase-mediated process, can be reused as oxidizing agent and this active oxygen species is reduced to H 2

  1. Betalain production is possible in anthocyanin-producing plant species given the presence of DOPA-dioxygenase and L-DOPA.

    Science.gov (United States)

    Harris, Nilangani N; Javellana, John; Davies, Kevin M; Lewis, David H; Jameson, Paula E; Deroles, Simon C; Calcott, Kate E; Gould, Kevin S; Schwinn, Kathy E

    2012-03-12

    Carotenoids and anthocyanins are the predominant non-chlorophyll pigments in plants. However, certain families within the order Caryophyllales produce another class of pigments, the betalains, instead of anthocyanins. The occurrence of betalains and anthocyanins is mutually exclusive. Betalains are divided into two classes, the betaxanthins and betacyanins, which produce yellow to orange or violet colours, respectively. In this article we show betalain production in species that normally produce anthocyanins, through a combination of genetic modification and substrate feeding. The biolistic introduction of DNA constructs for transient overexpression of two different dihydroxyphenylalanine (DOPA) dioxygenases (DODs), and feeding of DOD substrate (L-DOPA), was sufficient to induce betalain production in cell cultures of Solanum tuberosum (potato) and petals of Antirrhinum majus. HPLC analysis showed both betaxanthins and betacyanins were produced. Multi-cell foci with yellow, orange and/or red colours occurred, with either a fungal DOD (from Amanita muscaria) or a plant DOD (from Portulaca grandiflora), and the yellow/orange foci showed green autofluorescence characteristic of betaxanthins. Stably transformed Arabidopsis thaliana (arabidopsis) lines containing 35S: AmDOD produced yellow colouration in flowers and orange-red colouration in seedlings when fed L-DOPA. These tissues also showed green autofluorescence. HPLC analysis of the transgenic seedlings fed L-DOPA confirmed betaxanthin production. The fact that the introduction of DOD along with a supply of its substrate (L-DOPA) was sufficient to induce betacyanin production reveals the presence of a background enzyme, possibly a tyrosinase, that can convert L-DOPA to cyclo-DOPA (or dopaxanthin to betacyanin) in at least some anthocyanin-producing plants. The plants also demonstrate that betalains can accumulate in anthocyanin-producing species. Thus, introduction of a DOD and an enzyme capable of converting

  2. Betalain production is possible in anthocyanin-producing plant species given the presence of DOPA-dioxygenase and L-DOPA

    Directory of Open Access Journals (Sweden)

    Harris Nilangani N

    2012-03-01

    Full Text Available Abstract Background Carotenoids and anthocyanins are the predominant non-chlorophyll pigments in plants. However, certain families within the order Caryophyllales produce another class of pigments, the betalains, instead of anthocyanins. The occurrence of betalains and anthocyanins is mutually exclusive. Betalains are divided into two classes, the betaxanthins and betacyanins, which produce yellow to orange or violet colours, respectively. In this article we show betalain production in species that normally produce anthocyanins, through a combination of genetic modification and substrate feeding. Results The biolistic introduction of DNA constructs for transient overexpression of two different dihydroxyphenylalanine (DOPA dioxygenases (DODs, and feeding of DOD substrate (L-DOPA, was sufficient to induce betalain production in cell cultures of Solanum tuberosum (potato and petals of Antirrhinum majus. HPLC analysis showed both betaxanthins and betacyanins were produced. Multi-cell foci with yellow, orange and/or red colours occurred, with either a fungal DOD (from Amanita muscaria or a plant DOD (from Portulaca grandiflora, and the yellow/orange foci showed green autofluorescence characteristic of betaxanthins. Stably transformed Arabidopsis thaliana (arabidopsis lines containing 35S: AmDOD produced yellow colouration in flowers and orange-red colouration in seedlings when fed L-DOPA. These tissues also showed green autofluorescence. HPLC analysis of the transgenic seedlings fed L-DOPA confirmed betaxanthin production. Conclusions The fact that the introduction of DOD along with a supply of its substrate (L-DOPA was sufficient to induce betacyanin production reveals the presence of a background enzyme, possibly a tyrosinase, that can convert L-DOPA to cyclo-DOPA (or dopaxanthin to betacyanin in at least some anthocyanin-producing plants. The plants also demonstrate that betalains can accumulate in anthocyanin-producing species. Thus, introduction

  3. MCD encodes peroxisomal and cytoplasmic forms of malonyl-CoA decarboxylase and is mutated in malonyl-CoA decarboxylase deficiency

    NARCIS (Netherlands)

    Sacksteder, K. A.; Morrell, J. C.; Wanders, R. J.; Matalon, R.; Gould, S. J.

    1999-01-01

    Malonyl-CoA decarboxylase (MCD) catalyzes the proton-consuming conversion of malonyl-CoA to acetyl-CoA and CO(2). Although defects in MCD activity are associated with malonyl-CoA decarboxylase deficiency, a lethal disorder characterized by cardiomyopathy and developmental delay, the metabolic role

  4. Histidine Decarboxylase Deficiency Prevents Autoimmune Diabetes in NOD Mice

    OpenAIRE

    Alkan , Manal; Machavoine , François; Rignault , Rachel; Dam , Julie; Dy , Michel; Thieblemont , Nathalie

    2015-01-01

    International audience; Recent evidence has highlighted the role of histamine in inflammation. Since this monoamine has also been strongly implicated in the pathogenesis of type-1 diabetes, we assessed its effect in the nonobese diabetic (NOD) mouse model. To this end, we used mice (inactivated) knocked out for the gene encoding histidine decarboxylase, the unique histamine-forming enzyme, backcrossed on a NOD genetic background. We found that the lack of endogenous histamine in NOD HDC −/− m...

  5. Development of a novel ultrasensitive enzyme immunoassay for human glutamic acid decarboxylase 65 antibody.

    Science.gov (United States)

    Numata, Satoshi; Katakami, Hideki; Inoue, Shinobu; Sawada, Hirotake; Hashida, Seiichi

    2016-07-01

    We developed a novel, ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for determination of glutamic acid decarboxylase autoantibody concentrations in serum samples from patients with type 2 diabetes. We developed an immune complex transfer enzyme immunoassay for glutamic acid decarboxylase autoantibody and measured glutamic acid decarboxylase autoantibody from 22 patients with type 1 diabetes, 29 patients with type 2 diabetes, and 32 healthy controls. A conventional ELISA kit identified 10 patients with type 1 diabetes and one patient with type 2 diabetes as glutamic acid decarboxylase autoantibody positive, whereas 15 patients with type 1 diabetes and six patients with type 2 diabetes were identified as glutamic acid decarboxylase autoantibody positive using immune complex transfer enzyme immunoassay. Immune complex transfer enzyme immunoassay is a highly sensitive and specific assay for glutamic acid decarboxylase autoantibody and might be clinically useful for diabetic onset prediction and early diagnosis. © The Author(s) 2016.

  6. Brain 18F-DOPA PET and cognition in de novo Parkinson's disease

    International Nuclear Information System (INIS)

    Picco, Agnese; Arnaldi, Dario; Brugnolo, Andrea; Nobili, Flavio; Morbelli, Silvia; Bossert, Irene; Piccardo, Arnoldo; Girtler, Nicola; Marinelli, Lucio; Abbruzzese, Giovanni; Castaldi, Antonio; De Carli, Fabrizio; Campus, Claudio

    2015-01-01

    The role of mesocortical dopaminergic pathways in the cognitive function of patients with early Parkinson's disease (PD) needs to be further clarified. The study groups comprised 15 drug-naive patients with de novo PD and 10 patients with essential tremor (controls) who underwent 18 F-DOPA PET (static acquisition, normalization on mean cerebellar counts) and an extended neuropsychological test battery. Factor analysis with varimax rotation was applied to the neuropsychological test scores, to yield five factors from 16 original scores, which explained 82 % of the total variance. Correlations between cognitive factors and 18 F-DOPA uptake were assessed with SPM8, taking age and gender as nuisance variables. 18 F-DOPA uptake was significantly lower in PD patients than in controls in the bilateral striatum, mainly in the more affected (right) hemisphere, and in a small right temporal region. Significant positive correlations were found only in PD patients between the executive factor and 18 F-DOPA uptake in the bilateral anterior cingulate cortex (ACC) and the middle frontal gyrus, between the verbal fluency factor and 18 F-DOPA uptake in left BA 46 and the bilateral striatum, and between the visuospatial factor and 18 F-DOPA uptake in the left ACC and bilateral striatum. No correlations were found between 18 F-DOPA uptake and either the verbal memory factor or the abstraction-working memory factor. These data clarify the role of the mesocortical dopaminergic pathways in cognitive function in early PD, highlighting the medial frontal lobe, anterior cingulate, and left BA 46 as the main sites of cortical correlation with executive and language functions. (orig.)

  7. The relationship between rs3779084 in the dopa decarboxylase (DDC) gene and alcohol consumption is mediated by drinking motives in regular smokers.

    Science.gov (United States)

    Kristjansson, Sean D; Agrawal, Arpana; Lessov-Schlaggar, Christina N; Madden, Pamela A F; Cooper, M Lynne; Bucholz, Kathleen K; Sher, Kenneth J; Lynskey, Michael T; Heath, Andrew C

    2012-01-01

    Motivational models of alcohol use propose that the motivation to consume alcohol is the final common pathway to its use. Both alcohol consumption and drinking motives are influenced by latent genetic factors that partially overlap. This study investigated whether drinking motives mediate the associations between alcohol consumption and 2 single-nucleotide polymorphisms (SNPs) from genes involved in serotonin (TPH2; rs1386496) and dopamine synthesis (DDC; rs3779084). Based on earlier work showing that enhancement and coping motives were heritable in regular smokers but not in nonregular smokers, we hypothesized these motives would mediate the relationships between alcohol consumption and these SNPs in regular smokers. Drinking motives data were available from 830 young adult female twins (n = 344 regular smokers and n = 486 never/nonregular smokers). We used confirmatory factor analyses to model enhancement, coping, and alcohol consumption factors and to conduct mediation analyses in the regular smoker and never/nonregular smoker groups. Our hypothesis was partially supported. The relationship between alcohol consumption and rs1386496 was not mediated by drinking motives in either group. However, in the regular smokers, the relationship between alcohol consumption and rs3779084 was mediated by enhancement and coping motives. Carriers of the rs3779084 minor allele who were regular smokers reported more motivation to consume alcohol. Given this pattern of results was absent in the never/nonregular smokers, our results are consistent with a gene × smoking status interaction. In regular smokers, variability at the locus marked by rs3779084 in the DDC gene appears to index biologically based individual differences in the motivation to consume alcohol to attain or improve a positive affective state or to relieve a negative one. These results could be because of increased sensitivity to the reinforcing effects of alcohol among minor allele carriers who smoke, which might be due to structural or functional differences in mesorticolimic dopamine "reward" circuitry. Copyright © 2011 by the Research Society on Alcoholism.

  8. EFFECT OF CADMIUM(II) ON FREE RADICALS IN DOPA-MELANIN TESTED BY EPR SPECTROSCOPY.

    Science.gov (United States)

    Zdybel, Magdalena; Pilawa, Barbara; Chodurek, Ewa

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy may be applied to examine interactions of melanin with metal ions and drugs. In this work EPR method was used to examination of changes in free radical system of DOPA-melanin--the model eumelanin after complexing with diamagnetic cadmium(II) ions. Cadmium(II) may affect free radicals in melanin and drugs binding by this polymer, so the knowledge of modification of properties and free radical concentration in melanin is important to pharmacy. The effect of cadmium(II) in different concentrations on free radicals in DOPA-melanin was determined. EPR spectra of DOPA-melanin, and DOPA-melanin complexes with cadmium(II) were measured by an X-band (9.3 GHz) EPR spectrometer produced by Radiopan (Poznań, Poland) and the Rapid Scan Unit from Jagmar (Krak6w, Poland). The DOPA (3,4-dihydroxyphenylalanine) to metal ions molar ratios in the reaction mixtures were 2:1, 1:1, and 1: 2. High concentrations of o-semiquinone (g ~2.0040) free radicals (~10(21)-10(22) spin/g) characterize DOPA-melanin and its complexes with cadmium(II). Formation of melanin complexes with cadmium(II) increase free radical concentration in DOPA-melanin. The highest free radical concentration was obtained for DOPA-melanin-cadmium(II) (1:1) complexes. Broad EPR lines with linewidths: 0.37-0.73 mT, were measured. Linewidths increase after binding of cadmium(II) to melanin. Changes of integral intensities and linewidths with increasing microwave power indicate the homogeneous broadening of EPR lines, independently on the metal ion concentration. Slow spin-lattice relaxation processes existed in all the tested samples, their EPR lines saturated at low microwave powers. Cadmium(II) causes fastening of spin-lattice relaxation processes in DOPA-melanin. The EPR results bring to light the effect of cadmium(II) on free radicals in melanin, and probably as the consequence on drug binding to eumelanin.

  9. Renal hemodynamic response to L-dopa during acute renal failure in man

    International Nuclear Information System (INIS)

    Zech, P.; Collard, M.; Guey, A.; Plantier, J.; Bernard, M.; Berthoux, F.; Pinet, A.; Traeger, J.

    1975-01-01

    Twelve patients with acute renal failure underwent L.dopa infusion into a renal artery and 133 Xenon wash-out recordings before and during the infusion. Urine volume and sodium output were also compared during two 24 hours periods, before and after the procedure. Hemodynamic data were compared with data obtained from a matched group of patients receiving Furosemide (8 patients) in place of L.dopa. Only L.dopa infusion significantly increased outer cortical distribution. No blood flow change could be demonstrated in any component nor did the drug improve unitary excretion or the general course of the disease. Control data shows that reduced cortical distribution is the most consistent feature of acute renal failure, so that L.dopa does partially improve intrarenal hemodynamics in this condition. The failure of the drug to restore kidney function may be explained by the following reasons: inability of the agent to restore a normal wash-out pattern: involvment of non-hemodynamic factors, as suggested by comparing similar wash-out improvements after L.dopa in acute glomerulonephritis and in reversible acute renal failure [fr

  10. Boronophenylalanine uptake in C6 glioma model is dramatically increased by L-DOPA preloading

    Energy Technology Data Exchange (ETDEWEB)

    Capuani, S. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Enrico Fermi Center, Compendio Viminale, Rome (Italy)], E-mail: silvia.capuani@roma1.infn.it; Gili, T. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Enrico Fermi Center, Compendio Viminale, Rome (Italy); Bozzali, M. [Neuroimaging Laboratory, Santa Lucia Foundation, Via Ardeatina 306, Rome (Italy); Russo, S. [Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London (United Kingdom); Porcari, P. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Cametti, C. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Muolo, M. [Department of Biological Science, University ' Rome III' , Viale G. Marconi 446, Rome (Italy); D' Amore, E. [Serv. Qual./Sicurezza Sperim. Anim., Istituto Superiore di Sanita, Rome (Italy); Maraviglia, B. [Enrico Fermi Center, Compendio Viminale, Rome (Italy); Neuroimaging Laboratory, Santa Lucia Foundation, Via Ardeatina 306, Rome (Italy); Lazzarino, G. [Laboratory of Biochemistry, Department of Chemical Sciences, University of Catania, Viale A. Doria 6, Catania (Italy); Pastore, F.S. [Department of Neuroscience, Institute of Neurosurgery, University ' Tor Vergata' , Via Montpellier 1, Rome (Italy)

    2009-07-15

    One of the main limitations for BNCT effectiveness is the insufficient intake of {sup 10}B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using radiowave dielectric spectroscopy (RDS), with and without L-DOPA preloading. C6 glioma cells were also implanted in the brain of 25 rats, randomly assigned to two experimental branches: (1) intra-carotid BPA infusion; (2) intra-carotid BPA infusion after pre-treatment with L-DOPA, administrated 24 h before BPA infusion. All animals were sacrificed, and assessment of BPA concentrations in tumour tissue, normal brain, and blood samples was performed using high performance liquid chromatography (HPLC). L-DOPA preloading induced a massive increase of BPA concentration either in vitro on C6 glioma cells or in vivo in the animal model tumour. Moreover, no significant difference was found in the normal brain and blood samples between the two animal groups. This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT.

  11. Colorimetric detection of manganese(II) ions using gold/dopa nanoparticles.

    Science.gov (United States)

    Narayanan, Kannan Badri; Park, Hyun Ho

    2014-10-15

    We report here a one-pot, greener, eco-friendly strategy for the synthesis of gold nanoparticles using L-dopa. The as-prepared dopa-functionalized gold nanoparticles (AuNPs/dopa) can detect low concentrations of manganese(II) metal ions in aqueous solution. The binding forces between dopa and Mn(2+) ions cause dopa-functionalized gold nanoparticles to come closer together, decreasing the interparticle distance and aggregating it with a change in color of colloidal solution from red to purplish-blue. Dynamic light scattering (DLS) analysis showed a decreased surface charge on the surface of gold nanoparticles when exposed to Mn(2+) ions, which caused cross-linking aggregation. Transmission electron microscopic (TEM) images also revealed the aggregation of gold nanoparticles with the addition of Mn(2+) ions. The extinction ratio of absorbance at 700-550nm (A700/A550) was linear against the concentration of [Mn(2+)] ions. Thus, the optical absorption spectra of gold colloidal solution before and after the addition of Mn(2+) ions reveal the concentration of Mn(2+) ions in solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Renal hemodynamic response to L-dopa during acute renal failure in man

    Energy Technology Data Exchange (ETDEWEB)

    Zech, P; Collard, M; Guey, A; Plantier, J; Bernard, M; Berthoux, F; Pinet, A; Traeger, J [Hopital Edouard-Herriot, 69 - Lyon (France)

    1975-12-20

    Twelve patients with acute renal failure underwent L-dopa infusion into a renal artery and /sup 133/Xenon wash-out recordings before and during the infusion. Urine volume and sodium output were also compared during two 24 hours periods, before and after the procedure. Hemodynamic data were compared with data obtained from a matched group of patients receiving Furosemide (8 patients) in place of L-dopa. Only L-dopa infusion significantly increased outer cortical distribution. No blood flow change could be demonstrated in any component nor did the drug improve unitary excretion or the general course of the disease. Control data shows that reduced cortical distribution is the most consistent feature of acute renal failure, so that L-dopa does partially improve intrarenal hemodynamics in this condition. The failure of the drug to restore kidney function may be explained by the following reasons: inability of the agent to restore a normal wash-out pattern: involvment of non-hemodynamic factors, as suggested by comparing similar wash-out improvements after L-dopa in acute glomerulonephritis and in reversible acute renal failure.

  13. Boronophenylalanine uptake in C6 glioma model is dramatically increased by L-DOPA preloading

    International Nuclear Information System (INIS)

    Capuani, S.; Gili, T.; Bozzali, M.; Russo, S.; Porcari, P.; Cametti, C.; Muolo, M.; D'Amore, E.; Maraviglia, B.; Lazzarino, G.; Pastore, F.S.

    2009-01-01

    One of the main limitations for BNCT effectiveness is the insufficient intake of 10 B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using radiowave dielectric spectroscopy (RDS), with and without L-DOPA preloading. C6 glioma cells were also implanted in the brain of 25 rats, randomly assigned to two experimental branches: (1) intra-carotid BPA infusion; (2) intra-carotid BPA infusion after pre-treatment with L-DOPA, administrated 24 h before BPA infusion. All animals were sacrificed, and assessment of BPA concentrations in tumour tissue, normal brain, and blood samples was performed using high performance liquid chromatography (HPLC). L-DOPA preloading induced a massive increase of BPA concentration either in vitro on C6 glioma cells or in vivo in the animal model tumour. Moreover, no significant difference was found in the normal brain and blood samples between the two animal groups. This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT.

  14. Biochemical Evidence of L-Dopa Synthesis in a Cytokine-Resilient Aspergillus oryzae

    International Nuclear Information System (INIS)

    Ali, S.; Saleem, R.

    2016-01-01

    The present work describes the microbiological production of 3,4 dihydroxy-L-phenylalanine (L-dopa) from a cytokine-inhibited mold culture of Aspergillus oryzae (strain Ck-R6). A level of 15 μg/ml cytokine was found optimal for culture resistance and better dopa-dopamine activity. Synthetic L-tyrosine was used as a basal carbon source. The aerobic reactions were carried out using pre-grown mycelia as a direct tyrosinase source. The mycelia were cultivated using 200 ml of GPY mineral-salt medium and developed at 30 degree C for 48 h (240 rpm) in 500 ml Erlenmeyer flasks. L-dopa production was found optimal when L-ascorbic acid (5 mg/ml) was added 6 min after starting the reaction (120 rpm). The maximal production (2.2 mg/ml L-dopa) was obtained when L-tyrosine concentration was 2.5 mg/ml. Mycelial level (75 mg/ml) and time of reaction (40 min) were also evaluated. L-Tyrosine consumption was found to be 2.1 mg/ml. After optimizing the reaction conditions, particularly L-ascorbic acid addition, a 30 percent improved L-dopa yield was achieved compared to control when the parameters including time of reaction (40 min), L-tyrosine concentration (2.5 mg/ml) and temperature (50 degree C) were optimized by two-factorial Plackett-Burman design (PBD). (author)

  15. Prevention of iron- and copper-mediated DNA damage by catecholamine and amino acid neurotransmitters, L-DOPA, and curcumin: metal binding as a general antioxidant mechanism.

    Science.gov (United States)

    García, Carla R; Angelé-Martínez, Carlos; Wilkes, Jenna A; Wang, Hsiao C; Battin, Erin E; Brumaghim, Julia L

    2012-06-07

    Concentrations of labile iron and copper are elevated in patients with neurological disorders, causing interest in metal-neurotransmitter interactions. Catecholamine (dopamine, epinephrine, and norepinephrine) and amino acid (glycine, glutamate, and 4-aminobutyrate) neurotransmitters are antioxidants also known to bind metal ions. To investigate the role of metal binding as an antioxidant mechanism for these neurotransmitters, L-dihydroxyphenylalanine (L-DOPA), and curcumin, their abilities to prevent iron- and copper-mediated DNA damage were quantified, cyclic voltammetry was used to determine the relationship between their redox potentials and DNA damage prevention, and UV-vis studies were conducted to determine iron and copper binding as well as iron oxidation rates. In contrast to amino acid neurotransmitters, catecholamine neurotransmitters, L-DOPA, and curcumin prevent significant iron-mediated DNA damage (IC(50) values of 3.2 to 18 μM) and are electrochemically active. However, glycine and glutamate are more effective at preventing copper-mediated DNA damage (IC(50) values of 35 and 12.9 μM, respectively) than L-DOPA, the only catecholamine to prevent this damage (IC(50) = 73 μM). This metal-mediated DNA damage prevention is directly related to the metal-binding behaviour of these compounds. When bound to iron or copper, the catecholamines, amino acids, and curcumin significantly shift iron oxidation potentials and stabilize Fe(3+) over Fe(2+) and Cu(2+) over Cu(+), a factor that may prevent metal redox cycling in vivo. These results highlight the disparate antioxidant activities of neurotransmitters, drugs, and supplements and highlight the importance of considering metal binding when identifying antioxidants to treat and prevent neurodegenerative disorders.

  16. EPR studies of chromium(V) intermediates generated via reduction of chromium(VI) by DOPA and related catecholamines

    DEFF Research Database (Denmark)

    Pattison, D I; Lay, P A; Davies, Michael Jonathan

    2000-01-01

    The reductions of K2Cr2O7 by catecholamines, DOPA, DOPA-beta,beta-d2, N-acetyl-DOPA, alpha-methyl-DOPA, dopamine, adrenaline, noradrenaline, catechol, 1,2-dihydroxybenzoic acid (DHBA), and 4-tert-butylcatechol (TBC), produce a number of Cr(V) electron paramagnetic resonance (EPR) signals. These s......The reductions of K2Cr2O7 by catecholamines, DOPA, DOPA-beta,beta-d2, N-acetyl-DOPA, alpha-methyl-DOPA, dopamine, adrenaline, noradrenaline, catechol, 1,2-dihydroxybenzoic acid (DHBA), and 4-tert-butylcatechol (TBC), produce a number of Cr(V) electron paramagnetic resonance (EPR) signals...... deuteration or enrichment with 15N), and simulation of the signals, show that the superhyperfine couplings originate from the side chain protons, confirming that the catecholamine ligands are cyclized. At pH 3.5, a major short-lived EPR signal is observed for many of the substrates at g(iso) approximately 1......) species with a sixth ligand (e.g. H2O). Addition of catalase or deoxygenation of the solutions did not affect the main EPR signals. When the substrates were in excess (pH > 4.5), primary and secondary (cyclized) semiquinones were also detected. Semiquinone stabilization by Zn(II) complexation yielded...

  17. Synthesis and evaluation of radioiodinated 6-Iodo-L-DOPA as a cerebral L-amino acid transport marker

    International Nuclear Information System (INIS)

    Kawai, K.; Ohta, H.; Kubodera, A.; Channing, M.A.; Eckelman, W.C.

    1996-01-01

    Regioselective radioiodination of N-trifluoroacetyl 3,4-dimethoxy-6-trifluoroacetoxymercurio-L-phenylalanine ethyl ester 1 under no-carrier-added condition gave 6-[ 125 I]iodo protected L-DOPA with a labeling efficiency of more than 85%, and no-carrier-added 6-[ 125 I]I-L-DOPA was obtained with a radiochemical purity of over 95% after hydrolysis and chromatography. A nonradioactive standard of 6-iodo protected L-DOPA was synthesized by the iododemercuration of 6-mercuric trifluoroacetate protected L-DOPA 1 using I 2 in chloroform. 6-[ 125 I]I-L-DOPA showed high brain accumulation and rapid blood clearance in mice. The rat brain slice studies indicated high affinity of 6-[ 125 I]I-L-DOPA for carrier-mediated and stereoselective active transport systems. The tissue homogenate analysis revealed that most of the accumulated radioactivity was intact 6-[ 125 I]I-L-DOPA. Thus, 6-[ 123 I]I-L-DOPA appears to be a suitable single photon emission computed tomography (SPECT) tracer for the selective measurement of cerebral L-amino acid transport, having no affinity for dopamine metabolism

  18. Refractory status epilepticus and glutamic acid decarboxylase antibodies in adults: presentation, treatment and outcomes.

    Science.gov (United States)

    Khawaja, Ayaz M; Vines, Brannon L; Miller, David W; Szaflarski, Jerzy P; Amara, Amy W

    2016-03-01

    Glutamic acid decarboxylase antibodies (GAD-Abs) have been implicated in refractory epilepsy. The association with refractory status epilepticus in adults has been rarely described. We discuss our experience in managing three adult patients who presented with refractory status epilepticus associated with GAD-Abs. Case series with retrospective chart and literature review. Three patients without pre-existing epilepsy who presented to our institution with generalized seizures between 2013 and 2014 were identified. Seizures proved refractory to first and second-line therapies and persisted beyond 24 hours. Patient 1 was a 22-year-old female who had elevated serum GAD-Ab titres at 0.49 mmol/l (normal: status epilepticus. Causation cannot be established since GAD-Abs may be elevated secondary to concurrent autoimmune diseases or formed de novo in response to GAD antigen exposure by neuronal injury. Based on this report and available literature, there may be a role for immuno- and chemotherapy in the management of refractory status epilepticus associated with GAD-Abs.

  19. Serotonergic modulation of receptor occupancy in rats treated with L-DOPA after unilateral 6-OHDA lesioning

    DEFF Research Database (Denmark)

    Nahimi, Adjmal; Høltzermann, Mette; Landau, Anne M.

    2012-01-01

    Recent studies suggest that l-3,4 dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID), a severe complication of conventional L-DOPA therapy of Parkinson's disease, may be caused by dopamine (DA) release originating in serotonergic neurons. To evaluate the in vivo effect of a 5-HT(1A) agonist...... [(±)-8-hydroxy-2-(dipropylamino) tetralin hydrobromide, 8-OHDPAT] on the L-DOPA-induced increase in extracellular DA and decrease in [(11) C]raclopride binding in an animal model of advanced Parkinson's disease and LID, we measured extracellular DA in response to L-DOPA or a combination of L......-DOPA and the 5-HT(1A) agonist, 8-OHDPAT, with microdialysis, and determined [(11) C]raclopride binding to DA receptors, with micro-positron emission tomography, as the surrogate marker of DA release. Rats with unilateral 6-hydroxydopamine lesions had micro-positron emission tomography scans with [(11) C...

  20. Nociceptive Response to L-DOPA-Induced Dyskinesia in Hemiparkinsonian Rats.

    Science.gov (United States)

    Nascimento, G C; Bariotto-Dos-Santos, K; Leite-Panissi, C R A; Del-Bel, E A; Bortolanza, M

    2018-04-02

    Non-motor symptoms are increasingly identified to present clinical and diagnostic importance for Parkinson's disease (PD). The multifactorial origin of pain in PD makes this symptom of great complexity. The dopamine precursor, L-DOPA (L-3,4-dihydroxyphenylalanine), the classic therapy for PD, seems to be effective in pain threshold; however, there are no studies correlating L-DOPA-induced dyskinesia (LID) and nociception development in experimental Parkinsonism. Here, we first investigated nociceptive responses in a 6-hydroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease to a hind paw-induced persistent inflammation. Further, the effect of L-DOPA on nociception behavior at different times of treatment was investigated. Pain threshold was determined using von Frey and Hot Plate/Tail Flick tests. Dyskinesia was measured by abnormal involuntary movements (AIMs) induced by L-DOPA administration. This data is consistent to show that 6-OHDA-lesioned rats had reduced nociceptive thresholds compared to non-lesioned rats. Additionally, when these rats were exposed to a persistent inflammatory challenge, we observed increased hypernociceptive responses, namely hyperalgesia. L-DOPA treatment alleviated pain responses on days 1 and 7 of treatment, but not on day 15. During that period, we observed an inverse relationship between LID and nociception threshold in these rats, with a high LID rate corresponding to a reduced nociception threshold. Interestingly, pain responses resulting from CFA-induced inflammation were significantly enhanced during established dyskinesia. These data suggest a pro-algesic effect of L-DOPA-induced dyskinesia, which is confirmed by the correlation founded here between AIMs and nociceptive indexes. In conclusion, our results are consistent with the notion that central dopaminergic mechanism is directly involved in nociceptive responses in Parkinsonism condition.

  1. Glutamic acid decarboxylase isoform distribution in transgenic mouse septum: an anti-GFP immunofluorescence study.

    Science.gov (United States)

    Verimli, Ural; Sehirli, Umit S

    2016-09-01

    The septum is a basal forebrain region located between the lateral ventricles in rodents. It consists of lateral and medial divisions. Medial septal projections regulate hippocampal theta rhythm whereas lateral septal projections are involved in processes such as affective functions, memory formation, and behavioral responses. Gamma-aminobutyric acidergic neurons of the septal region possess the 65 and 67 isoforms of the enzyme glutamic acid decarboxylase. Although data on the glutamic acid decarboxylase isoform distribution in the septal region generally appears to indicate glutamic acid decarboxylase 67 dominance, different studies have given inconsistent results in this regard. The aim of this study was therefore to obtain information on the distributions of both of these glutamic acid decarboxylase isoforms in the septal region in transgenic mice. Two animal groups of glutamic acid decarboxylase-green fluorescent protein knock-in transgenic mice were utilized in the experiment. Brain sections from the region were taken for anti-green fluorescent protein immunohistochemistry in order to obtain estimated quantitative data on the number of gamma-aminobutyric acidergic neurons. Following the immunohistochemical procedures, the mean numbers of labeled cells in the lateral and medial septal nuclei were obtained for the two isoform groups. Statistical analysis yielded significant results which indicated that the 65 isoform of glutamic acid decarboxylase predominates in both lateral and medial septal nuclei (unpaired two-tailed t-test p glutamic acid decarboxylase isoform 65 in the septal region in glutamic acid decarboxylase-green fluorescent protein transgenic mice.

  2. Retinoic acid modulation of ultraviolet light-induced epidermal ornithine decarboxylase activity

    International Nuclear Information System (INIS)

    Lowe, N.J.; Breeding, J.

    1982-01-01

    Irradiation of skin with ultraviolet light of sunburn range (UVB) leads to a large and rapid induction of the polyamine biosynthetic enzyme ornithine decarboxylase in the epidermis. Induction of epidermal ornithine decarboxylase also occurs following application of the tumor promoting agent 12-0-tetradecanoylphorbol-13 acetate and topical retinoic acid is able to block both this ornithine decarboxylase induction and skin tumor promotion. In the studies described below, topical application of retinoic acid to hairless mouse skin leads to a significant inhibition of UVB-induced epidermal ornithine decarboxylase activity. The degree of this inhibition was dependent on the dose, timing, and frequency of the application of retinoic acid. To show significant inhibition of UVB-induced ornithine decarboxylase the retinoic acid had to be applied within 5 hr of UVB irradiation. If retinoic acid treatment was delayed beyond 7 hr following UVB, then no inhibition of UVB-induced ornithine decarboxylase was observed. The quantities of retinoic acid used (1.7 nmol and 3.4 nmol) have been shown effective at inhibiting 12-0-tetradecanoyl phorbol-13 acetate induced ornithine decarboxylase. The results show that these concentrations of topical retinoic acid applied either before or immediately following UVB irradiation reduces the UVB induction of epidermal ornithine decarboxylase. The effect of retinoic acid in these regimens on UVB-induced skin carcinogenesis is currently under study

  3. Diurnal changes in polyamine content, arginine and ornithine decarboxylase, and diamine oxidase in tobacco leaves

    Czech Academy of Sciences Publication Activity Database

    Gemperlová, Lenka; Nováková, Marie; Vaňková, Radomíra; Eder, Josef; Cvikrová, Milena

    2006-01-01

    Roč. 57, č. 6 (2006), s. 1413-1421 ISSN 0022-0957 R&D Projects: GA ČR GA206/03/0369 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arginine decarboxylase * diamine oxidase * ornithine decarboxylase Subject RIV: ED - Physiology Impact factor: 3.630, year: 2006

  4. Presynaptic mechanisms of L-DOPA-induced dyskinesia: the findings, the debate, the therapeutic implications.

    Directory of Open Access Journals (Sweden)

    M Angela eCenci

    2014-12-01

    Full Text Available The dopamine precursor L-DOPA has been the most effective treatment for Parkinson´s disease (PD for over 40 years. However, the response to this treatment changes during the progression of PD, and most patients develop dyskinesias (abnormal involuntary movements and motor fluctuations within a few years of L-DOPA therapy. There is wide consensus that these motor complications depend on both pre- and post-synaptic disturbances of nigrostriatal dopamine transmission. Several presynaptic mechanisms converge to generate large dopamine swings in the brain concomitant with the peaks-and-troughs of plasma L-DOPA levels, while post-synaptic changes engender abnormal functional responses in dopaminoceptive neurons. While this general picture is well-accepted, the relative contribution of different factors remains a matter of debate. A particularly animated debate has been growing around putative players on the presynaptic side of the cascade. To what extent do presynaptic disturbances in dopamine transmission depend on deficiency/dysfunction of the dopamine transporter, aberrant release of dopamine from serotonin neurons, or gliovascular mechanisms? And does noradrenaline (which is synthetized from dopamine play a role? This review article will summarize key findings, controversies, and pending questions regarding the presynaptic mechanisms of L-DOPA-induced dyskinesia. Intriguingly, the debate around these mechanisms has spurred research into previously unexplored facets of brain plasticity that have far-reaching implications to the treatment of neuropsychiatric disease.

  5. The applications of 18F-DOPA PET in Parkinson's disease

    International Nuclear Information System (INIS)

    Zuo Chuantao

    2000-01-01

    The injury of the presynaptic nigro-striae dopaminergic projection is the important mechanism of Parkinson's disease (PD). 18 F-DOPA PET provides a measure of the structure as well as the biochemical integrity of the dopaminergic neurons, which contribute to the early diagnosis, differentiation diagnosis, prognosis evaluation of PD

  6. The role of L-DOPA on melanization and mycelial production in Malassezia furfur.

    Directory of Open Access Journals (Sweden)

    Sirida Youngchim

    Full Text Available Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization.

  7. Measurement of striatal dopamine metabolism with 6-[18F]-fluoro-L-dopa and PET

    International Nuclear Information System (INIS)

    Kuwabara, Y.; Otsuka, M.; Ichiya, Y.; Yoshikai, T.; Fukumura, T.; Masuda, K.; Kato, M.; Taniwaki, T.

    1992-01-01

    Striatal dopamine metabolism was studied with 6-[ 18 F]-fluoro-L-dopa ( 18 F-DOPA) and PET. The subjects were normal controls, and patients with Parkinson's disease (PD), parkinsonism, multiple system atrophy (MSA), progressive supranuclear palsy (PSP), Alzheimer's disease (AD), Huntington's disease (HD) and other cerebral disorders. Cerebral glucose metabolism (CMRGlc) was also measured in these patients. Striatal dopamine metabolism was evaluated by the relative striatal uptake of 18 F-DOPA referring cerebellum (S/C ratio). In normal controls, the S/C ratio was 2.82 ± 0.32 (n = 6, mean ± SD) at 120 min after injection of 18 F-DOPA. The S/C ratio was low in patients with PD, parkinsonism, MSA and PSP compared to the normal controls and thus coincident with the symptoms of parkinsonism due to decrease in striatal dopamine concentration. The decrease in the striatal CMRGlc was also observed in patients with parkinsonism and PSP, and it was preserved in patients with PD, thus representing that more neurons were damaged in patients with parkinsonism and PSP than in patients with PD. A patient with AD having symptoms of parkinsonism also showed a decrease in S/C ratio. In a patient with HD, the striatal CMRGlc sharply decreased, but the S/C ratio was normal. The measurements of striatal dopamine and glucose metabolism with PET may be useful for studying the pathophysiological mechanism in patients with cerebral disorders. (author)

  8. The epidermal melanocyte system in individuals of Scandinavian origin, determined by DOPA-staining and TEM

    DEFF Research Database (Denmark)

    Drzewiecki, K T; Piltz-Drzewiecka, J

    1979-01-01

    The quantitative evaluation of DOPA-positive epidermal melanocytes in 16 patients of Scandinavian origin showed both individual and regional differences in the melanocyte count. Our data is in agreement with other published studies. The distribution in the number of melanocytes varies significant...

  9. l-Dopa responsiveness is associated with distinctive connectivity patterns in advanced Parkinson's disease.

    Science.gov (United States)

    Akram, Harith; Wu, Chengyuan; Hyam, Jonathan; Foltynie, Thomas; Limousin, Patricia; De Vita, Enrico; Yousry, Tarek; Jahanshahi, Marjan; Hariz, Marwan; Behrens, Timothy; Ashburner, John; Zrinzo, Ludvic

    2017-06-01

    Neuronal loss and dopamine depletion alter motor signal processing between cortical motor areas, basal ganglia, and the thalamus, resulting in the motor manifestations of Parkinson's disease. Dopamine replacement therapy can reverse these manifestations with varying degrees of improvement. To evaluate functional connectivity in patients with advanced Parkinson's disease and changes in functional connectivity in relation to the degree of response to l-dopa, 19 patients with advanced Parkinson's disease underwent resting-state functional magnetic resonance imaging in the on-medication state. Scans were obtained on a 3-Tesla scanner in 3 × 3 × 2.5 mm 3 voxels. Seed-based bivariate regression analyses were carried out with atlas-defined basal ganglia regions as seeds, to explore relationships between functional connectivity and improvement in the motor section of the UPDRS-III following an l-dopa challenge. False discovery rate-corrected P was set at basal ganglia resting-state functional connectivity patterns associated with different degrees of l-dopa responsiveness in patients with advanced Parkinson's disease. l-Dopa exerts a graduated influence on remapping connectivity in distinct motor control networks, potentially explaining some of the variance in treatment response. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  10. The Role of L-DOPA on Melanization and Mycelial Production in Malassezia Furfur

    Science.gov (United States)

    Youngchim, Sirida; Nosanchuk, Joshua D.; Pornsuwan, Soraya; Kajiwara, Susumu; Vanittanakom, Nongnuch

    2013-01-01

    Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization. PMID:23762233

  11. Presynaptic Mechanisms of l-DOPA-Induced Dyskinesia: The Findings, the Debate, and the Therapeutic Implications.

    Science.gov (United States)

    Cenci, M Angela

    2014-01-01

    The dopamine (DA) precursor l-DOPA has been the most effective treatment for Parkinson's disease (PD) for over 40 years. However, the response to this treatment changes with disease progression, and most patients develop dyskinesias (abnormal involuntary movements) and motor fluctuations within a few years of l-DOPA therapy. There is wide consensus that these motor complications depend on both pre- and post-synaptic disturbances of nigrostriatal DA transmission. Several presynaptic mechanisms converge to generate large DA swings in the brain concomitant with the peaks-and-troughs of plasma l-DOPA levels, while post-synaptic changes engender abnormal functional responses in dopaminoceptive neurons. While this general picture is well-accepted, the relative contribution of different factors remains a matter of debate. A particularly animated debate has been growing around putative players on the presynaptic side of the cascade. To what extent do presynaptic disturbances in DA transmission depend on deficiency/dysfunction of the DA transporter, aberrant release of DA from serotonin neurons, or gliovascular mechanisms? And does noradrenaline (which is synthetized from DA) play a role? This review article will summarize key findings, controversies, and pending questions regarding the presynaptic mechanisms of l-DOPA-induced dyskinesia. Intriguingly, the debate around these mechanisms has spurred research into previously unexplored facets of brain plasticity that have far-reaching implications to the treatment of neuropsychiatric disease.

  12. 18F-DOPA PET/CT and MRI Findings in a Patient With Multiple Meningiomas.

    Science.gov (United States)

    Calabria, Ferdinando F; Chiaravalloti, Agostino; Calabria, Eros N; Grillea, Giovanni; Schillaci, Orazio

    2016-08-01

    A 56-year-old man was referred to our Department for a 2-year story of upper limb tremor, severe headache, and episodes of confusion. Brain F-DOPA PET/CT showed multiple areas of tracer uptake in the two hemispheres of the brain. Subsequent MRI displayed demyelinating foci with high contrast enhancement. Histological specimen confirmed the diagnosis of multiple meningiomas.

  13. Enhanced production of L-DOPA in cell cultures of Mucuna pruriens L. and Mucuna prurita H.

    Science.gov (United States)

    Raghavendra, S; Kumar, V; Ramesh, C K; Khan, M H Moinuddin

    2012-01-01

    A comparative study on the production of 3,4-dihydroxyphenylalanine (L-DOPA) was carried out in cell cultures of two Mucuna species by elicitor treatment and precursor feeding. The influence of elicitors and the precursor molecule on L-DOPA production, polyphenol oxidase (PPO) and tyrosinase activities was also studied. Callus cultures were initiated in Mucuna pruriens L. and Mucuna prurita H. on MS medium supplemented with BAP and IAA at different concentrations. Suspension cultures were established in MS liquid medium supplemented with BAP, IAA, the elicitors methyl jasmonate, chitin and pectin or the precursor L-tyrosine at different concentrations for L-DOPA production. Compared to the controls, several-fold increases in L-DOPA concentration were observed in elicitor-treated and precursor-fed suspension cultures of both plant species. L-DOPA concentrations were comparatively higher in precursor-fed cultures than those receiving elicitor treatments. A parallel increase in tyrosinase and PPO levels was also observed. Loss of cell viability was observed at high concentrations of elicitor-treated cultures, whereas L-tyrosine did not cause any cell death. Compared to elicitor treatments, precursor feeding resulted in higher concentrations of L-DOPA production and tyrosinase activity. The efficacy of L-DOPA production was found to be higher for suspension cultures of M. pruriens compared to M. prurita in all treatments.

  14. Biochemical characterization of a novel tyrosine phenol-lyase from Fusobacterium nucleatum for highly efficient biosynthesis of l-DOPA.

    Science.gov (United States)

    Zheng, Ren-Chao; Tang, Xiao-Ling; Suo, Hui; Feng, Li-Lin; Liu, Xiao; Yang, Jian; Zheng, Yu-Guo

    2018-05-01

    Tyrosine phenol-lyase (TPL) catalyzes the reversible cleavage of l-tyrosine to phenol, pyruvate and ammonia. When pyrocatechol is substituted for phenol, l-dihydroxyphenylalanine (l-DOPA) is produced. The TPL-catalyzed route was regarded as the most economic process for l-DOPA production. In this study, a novel TPL from Fusobacterium nucleatum (Fn-TPL) was successfully overexpressed in Escherichia coli and screened for l-DOPA synthesis with a specific activity of 2.69Umg -1 . Fn-TPL was found to be a tetramer, and the optimal temperature and pH for α, β-elimination of l-tyrosine was 60°C and pH 8.5, respectively. The enzyme showed broad substrate specificity toward natural and synthetic l-amino acids. Kinetic analysis suggested that the k cat /K m value for l-tyrosine decomposition was much higher than that for l-DOPA decomposition, while Fn-TPL exhibited similar catalytic efficiency for synthesis of l-tyrosine and l-DOPA. With whole cells of recombinant E. coli as biocatalyst, l-DOPA yield reached 110gL -1 with a pyrocatechol conversion of 95%, which was comparable to the reported highest level. The results demonstrated the great potential of Fn-TPL for industrial production of l-DOPA. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. High performance microbiological transformation of L-tyrosine to L-dopa by Yarrowia lipolytica NRRL-143

    Directory of Open Access Journals (Sweden)

    Shultz Jeffry L

    2007-08-01

    Full Text Available Abstract Background The 3,4-dihydroxy phenyl L-alanine (L-dopa is a drug of choice for Parkinson's disease, controlling changes in energy metabolism enzymes of the myocardium following neurogenic injury. Aspergillus oryzae is commonly used for L-dopa production; however, potential improvements in ease of handling, growth rate and environmental impact have led to an interest in exploiting alternative yeasts. The two important elements required for L-dopa production are intracellular tyrosinases (thus pre-grown yeast cells are required for the transformation of L-tyrosine to L-dopa and L-ascorbate, which acts as a reducing agent. Results Pre-grown cells of Yarrowia lipolytica NRRL-143 were used for the microbiological transformation of L-tyrosine to L-dopa. Different diatomite concentrations (0.5–3.0 mg/ml were added to the acidic (pH 3.5 reaction mixture. Maximum L-dopa biosynthesis (2.96 mg/ml L-dopa from 2.68 mg/ml L-tyrosine was obtained when 2.0 mg/ml diatomite was added 15 min after the start of the reaction. After optimizing reaction time (30 min, and yeast cell concentration (2.5 mg/ml, an overall 12.5 fold higher L-dopa production rate was observed when compared to the control. Significant enhancements in Yp/s, Qs and qs over the control were observed. Conclusion Diatomite (2.0 mg/ml addition 15 min after reaction commencement improved microbiological transformation of L-tyrosine to L-dopa (3.48 mg/ml; p ≤ 0.05 by Y. lipolytica NRRL-143. A 35% higher substrate conversion rate was achieved when compared to the control.

  16. Activities of Arginine and Ornithine Decarboxylases in Various Plant Species 1

    Science.gov (United States)

    Birecka, Helena; Bitonti, Alan J.; McCann, Peter P.

    1985-01-01

    In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to Vmax, ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. α-Difluoromethylornithine and α-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species. No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed. In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum. PMID:16664442

  17. Uncovering the Lactobacillus plantarum WCFS1 Gallate Decarboxylase Involved in Tannin Degradation

    Science.gov (United States)

    Jiménez, Natalia; Curiel, José Antonio; Reverón, Inés; de las Rivas, Blanca

    2013-01-01

    Lactobacillus plantarum is a lactic acid bacterium able to degrade tannins by the subsequent action of tannase and gallate decarboxylase enzymes. The gene encoding tannase had previously been identified, whereas the gene encoding gallate decarboxylase is unknown. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of gallic-acid induced L. plantarum extracts showed a 54-kDa protein which was absent in the uninduced cells. This protein was identified as Lp_2945, putatively annotated UbiD. Homology searches identified ubiD-like genes located within three-gene operons which encoded the three subunits of nonoxidative aromatic acid decarboxylases. L. plantarum is the only bacterium in which the lpdC (lp_2945) gene and the lpdB and lpdD (lp_0271 and lp_0272) genes are separated in the chromosome. Combination of extracts from recombinant Escherichia coli cells expressing the lpdB, lpdC, and lpdC genes demonstrated that LpdC is the only protein required to yield gallate decarboxylase activity. However, the disruption of these genes in L. plantarum revealed that the lpdB and lpdC gene products are essential for gallate decarboxylase activity. Similar to L. plantarum tannase, which exhibited activity only in esters derived from gallic and protocatechuic acids, purified His6-LpdC protein from E. coli showed decarboxylase activity against gallic and protocatechuic acids. In contrast to the tannase activity, gallate decarboxylase activity is widely present among lactic acid bacteria. This study constitutes the first genetic characterization of a gallate decarboxylase enzyme and provides new insights into the role of the different subunits of bacterial nonoxidative aromatic acid decarboxylases. PMID:23645198

  18. Regulation of Pleiotrophin and Fyn in the striatum of rats undergoing L-DOPA-induced dyskinesia.

    Science.gov (United States)

    Gomez, Gimena; Saborido, Mariano D; Bernardi, M Alejandra; Gershanik, Oscar S; Taravini, Irene R; Ferrario, Juan E

    2018-02-14

    L-DOPA is the gold standard pharmacological therapy for symptomatic treatment of Parkinson's disease (PD), however, its long-term use is associated with the emergence of L-DOPA-induced dyskinesia (LID). Understanding the underlying molecular mechanisms of LID is crucial for the development of newer and more effective therapeutic approaches. In previous publications, we have shown that Pleiotrophin (PTN), a developmentally regulated trophic factor, is up-regulated by L-DOPA in the striatum of dopamine denervated rats. We have also shown that both mRNA and protein levels of RPTPζ/β, a PTN receptor, were upregulated in the same experimental condition and expressed in striatal medium spiny neurons. The PTN-RPTPζ/β intracellular pathway has not been fully explored and it might be implicated in the striatal plastic changes triggered by L-DOPA treatment. RPTPζ/β is part of the postsynaptic density zone and modulates Fyn, a Src tyrosine kinase that regulates the NR2A and NR2B subunits of the NMDA receptor and has been singled out as a key molecule in the development of LID. In this study, we evaluated the changes in PTN and Fyn protein levels and Fyn phosphorylation status in the 6-OHDA rat model of PD rendered dyskinetic with L-DOPA. We found an increase in the number of PTN immunoreactive neurons, no changes in the amount of total Fyn but a significant increase in Fyn phosphorylation in the dorsolateral striatum of dyskinetic rats. Our results support the idea that both PTN and Fyn may be involved in the development of LID, further contributing to the understanding of its molecular mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Ornithine decarboxylase regulates the activity and localization of rhoA via polyamination

    International Nuclear Information System (INIS)

    Maekitie, Laura T.; Kanerva, Kristiina; Andersson, Leif C.

    2009-01-01

    Ornithine decarboxylase (ODC) is the rate-limiting enzyme of polyamine synthesis. Polyamines and ODC are connected to cell proliferation and transformation. Resting cells display a low ODC activity while normal, proliferating cells display fluctuations in ODC activity that coincide with changes in the actin cytoskeleton during the cell cycle. Cancerous cells display constitutively elevated ODC activity. Overexpression of ODC in NIH 3T3 fibroblasts induces a transformed phenotype. The cytoskeletal rearrangements during cytokinesis and cell transformation are intimately coupled to the ODC activity but the molecular mechanisms have remained elusive. In this study we investigated how ODC and polyamines influence the organization of the cytoskeleton. Given that the small G-proteins of the rho family are key modulators of the actin cytoskeleton, we investigated the molecular interactions of rhoA with ODC and polyamines. Our results show that transglutaminase-catalyzed polyamination of rhoA regulates its activity. The polyamination status of rhoA crucially influences the progress of the cell cycle as well as the rate of transformation of rat fibroblasts infected with temperature-sensitive v-src. We also show that ODC influences the intracellular distribution of rhoA. These findings provide novel insights into the mechanisms by which ODC and polyamines regulate the dynamics of the cytoskeleton during cell proliferation and transformation

  20. Altered subcellular localization of ornithine decarboxylase in Alzheimer's disease brain

    International Nuclear Information System (INIS)

    Nilsson, Tatjana; Bogdanovic, Nenad; Volkman, Inga; Winblad, Bengt; Folkesson, Ronnie; Benedikz, Eirikur

    2006-01-01

    The amyloid precursor protein can through ligand-mimicking induce expression of ornithine decarboxylase (ODC), the initial and rate-limiting enzyme in polyamine biosynthesis. We report here the regional distribution and cellular localization of ODC immunoreactivity in Alzheimer's disease (AD) brains. In frontal cortex and hippocampus of control cases, the most pronounced ODC immunoreactivity was found in the nucleus. In possible and definite AD the immunoreactivity had shifted to the cytoplasm. In cerebellum of control cases, ODC staining was found in a small portion of Purkinje cells, mostly in the nucleus. In AD, both possible and definite, the number of stained Purkinje cells increased significantly and immunoreactivity was shifted to the cytoplasm, even though it was still prominent in the nucleus. In conclusion, our study reveals an early shift of the ODC immunoreactivity in AD from the nuclear compartment towards the cytoplasm

  1. An endosymbiont positively modulates ornithine decarboxylase in host trypanosomatids

    International Nuclear Information System (INIS)

    Frossard, Mariana Lins; Seabra, Sergio Henrique; Matta, Renato Augusto da; Souza, Wanderley de; Garcia de Mello, Fernando; Motta, Maria Cristina Machado

    2006-01-01

    Summary: Some trypanosomatids, such as Crithidia deanei, are endosymbiont-containing species. Aposymbiotic strains are obtained after antibiotic treatment, revealing interesting aspects of this symbiotic association. Ornithine decarboxylase (ODC) promotes polyamine biosynthesis and contributes to cell proliferation. Here, we show that ODC activity is higher in endosymbiont-bearing trypanosomatids than in aposymbiotic cells, but isolated endosymbionts did not display this enzyme activity. Intriguingly, expressed levels of ODC were similar in both strains, suggesting that ODC is positively modulated in endosymbiont-bearing cells. When the aposymbiotic strain was grown in conditioned medium, obtained after cultivation of the endosymbiont-bearing strain, cellular proliferation as well as ODC activity and localization were similar to that observed in the endosymbiont-containing trypanosomatids. Furthermore, dialyzed-heated medium and trypsin treatment reduced ODC activity of the aposymbiont strain. Taken together, these data indicate that the endosymbiont can enhance the protozoan ODC activity by providing factors of protein nature, which increase the host polyamine metabolism

  2. The effect of L-dopa in Parkinson's disease as revealed by neurophysiological studies of motor and sensory functions.

    Science.gov (United States)

    Suppa, Antonio; Bologna, Matteo; Conte, Antonella; Berardelli, Alfredo; Fabbrini, Giovanni

    2017-02-01

    This review will first discuss evidence of motor and sensory abnormalities as yielded by neurophysiological techniques in patients with PD. It will then go on to describe the effects of L-dopa replacement on motor and sensory abnormalities in PD as assessed by neurophysiological studies. Areas covered: We analyzed papers in English using Pubmed with the following keywords: L-dopa, dopamine, bradykinesia, basal ganglia, kinematic analysis, TMS, motor cortex plasticity, motor cortex excitability, somatosensory discrimination threshold, pain Expert commentary: L-dopa improves the amplitude and speed of upper limb voluntary movements, but it does not restore abnormalities in the sequence effect or voluntary facial movements. L-dopa only partially normalizes changes in motor cortex excitability and plasticity and has also contrasting effects on the sensory system and on sensory-motor integration. The neurophysiological studies reviewed here show that PD is more than a hypo-dopaminergic disease, and non-dopaminergic mechanisms should also be considered.

  3. Effect of hexoses on the levels of pyruvate decarboxylase in Mucor rouxii.

    OpenAIRE

    Barrera, C R; Corral, J

    1980-01-01

    Pyruvate decarboxylase activity in the dimorphic fungus Mucor rouxii increased 25- to 35-fold in yeastlike and mycelial cells grown in the presence of glucose as compared to the activity observed in mycelial cultures grown in the absence of glucose.

  4. Volumetric assessment of recurrent or progressive gliomas: comparison between F-DOPA PET and perfusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cicone, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Filss, Christian P.; Langen, Karl-Josef [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; RWTH Aachen Univ. Hospital (Germany). Dept. of Nuclear Medicine; Minniti, Giuseppe; Scaringi, Claudia [Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Rossi-Espagnet, Camilla; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Sapienza Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.); Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Galldiks, Norbert [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Cologne Univ. (Germany). Dept. of Neurology; Shah, N. Jon [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine

    2015-05-01

    To compare the diagnostic information obtained with 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET and relative cerebral blood volume (rCBV) maps in recurrent or progressive glioma. All patients with recurrent or progressive glioma referred for F-DOPA imaging at our institution between May 2010 and May 2014 were retrospectively included, provided that macroscopic disease was visible on conventional MRI images and that rCBV maps were available for comparison. The final analysis included 50 paired studies (44 patients). After image registration, automatic tumour segmentation of both sets of images was performed using the average signal in a large reference VOI including grey and white matter multiplied by 1.6. Tumour volumes identified by both modalities were compared and their spatial congruence calculated. The distances between F-DOPA uptake and rCBV hot spots, tumour-to-brain ratios (TBRs) and normalized histograms were also computed. On visual inspection, 49 of the 50 F-DOPA and 45 of the 50 rCBV studies were classified as positive. The tumour volume delineated using F-DOPA (F-DOPA{sub vol} {sub 1.6}) greatly exceeded that of rCBV maps (rCBV{sub vol} {sub 1.6}). The median F-DOPA{sub vol} {sub 1.6} and rCBV{sub vol} {sub 1.6} were 11.44 ml (range 0 - 220.95 ml) and 1.04 ml (range 0 - 26.30 ml), respectively (p < 0.00001). Overall, the median overlapping volume was 0.27 ml, resulting in a spatial congruence of 1.38 % (range 0 - 39.22 %). The mean hot spot distance was 27.17 mm (±16.92 mm). F-DOPA uptake TBR was significantly higher than rCBV TBR (1.76 ± 0.60 vs. 1.15 ± 0.52, respectively; p < 0.0001). The histogram analysis showed that F-DOPA provided better separation of tumour from background. In 6 of the 50 studies (12 %), however, physiological uptake in the striatum interfered with tumour delineation. The information provided by F-DOPA PET and rCBV maps are substantially different. Image interpretation is easier and a larger tumour extent

  5. The influence of L-DOPA on the accumulation of lipid peroxidation products in some brain structures affected by radiation

    International Nuclear Information System (INIS)

    Babaev, R.A.; Kocharli, R.Kh.; Akhmedova, G.Sh.; Gasanova, A.A.; Babaev, Kh.F.

    1990-01-01

    A study was made of the effect of L-DOPA on the dynamics of changes in lipid peroxidation products (LPP) and the content of various types of SH-groups in certain brain structures (oblongata, cerebellum, visual and sensorimotor cortex) and their synaptosomal fractions upon irradiation. The preadministration of L-DOPA to irradiated rats inhibited LPP accumulation, prevented the decrease in the content of various types of thiols and thus exerted an antioxidant effect

  6. Total {sup 18}F-dopa PET tumour uptake reflects metabolic endocrine tumour activity in patients with a carcinoid tumour

    Energy Technology Data Exchange (ETDEWEB)

    Fiebrich, Helle-Brit; Walenkamp, Annemiek M.; Vries, Elisabeth G.E. de [University Medical Centre Groningen, Department of Medical Oncology, Groningen (Netherlands); Jong, Johan R. de; Koopmans, Klaas Pieter; Dierckx, Rudi A.J.O.; Brouwers, Adrienne H. [University Medical Centre Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Kema, Ido P. [University Medical Centre Groningen, Department of Laboratory Medicine, Groningen (Netherlands); Sluiter, Wim; Links, Thera P. [University Medical Centre Groningen, Department of Endocrinology, Groningen (Netherlands)

    2011-10-15

    Positron emission tomography (PET) using 6-[{sup 18}F]fluoro-L-dihydroxyphenylalanine ({sup 18}F-dopa) has an excellent sensitivity to detect carcinoid tumour lesions. {sup 18}F-dopa tumour uptake and the levels of biochemical tumour markers are mediated by tumour endocrine metabolic activity. We evaluated whether total {sup 18}F-dopa tumour uptake on PET, defined as whole-body metabolic tumour burden (WBMTB), reflects tumour load per patient, as measured with tumour markers. Seventy-seven consecutive carcinoid patients who underwent an {sup 18}F-dopa PET scan in two previously published studies were analysed. For all tumour lesions mean standardised uptake values (SUVs) at 40% of the maximal SUV and tumour volume on {sup 18}F-dopa PET were determined and multiplied to calculate a metabolic burden per lesion. WBMTB was the sum of the metabolic burden of all individual lesions per patient. The 24-h urinary serotonin, urine and plasma 5-hydroxindoleacetic acid (5-HIAA), catecholamines (nor)epinephrine, dopamine and their metabolites, measured in urine and plasma, and serum chromogranin A served as tumour markers. All but 1 were evaluable for WBMTB; 74 patients had metastatic disease. {sup 18}F-dopa PET detected 979 lesions. SUV{sub max} on {sup 18}F-dopa PET varied up to 29-fold between individual lesions within the same patients. WBMTB correlated with urinary serotonin (r = 0.51) and urinary and plasma 5-HIAA (r = 0.78 and 0.66). WBMTB also correlated with urinary norepinephrine, epinephrine, dopamine and plasma dopamine, but not with serum chromogranin A. Tumour load per patient measured with {sup 18}F-dopa PET correlates with tumour markers of the serotonin and catecholamine pathway in urine and plasma in carcinoid patients, reflecting metabolic tumour activity. (orig.)

  7. Quantitative Determination of L-DOPA in Seeds of Mucuna Pruriens Germplasm by High Performance Thin Layer Chromatography.

    Science.gov (United States)

    Raina, Archana P; Khatri, Renu

    2011-07-01

    Mucuna pruriens Linn. is an important medicinal plant used for treatment of Parkinson's disease and many others in ancient Indian medical system. L-DOPA extracted from seeds of Mucuna is a constituent of more than 200 indigenous drug formulations and is more effective as drug than the synthetic counterpart. A densitometric high performance thin-layer chromatographic (HPTLC) method was developed for quantification of L-DOPA content present in the seeds extract. The method involves separation of L-DOPA on precoated silica gel 60 GF(254) HPTLC plates using a solvent system of n-butanol-acetic-acid-water (4:1:1, v/v) as the mobile phase. Quantification was done at 280 nm using absorbance reflectance mode. Linearity was found in the concentration range of 100 to 1000 ng/spot with the correlation coefficient value of 0.9980. The method was validated for accuracy, precision and repeatability. Mean recovery was 100.89%. The LOD and LOQ for L-DOPA determination were found to be 3.41 ng/spot and 10.35 ng/spot respectively. The proposed HPTLC method was found to be precise, specific and accurate for quantitative determination of L-DOPA. It can be used for rapid screening of large germplasm collections of Mucuna pruriens for L-DOPA content. The method was used to study variation in fifteen accessions of Mucuna germplasm collected from different geographical regions.

  8. L-DOPA therapy interferes with urine catecholamine analysis in children with suspected neuroblastoma: a case series.

    Science.gov (United States)

    Kelly, Alison U; Srivastava, Rajeev; Dow, Ellie; Davidson, D Fraser

    2017-09-01

    Neuroblastoma is the most common solid extracranial malignancy diagnosed in childhood. Clinical presentation is variable, and metastatic disease is common at diagnosis. Analyses of urinary catecholamines and their metabolites are commonly requested as a first-line investigation when clinical suspicion exists. Levodopa (L-Dopa) therapy is utilized as a treatment for a number of disorders in childhood, including Dopa-responsive dystonia. Neuroblastoma may mimic some of the clinical features of this disorder. L-Dopa can interfere with analysis of urinary catecholamines and their metabolites and complicate the interpretation of results. We present the cases of three children who were prescribed L-dopa at the time of analysis of urinary catecholamines and metabolites as a screen for neuroblastoma, but who did not have the disease. Comparison of their results with those from cases with true neuroblastoma reveal that it is impossible to reliably distinguish true neuroblastoma from L-Dopa therapy using these tests. We recommend that patients should be off L-dopa therapy, if possible when these tests are performed. These cases illustrate the importance of providing clinical details and drug history to the laboratory in order to avoid diagnostic confusion.

  9. Vascular endothelial growth factor is upregulated by l-dopa in the parkinsonian brain: implications for the development of dyskinesia

    Science.gov (United States)

    Francardo, Veronica; Lindgren, Hanna S.; Sillivan, Stephanie E.; O’Sullivan, Sean S.; Luksik, Andrew S.; Vassoler, Fair M.; Lees, Andrew J.; Konradi, Christine

    2011-01-01

    Angiogenesis and increased permeability of the blood–brain barrier have been reported to occur in animal models of Parkinson’s disease and l-dopa-induced dyskinesia, but the significance of these phenomena has remained unclear. Using a validated rat model of l-dopa-induced dyskinesia, this study demonstrates that chronic treatment with l-dopa dose dependently induces the expression of vascular endothelial growth factor in the basal ganglia nuclei. Vascular endothelial growth factor was abundantly expressed in astrocytes and astrocytic processes in the proximity of blood vessels. When co-administered with l-dopa, a small molecule inhibitor of vascular endothelial growth factor signalling significantly attenuated the development of dyskinesia and completely blocked the angiogenic response and associated increase in blood–brain barrier permeability induced by the treatment. The occurrence of angiogenesis and vascular endothelial growth factor upregulation was verified in post-mortem basal ganglia tissue from patients with Parkinson’s disease with a history of dyskinesia, who exhibited increased microvascular density, microvascular nestin expression and an upregulation of vascular endothelial growth factor messenger ribonucleic acid. These congruent findings in the rat model and human patients indicate that vascular endothelial growth factor is implicated in the pathophysiology of l-dopa-induced dyskinesia and emphasize an involvement of the microvascular compartment in the adverse effects of l-dopa pharmacotherapy in Parkinson’s disease. PMID:21771855

  10. Ageing effect on 18F-DOPA and 123I-MIBG uptake: a cross-sectional study.

    Science.gov (United States)

    Chiaravalloti, Agostino; Barbagallo, Gaetano; Ricci, Maria; Sannino, Pasqualina; Karalis, Georgios; Ursini, Francesco; Schillaci, Orazio

    2018-06-01

    The aim of this study was to investigate the relationship between age and uptake of fluorine-18-L-dihydroxyphenylalanine (F-DOPA) in the brain and myocardial uptake of iodine-123-metaiodobenzylguanidine (I-MIBG) in normal adult participants. To this end, a total of 72 healthy participants were enroled. Of these, 37 individuals (male, 21; female, 16; mean age: 60±12 years; age range: 38-85 years) underwent F-DOPA PET/CT, whereas 35 individuals (male, 19; female, 16; mean age: 61±17 years; age range: 17-87 years) underwent I-MIBG scintigraphy. For F-DOPA PET/CT, regions of interest were placed on the caudate nucleus, globus pallidus and putamen by means of the WFU Pickatlas tool implemented in SPM8 and further analysed after a normalization process. For I-MIBG scintigraphy, regions of interest were set over the upper mediastinum and a heart-to-mediastinum count ratio was calculated. The relation between age and normalized F-DOPA values or heart-to-mediastinum ratio values was examined using correlation analysis of variance and Pearson's correlation coefficient. We did not find any significant relationship between age and F-DOPA and I-MIBG uptake, respectively. Our findings suggest that both brain F-DOPA PET/CT and cardiac I-MIBG scintigraphy represent age-independent biomarkers whose analyses of quantitative uptake may not require adjustment for patients' age.

  11. Conformational reduction of DOPA in the gas phase studied by laser desorption supersonic jet laser spectroscopy.

    Science.gov (United States)

    Ishiuchi, Shun-ichi; Mitsuda, Haruhiko; Asakawa, Toshiro; Miyazaki, Mitsuhiko; Fujii, Masaaki

    2011-05-07

    The conformational reduction in catecholamine neurotransmitters was studied by resonance enhanced multi photon ionization (REMPI), ultraviolet-ultraviolet (UV-UV) hole burning and infrared (IR) dip spectroscopy with applying a laser desorption supersonic jet technique to DOPA, which is one of the catecholamine neurotransmitters and has one more phenolic OH group than tyrosine. It is concluded that DOPA has a single observable conformer in the gas phase at low temperature. Quantum chemical calculations at several levels with or without the dispersion correction were also carried out to study stable conformations. From the comparison between the computational IR spectra and the experimental ones, the most stable structure was determined. It is strongly suggested that the conformational reduction is caused by electrostatic interactions, such as a dipole-dipole interaction, between the chain and OH groups. This journal is © the Owner Societies 2011

  12. Synthesis of no-carrier-added L- and D-[1-11C]-DOPA

    International Nuclear Information System (INIS)

    Bolster, J.M.; Vaalburg, W.; Veen, W. van; Dijk, Th. van; Molen, H.D. van der; Wynberg, H.; Woldring, M.G.; Rijksuniversiteit Groningen

    1983-01-01

    No-carrier-added DL-[1- 11 C]-DOPA has been synthesized by carboxylation of an α-lithioisocyanide with a radiochemical yield of up to 15% without correction for decay. The total synthesis time is 30 min. The resolution of the D- and L-isomers was accomplished within 16 min by HPLC using a chiral stationary phase and a phosphate buffer of pH 4.5 as eluent. (author)

  13. Rapid synthesis and purification of carbon-11 labelled DOPA: a potential agent for brain studies

    International Nuclear Information System (INIS)

    Reiffers, S.; Beerling-van der Molen, H.D.; Vaalburg, W.; Hoeve, W. ten; Paans, A.M.J.; Korf, J.; Woldring, M.G.; Wynberg, H.

    1977-01-01

    A rapid method for preparation and purification of β-(3,4-dihydroxyphenyl)-D,L-α-alanine-1- 11 C( 11 C-DOPA), using 11 CO 2 as the radioactive precursor is described. Carboxylation of an α-lithioisocyanide, containing protected hydroxylic groups, was followed by a three-step hydrolysis of the intermediate αioscyano carboxylic acid. Preliminary experiments in rats indicate that the compound is preferentially decarboxylated in brain areas rich in dopamine containing neurons. (author)

  14. Usefulness of [18F]-DA and [18F]-DOPA for PET imaging in a mouse model of pheochromocytoma

    International Nuclear Information System (INIS)

    Martiniova, Lucia; Cleary, Susannah; Lai, Edwin W.; Kiesewetter, Dale O.; Seidel, Jurgen; Dawson, Linda F.; Phillips, Jacqueline K.; Thomasson, David; Chen Xiaoyuan; Eisenhofer, Graeme; Powers, James F.; Kvetnansky, Richard

    2012-01-01

    Purpose: To evaluate the usefulness of [ 18 F]-6-fluorodopamine ([ 18 F]-DA) and [ 18 F]-L-6-fluoro-3,4-dihydroxyphenylalanine ([ 18 F]-DOPA) positron emission tomography (PET) in the detection of subcutaneous (s.c.) and metastatic pheochromocytoma in mice; to assess the expression of the norepinephrine transporter (NET) and vesicular monoamine transporters 1 and 2 (VMAT1 and VMAT2), all important for [ 18 F]-DA and [ 18 F]-DOPA uptake. Furthermore, to compare tumor detection by micro-computed tomography (microCT) to magnetic resonance imaging (MRI) in individual mouse. Methods: SUV max values were calculated from [ 18 F]-DA and [ 18 F]-DOPA PET, tumor-to-liver ratios (TLR) were obtained and expression of NET, VMAT1 and VMAT2 was evaluated. Results: [ 18 F]-DA detected less metastatic lesions compared to [ 18 F]-DOPA. TLR values for liver metastases were 2.26–2.71 for [ 18 F]-DOPA and 1.83–2.83 for [ 18 F]-DA. A limited uptake of [ 18 F]-DA was found in s.c. tumors (TLR=0.22-0.27) compared to [ 18 F]-DOPA (TLR=1.56-2.24). Overall, NET and VMAT2 were expressed in all organ and s.c. tumors. However, s.c. tumors lacked expression of VMAT1. We confirmed [ 18 F]-DA's high affinity for the NET for its uptake and VMAT1 and VMAT2 for its storage and retention in pheochromocytoma cell vesicles. In contrast, [ 18 F]-DOPA was found to utilize only VMAT2. Conclusion: MRI was superior in the detection of all organ tumors compared to microCT and PET. [ 18 F]-DOPA had overall better sensitivity than [ 18 F]-DA for the detection of metastases. Subcutaneous tumors were localized only with [ 18 F]-DOPA, a finding that may reflect differences in expression of VMAT1 and VMAT2, perhaps similar to some patients with pheochromocytoma where [ 18 F]-DOPA provides better visualization of lesions than [ 18 F]-DA.

  15. Production of dopamine by aromatic L-amino acid decarboxylase cells after spinal cord injury

    DEFF Research Database (Denmark)

    Ren, Liqun; Wienecke, Jacob; Hultborn, Hans

    2016-01-01

    adopted as we used previously (Wienecke et al., J. Neurosci. 34, 11984, 2014). In the chronic SCI rats (> 45d), no AADC cells expressed DA if there was no exogenous L-dopa application. However, following administration of a peripheral AADC inhibitor (carbidopa) with or without a monoamine oxidase...... inhibitor (pargyline) co-application, systemic administration of L-dopa resulted in ~ 94% of AADC cells to become DA-immunopositive in the spinal cord below the lesion, whereas in normal or sham-operated rats none or very few of AADC cells became DA-immunopositive with the same treatment. Using tail...

  16. Histidine Decarboxylase Deficiency Prevents Autoimmune Diabetes in NOD Mice

    Directory of Open Access Journals (Sweden)

    Manal Alkan

    2015-01-01

    Full Text Available Recent evidence has highlighted the role of histamine in inflammation. Since this monoamine has also been strongly implicated in the pathogenesis of type-1 diabetes, we assessed its effect in the nonobese diabetic (NOD mouse model. To this end, we used mice (inactivated knocked out for the gene encoding histidine decarboxylase, the unique histamine-forming enzyme, backcrossed on a NOD genetic background. We found that the lack of endogenous histamine in NOD HDC−/− mice decreased the incidence of diabetes in relation to their wild-type counterpart. Whereas the proportion of regulatory T and myeloid-derived suppressive cells was similar in both strains, histamine deficiency was associated with increased levels of immature macrophages, as compared with wild-type NOD mice. Concerning the cytokine pattern, we found a decrease in circulating IL-12 and IFN-γ in HDC−/− mice, while IL-6 or leptin remained unchanged, suggesting that histamine primarily modulates the inflammatory environment. Paradoxically, exogenous histamine given to NOD HDC−/− mice provided also protection against T1D. Our study supports the notion that histamine is involved in the pathogenesis of diabetes, thus providing additional evidence for its role in the regulation of the immune response.

  17. Urtica dioica Effect on Malonyl-CoA Decarboxylase

    Directory of Open Access Journals (Sweden)

    Qujeq

    2014-09-01

    Full Text Available Background The malonyl-CoA decarboxylase (MCD, EC.4.1.1.9 enzyme regulates malonyl-CoA levels. The effect of aerial parts extracts of Urtica dioica (UD on MCD is poorly understood. Objectives The present experiment was undertaken to evaluate the effect of UD aerial parts extracts on MCD level. Materials and Methods In this experimental study, two groups of rats were used: normal and hyperglycemic group. Then UD aerial parts extracts (5 mg /500 µL administrated to the hyperglycemic group of rats and finally, the MCD and insulin levels were measured in both groups. Results Interestingly, we observed that the UD aerial parts extracts powder caused a significant (P < 0.05 increase in insulin level during the experiment, from the base level of 0.36 ± 0.07 μg/L to the peak value of 0.52 ± 0.15 μg/L. Also, it caused a significant (P < 0.05 decrease in MCD level, from the base level of 29.68 ±1.29 pg/mL to the bottom value of 22.12 ± 2.41 pg/mL. Conclusions The results of the present study indicate that UD aerial part extracts would decrease MCD level in hyperglycemic rats.

  18. DOPA, a Digital Observatory for Protected Areas including Monitoring and Forecasting Services

    Science.gov (United States)

    Dubois, Gregoire; Hartley, Andrew; Peedell, Stephen; de Jesus, Jorge; Ó Tuama, Éamonn; Cottam, Andrew; May, Ian; Fisher, Ian; Nativi, Stefano; Bertrand, Francis

    2010-05-01

    The Digital Observatory for Protected Areas (DOPA) is a biodiversity information system currently developed as an interoperable web service at the Joint Research Centre of the European Commission in collaboration with other international organizations, including GBIF, UNEP-WCMC, Birdlife International and RSPB. DOPA is designed to assess the state and pressure of Protected Areas (PAs) and to prioritize them accordingly, in order to support decision making and fund allocation processes. To become an operational web service allowing the automatic monitoring of protected areas, DOPA needs to be able to capture the dynamics of spatio-temporal changes in habitats and anthropogenic pressure on PAs as well as the changes in the species distributions. Because some of the most valuable natural ecosystems and species on the planet cover large areas making field monitoring methods very difficult for a large scale assessment, the automatic collection and processing of remote sensing data are processes at the heart of the problem. To further be able to forecast changes due to climate change, DOPA has to rely on an architecture that enables it to communicate with the appropriate modeling web services. The purpose of this presentation is to present the architecture of the DOPA with special attention to e-Habitat, its web processing service designed for assessing the irreplaceability of habitats as well as for the modeling of habitats under different climate change scenarios. The use of open standards for spatial data and of open source programming languages for the development of the core functionalities of the system are expected to encourage the participation of the scientific community beyond the current partnerships and to favour the sharing of such an observatory which could be installed at any other location. Acknowledgement: Part of this work is funded under the 7th Framework Programme by the EuroGEOSS (www.eurogeoss.eu) project of the European Commission. The views

  19. Novel L-Dopa and dopamine prodrugs containing a 2-phenyl-imidazopyridine moiety.

    Science.gov (United States)

    Denora, Nunzio; Laquintana, Valentino; Lopedota, Angela; Serra, Mariangela; Dazzi, Laura; Biggio, Giovanni; Pal, Dhananjay; Mitra, Ashim K; Latrofa, Andrea; Trapani, Giuseppe; Liso, Gaetano

    2007-07-01

    The aim of this study was to gain insight into the feasibility of enhancing the delivery of L-Dopa and dopamine to the brain by linking these neurotransmitters and L-Dopa ethyl ester to 2-phenyl-3-carboxymethyl-imidazopyridine compounds giving rise to the so-called Dopimid compounds. A number of Dopimid compounds were synthesized and both stability and binding studies to dopaminergic and benzodiazepine receptors were performed. To evaluate whether Dopimid compounds are P-gp substrates, [(3)H]ritonavir uptake experiments and bi-directional transport studies on confluent MDCKII-MDR1 monolayers were carried out. The brain penetration properties of Dopimid compounds were estimated by the Clark's computational model and evaluated by investigation of their transport across BBMECs monolayers. The dopamine levels following the intraperitoneal administration of the selected Dopimid compounds were measured in vivo by using brain microdialysis in rat. Tested compounds were adequately stable in solution buffered at pH 7.4 but undergo faster cleavage in dilute rat serum at 37 degrees C. Receptor binding studies showed that Dopimid compounds are essentially devoid of affinity for dopaminergic and benzodiazepine receptors. [(3)H]ritonavir uptake experiments indicated that selected Dopimid compounds, like L-Dopa and dopamine hydrochloride, are not substrates of P-gp and it was also confirmed by bi-directional transport experiments across MDCKII-MDR1 monolayers. By Clark's model a significant brain penetration was deduced for L-Dopa ethyl ester and dopamine derivatives. Transport studies involving BBMECs monolayers indicated that some of these compounds should be able to cross the BBB. Interestingly, the rank order of apparent permeability (P (app)) values observed in these assays parallels that calculated by the computational approach. Brain microdialysis experiments in rat showed that intraperitoneal acute administration of some Dopimid compounds induced a dose-dependent increase

  20. A new knock-in mouse model of l-DOPA-responsive dystonia.

    Science.gov (United States)

    Rose, Samuel J; Yu, Xin Y; Heinzer, Ann K; Harrast, Porter; Fan, Xueliang; Raike, Robert S; Thompson, Valerie B; Pare, Jean-Francois; Weinshenker, David; Smith, Yoland; Jinnah, Hyder A; Hess, Ellen J

    2015-10-01

    Abnormal dopamine neurotransmission is associated with many different genetic and acquired dystonic disorders. For instance, mutations in genes critical for the synthesis of dopamine, including GCH1 and TH cause l-DOPA-responsive dystonia. Despite evidence that implicates abnormal dopamine neurotransmission in dystonia, the precise nature of the pre- and postsynaptic defects that result in dystonia are not known. To better understand these defects, we generated a knock-in mouse model of l-DOPA-responsive dystonia (DRD) mice that recapitulates the human p.381Q>K TH mutation (c.1141C>A). Mice homozygous for this mutation displayed the core features of the human disorder, including reduced TH activity, dystonia that worsened throughout the course of the active phase, and improvement in the dystonia in response to both l-DOPA and trihexyphenidyl. Although the gross anatomy of the nigrostriatal dopaminergic neurons was normal in DRD mice, the microstructure of striatal synapses was affected whereby the ratio of axo-spinous to axo-dendritic corticostriatal synaptic contacts was reduced. Microinjection of l-DOPA directly into the striatum ameliorated the dystonic movements but cerebellar microinjections of l-DOPA had no effect. Surprisingly, the striatal dopamine concentration was reduced to ∼1% of normal, a concentration more typically associated with akinesia, suggesting that (mal)adaptive postsynaptic responses may also play a role in the development of dystonia. Administration of D1- or D2-like dopamine receptor agonists to enhance dopamine signalling reduced the dystonic movements, whereas administration of D1- or D2-like dopamine receptor antagonists to further reduce dopamine signalling worsened the dystonia, suggesting that both receptors mediate the abnormal movements. Further, D1-dopamine receptors were supersensitive; adenylate cyclase activity, locomotor activity and stereotypy were exaggerated in DRD mice in response to the D1-dopamine receptor agonist SKF

  1. Direct comparison of FP-CIT SPECT and F-DOPA PET in patients with Parkinson's disease and healthy controls

    International Nuclear Information System (INIS)

    Eshuis, S.A.; Maguire, R.P.; Leenders, K.L.; Jager, P.L.; Jonkman, S.; Dierckx, R.A.

    2009-01-01

    Diagnosing Parkinson's disease (PD) on clinical grounds may be difficult, especially in the early stages of the disease. F-DOPA PET and FP-CIT SPECT scans are able to determine presynaptic dopaminergic activity in different ways. The aim of this study was to determine and compare the sensitivity and specificity of the two methods in the detection of striatal dopaminergic deficits in the same cohort of PD patients and healthy controls. Movement disorder specialists recruited 11 patients with early-stage PD and 17 patients with advanced PD. The patients underwent both an FP-CIT SPECT scan and an F-DOPA PET scan. In addition, 10 FP-CIT SPECT scans or 10 F-DOPA PET scans were performed in 20 healthy controls. A template with regions of interest was used to sample tracer activity of the caudate, putamen and a reference region in the brain. The outcome parameter was the striatooccipital ratio (SOR). Normal SOR values were determined in the controls. The sensitivity and specificity of both scanning methods were calculated. FP-CIT SPECT and F-DOPA PET scans were both able to discriminate PD patients from healthy controls. For the early phases of the disease, sensitivity and specificity of the contralateral striatal and putaminal uptake of FP-CIT and F-DOPA was 100%. When only caudate uptake was considered, the specificities were 100% and 90% for FP-CIT and F-DOPA, respectively, while the sensitivity was 91% for both scanning techniques. FP-CIT SPECT and F-DOPA PET scans are both able to diagnose presynaptic dopaminergic deficits in early phases of PD with excellent sensitivity and specificity. (orig.)

  2. Brain {sup 18}F-DOPA PET and cognition in de novo Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Picco, Agnese; Arnaldi, Dario; Brugnolo, Andrea; Nobili, Flavio [University of Genoa and IRCCS AOU San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Genoa (Italy); Morbelli, Silvia; Bossert, Irene [University of Genoa and IRCCS AOU San Martino-IST, Nuclear Medicine, Department of Health Sciences (DISSAL), Genoa (Italy); Piccardo, Arnoldo [Ospedali Galliera, Nuclear Medicine, Department of Imaging Diagnostics, Genoa (Italy); Girtler, Nicola [University of Genoa and IRCCS AOU San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Genoa (Italy); IRCCS San Martino-IST, Clinical Psychology and Psychotherapy Unit, Genoa (Italy); Marinelli, Lucio; Abbruzzese, Giovanni [University of Genoa and IRCCS AOU San Martino-IST, Neurological Rehabilitation, Department of Neuroscience (DINOGMI), Genoa (Italy); Castaldi, Antonio [Ospedali Galliera, Radiology, Department of Imaging Diagnostics, Genoa (Italy); De Carli, Fabrizio [Consiglio Nazionale delle Ricerche (CNR), Institute of Bioimaging and Molecular Physiology, Genoa (Italy); Campus, Claudio [Istituto Italiano di Tecnologia, Genoa (Italy)

    2015-03-28

    The role of mesocortical dopaminergic pathways in the cognitive function of patients with early Parkinson's disease (PD) needs to be further clarified. The study groups comprised 15 drug-naive patients with de novo PD and 10 patients with essential tremor (controls) who underwent {sup 18}F-DOPA PET (static acquisition, normalization on mean cerebellar counts) and an extended neuropsychological test battery. Factor analysis with varimax rotation was applied to the neuropsychological test scores, to yield five factors from 16 original scores, which explained 82 % of the total variance. Correlations between cognitive factors and {sup 18}F-DOPA uptake were assessed with SPM8, taking age and gender as nuisance variables. {sup 18}F-DOPA uptake was significantly lower in PD patients than in controls in the bilateral striatum, mainly in the more affected (right) hemisphere, and in a small right temporal region. Significant positive correlations were found only in PD patients between the executive factor and {sup 18}F-DOPA uptake in the bilateral anterior cingulate cortex (ACC) and the middle frontal gyrus, between the verbal fluency factor and {sup 18}F-DOPA uptake in left BA 46 and the bilateral striatum, and between the visuospatial factor and {sup 18}F-DOPA uptake in the left ACC and bilateral striatum. No correlations were found between {sup 18}F-DOPA uptake and either the verbal memory factor or the abstraction-working memory factor. These data clarify the role of the mesocortical dopaminergic pathways in cognitive function in early PD, highlighting the medial frontal lobe, anterior cingulate, and left BA 46 as the main sites of cortical correlation with executive and language functions. (orig.)

  3. Screening method for detection of immediate amino acid decarboxylases--producing bacteria implicated in food poisoning.

    Science.gov (United States)

    Hussain, Husniza; Mohd Fuat, A R; Vimala, B; Ghazali, H M

    2011-08-01

    Assessment of amino acid decarboxylase activity can be conducted using tubed broth or plated agar. In this study, the test was carried out in microtitre plates containing lysine, ornithine, arginine, tyrosine, tryptophan, phenylalanine or histidine as biogenic amine precursors. Møller decarboxylase base broth (MDB) with or without 1% of a known amino acid were added to wells of a 96 well-microtitre plate. The wells were inoculated with Escherichia coli, Klebsiella pneumoniae, Acinetobacter anitratus or Staphylococcus aureus to the final concentration of 6.0 x 10(7) cfu/ml and incubated at 35ºC. The absorbance of the culture broth was read at 570 nm at 0, 1.0, 2.0, 3.0, 4.0, 5.5, 6.5 and 7.5 hour. Comparison of means of A'(570) between 0 hour and a specified incubation time was determined statistically. Positive decarboxylase activities were detected in the media inoculated with E. coli and K. pneumoniae in less than 6 hours. The current method is suitable for immediate producers of amino acid decarboxylase enzymes. It costs less as it uses less amino acid and it has the potential to be used for screening aliquots of food materials for amino acid decarboxylase activities.

  4. L-3,4-Dihydroxyphenylalanine (l-DOPA) induces neuroendocrinological, physiological, and immunological regulation in white shrimp, Litopenaeus vannamei.

    Science.gov (United States)

    Mapanao, Ratchaneegorn; Kuo, Hsin-Wei; Chang, Chin-Chuan; Liu, Kuan-Fu; Cheng, Winton

    2018-03-01

    L-3,4-Dihydroxyphenylalanine (l-DOPA) is a precursor for dopamine (DA) synthesis. Assessments were conducted to analyze the effects of l-DOPA on mediating regulation of neuroendocrinological, immunological, and physiological parameters in the shrimp, Litopenaeus vannamei when they were individually injected with 0.01 N HCl or l-DOPA at 0.5 or 1.0 μmol shrimp -1 for 60, 120, and 240 min. For catecholamine synthesis evaluation, tyrosine hydroxylase (TH) and DA beta hydroxylase (DBH) activities, l-DOPA, DA, and norepinephrine (NE) levels in hemolymph were determined. The total hemocyte count (THC), differential hemocyte count (DHC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, phagocytic activity, and clearance efficiency in response to the pathogen, Vibrio alginolyticus were assessed for immune responses, and plasma glucose and lactate levels were for physiological response. Results showed that the TH activity, THC, hyaline cells (HCs), and semigranular cells (SGCs) at 120 min, DA levels at 60-240 min, PO activity in hemocytes per 50 μL of hemolymph at 60-120 min, and PO activity per granulocyte (granular cells (GCs) + SGCs) at 60 min significantly increased, but TH activity, l-DOPA levels, GCs, SGCs, and respiratory bursts in hemocytes per 10 μL of hemolymph at 60 min, respiratory bursts per hemocyte and SOD activity at 120 min, phagocytic activity at 60-240 min, and the clearance efficiency at 60-120 min significantly decreased in shrimp injected with l-DOPA at 1.0 μmol shrimp -1 . In another experiment, 60 min after shrimp had received l-DOPA at 0.5 or 1.0 μmol shrimp -1 , they were challenged with an injection of V. alginolyticus at 2 × 10 5  colony-forming units (cfu) shrimp -1 . The injection of l-DOPA at 1.0 μmol shrimp -1 also significantly increased the cumulative mortality of shrimp by 16.7%, compared to the HCl-challenged control after 120 h. These results suggest

  5. Estimation of L-dopa from Mucuna pruriens LINN and formulations containing M. pruriens by HPTLC method.

    Science.gov (United States)

    Modi, Ketan Pravinbhai; Patel, Natvarlal Manilal; Goyal, Ramesh Kishorilal

    2008-03-01

    A selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed for the analysis of L-dopa in Mucuna pruriens seed extract and its formulations. The method involves densitometric evaluation of L-dopa after resolving it by HPTLC on silica gel plates with n-butanol-acetic acid-water (4.0+1.0+1.0, v/v) as the mobile phase. Densitometric analysis of L-dopa was carried out in the absorbance mode at 280 nm. The relationship between the concentration of L-dopa and corresponding peak areas was found to be linear in the range of 100 to 1200 ng/spot. The method was validated for precision (inter and intraday), repeatability, and accuracy. Mean recovery was 100.30%. The relative standard deviation (RSD) values of the precision were found to be in the range 0.64-1.52%. In conclusion, the proposed TLC method was found to be precise, specific and accurate and can be used for identification and quantitative determination of L-dopa in herbal extract and its formulations.

  6. Inducing mutations through γ-irradiation in seeds of Mucuna pruriens for developing high L-DOPA-yielding genotypes.

    Science.gov (United States)

    Singh, Susheel Kumar; Yadav, Deepti; Lal, Raj Kishori; Gupta, Madan M; Dhawan, Sunita Singh

    2017-04-01

    To develop elite genotypes in Mucuna pruriens (L.) DC with high L-DOPA (L-3, 4 dihydroxyphenylalanine) yields, with non-itching characteristics and better adaptability by applying γ-irradiation. Molecular and chemical analysis was performed for screening based on specific characteristics desired for developing suitable genotypes. Developed, mutant populations were analyzed for L-DOPA % in seeds through TLC (thin layer chromatography), and the results obtained were validated with the HPLC (High performance liquid chromatography). The DNA (Deoxyribonucleic acid) was isolated from the leaf at the initial stage and used for DNA polymorphism. RNA (Ribonucleic acid) was isolated from the leaf during maturity and used for expression analysis. The selected mutant T-I-7 showed 5.7% L-DOPA content compared to 3.18% of parent CIM-Ajar. The total polymorphism obtained was 57% with the molecular marker analysis. The gene expression analysis showed higher fold change expression of the dopadecarboxylase gene (DDC) in control compared to selected mutants (T-I-7, T-II-23, T-IV-9, T-VI-1). DNA polymorphism was used for the screening of mutants for efficient screening at an early stage. TLC was found suitable for the large-scale comparative chemical analysis of L-DOPA. The expression profile of DDC clearly demonstrated the higher yields of L-DOPA in selected mutants developed by γ-irradiation in the seeds of the control.

  7. Mussel-Inspired Protein Nanoparticles Containing Iron(III)-DOPA Complexes for pH-Responsive Drug Delivery.

    Science.gov (United States)

    Kim, Bum Jin; Cheong, Hogyun; Hwang, Byeong Hee; Cha, Hyung Joon

    2015-06-15

    A novel bioinspired strategy for protein nanoparticle (NP) synthesis to achieve pH-responsive drug release exploits the pH-dependent changes in the coordination stoichiometry of iron(III)-3,4-dihydroxyphenylalanine (DOPA) complexes, which play a major cross-linking role in mussel byssal threads. Doxorubicin-loaded polymeric NPs that are based on Fe(III)-DOPA complexation were thus synthesized with a DOPA-modified recombinant mussel adhesive protein through a co-electrospraying process. The release of doxorubicin was found to be predominantly governed by a change in the structure of the Fe(III)-DOPA complexes induced by an acidic pH value. It was also demonstrated that the fabricated NPs exhibited effective cytotoxicity towards cancer cells through efficient cellular uptake and cytosolic release. Therefore, it is anticipated that Fe(III)-DOPA complexation can be successfully utilized as a new design principle for pH-responsive NPs for diverse controlled drug-delivery applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Ultraviolet radiation induction of ornithine decarboxylase in rat keratinocytes

    International Nuclear Information System (INIS)

    Rosen, C.F.; Gajic, D.; Drucker, D.J.

    1990-01-01

    UV radiation plays an important role in the induction of cutaneous malignancy, including basal cell and squamous cell carcinomas and malignant melanoma. In addition to its effects on DNA damage and repair mechanisms, UV radiation has been shown to modulate the expression of specific genes, altering the levels of their mRNAs and the synthesis of their corresponding proteins. In order to gain further information about the molecular effects of UV radiation, we have studied the regulation of ornithine decarboxylase (ODC) gene expression in response to UVB radiation. ODC is the rate-limiting enzyme in polyamine biosynthesis, is involved in growth and differentiation, and has been implicated in carcinogenesis. Keratinocytes grown in culture were either sham-irradiated or exposed to increasing doses of UVB (1-5 mJ/cm2). Northern blot analysis of keratinocyte RNA under basal conditions demonstrated the presence of two ODC mRNA transcripts. Increasing exposure to UVB resulted in a dose-dependent increase in the levels of both ODC mRNA transcripts. The induction of ODC gene expression following UVB was noted 2 h after UVB exposure, and ODC mRNA levels continued to increase up to 24 h after UVB exposure. The UVB-induced increase in ODC gene expression was not serum dependent, despite the ability of serum alone to induce ODC gene expression. The mRNA transcripts for actin and hexosaminidase A were not induced after UVB exposure. These studies show that the UVB-induced increase in ODC activity is due, at least in part, to an increase in ODC gene expression and they provide a useful model for the analysis of the molecular effects of UVB radiation

  9. Ultraviolet radiation induction of ornithine decarboxylase in rat keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, C.F.; Gajic, D.; Drucker, D.J. (Women' s College Hospital, Toronto, Ontario (Canada))

    1990-05-01

    UV radiation plays an important role in the induction of cutaneous malignancy, including basal cell and squamous cell carcinomas and malignant melanoma. In addition to its effects on DNA damage and repair mechanisms, UV radiation has been shown to modulate the expression of specific genes, altering the levels of their mRNAs and the synthesis of their corresponding proteins. In order to gain further information about the molecular effects of UV radiation, we have studied the regulation of ornithine decarboxylase (ODC) gene expression in response to UVB radiation. ODC is the rate-limiting enzyme in polyamine biosynthesis, is involved in growth and differentiation, and has been implicated in carcinogenesis. Keratinocytes grown in culture were either sham-irradiated or exposed to increasing doses of UVB (1-5 mJ/cm2). Northern blot analysis of keratinocyte RNA under basal conditions demonstrated the presence of two ODC mRNA transcripts. Increasing exposure to UVB resulted in a dose-dependent increase in the levels of both ODC mRNA transcripts. The induction of ODC gene expression following UVB was noted 2 h after UVB exposure, and ODC mRNA levels continued to increase up to 24 h after UVB exposure. The UVB-induced increase in ODC gene expression was not serum dependent, despite the ability of serum alone to induce ODC gene expression. The mRNA transcripts for actin and hexosaminidase A were not induced after UVB exposure. These studies show that the UVB-induced increase in ODC activity is due, at least in part, to an increase in ODC gene expression and they provide a useful model for the analysis of the molecular effects of UVB radiation.

  10. [F-18]fluoro-meta-L-tyrosine is a better PET tracer than [F-18]fluoro-L-dopa for the delineation of dopaminergic structures in the human brain

    International Nuclear Information System (INIS)

    Firnau, G.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

    1990-01-01

    Fluorine-18 labelled fluoro-m-L-tyrosine (FmLtyr) and fluoro-L-Dopa (F-Dopa) have been synthesized, and the utility of FmLtyr for PET investigations of dopaminergic brain regions has been compared to that of F-dopa. Experimental results from both monkey and human studies indicate that FmLtyr gives better delineation of striatum, and is a better PET tracer than F-dopa

  11. A rapid non invasive L-DOPA-¹³C breath test for optimally suppressing extracerebral AADC enzyme activity - toward individualizing carbidopa therapy in Parkinson’s disease.

    Science.gov (United States)

    Modak, Anil; Durso, Raymon; Josephs, Ephraim; Rosen, David

    2012-01-01

    Peripheral carbidopa (CD) levels directly impact on central dopamine (DA) production in Parkinson disease (PD) through extracerebral inhibition of dopa decarboxylase (AADC) resulting in an increase in levodopa (LD) bioavailability. Recent data suggests that higher CD doses than those presently used in PD treatment may result in improved clinical response. Optimizing CD doses in individual patients may, therefore, result in ideal individualized treatment. A single center, randomized, double-blind study was carried out recruiting 5 Parkinson’s disease (PD) patients already on LD/CD and 1 treatment näve PD patient using stable isotope labeled LD-1-¹³C as a substrate for a noninvasive breath test to evaluate individual AADC enzyme activity. Each patient was studied five times, receiving 200 mg LD-¹³C at each visit along with one of five randomized CD doses (0, 25, 50, 100 and 200 mg). The metabolite ¹³CO₂ in breath was measured for evaluating AADC enzyme activity and plasma metabolite levels for LD-¹³C and homovanillic acid (HVA) were measured for 4 hours. HVA in plasma and ¹³CO₂ in breath are metabolic products of LD. We found a significant positive correlation of ¹³CO₂ DOB AUC0-240 with serum HVA AUC0-240 following the oral dose of LD-1-¹³C for all 5 doses of CD (r² = 0.9378). With increasing inhibition of AADC enzyme activity with CD, we observed an increase in the plasma concentration of LD.We found an inverse correlation of the 13CO2 DOB AUC with serum LD-¹³C AUC. Our studies indicate the optimal dose of CD for maximal suppression of AADC enzyme activity can be determined for each individual from ¹³CO₂ generation in breath. The LD-breath test can be a useful noninvasive diagnostic tool for evaluation of AADC enzyme activity using the biomarker ¹³CO₂ in breath, a first step in personalizing CD doses for PD patients.

  12. L-DOPA concentration variation in the leaf and flower tissues of six faba bean lines with common and rare flower colors

    Science.gov (United States)

    Faba bean is one of the a few plant species that can produce the medicinally important molecule, L-3,4-dihydroxy phenylalanine (L-DOPA), the major ingredient of several prescription drugs used to treat Parkinson’s disease. L-DOPA can cross the blood-brain barrier, where it is converted to dopamine, ...

  13. Ornithine Decarboxylase Activity Is Required for Prostatic Budding in the Developing Mouse Prostate.

    Directory of Open Access Journals (Sweden)

    Melissa Gamat

    Full Text Available The prostate is a male accessory sex gland that produces secretions in seminal fluid to facilitate fertilization. Prostate secretory function is dependent on androgens, although the mechanism by which androgens exert their effects is still unclear. Polyamines are small cationic molecules that play pivotal roles in DNA transcription, translation and gene regulation. The rate-limiting enzyme in polyamine biosynthesis is ornithine decarboxylase, which is encoded by the gene Odc1. Ornithine decarboxylase mRNA decreases in the prostate upon castration and increases upon administration of androgens. Furthermore, testosterone administered to castrated male mice restores prostate secretory activity, whereas administering testosterone and the ornithine decarboxylase inhibitor D,L-α-difluromethylornithine (DFMO to castrated males does not restore prostate secretory activity, suggesting that polyamines are required for androgens to exert their effects. To date, no one has examined polyamines in prostate development, which is also androgen dependent. In this study, we showed that ornithine decarboxylase protein was expressed in the epithelium of the ventral, dorsolateral and anterior lobes of the adult mouse prostate. Ornithine decarboxylase protein was also expressed in the urogenital sinus (UGS epithelium of the male and female embryo prior to prostate development, and expression continued in prostatic epithelial buds as they emerged from the UGS. Inhibiting ornithine decarboxylase using DFMO in UGS organ culture blocked the induction of prostatic buds by androgens, and significantly decreased expression of key prostate transcription factor, Nkx3.1, by androgens. DFMO also significantly decreased the expression of developmental regulatory gene Notch1. Other genes implicated in prostatic development including Sox9, Wif1 and Srd5a2 were unaffected by DFMO. Together these results indicate that Odc1 and polyamines are required for androgens to exert their

  14. Enhanced permeability and antifouling performance of cellulose acetate ultrafiltration membrane assisted by l-DOPA functionalized halloysite nanotubes.

    Science.gov (United States)

    Mu, Keguang; Zhang, Dalun; Shao, Ziqiang; Qin, Dujian; Wang, Yalong; Wang, Shuo

    2017-10-15

    l-Dopa functionalized halloysite nanotubes (HNTs) were prepared by the self-polymerization of l-dopa in the weak alkaline condition. Then different contents of l-dopa coated HNTs (LPDHNTs) were blended into cellulose acetate to prepare enhanced performance ultrafiltration membranes via the phase inversion method. The HNTs and LPDHNTs were characterized by FTIR, XPS, and TEM anysis. And the membranes morphologies, separation performance, antifouling performance, mechanical properties and hydrophilicity were also investigated. It was found that the composite membranes exhibited excellent antifouling performance. The pure water flux of 3.0wt% LPDHNTs/CA membrane increased from 11.4Lm -2 h -1 to 92.9Lm -2 h -1 , while the EA rejection ratio of the membrane was about 91.2%. In addition, the mechanical properties of the resultant membranes were strengthened compared with the CA ultrafiltration membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Data Elevator

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-29

    Data Elevator: Efficient Asynchronous Data Movement in Hierarchical Storage Systems Multi-layer storage subsystems, including SSD-based burst buffers and disk-based parallel file systems (PFS), are becoming part of HPC systems. However, software for this storage hierarchy is still in its infancy. Applications may have to explicitly move data among the storage layers. We propose Data Elevator for transparently and efficiently moving data between a burst buffer and a PFS. Users specify the final destination for their data, typically on PFS, Data Elevator intercepts the I/O calls, stages data on burst buffer, and then asynchronously transfers the data to their final destination in the background. This system allows extensive optimizations, such as overlapping read and write operations, choosing I/O modes, and aligning buffer boundaries. In tests with large-scale scientific applications, Data Elevator is as much as 4.2X faster than Cray DataWarp, the start-of-art software for burst buffer, and 4X faster than directly writing to PFS. The Data Elevator library uses HDF5's Virtual Object Layer (VOL) for intercepting parallel I/O calls that write data to PFS. The intercepted calls are redirected to the Data Elevator, which provides a handle to write the file in a faster and intermediate burst buffer system. Once the application finishes writing the data to the burst buffer, the Data Elevator job uses HDF5 to move the data to final destination in an asynchronous manner. Hence, using the Data Elevator library is currently useful for applications that call HDF5 for writing data files. Also, the Data Elevator depends on the HDF5 VOL functionality.

  16. AUTOANTIBODIES TO GLUTAMIC ACID DECARBOXYLASE AS A PATHOGENETIC MARKER OF TYPE I DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    N. V. Piven

    2011-01-01

    Full Text Available Abstract. A new method of enzyme-linked immunosorbent assay (in solid-phase ELISA format has been developed to determine concentrations of autoantibodies to glutamic acid decarboxylase, as well as an evidencebased methodology is proposed for its medical implications, as a quantitative pathogenetic predictive marker of autoimmune diagnostics in type 1 diabetes mellitus. This technique could be implied for serial production of diagnostic reagent kits, aimed for detection of autoantibodies to glutamic acid decarboxylase by means of ELISA approach. (Med. Immunol., 2011, vol. 13, N 2-3, pp 257-260

  17. The preparation and antibacterial effects of dopa-cotton/AgNPs

    International Nuclear Information System (INIS)

    Xu Hong; Shi Xue; Ma Hui; Lv Yihang; Zhang Linping; Mao Zhiping

    2011-01-01

    Silver nanoparticles (AgNPs) have been known to have powerful antibacterial activity. In this paper, in situ generation of AgNPs on the surface of dopamine modified cotton fabrics (dopa-cotton/AgNPs) in aqueous solution under room temperature is presented. X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FE-SEM) were used to analyze the surface chemical composition and the morphology of the modified cotton fabrics, respectively. The results indicated that the surface of cotton fabrics was successfully coated with polydopamine and AgNPs. The cotton fabrics with AgNPs showed durable antibacterial activity.

  18. Tratamento da síndrome parkinsoniana pelo L-dopa

    Directory of Open Access Journals (Sweden)

    Roberto Melaragno

    1971-12-01

    Full Text Available O trabalho refere o tratamento com L-Dopa de 33 pacientes internados, sendo 19 homens e 14 mulheres. Os casos foram agrupados, segundo uma classificação esquemática, em leves, moderados, intensos e severos. As idades dos pacientes, previamente operados ou não, variaram de 42 a 78 anos. O esquema de medicação constou de administração de L-Dopa na dose inicial de 500 mg associado a um inibidor da MAO. A dose de L-Dopa era elevada de 500 mg cada 3 ou 4 dias, segundo a tolerância de cada paciente. Todos os sintomas dependentes, direta ou indiretamente, da rigidez tiveram melhoras mais nítidas em relação aos tremores. Durante a administração do medicamento os teores sangüíneos de ácido úrico e uréia, mostraram tendência para se elevar; a reserva alcalina, pelo contrário, tendeu para a diminuição; o hemograma revelou muitas vezes eosinofilia por vezes intensa. Os efeitos colaterais foram catalogados em dois tipos — efeitos adrenérgicos e efeitos dopaminérgicos — correspondentes a duas fases: uma primeira, de pequena duração, na qual foram usados concomitantemente o L-Dopa e um inibidor da MAO, surgindo cefaléia hipertensão arterial paroxística, rubor facial, sudorese, tenesmo vesical e angina pectoris; numa segunda fase surgiram os efeitos colaterais ditos dopaminérgicos, proporcionais à gravidade clínica do caso, cujas manifestações principais foram hipotensão arterial, sudorese fria, arritmia cardíaca e lipotimia. As complicações clínicas gerais eram representados habitualmente por anorexia, obstipação intestinal, náuseas, vômitos, discretas alterações do estado psíquico com depressão e euforia. Dentre as complicações neurológicas foram assinalados o estado parkinsonóide, discinesias e acatisia.

  19. Gypenosides attenuate the development of L-DOPA-induced dyskinesia in 6-hydroxydopamine-lesioned rat model of Parkinson's disease.

    Science.gov (United States)

    Shin, Keon Sung; Zhao, Ting Ting; Park, Keun Hong; Park, Hyun Jin; Hwang, Bang Yeon; Lee, Chong Kil; Lee, Myung Koo

    2015-04-21

    Gypenosides (GPS) and ethanol extract of Gynostemma pentaphyllum (GP-EX) show anxiolytic effects on affective disorders in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse model of Parkinson's disease (PD). Long-term administration of L-3,4-dihydroxyphenylalanine (L-DOPA) leads to the development of severe motor side effects such as L-DOPA-induced-dyskinesia (LID) in PD. The present study investigated the effects of GPS and GP-EX on LID in a 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD. Daily administration of L-DOPA (25 mg/kg) in the 6-OHDA-lesioned rat model of PD for 22 days induced expression of LID, which was determined by the body and locomotive AIMs scores and contralateral rotational behaviors. However, co-treatments of GPS (25 and 50 mg/kg) or GP-EX (50 mg/kg) with L-DOPA significantly attenuated the development of LID without compromising the anti-parkinsonian effects of L-DOPA. In addition, the increases in ∆FosB expression and ERK1/2 phosphorylation in 6-OHDA-lesioned rats induced by L-DOPA administration were significantly reduced by co-treatment with GPS (25 and 50 mg/kg) or GP-EX (50 mg/kg). These results suggest that GPS (25 and 50 mg/kg) and GP-EX (50 mg/kg) effectively attenuate the development of LID by modulating the biomarker activities of ∆FosB expression and ERK1/2 phosphorylation in the 6-OHDA-lesioned rat model of PD. GPS and GP-EX will be useful adjuvant therapeutics for LID in PD.

  20. {sup 18}F-DOPA PET/CT in the diagnosis and localization of persistent medullary thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Archier, Aurelien; Mundler, Olivier [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Aix-Marseille University, European Center for Research in Medical Imaging, Marseille (France); Heimburger, Celine [University Hospitals of Strasbourg, Department of Biophysics and Nuclear Medicine, Strasbourg (France); Guerin, Carole; Palazzo, Fausto F.; Henry, Jean-Francois; Sebag, Frederic [Aix-Marseille University, Department of Endocrine Surgery, Conception Hospital, Marseille (France); Morange, Isabelle [Aix-Marseille University, Department of Endocrinology, Conception Hospital, Marseille (France); Schneegans, Olivier [Paul Strauss Cancer Center, Department of Nuclear Medicine, Strasbourg (France); Abdullah, Ahmad Esmaeel [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Imperiale, Alessio [University Hospitals of Strasbourg, Department of Biophysics and Nuclear Medicine, Strasbourg (France); ICube, UMR 7357 University of Strasbourg/CNRS and FMTS, Faculty of Medicine, Strasbourg (France); Taieb, David [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Aix-Marseille University, European Center for Research in Medical Imaging, Marseille (France); Institut Paoli-Calmettes, Inserm UMR1068 Marseille Cancerology Research Center, Marseille (France)

    2016-06-15

    To evaluate the performance of {sup 18}F-l-dihydroxyphenylalanine ({sup 18}F-DOPA) PET/CT in the detection of locoregional and distant medullary thyroid carcinoma (MTC) metastases and to compare imaging findings with histological data. We retrospectively evaluated 86 MTC patients with persistently high serum calcitonin levels after initial surgery who had undergone {sup 18}F-DOPA PET/CT between January 2007 and December 2014 in two referral centres. They were followed up for at least 6 months after the PET/CT assessment. The results were compared with histological data or with the findings obtained during follow-up using a complementary imaging modality. {sup 18}F-DOPA PET/CT was positive in 65 of the 86 patients, corresponding to a patient-based sensitivity of 75.6 %. Distant metastatic disease (M1) was seen in 29 patients including 11 with previously unknown metastases revealed only by PET/CT. Among the 36 patients without distant metastatic spread, 25 had nodal involvement limited to the neck, and 10 of these 25 patients underwent reoperation. The lymph node compartment-based sensitivity of {sup 18}F-DOPA PET/CT was 100 % in the two institutions but lesion-based sensitivity was only 24 %. Preoperative and postoperative median calcitonin levels were 405 pg/mL (range 128 - 1,960 pg/mL) and 259 pg/mL (range 33 - 1,516 pg/mL), respectively. None of the patients achieved normalization of serum calcitonin after reoperation. {sup 18}F-DOPA PET/CT enables early diagnosis of a significant number of patients with distant metastasis. It has a limited sensitivity in the detection of residual disease but provides high performance for regional analysis. A surgical compartment-oriented approach could be the approach of choice whatever the number of nodes revealed by {sup 18}F-DOPA PET/CT. (orig.)

  1. 18F-DOPA PET/CT in the diagnosis and localization of persistent medullary thyroid carcinoma

    International Nuclear Information System (INIS)

    Archier, Aurelien; Mundler, Olivier; Heimburger, Celine; Guerin, Carole; Palazzo, Fausto F.; Henry, Jean-Francois; Sebag, Frederic; Morange, Isabelle; Schneegans, Olivier; Abdullah, Ahmad Esmaeel; Imperiale, Alessio; Taieb, David

    2016-01-01

    To evaluate the performance of 18 F-l-dihydroxyphenylalanine ( 18 F-DOPA) PET/CT in the detection of locoregional and distant medullary thyroid carcinoma (MTC) metastases and to compare imaging findings with histological data. We retrospectively evaluated 86 MTC patients with persistently high serum calcitonin levels after initial surgery who had undergone 18 F-DOPA PET/CT between January 2007 and December 2014 in two referral centres. They were followed up for at least 6 months after the PET/CT assessment. The results were compared with histological data or with the findings obtained during follow-up using a complementary imaging modality. 18 F-DOPA PET/CT was positive in 65 of the 86 patients, corresponding to a patient-based sensitivity of 75.6 %. Distant metastatic disease (M1) was seen in 29 patients including 11 with previously unknown metastases revealed only by PET/CT. Among the 36 patients without distant metastatic spread, 25 had nodal involvement limited to the neck, and 10 of these 25 patients underwent reoperation. The lymph node compartment-based sensitivity of 18 F-DOPA PET/CT was 100 % in the two institutions but lesion-based sensitivity was only 24 %. Preoperative and postoperative median calcitonin levels were 405 pg/mL (range 128 - 1,960 pg/mL) and 259 pg/mL (range 33 - 1,516 pg/mL), respectively. None of the patients achieved normalization of serum calcitonin after reoperation. 18 F-DOPA PET/CT enables early diagnosis of a significant number of patients with distant metastasis. It has a limited sensitivity in the detection of residual disease but provides high performance for regional analysis. A surgical compartment-oriented approach could be the approach of choice whatever the number of nodes revealed by 18 F-DOPA PET/CT. (orig.)

  2. In vivo detection of cranial dopaminergic processes: studies with L-1-C-11-Dopa and C-11-labelled ADTN derivatives

    International Nuclear Information System (INIS)

    Werf, J.F.v.d.; Kuilman, T.; Molen, H.D.v.d.; Paans, A.M.J.; Wiegman, T.; Korf, J.; Vaalburg, W.

    1982-01-01

    In this article, probably the first in literature, some results are presented of in vivo studies of carbon-11-labelled dopamine agonists in cats and dogs with positron emission tomography. Recently a method for the separation of D- and L-dopa enantiomers from the DL-dopa mixture was developed. These three compounds were injected intravenously and with PET cold spots in the striatium of dog's brains could be obtained, independently of pretreatment with carbidopa. The synthesis of carbon-11-labelled ADTN derivatives and their uses is discussed. (Auth.)

  3. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Loginovskiy, V.I.; Medinger, N.V.; Rasskazov, V.A.; Solonitsyn, V.A.

    1983-01-01

    An elevator is proposed which includes a body, spring loaded cams and a shut-off ring. To increase the reliability of the elevator by eliminating the possibility of spontaneous shifting of the shut-off ring, the latter is equipped with handles hinged to it and is made with evolvent grooves. The cams are equipped with rollers installed in the evolvent grooves of the shut off ring, where the body is made with grooves for the handles.

  4. Monocular Elevation Deficiency - Double Elevator Palsy

    Science.gov (United States)

    ... Español Condiciones Chinese Conditions Monocular Elevation Deficiency/ Double Elevator Palsy En Español Read in Chinese What is monocular elevation deficiency (Double Elevator Palsy)? Monocular Elevation Deficiency, also known by the ...

  5. Dosage-dependent non-linear effect of L-dopa on human motor cortex plasticity.

    Science.gov (United States)

    Monte-Silva, Katia; Liebetanz, David; Grundey, Jessica; Paulus, Walter; Nitsche, Michael A

    2010-09-15

    The neuromodulator dopamine affects learning and memory formation and their likely physiological correlates, long-term depression and potentiation, in animals and humans. It is known from animal experiments that dopamine exerts a dosage-dependent, inverted U-shaped effect on these functions. However, this has not been explored in humans so far. In order to reveal a non-linear dose-dependent effect of dopamine on cortical plasticity in humans, we explored the impact of 25, 100 and 200 mg of L-dopa on transcranial direct current (tDCS)-induced plasticity in twelve healthy human subjects. The primary motor cortex served as a model system, and plasticity was monitored by motor evoked potential amplitudes elicited by transcranial magnetic stimulation. As compared to placebo medication, low and high dosages of L-dopa abolished facilitatory as well as inhibitory plasticity, whereas the medium dosage prolonged inhibitory plasticity, and turned facilitatory plasticity into inhibition. Thus the results show clear non-linear, dosage-dependent effects of dopamine on both facilitatory and inhibitory plasticity, and support the assumption of the importance of a specific dosage of dopamine optimally suited to improve plasticity. This might be important for the therapeutic application of dopaminergic agents, especially for rehabilitative purposes, and explain some opposing results in former studies.

  6. DAT1 polymorphism determines L-DOPA effects on learning about others' prosociality.

    Directory of Open Access Journals (Sweden)

    Christoph Eisenegger

    Full Text Available Despite that a wealth of evidence links striatal dopamine to individualś reward learning performance in non-social environments, the neurochemical underpinnings of such learning during social interaction are unknown. Here, we show that the administration of 300 mg of the dopamine precursor L-DOPA to 200 healthy male subjects influences learning about a partners' prosocial preferences in a novel social interaction task, which is akin to a repeated trust game. We found learning to be modulated by a well-established genetic marker of striatal dopamine levels, the 40-bp variable number tandem repeats polymorphism of the dopamine transporter (DAT1 polymorphism. In particular, we found that L-DOPA improves learning in 10/10R genoype subjects, who are assumed to have lower endogenous striatal dopamine levels and impairs learning in 9/10R genotype subjects, who are assumed to have higher endogenous dopamine levels. These findings provide first evidence for a critical role of dopamine in learning whether an interaction partner has a prosocial or a selfish personality. The applied pharmacogenetic approach may open doors to new ways of studying psychiatric disorders such as psychosis, which is characterized by distorted perceptions of others' prosocial attitudes.

  7. Clinical Investigation of the Dopaminergic System with PET and FLUORINE-18-FLUORO-L-DOPA.

    Science.gov (United States)

    Oakes, Terrence Rayford

    1995-01-01

    Positron Emission Tomography (PET) is a tool that provides quantitative physiological information. It is valuable both in a clinical environment, where information is sought for an individual, and in a research environment, to answer more fundamental questions about physiology and disease states. PET is particularly attractive compared to other nuclear medicine imaging techniques in cases where the anatomical regions of interest are small or when true metabolic rate constants are required. One example with both of these requirements is the investigation of Parkinson's Disease, which is characterized as a presynaptic motor function deficit affecting the striatum. As dopaminergic neurons die, the ability of the striatum to affect motor function decreases. The extent of functional neuronal damage in the small sub-structures may be ascertained by measuring the ability of the caudate and putamen to trap and store dopamine, a neurotransmitter. PET is able to utilize a tracer of dopamine activity, ^ {18}F- scL-DOPA, to quantitate the viability of the striatum. This thesis work deals with implementing and optimizing the many different elements that compose a PET study of the dopaminergic system, including: radioisotope production; conversion of aqueous ^{18}F ^-into [^ {18}F]-F2; synthesis of ^{18}F- scL -DOPA; details of the PET scan itself; measurements to estimate the radiation dosimetry; accurate measurement of a plasma input function; and the quantitation of dopaminergic activity in normal human subjects as well as in Parkinson's Disease patients.

  8. L-tyrosine and L-DOPA as hormone-like regulators of melanocytes functions

    Science.gov (United States)

    Slominski, Andrzej; Zmijewski, Michal; Pawelek, John

    2011-01-01

    Summary Evidence reveals that L-tyrosine and L-DOPA, besides serving as substrates and intermediates of melanogenesis, are also bioregulatory agents acting not only as inducers and positive regulators of melanogenesis but also as regulators of other cellular functions. These can be mediated through action on specific receptors or through non-receptor mediated mechanisms. The substrate induced (L-tyrosine and/or L-DOPA) melanogenic pathway would autoregulate itself as well as it would regulate the melanocyte functions through activity of its structural or regulatory proteins and through intermediates of melanogenesis and melanin itself. Dissection of regulatory and autoregulatory elements of this process may elucidate how substrate induced autoregulatory pathways have evolved from prokaryotic or simple eukaryotic organisms to complex systems in vertebrates. This could substantiate older theory proposing that receptors for amino-acid derived hormones arose from the receptors for those amino acids, and that nuclear receptors evolved from primitive intracellular receptors binding nutritional factors or metabolic intermediates. PMID:21834848

  9. Pilot study of atomoxetine in patients with Parkinson's disease and dopa-unresponsive Freezing of Gait.

    Science.gov (United States)

    Revuelta, Gonzalo J; Embry, Aaron; Elm, Jordan J; Gregory, Chris; Delambo, Amy; Kautz, Steve; Hinson, Vanessa K

    2015-01-01

    Freezing of gait (FoG) is a common and debilitating condition in Parkinson's disease (PD) associated with executive dysfunction. A subtype of FoG does not respond to dopaminergic therapy and may be related to noradrenergic deficiency. This pilot study explores the effects of atomoxetine on gait in PD patients with dopa-unresponsive FoG using a novel paradigm for objective gait assessment. Ten patients with PD and dopa-unresponsive FoG were enrolled in this eight-week open label pilot study. Assessments included an exploratory gait analysis protocol that quantified spatiotemporal parameters during straight-away walking and turning, while performing a dual task. Clinical, and subjective assessments of gait, quality of life, and safety were also administered. The primary outcome was a validated subjective assessment for FoG (FOG-Q). Atomoxetine was well tolerated, however, no significant change was observed in the primary outcome. The gait analysis protocol correlated well with clinical scales, but not with subjective assessments. DBS patients were more likely to increase gait velocity (p = 0.033), and improved in other clinical assessments. Objective gait analysis protocols assessing gait while dual tasking are feasible and useful for this patient population, and may be superior correlates of FoG severity than subjective measures. These findings can inform future trials in this population.

  10. The Degradation of 14C-Glutamic Acid by L-Glutamic Acid Decarboxylase.

    Science.gov (United States)

    Dougherty, Charles M; Dayan, Jean

    1982-01-01

    Describes procedures and semi-micro reaction apparatus (carbon dioxide trap) to demonstrate how a particular enzyme (L-Glutamic acid decarboxylase) may be used to determine the site or sites of labeling in its substrate (carbon-14 labeled glutamic acid). Includes calculations, solutions, and reagents used. (Author/SK)

  11. DPD epitope-specific glutamic acid decarboxylase GAD)65 autoantibodies in children with Type 1 diabetes

    Science.gov (United States)

    To study whether DPD epitope-specific glutamate decarboxylase autoantibodies are found more frequently in children with milder forms of Type 1 diabetes. We prospectively evaluated 75 children with new-onset autoimmune Type 1 diabetes, in whom we collected demographic, anthropometric and clinical dat...

  12. Sensing and adaptation to low pH mediated by inducible amino acid decarboxylases in Salmonella.

    Science.gov (United States)

    Viala, Julie P M; Méresse, Stéphane; Pocachard, Bérengère; Guilhon, Aude-Agnès; Aussel, Laurent; Barras, Frédéric

    2011-01-01

    During the course of infection, Salmonella enterica serovar Typhimurium must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments. Three low pH inducible amino acid decarboxylases were annotated in the genome of S. Typhimurium, AdiA, CadA and SpeF, which are specific for arginine, lysine and ornithine, respectively. In this study, we characterized and compared the contributions of those enzymes in response to acidic challenges. Individual mutants as well as a strain deleted for the three genes were tested for their ability (i) to survive an extreme acid shock, (ii) to grow at mild acidic pH and (iii) to infect the mouse animal model. We showed that the lysine decarboxylase CadA had the broadest range of activity since it both had the capacity to promote survival at pH 2.3 and growth at pH 4.5. The arginine decarboxylase AdiA was the most performant in protecting S. Typhimurium from a shock at pH 2.3 and the ornithine decarboxylase SpeF conferred the best growth advantage under anaerobiosis conditions at pH 4.5. We developed a GFP-based gene reporter to monitor the pH of the environment as perceived by S. Typhimurium. Results showed that activities of the lysine and ornithine decarboxylases at mild acidic pH did modify the local surrounding of S. Typhimurium both in culture medium and in macrophages. Finally, we tested the contribution of decarboxylases to virulence and found that these enzymes were dispensable for S. Typhimurium virulence during systemic infection. In the light of this result, we examined the genomes of Salmonella spp. normally responsible of systemic infection and observed that the genes encoding these enzymes were not well conserved, supporting the idea that these enzymes may be not required during systemic infection.

  13. Sensing and adaptation to low pH mediated by inducible amino acid decarboxylases in Salmonella.

    Directory of Open Access Journals (Sweden)

    Julie P M Viala

    Full Text Available During the course of infection, Salmonella enterica serovar Typhimurium must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments. Three low pH inducible amino acid decarboxylases were annotated in the genome of S. Typhimurium, AdiA, CadA and SpeF, which are specific for arginine, lysine and ornithine, respectively. In this study, we characterized and compared the contributions of those enzymes in response to acidic challenges. Individual mutants as well as a strain deleted for the three genes were tested for their ability (i to survive an extreme acid shock, (ii to grow at mild acidic pH and (iii to infect the mouse animal model. We showed that the lysine decarboxylase CadA had the broadest range of activity since it both had the capacity to promote survival at pH 2.3 and growth at pH 4.5. The arginine decarboxylase AdiA was the most performant in protecting S. Typhimurium from a shock at pH 2.3 and the ornithine decarboxylase SpeF conferred the best growth advantage under anaerobiosis conditions at pH 4.5. We developed a GFP-based gene reporter to monitor the pH of the environment as perceived by S. Typhimurium. Results showed that activities of the lysine and ornithine decarboxylases at mild acidic pH did modify the local surrounding of S. Typhimurium both in culture medium and in macrophages. Finally, we tested the contribution of decarboxylases to virulence and found that these enzymes were dispensable for S. Typhimurium virulence during systemic infection. In the light of this result, we examined the genomes of Salmonella spp. normally responsible of systemic infection and observed that the genes encoding these enzymes were not well conserved, supporting the idea that these enzymes may be not required during systemic infection.

  14. Disease-specific monoclonal antibodies targeting glutamate decarboxylase impair GABAergic neurotransmission and affect motor learning and behavioral functions

    Directory of Open Access Journals (Sweden)

    Mario U Manto

    2015-03-01

    Full Text Available Autoantibodies to the smaller isoform of glutamate decarboxylase can be found in patients with type 1 diabetes and a number of neurological disorders, including stiff-person syndrome, cerebellar ataxia and limbic encephalitis. The detection of disease-specific autoantibody epitopes led to the hypothesis that distinct glutamate decarboxylase autoantibodies may elicit specific neurological phenotypes. We explored the in vitro/in vivo effects of well-characterized monoclonal glutamate decarboxylase antibodies. We found that glutamate decarboxylase autoantibodies present in patients with stiff person syndrome (n = 7 and cerebellar ataxia (n = 15 recognized an epitope distinct from that recognized by glutamate decarboxylase autoantibodies present in patients with type 1 diabetes mellitus (n = 10 or limbic encephalitis (n = 4. We demonstrated that the administration of a monoclonal glutamate decarboxylase antibody representing this epitope specificity (1 disrupted in vitro the association of glutamate decarboxylase with γ-Aminobutyric acid containing synaptic vesicles, (2 depressed the inhibitory synaptic transmission in cerebellar slices with a gradual time course and a lasting suppressive effect, (3 significantly decreased conditioned eyelid responses evoked in mice, with no modification of learning curves in the classical eyeblink-conditioning task, (4 markedly impaired the facilitatory effect exerted by the premotor cortex over the motor cortex in a paired-pulse stimulation paradigm, and (5 induced decreased exploratory behavior and impaired locomotor function in rats. These findings support the specific targeting of glutamate decarboxylase by its autoantibodies in the pathogenesis of stiff-person syndrome and cerebellar ataxia. Therapies of these disorders based on selective removal of such glutamate decarboxylase antibodies could be envisioned.

  15. A Rare Case of Cerebellar Ataxia Due to Voltage-Gated Calcium Channel and Glutamic Acid Decarboxylase Autoantibodies.

    Science.gov (United States)

    Annunziata, Giuseppe; Lobo, Pamela; Carbuccia, Cristian

    2017-11-27

    BACKGROUND Autoimmune cerebellar ataxia can be paraneoplastic in nature or can occasionally present without evidence of an ongoing malignancy. The detection of specific autoantibodies has been statistically linked to different etiologies. CASE REPORT A 55-year-old African-American woman with hypertension and a past history of morbid obesity and uncontrolled diabetes status post gastric bypass four years prior to the visit (with significantly improved body mass index and hemoglobin A1c controlled at the time of the clinical encounter) presented to the office complaining of gradual onset of unsteadiness and recurrent falls for the past three years, as well as difficulties coordinating routine daily activities. The neurologic exam showed moderate dysarthria and ataxic gait with bilateral dysmetria and positive Romberg test. Routine laboratory test results were only remarkable for a mild elevation of erythrocyte sedimentation rate, and most laboratory and imaging tests for common causes of ataxia failed to demonstrate an etiology. Upon further workup, evidence of anti-voltage-gated calcium channel and anti-glutamic acid decarboxylase antibody was demonstrated. She was then treated with intravenous immunoglobulins with remarkable clinical improvement. CONCLUSIONS We present a case of antibody-mediated ataxia not associated with malignancy. While ataxia is rarely related to autoantibodies, in such cases it is critical to understand the etiology of this disabling condition in order to treat it correctly. Clinicians should be aware of the possible association with specific autoantibodies and the necessity to rule out an occult malignancy in such cases.

  16. Variation of L-DOPA in the leaf and flower tissues of seven faba bean accessions with different flower colors

    Science.gov (United States)

    Faba bean (Vicia faba L.) has been selected to adapt to a wide range of environments worldwide and is grown for different end-uses such as food, feed, forage and green manure. Particularly noteworthy in faba bean is the medicinally important component L-3,4-dihydroxy phenylalanine (L-DOPA), the majo...

  17. Role of Serotonin Neurons in L-DOPA- and Graft-Induced Dyskinesia in a Rat Model of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Eunju Shin

    2012-01-01

    Full Text Available L-DOPA, the most effective drug to treat motor symptoms of Parkinson's disease, causes abnormal involuntary movements, limiting its use in advanced stages of the disease. An increasing body of evidence points to the serotonin system as a key player in the appearance of L-DOPA-induced dyskinesia (LID. In fact, exogenously administered L-DOPA can be taken up by serotonin neurons, converted to dopamine and released as a false transmitter, contributing to pulsatile stimulation of striatal dopamine receptors. Accordingly, destruction of serotonin fibers or silencing serotonin neurons by serotonin agonists could counteract LID in animal models. Recent clinical work has also shown that serotonin neurons are present in the caudate/putamen of patients grafted with embryonic ventral mesencephalic cells, producing intense serotonin hyperinnervation. These patients experience graft-induced dyskinesia (GID, a type of dyskinesia phenotypically similar to the one induced by L-DOPA but independent from its administration. Interestingly, the 5-HT1A receptor agonist buspirone has been shown to suppress GID in these patients, suggesting that serotonin neurons might be involved in the etiology of GID as for LID. In this paper we will discuss the experimental and clinical evidence supporting the involvement of the serotonin system in both LID and GID.

  18. Development of a microchip-pulsed electrochemical method for rapid determination of L-DOPA and tyrosine in Mucuna pruriens.

    Science.gov (United States)

    Li, Xinchun; Chen, Zuanguang; Yang, Fan; Pan, Jianbin; Li, Yinbao

    2013-05-01

    L-3,4-dihydroxyphenylalanine (L-DOPA) is a well-recognized therapeutic compound to Parkinson's disease. Tyrosine is a precursor for the biosynthesis of L-DOPA, both of which are widely found in traditional medicinal material, Mucuna pruriens. In this paper, we described a validated novel analytical method based on microchip capillary electrophoresis with pulsed electrochemical detection for the simultaneous measurement of L-DOPA and tyrosine in M. pruriens. This protocol adopted end-channel amperometric detection using platinum disk electrode on a homemade glass/polydimethylsiloxane electrophoresis microchip. The background buffer consisted of 10 mM borate (pH 9.5) and 0.02 mM cetyltrimethylammonium bromide, which can produce an effective resolution for the two analytes. In the optimal condition, sufficient electrophoretic separation and sensitive detection for the target analytes can be realized within 60 s. Both tyrosine and L-DOPA yielded linear response in the concentration range of 5.0-400 μM (R(2) > 0.99), and the LOD were 0.79 and 1.1 μM, respectively. The accuracy and precision of the established method were favorable. The present method shows several merits such as facile apparatus, high speed, low cost and minimal pollution, and provides a means for the pharmacologically active ingredients assay in M. pruriens. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. EVALUATING THE ACCUMULATION TREND OF L-DOPA IN DARK-GERMINATED SEEDS AND SUSPENSION CULTURES OF Phaseolus vulgaris L. BY AN EFFICIENT UV-SPECTROPHOTOMETRIC METHOD

    Directory of Open Access Journals (Sweden)

    Samira Rahmani-Nezhad

    Full Text Available Seed germination and plant cell cultures provide an alternative mean for producing secondary metabolites. The present study is an attempt to evaluate the effect of seed dark germination and some elicitors and precursors on the production of L-DOPA in Phaseolus vulgaris L. Callus cultured on Murashige and Skoog medium supplemented with various concentrations of different plant growth regulators. L-DOPA produced was quantified by UV-spectrophotometric method. In this study, a user-friendly, quick, and economical UV-spectrophotometric method was described to determine L-DOPA content in extracts from 33 biotypes of Phaseolus vulgaris L. The method is based on the nitrosation of L-DOPA to form a yellow solution and then formation of a red solution by adding base which is measurable at 470 nm. According to our statistical studies, this method showed high efficiency and selectivity for quantitative determination of L-DOPA in herbal extracts from dried plant seeds, dark-germinated seeds and callus cultures. L-DOPA content in dark-germinated seeds and suspension cultures increased significantly to approximately several-fold compared to the control. The implication from this study is that elicitor treatment and precursor feeding of Phaseolus vulgaris L. can significantly improve the parkinson’s relevant L-DOPA content.

  20. 18F-DOPA PET and enhanced CT imaging for congenital hyperinsulinism: initial UK experience from a technologist's perspective.

    Science.gov (United States)

    Meintjes, Marguerite; Endozo, Raymond; Dickson, John; Erlandsson, Kjel; Hussain, Khalid; Townsend, Caroline; Menezes, Leon; Bomanji, Jamshed

    2013-06-01

    Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycaemia in infants and children. Histologically, there are two subgroups, diffuse and focal. The aim of this study was to evaluate the accuracy of (18)F-fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET/computed tomography (CT) and contrast-enhanced CT in distinguishing between focal and diffuse lesions in infants with CHI who are unresponsive to medical therapy. In addition, this paper describes the detailed protocol used for imaging and analysis of (18)F-DOPA PET/CT images in our clinical practice. Twenty-two (18)F-DOPA PET/CT and contrast-enhanced CT imaging studies were carried out on 18 consecutive patients (nine boys and nine girls) with CHI (median age, 2 years and 1 month; range, 1-84 months) who had positive dominant ABCC8 mutation genetic results or negative ABCC8/t results but did not respond to first-line medical therapy with high-dose diazoxide. (18)F-DOPA was produced by the cyclotron unit of Woolfson Molecular Imaging Centre, Manchester, and transported to our centre in central London after synthesis and implementation of quality control measures. (18)F-DOPA was administered intravenously at a dose of 4 MBq/kg, and iodine contrast medium was injected intravenously at a dose of 1.5 ml/kg. Single bed position PET/CT images of the pancreas were acquired under light sedation with oral chloral hydrate. Four PET dynamic data acquisition scans were taken 20, 40, 50 and 60 min after injection for a duration of 10 min each. The results were assessed by visual interpretation and quantitative measurements of standardized uptake values (SUVs) in the head, body, and tail of the pancreas. Of the 18 patients, 13 showed diffuse and five showed focal (18)F-DOPA PET pancreatic uptake. Three regions of interest were drawn over the head, body and tail of the pancreas to calculate the SUV(max). Using the formula - highest SUV(max)/next highest SUV(max) - a ratio was calculated. Five patients had

  1. Elevator wheel

    Energy Technology Data Exchange (ETDEWEB)

    Zhornik, V.I.; Cherkov, Ye.M.; Simonov, A.A.

    1982-01-01

    An elevator wheel is suggested for unloading a sunken product from a bath of a heavy-average separator including discs of a bucket with inner walls, and covering sheets hinged to the buckets. In order to improve the degree of dehydration of the removed product, the inner wall of each bucket is made of sheets installed in steps with gaps of one in relation to the other.

  2. Sequential analysis: manganese, catecholamines, and L-dopa induced dyskinesia. [Cat's brain

    Energy Technology Data Exchange (ETDEWEB)

    Papavasiliou, P S; Miller, S T; Cotzias, G C; Kraner, H W; Hsieh, R S

    1975-01-01

    The paper specifies methodology for the sequential determination of manganese and catecholamines in selfsame brain samples and shows correlations between them. Small samples were obtained from five regions of brain of cats that had received either saline or levodopa. The doses of levodopa were varied so that although all animals reacted, some developed dyskinesia while others did not. Each sample was first analyzed nondestructively for manganese and then destructively for dopa and dopamine; thus errors inherent in analyzing separate samples, due to the structural heterogeneity of the brain, were avoided. Statistically significant correlations were found (1) between levodopa-induced dyskinesia and the concentrations of dopamine and manganese in some of the regions analysed, and (2) between the concentrations of dopamine and of manganese in the caudates of the cats receiving the highest doses of levodopa. (auth)

  3. Synthesis of racemic [3-11C]phenylalanine and [3-11C] DOPA

    International Nuclear Information System (INIS)

    Halldin, C.; Laangstroem, B.

    1984-01-01

    The synthesis of racemic [3- 11 C]phenylalanine and [3- 11 C]DOPA is reported. The [ 11 C]benzaldehyde and [ 11 C]veratraldehyde prepared in a two-step reaction from the corresponding [ 11 C]acid salt and [ 11 C]alcohol, by means of selective oxidation with tetrabutylammonium hydrogen chromate, were reacted with 2-phenyl-5-oxazolone or 2-(4-chloro)phenyl-5-oxazolone in the presence of a tertiary amine to give the corresponding [α- 11 C]-4-arylene-2-aryl-5-oxazolones. Ring opening of these olefins, hydrogenation, and removal of protecting groups was carried out in one step using hydroiodic cid/phosphorus, with the production of the racemic [3- 11 C]amino acids in 8-30% radiochemical yield (starting with 11 CO 2 ) within 52-60 min (including LC separation). (author)

  4. Contributions of positron emission tomography to elucidating the pathogenesis of idiopathic Parkinsonism and dopa responsive dystonia

    International Nuclear Information System (INIS)

    Calne, D.B.; Fuente-Fernandez, R. de la; Kishore, A.

    1996-01-01

    The metabolic mapping of brain activity. using PET, confirms the conventional wisdom of neurophysiology. In studies of pathophysiology, PET has yielded evidence that has generated new hypotheses. Progression of the lesion detectable with fluorodopa, in human subjects exposed to MPTP, raises the possibility of a transient environmental event being a cause of progressive neurodegeneration. Studies with fluorodopa in Idiopathic Parkinsonism indicate that the rate of loss of neurons is faster initially, and then tends to approach the normal age-related decline. In dopa responsive dystonia, the finding of normal fluorodopa PET led to the prediction that the lesion would be functional rather than anatomical; this has been confirmed by the identification of a defect in dopamine synthesis in this disorder. Finally, new PET ligands show promise for future studies designed to unravel the pathogenesis of diseases involving the basal ganglia. (author)

  5. Accuracy of F-DOPA PET and perfusion-MRI for differentiating radionecrotic from progressive brain metastases after radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Cicone, Francesco; Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; ' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Minniti, Giuseppe; Scaringi, Claudia; Maurizi Enrici, Riccardo [' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Romano, Andrea; Tavanti, Francesca; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.)

    2015-01-15

    We assessed the performance of 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET for differentiating radionecrosis (RN) from tumour progression (PD) in a population of patients with brain metastases, treated with stereotactic radiosurgery. The accuracy of F-DOPA PET was compared with that of perfusion-weighted magnetic resonance (perfusion-MR). In 42 patients with a total of 50 brain metastases from various primaries F-DOPA PET/CT was performed because of suspected radiological progression at the site of previously irradiated brain metastasis. Several semiquantitative PET parameters were recorded, and their diagnostic accuracy was compared by receiver operating characteristic curve analyses. The diagnosis was established by either surgery or follow-up. A comparison was made between F-DOPA PET and perfusion-MR sequences acquired no more than 3 weeks apart. Definitive outcome was available in 46 of the 50 lesions (20 PD, 26 RN). Of the 46 lesions, 11 were surgically excised while in the remaining 35 lesions the diagnosis was established by radiological and clinical criteria. The best diagnostic performance was obtained using the semiquantitative PET parameter maximum lesion to maximum background uptake ratio (SUVL{sub max}/Bkgr{sub max}). With a cut-off value of 1.59, a sensitivity of 90 % and a specificity of 92.3 % were achieved in differentiating RN from PD lesions (accuracy 91.3 %). Relative cerebral blood volume (rCBV) derived from perfusion-MR was available for comparison in 37 of the 46 metastases. Overall accuracy of rCBV was lower than that of all semiquantitative PET parameters under study. The best differentiating rCBV cut-off value was 2.14; this yielded a sensitivity of 86.7 % and a specificity of 68.2 % (accuracy 75.6 %). F-DOPA PET is a highly accurate tool for differentiating RN from PD brain metastases after stereotactic radiosurgery. In this specific setting, F-DOPA PET seems to perform better than perfusion-MR. (orig.)

  6. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, A.S.; Peshkov, L.P.; Rozin, M.M.; Shestov, A.G.

    1983-01-01

    An elevator is proposed which includes a body, a flap, a lock with a catch and a spring-loaded shut-off clamp in the form of upper and lower horizontal levers which are connected by a handle and an axle and one end of which is made in the form of an eccentric cam. The size of the eccentricity of the cam of the levers is increased toward the handle of the clamp in order to increase the operational reliability and to extend the service life.

  7. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Rastorguyev, M.A.; Maloyarovslavtesv, D.A.; Prokopov, O.I.; Tukayev, Sh.V.; Zanilov, I.F.

    1983-01-01

    An elevator is proposed which includes a body with a turning collar locking device and a rod with longitudinal grooves, which are flexibly linked with jaws positioned in grooves in the body. To increase safety through ensuring automatic locking of the jaws in the closed position, the locking device is made in the form of head on wedges, spring loaded relative to the collar and made with cams and positioned with the capability of interacting with the grooves of the rod and through the cams with the collar.

  8. EFFECT OF AERO-/ANAEROBIOSIS ON DECARBOXYLASE ACTIVITY OF SELECTED LACTIC ACID BACTERIA

    Directory of Open Access Journals (Sweden)

    Stanislav Kráčmar

    2010-05-01

    Full Text Available Biogenic amines are undesirable compounds produced in foods mainly through bacterial decarboxylase activity. The aim of this study was to investigate some environmental conditions (particularly aero/anaerobiosis, sodium chloride concentration (0–2% w/w, and amount of lactose (0–1% w/w on the activity of tyrosine decarboxylase enzymes of selected six technological important Lactococcus lactis strains. The levels of parameters tested were chosen according to real situation in fermented dairy products technology (especially cheese-making. Tyramine was determined by the ion-exchange chromatography with post-column ninhydrine derivatization and spectrophotometric detection. Tyrosine decarboxylation occurred during the active growth phase. Under the model conditions used, oxygen availability had influence on tyramine production, anaerobiosis seemed to favour the enzyme activity because all L. lactis strains produced higher tyramine amount. doi:10.5219/43

  9. Glutamate decarboxylase activity in rat brain during experimental epileptic seizures induced by pilocarpine

    Energy Technology Data Exchange (ETDEWEB)

    Netopilova, M; Drsata, J [Department of Biochemical Sciences, Faculty of Pharmacy, Charles University, 50005 Hradec Kralove (Czech Republic); Haugvicova, R; Kubova, H; Mares, P [Institute of Physiology, Czech Academy of Sciences, 14220 Prague (Czech Republic)

    1998-07-01

    Glutamate decarboxylase (GAD) activity was studied rat brain parts in a pilocarpine model of epileptic seizures. An increased enzyme activity was found in hippocampus a cerebellum during the acute phase of seizures, while the cortex and cerebellum showed increased GAD activity in the chronic phase of the process. Systematic administration of pilocarpine to rats induces status epilepticus. The aim of this research was to find out if seizures induced by pilocarpine are connected changes in glutamate decarboxylase activity, the enzyme that catalyzes synthesis of inhibitory neurotransmitter GABA. GAD was assayed by means of radiometric method using {sup 14}C-carboxyl-labelled glutamate and measurement of {sup 14}CO{sub 2} radioactivity. Obtained results suggest that pilocarpine seizures are connected with changes of GAD activity in individual parts of rat brain. (authors)

  10. Glutamate decarboxylase activity in rat brain during experimental epileptic seizures induced by pilocarpine

    International Nuclear Information System (INIS)

    Netopilova, M.; Drsata, J.; Haugvicova, R.; Kubova, H.; Mares, P.

    1998-01-01

    Glutamate decarboxylase (GAD) activity was studied rat brain parts in a pilocarpine model of epileptic seizures. An increased enzyme activity was found in hippocampus a cerebellum during the acute phase of seizures, while the cortex and cerebellum showed increased GAD activity in the chronic phase of the process. Systematic administration of pilocarpine to rats induces status epilepticus. The aim of this research was to find out if seizures induced by pilocarpine are connected changes in glutamate decarboxylase activity, the enzyme that catalyzes synthesis of inhibitory neurotransmitter GABA. GAD was assayed by means of radiometric method using 14 C-carboxyl-labelled glutamate and measurement of 14 CO 2 radioactivity. Obtained results suggest that pilocarpine seizures are connected with changes of GAD activity in individual parts of rat brain. (authors)

  11. L-DOPA Preloading Increases the Uptake of Borophenylalanine in C6 Glioma Rat Model: A New Strategy to Improve BNCT Efficacy

    International Nuclear Information System (INIS)

    Capuani, Silvia; Gili, Tommaso; Bozzali, Marco; Russo, Salvatore; Porcari, Paola; Cametti, Cesare; D'Amore, Emanuela; Colasanti, Marco; Venturini, Giorgio; Maraviglia, Bruno; Lazzarino, Giuseppe; Pastore, Francesco S.

    2008-01-01

    Purpose: Boron neutron capture therapy (BNCT) is a radiotherapeutic modality based on 10 B(n,α) 7 Li reaction, for the treatment of malignant gliomas. One of the main limitations for BNCT effectiveness is the insufficient intake of 10 B nuclei in the tumor cells. This work was aimed at investigating the use of L-DOPA as a putative enhancer for 10 B-drug 4-dihydroxy-borylphenylalanine (BPA) uptake in the C6-glioma model. The investigation was first performed in vitro and then extended to the animal model. Methods and Materials: BPA accumulation in C6-glioma cells was assessed using radiowave dielectric spectroscopy, with and without L-DOPA preloading. Two L-DOPA incubation times (2 and 4 hours) were investigated, and the corresponding effects on BPA accumulation were quantified. C6-glioma cells were also implanted in the brain of 32 rats, and tumor growth was monitored by magnetic resonance imaging. Rats were assigned to two experimental branches: (1) BPA administration; (2) BPA administration after pretreatment with L-DOPA. All animals were sacrificed, and assessments of BPA concentrations in tumor tissue, normal brain, and blood samples were performed using high-performance liquid chromatography. Results: L-DOPA preloading induced a massive increase of BPA concentration in C6-glioma cells only after a 4-hour incubation. In the animal model, L-DOPA pretreatment produced a significantly higher accumulation of BPA in tumor tissue but not in normal brain and blood samples. Conclusions: This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT. L-DOPA preloading effect is discussed in terms of membrane transport mechanisms

  12. Effect of l-DOPA on local field potential relationship between the pedunculopontine nucleus and primary motor cortex in a rat model of Parkinson's disease.

    Science.gov (United States)

    Geng, Xiwen; Wang, Xuenan; Xie, Jinlu; Zhang, Xiao; Wang, Xiusong; Hou, Yabing; Lei, Chengdong; Li, Min; Han, Hongyu; Yao, Xiaomeng; Zhang, Qun; Wang, Min

    2016-12-15

    Levodopa (l-DOPA) has been proved to reverse the pathologic neuron activities in many brain regions related to Parkinson's disease (PD). But little is known about the effect of l-DOPA on the altered electrophysiological coherent activities between pedunculopontine nucleus (PPN) and motor cortex. To investigate this, local field potentials (LFPs) of PPN and primary motor cortex (M1) were recorded simultaneously in control, 6-hydroxydopamine lesioned and lesioned rats with l-DOPA chronic treatment. The results revealed that in resting state, chronic l-DOPA treatment could correct the suppressed power of LFPs in PPN and M1 in low-frequency band (1-7Hz) and the enhanced power in high-frequency band (7-70Hz in PPN and 12-70Hz in M1) of lesioned rats. In locomotor state, l-DOPA treatment could correct the alterations in most of frequency bands except the δ band in PPN and α band in M1. Moreover, l-DOPA could also reverse the altered coherent relationships caused by dopamine depletion in resting state between PPN and M1 in β band. And in locomotor state, l-DOPA had therapeutic effect on the alterations in δ and β bands but not in the α band. These findings provide evidence that l-DOPA can reverse the altered LFP activities in PPN and M1 and their relationships in a rat model of PD, which contributes to better understanding the electrophysiological mechanisms of the pathophysiology and therapy of PD. Copyright © 2016. Published by Elsevier B.V.

  13. Neurological disorders associated with glutamic acid decarboxylase antibodies: a Brazilian series

    Directory of Open Access Journals (Sweden)

    Maurício Fernandes

    2012-09-01

    Full Text Available Neurological disorders associated with glutamic acid decarboxylase (GAD antibodies are rare pleomorphic diseases of uncertain cause, of which stiff-person syndrome (SPS is the best-known. Here, we described nine consecutive cases of neurological disorders associated with anti-GAD, including nine patients with SPS and three cases with cerebellar ataxia. Additionally, four had hypothyroidism, three epilepsy, two diabetes mellitus and two axial myoclonus.

  14. AUTOANTIBODIES TO GLUTAMIC ACID DECARBOXYLASE AS A PATHOGENETIC MARKER OF TYPE I DIABETES MELLITUS

    OpenAIRE

    N. V. Piven; L. N. Lukhverchyk; A. I. Burakovsky; N. V. Polegenkaya; M. V. Karpovich

    2011-01-01

    Abstract. A new method of enzyme-linked immunosorbent assay (in solid-phase ELISA format) has been developed to determine concentrations of autoantibodies to glutamic acid decarboxylase, as well as an evidencebased methodology is proposed for its medical implications, as a quantitative pathogenetic predictive marker of autoimmune diagnostics in type 1 diabetes mellitus. This technique could be implied for serial production of diagnostic reagent kits, aimed for detection of autoantibodies to g...

  15. Cognitive decline in a patient with anti-glutamic acid decarboxylase autoimmunity; case report

    OpenAIRE

    Takagi, Masahito; Yamasaki, Hiroshi; Endo, Keiko; Yamada, Tetsuya; Kaneko, Keizo; Oka, Yoshitomo; Mori, Etsuro

    2011-01-01

    Abstract Background Glutamic acid decarboxylase (GAD) is the rate-limiting enzyme for producing γ-aminobutyric acid, and it has been suggested that antibodies against GAD play a role in neurological conditions and type 1 diabetes. However, it is not known whether dementia appears as the sole neurological manifestation associated with anti-GAD antibodies in the central nervous system. Case presentation We describe the clinical, neuropsychological, and neuroradiological findings of a 73-year-ol...

  16. Limbic encephalitis with antibodies to glutamic acid decarboxylase presenting with brainstem symptoms

    Directory of Open Access Journals (Sweden)

    Faruk Incecik

    2015-01-01

    Full Text Available Limbic encephalitis (LE is a neurological syndrome that may present in association with cancer, infection, or as an isolate clinical condition often accompanying autoimmune disorders. LE associated with glutamic acid decarboxylase antibodies (anti-GAD is rare in children. Here, we characterized the clinical and laboratory features of a patient presenting with brainstem involvement with non-paraneoplastic LE associated with anti-GAD antibodies. In our patient, after plasma exchange, we determined a dramatic improvement of the neurological deficits.

  17. Perturbation of the Monomer-Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Forest H.; Rogers, Megan P.; Paul, Lake N.; McLeish, Michael J. [IUPUI; (Purdue)

    2014-08-14

    The X-ray structure of benzoylformate decarboxylase (BFDC) from Pseudomonas putida ATCC 12633 shows it to be a tetramer. This was believed to be typical of all thiamin diphosphate-dependent decarboxylases until recently when the structure of KdcA, a branched-chain 2-keto acid decarboxylase from Lactococcus lactis, showed it to be a homodimer. This lent credence to earlier unfolding experiments on pyruvate decarboxylase from Saccharomyces cerevisiae that indicated that it might be active as a dimer. To investigate this possibility in BFDC, we sought to shift the equilibrium toward dimer formation. Point mutations were made in the noncatalytic monomer–monomer interfaces, but these had a minimal effect on both tetramer formation and catalytic activity. Subsequently, the R141E/Y288A/A306F variant was shown by analytical ultracentrifugation to be partially dimeric. It was also found to be catalytically inactive. Further experiments revealed that just two mutations, R141E and A306F, were sufficient to markedly alter the dimer–tetramer equilibrium and to provide an ~450-fold decrease in kcat. Equilibrium denaturation studies suggested that the residual activity was possibly due to the presence of residual tetramer. The structures of the R141E and A306F variants, determined to <1.5 Å resolution, hinted that disruption of the monomer interfaces will be accompanied by movement of a loop containing Leu109 and Leu110. As these residues contribute to the hydrophobicity of the active site and the correct positioning of the substrate, it seems that tetramer formation may well be critical to the catalytic activity of BFDC.

  18. Bucket elevator

    OpenAIRE

    Chromek, Jiří

    2013-01-01

    Cílem této bakalářské práce je návrh svislého korečkového elevátoru, který má sloužit k dopravě obilovin s dopravní výškou 19 m a dopravovaným množstvím 100 t/hod. Práce se skládá z popisu korečkového elevátoru a jeho hlavních částí, zmiňující se v úvodní rešerši. Tato práce je zaměřena na funkční a kapacitní výpočet, určení pohonu a napínacího zařízení. Další výpočet je kontrolní, skládající se z pevnostní kontroly hnacího hřídele, výpočtu pera, životnosti ložisek a výpočtu napínacího zaříze...

  19. Novel protein–protein interaction between spermidine synthase and S-adenosylmethionine decarboxylase from Leishmania donovani

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Arjun K.; Agnihotri, Pragati; Srivastava, Vijay Kumar; Pratap, J. Venkatesh, E-mail: jvpratap@cdri.res.in

    2015-01-09

    Highlights: • L. donovani spermidine synthase and S-adenosylmethionine decarboxylase have been cloned and purified. • S-adenosylmethionine decarboxylase has autocatalytic property. • GST pull down assay shows the two proteins to form a metabolon. • Isothermal titration calorimetry shows that binding was exothermic having K{sub d} value of 0.4 μM. • Interaction confirmed by fluorescence spectroscopy and size exclusion chromatography. - Abstract: Polyamine biosynthesis pathway has long been considered an essential drug target for trypanosomatids including Leishmania. S-adenosylmethionine decarboxylase (AdoMetDc) and spermidine synthase (SpdSyn) are enzymes of this pathway that catalyze successive steps, with the product of the former, decarboxylated S-adenosylmethionine (dcSAM), acting as an aminopropyl donor for the latter enzyme. Here we have explored the possibility of and identified the protein–protein interaction between SpdSyn and AdoMetDc. The protein–protein interaction has been identified using GST pull down assay. Isothermal titration calorimetry reveals that the interaction is thermodynamically favorable. Fluorescence spectroscopy studies also confirms the interaction, with SpdSyn exhibiting a change in tertiary structure with increasing concentrations of AdoMetDc. Size exclusion chromatography suggests the presence of the complex as a hetero-oligomer. Taken together, these results suggest that the enzymes indeed form a heteromer. Computational analyses suggest that this complex differs significantly from the corresponding human complex, implying that this complex could be a better therapeutic target than the individual enzymes.

  20. Tumor-promoting phorbol ester amplifies the inductions of tyrosine aminotransferase and ornithine decarboxylase by glucocorticoid

    International Nuclear Information System (INIS)

    Kido, H.; Fukusen, N.; Katunuma, N.

    1987-01-01

    In adrenalectomized rats, the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) markedly enhanced the inductions of tyrosine aminotransferase (TAT) and ornithine decarboxylase by glucocorticoids, even with sufficient concentration of glucocorticoids to have a maximal effect, whereas it had no effect on TAT activity and increased ornithine decarboxylase activity only slightly in the absence of glucocorticoids. Phorbol derivatives and components of TPA such as 4β-phorbol, phorbol 12-tetradecanoate, phorbol 13-acetate, and 4-O-methylphorbol 12-tetradecanoate 13-acetate, which have no tumor-promoting activity or ability to activate protein kinase C, did not have any effect on TAT induction by glucocorticoid. TPA enhanced the induction of TAT by various glucocorticoids but had no effect on induction of TAT by glucagon or insulin and did not enhance the induction of glucose-6-phosphate dehydrogenase by 17β-estradiol. These results suggest that TPA specifically enhances the induction of TAT and ornithine decarboxylase by glucocorticoids. Similar effects of TPA on TAT induction by glucocorticoid were observed in primary cultures of adult rat hepatocytes. Another activator of protein kinase C, rac-1,2-dioctanoylglycerol, was also found to have similar effects on the cells

  1. Overexpression, purification, crystallization and preliminary structural studies of p-coumaric acid decarboxylase from Lactobacillus plantarum

    International Nuclear Information System (INIS)

    Rodríguez, Héctor; Rivas, Blanca de las; Muñoz, Rosario; Mancheño, José M.

    2007-01-01

    The enzyme p-coumaric acid decarboxylase (PDC) from L. plantarum has been recombinantly expressed, purified and crystallized. The structure has been solved at 2.04 Å resolution by the molecular-replacement method. The substrate-inducible p-coumaric acid decarboxylase (PDC) from Lactobacillus plantarum has been overexpressed in Escherichia coli, purified and confirmed to possess decarboxylase activity. The recombinant His 6 -tagged enzyme was crystallized using the hanging-drop vapour-diffusion method from a solution containing 20%(w/v) PEG 4000, 12%(w/v) 2-propanol, 0.2 M sodium acetate, 0.1 M Tris–HCl pH 8.0 with 0.1 M barium chloride as an additive. Diffraction data were collected in-house to 2.04 Å resolution. Crystals belonged to the tetragonal space group P4 3 , with unit-cell parameters a = b = 43.15, c = 231.86 Å. The estimated Matthews coefficient was 2.36 Å 3 Da −1 , corresponding to 48% solvent content, which is consistent with the presence of two protein molecules in the asymmetric unit. The structure of PDC has been determined by the molecular-replacement method. Currently, the structure of PDC complexed with substrate analogues is in progress, with the aim of elucidating the structural basis of the catalytic mechanism

  2. Overexpression, purification, crystallization and preliminary structural studies of p-coumaric acid decarboxylase from Lactobacillus plantarum

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Héctor; Rivas, Blanca de las; Muñoz, Rosario [Instituto de Fermentaciones Industriales, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Mancheño, José M., E-mail: xjosemi@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Instituto de Fermentaciones Industriales, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)

    2007-04-01

    The enzyme p-coumaric acid decarboxylase (PDC) from L. plantarum has been recombinantly expressed, purified and crystallized. The structure has been solved at 2.04 Å resolution by the molecular-replacement method. The substrate-inducible p-coumaric acid decarboxylase (PDC) from Lactobacillus plantarum has been overexpressed in Escherichia coli, purified and confirmed to possess decarboxylase activity. The recombinant His{sub 6}-tagged enzyme was crystallized using the hanging-drop vapour-diffusion method from a solution containing 20%(w/v) PEG 4000, 12%(w/v) 2-propanol, 0.2 M sodium acetate, 0.1 M Tris–HCl pH 8.0 with 0.1 M barium chloride as an additive. Diffraction data were collected in-house to 2.04 Å resolution. Crystals belonged to the tetragonal space group P4{sub 3}, with unit-cell parameters a = b = 43.15, c = 231.86 Å. The estimated Matthews coefficient was 2.36 Å{sup 3} Da{sup −1}, corresponding to 48% solvent content, which is consistent with the presence of two protein molecules in the asymmetric unit. The structure of PDC has been determined by the molecular-replacement method. Currently, the structure of PDC complexed with substrate analogues is in progress, with the aim of elucidating the structural basis of the catalytic mechanism.

  3. Effects of trihexyphenidyl and L-dopa on brain muscarinic cholinergic receptor binding measured by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Shinotoh, H; Asahina, M; Hirayama, K [Dept. of Neurology, School of Medicine, Chiba Univ., Chiba (Japan); Inoue, O; Suhara, T; Tateno, Y [Division of Clinical Research, National Inst. of Radiological Sciences, Chiba (Japan)

    1994-01-01

    The effects of pharmacological intervention on brain muscarinic cholinergic receptor (mAChR) binding were assessed in seven patients with Parkinson's disease by positron emission tomography and carbon-11 labelled N-methyl-4-piperidyl benzilate ([[sup 11]C]NMPB). [[sup 11]C]NMPB was injected twice, approximately 2 hours apart, in each patient, to assess the effect of single doses of 4 mg of trihexyphenidyl (n=5) or 400 mg of L-dopa with 57 mg of benserazide (n=2) on the binding parameter of mAChRs (K[sub 3]). There was a mean 28% inhibition of K[sub 3] values in the brain in the presence of trihexyphenidyl, which was assumed to reflect mAChR occupancy. No significant change in K[sub 3] was observed in the presence of L-dopa. This study demonstrates the feasibility of measuring mAChR occupancy by an anticholinergic medication with PET.

  4. Glutamic acid decarboxylase antibodies are indicators of the course, but not of the onset, of diabetes in middle-aged adults: the Atherosclerosis Risk in Communities Study

    Directory of Open Access Journals (Sweden)

    A. Vigo

    2007-07-01

    Full Text Available To efficiently examine the association of glutamic acid decarboxylase antibody (GADA positivity with the onset and progression of diabetes in middle-aged adults, we performed a case-cohort study representing the ~9-year experience of 10,275 Atherosclerosis Risk in Communities Study participants, initially aged 45-64 years. Antibodies to glutamic acid decarboxylase (GAD65 were measured by radioimmunoassay in 580 incident diabetes cases and 544 non-cases. The overall weighted prevalence of GADA positivity (³1 U/mL was 7.3%. Baseline risk factors, with the exception of smoking and interleukin-6 (P £ 0.02, were generally similar between GADA-positive and -negative individuals. GADA positivity did not predict incident diabetes in multiply adjusted (HR = 1.04; 95%CI = 0.55, 1.96 proportional hazard analyses. However, a small non-significant adjusted risk (HR = 1.29; 95%CI = 0.58, 2.88 was seen for those in the highest tertile (³2.38 U/mL of positivity. GADA-positive and GADA-negative non-diabetic individuals had similar risk profiles for diabetes, with central obesity and elevated inflammation markers, aside from glucose, being the main predictors. Among diabetes cases at study's end, progression to insulin treatment increased monotonically as a function of baseline GADA level. Overall, being GADA positive increased risk of progression to insulin use almost 10 times (HR = 9.9; 95%CI = 3.4, 28.5. In conclusion, in initially non-diabetic middle-aged adults, GADA positivity did not increase diabetes risk, and the overall baseline profile of risk factors was similar for positive and negative individuals. Among middle-aged adults, with the possible exception of those with the highest GADA levels, autoimmune pathophysiology reflected by GADA may become clinically relevant only after diabetes onset.

  5. Novel use of F-DOPA PET/CT imaging in a child with paraganglioma/pheochromocytoma syndrome

    International Nuclear Information System (INIS)

    Levine, Daniel S.; Nadel, Helen R.; Metzger, Daniel L.; Oviedo, Angelica; Adam, Michael J.; Skarsgard, Erik

    2011-01-01

    We report the use of F-DOPA PET/CT imaging in the evaluation of a teenager with marked hypertension and right pararenal, left adrenal and left para-aortic mass lesions. The use of the modality for this clinical application has not been described previously within the pediatric imaging literature. The value of this technique relative to conventional imaging modalities is discussed and warrants consideration of its use, if available, for evaluating children with suspected paragangliomas/pheochromocytomas. (orig.)

  6. Physical Exercise Modulates L-DOPA-Regulated Molecular Pathways in the MPTP Mouse Model of Parkinson's Disease.

    Science.gov (United States)

    Klemann, Cornelius J H M; Xicoy, Helena; Poelmans, Geert; Bloem, Bas R; Martens, Gerard J M; Visser, Jasper E

    2018-07-01

    Parkinson's disease (PD) is characterized by the degeneration of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc), resulting in motor and non-motor dysfunction. Physical exercise improves these symptoms in PD patients. To explore the molecular mechanisms underlying the beneficial effects of physical exercise, we exposed 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrimidine (MPTP)-treated mice to a four-week physical exercise regimen, and subsequently explored their motor performance and the transcriptome of multiple PD-linked brain areas. MPTP reduced the number of DA neurons in the SNpc, whereas physical exercise improved beam walking, rotarod performance, and motor behavior in the open field. Further, enrichment analyses of the RNA-sequencing data revealed that in the MPTP-treated mice physical exercise predominantly modulated signaling cascades that are regulated by the top upstream regulators L-DOPA, RICTOR, CREB1, or bicuculline/dalfampridine, associated with movement disorders, mitochondrial dysfunction, and epilepsy-related processes. To elucidate the molecular pathways underlying these cascades, we integrated the proteins encoded by the exercise-induced differentially expressed mRNAs for each of the upstream regulators into a molecular landscape, for multiple key brain areas. Most notable was the opposite effect of physical exercise compared to previously reported effects of L-DOPA on the expression of mRNAs in the SN and the ventromedial striatum that are involved in-among other processes-circadian rhythm and signaling involving DA, neuropeptides, and endocannabinoids. Altogether, our findings suggest that physical exercise can improve motor function in PD and may, at the same time, counteract L-DOPA-mediated molecular mechanisms. Further, we hypothesize that physical exercise has the potential to improve non-motor symptoms of PD, some of which may be the result of (chronic) L-DOPA use.

  7. Novel use of F-DOPA PET/CT imaging in a child with paraganglioma/pheochromocytoma syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Daniel S.; Nadel, Helen R. [University of British Columbia, Department of Radiology and Nuclear Medicine, British Columbia Children' s Hospital, Vancouver (Canada); Metzger, Daniel L. [University of British Columbia, Department of Pediatrics, Division of Endocrinology, British Columbia Children' s Hospital, Vancouver (Canada); Oviedo, Angelica [University of British Columbia, Department of Pathology, British Columbia Children' s Hospital, Vancouver (Canada); Adam, Michael J. [University of British Columbia, Department of PET Chemistry, Tri-University Meson Facility (TRIUMF), Vancouver (Canada); Skarsgard, Erik [University of British Columbia, Department of Surgery, British Columbia Children' s Hospital, Vancouver (Canada)

    2011-10-15

    We report the use of F-DOPA PET/CT imaging in the evaluation of a teenager with marked hypertension and right pararenal, left adrenal and left para-aortic mass lesions. The use of the modality for this clinical application has not been described previously within the pediatric imaging literature. The value of this technique relative to conventional imaging modalities is discussed and warrants consideration of its use, if available, for evaluating children with suspected paragangliomas/pheochromocytomas. (orig.)

  8. NADPH oxidase-derived H2O2 subverts pathogen signaling by oxidative phosphotyrosine conversion to PB-DOPA

    Science.gov (United States)

    Alvarez, Luis A.; Kovačič, Lidija; Rodríguez, Javier; Gosemann, Jan-Hendrik; Kubica, Malgorzata; Pircalabioru, Gratiela G.; Friedmacher, Florian; Cean, Ada; Ghişe, Alina; Sărăndan, Mihai B.; Puri, Prem; Daff, Simon; Plettner, Erika; von Kriegsheim, Alex; Bourke, Billy; Knaus, Ulla G.

    2016-01-01

    Strengthening the host immune system to fully exploit its potential as antimicrobial defense is vital in countering antibiotic resistance. Chemical compounds released during bidirectional host–pathogen cross-talk, which follows a sensing-response paradigm, can serve as protective mediators. A potent, diffusible messenger is hydrogen peroxide (H2O2), but its consequences on extracellular pathogens are unknown. Here we show that H2O2, released by the host on pathogen contact, subverts the tyrosine signaling network of a number of bacteria accustomed to low-oxygen environments. This defense mechanism uses heme-containing bacterial enzymes with peroxidase-like activity to facilitate phosphotyrosine (p-Tyr) oxidation. An intrabacterial reaction converts p-Tyr to protein-bound dopa (PB-DOPA) via a tyrosinyl radical intermediate, thereby altering antioxidant defense and inactivating enzymes involved in polysaccharide biosynthesis and metabolism. Disruption of bacterial signaling by DOPA modification reveals an infection containment strategy that weakens bacterial fitness and could be a blueprint for antivirulence approaches. PMID:27562167

  9. Involuntary expiratory phonation as a dose-related consequence of L-dopa therapy in a patient with Parkinson's disease.

    Science.gov (United States)

    Ishii, Kosuke; Kumada, Masanobu; Ueki, Akira; Yamamoto, Masanori; Hirose, Hajime

    2003-12-01

    We report a case of involuntary phonation caused by abnormal vocal cord movements during expiration in a patient with Parkinson's disease. A 60-year-old woman had been treated for parkinsonism at the outpatient clinic of the Department of Neurology since August 1999. She began to groan involuntarily in the daytime in September 2001. She could not eat well while groaning. Stridor was not noted during sleep at night. Endoscopic examination of the larynx revealed insufficient abduction of the bilateral vocal cords, although the glottis was not so small as to cause stridor during inspiration. During expiration, however, the vocal cords adducted, resulting in the involuntary production of voice. Electromyography showed an increase in the activity of the thyroarytenoid and lateral cricoarytenoid muscles. This muscle activity was further enhanced during inspiration. The involuntary phonation disappeared when the patient's dose of L-dopa was decreased, although she had a decrease in her systemic mobility as well. When the dose of L-dopa was increased to the therapeutic level, involuntary phonation recurred, and her voluntary systemic activity improved. In the present case, it was considered that excessive dopaminergic denervation occurred in the nerve innervating the laryngeal adductors. Involuntary voice appeared to be produced by hypertonus of the laryngeal adductors because of a lowering in the threshold level for L-dopa, even though the drug was administered at the usual dose.

  10. Mapping of central dopamine synthesis in man, using positron emission tomography with L-[β-11C]DOPA

    International Nuclear Information System (INIS)

    Ito, Hiroshi; Shidahara, Miho; Takano, Harumasa; Takahashi, Hidehiko; Nozaki, Shoko; Suhara, Tetsuya

    2007-01-01

    The objective of this study was to estimate the presynaptic function of the central dopaminergic system, positron emission tomography measurement of the endogenous dopamine synthesis rate was performed with L-[β- 11 C]dihydroxyphenylanine (DOPA). In the present study, we developed a simple method for calculating an indicator of the dopamine synthesis rate with L-[β- 11 C]DOPA on a voxel-by-voxel basis for parametric mapping. After intravenous injection of L-[β- 11 C]DOPA, dynamic scanning was performed on ten healthy men for 89 min. The dopamine synthesis ratio was calculated on a voxel-by-voxel basis as the ratio of the area under the time-activity curves of brain regions to the reference brain region, that is, occipital cortex. The overall uptake rate constant as an indicator of dopamine synthesis was also calculated by kinetic and graphical analyses. The dopamine synthesis ratio calculated by the present method was in good agreement with the indicators of dopamine synthesis calculated by kinetic and graphical analyses, although a systemic underestimation was observed, especially when the integration interval was set in the early phase of the scan duration. In particular, underestimations were prominent in brain regions with relatively lower influx rate constant K 1 . By this method, regional dopamine synthesis could be estimated on a voxel-by-voxel basis. This method does not need an arterial input function and should prove to be useful for clinical research. (author)

  11. NADPH oxidase-derived H2O2 subverts pathogen signaling by oxidative phosphotyrosine conversion to PB-DOPA.

    Science.gov (United States)

    Alvarez, Luis A; Kovačič, Lidija; Rodríguez, Javier; Gosemann, Jan-Hendrik; Kubica, Malgorzata; Pircalabioru, Gratiela G; Friedmacher, Florian; Cean, Ada; Ghişe, Alina; Sărăndan, Mihai B; Puri, Prem; Daff, Simon; Plettner, Erika; von Kriegsheim, Alex; Bourke, Billy; Knaus, Ulla G

    2016-09-13

    Strengthening the host immune system to fully exploit its potential as antimicrobial defense is vital in countering antibiotic resistance. Chemical compounds released during bidirectional host-pathogen cross-talk, which follows a sensing-response paradigm, can serve as protective mediators. A potent, diffusible messenger is hydrogen peroxide (H2O2), but its consequences on extracellular pathogens are unknown. Here we show that H2O2, released by the host on pathogen contact, subverts the tyrosine signaling network of a number of bacteria accustomed to low-oxygen environments. This defense mechanism uses heme-containing bacterial enzymes with peroxidase-like activity to facilitate phosphotyrosine (p-Tyr) oxidation. An intrabacterial reaction converts p-Tyr to protein-bound dopa (PB-DOPA) via a tyrosinyl radical intermediate, thereby altering antioxidant defense and inactivating enzymes involved in polysaccharide biosynthesis and metabolism. Disruption of bacterial signaling by DOPA modification reveals an infection containment strategy that weakens bacterial fitness and could be a blueprint for antivirulence approaches.

  12. Albizia lebbeck suppresses histamine signaling by the inhibition of histamine H1 receptor and histidine decarboxylase gene transcriptions.

    Science.gov (United States)

    Nurul, Islam Mohammed; Mizuguchi, Hiroyuki; Shahriar, Masum; Venkatesh, Pichairajan; Maeyama, Kazutaka; Mukherjee, Pulok K; Hattori, Masashi; Choudhuri, Mohamed Sahabuddin Kabir; Takeda, Noriaki; Fukui, Hiroyuki

    2011-11-01

    Histamine plays major roles in allergic diseases and its action is mediated mainly by histamine H(1) receptor (H1R). We have demonstrated that histamine signaling-related H1R and histidine decarboxylase (HDC) genes are allergic diseases sensitive genes and their expression level affects severity of the allergic symptoms. Therefore, compounds that suppress histamine signaling should be promising candidates as anti-allergic drugs. Here, we investigated the effect of the extract from the bark of Albizia lebbeck (AL), one of the ingredients of Ayruvedic medicines, on H1R and HDC gene expression using toluene-2,4-diisocyanate (TDI) sensitized allergy model rats and HeLa cells expressing endogenous H1R. Administration of the AL extract significantly decreased the numbers of sneezing and nasal rubbing. Pretreatment with the AL extract suppressed TDI-induced H1R and HDC mRNA elevations as well as [(3)H]mepyramine binding, HDC activity, and histamine content in the nasal mucosa. AL extract also suppressed TDI-induced up-regulation of IL-4, IL-5, and IL-13 mRNA. In HeLa cells, AL extract suppressed phorbol-12-myristate-13-acetate- or histamine-induced up-regulation of H1R mRNA. Our data suggest that AL alleviated nasal symptoms by inhibiting histamine signaling in TDI-sensitized rats through suppression of H1R and HDC gene transcriptions. Suppression of Th2-cytokine signaling by AL also suggests that it could affect the histamine-cytokine network. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Preliminary Study on Purification and Identification of Aromatic Acid Amino L-Dopa From Malaysia Freshwater Green Mussel Byssus

    International Nuclear Information System (INIS)

    Saiful Irwan Zubairi; Wan Rosmaryana Wan Musa; Syed Anuar Faua'ad Syed Mohammad

    2014-01-01

    L-DOPA (L-3, 4-dihydroxyphenylalanine) is a type of aromatic amino acid which can be detected by using acidic extraction and purification method involving adhesive byssus green mussel protein. The main objective of this study is to identify and purify the aromatic amino acid L-DOPA via the utilization of gel Sephadex G-200 filtration chromatography based on two types of acidic and basic mobile phase solution. The crushing and homogenizing for adhesive byssus green mussel were conducted using a mortar and a pestle with the aid of liquid nitrogen. The samples that had been crushed were then mixed and dissolved in perchloric acid 0.7 %, 1.0 % and 1.5 % (v/ v) (pre-treatment) prior to the extraction process. The extraction was carried out by centrifuging the extracts at 11,000 rpm for about 10 mins and at a temperature of 10 degree Celsius to obtain supernatant S1. The supernatant was mixed with acetone and sulphuric acid and centrifuged for the second time to produce a pellet and then it was dissolved in the respective mobile phase solutions prior to purification process. Purification was later performed using two mobile phase solutions which were acetic acid 5 % (v/ v) and NaOH 1 M. The absorbance (abs) value of each purified protein extract fractions was collected and analysed at 214 nm to 400 nm with the help of UV-spectrophotometer. The highest abs value was selected for identification and verification of amino acid L-DOPA in the purified solution. Verification was carried out by utilizing high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). The results showed that the use of 0.7 % (v/ v) perchloric acid and 5 % (v/ v) acetic acid for pre-treatment process and mobile phase solution of purification process respectively, yielded the highest effluent abs profile at a wavelength of 260 nm. TLC analysis proved the existence of several important amino acids besides L-DOPA which were tyrosine and phenylalanine after 78 hrs of collection of

  14. Clinical value of {sup 18}F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography ({sup 18}F-DOPA PET/CT) for detecting pheochromocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Luster, Markus; Zeich, Katrin; Glatting, Gerhard; Buck, Andreas K.; Solbach, Christoph; Reske, Sven N. [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); Karges, Wolfram [RWTH Aachen, Division of Endocrinology and Diabetes, Aachen (Germany); Pauls, Sandra [University of Ulm, Department of Radiology, Ulm (Germany); Verburg, Frederik A. [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Dralle, Henning [University Halle-Wittenberg, Department of General, Visceral and Vascular Surgery, Halle (Germany); Neumaier, Bernd [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); Max-Planck-Institut fuer Neurologische Forschung, Section for Radiochemistry, Cologne (Germany); Mottaghy, Felix M. [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany)

    2010-03-15

    In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor {sup 18}F-fluorodihydroxyphenylalanine ({sup 18}F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined {sup 18}F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone. {sup 18}F-DOPA PET, CT and {sup 18}F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology. Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of {sup 18}F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value. {sup 18}F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do {sup 18}F-DOPA PET or CT alone. (orig.)

  15. Clinical value of 18F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography (18F-DOPA PET/CT) for detecting pheochromocytoma

    International Nuclear Information System (INIS)

    Luster, Markus; Zeich, Katrin; Glatting, Gerhard; Buck, Andreas K.; Solbach, Christoph; Reske, Sven N.; Karges, Wolfram; Pauls, Sandra; Verburg, Frederik A.; Dralle, Henning; Neumaier, Bernd; Mottaghy, Felix M.

    2010-01-01

    In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor 18 F-fluorodihydroxyphenylalanine ( 18 F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined 18 F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone. 18 F-DOPA PET, CT and 18 F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology. Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of 18 F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value. 18 F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do 18 F-DOPA PET or CT alone. (orig.)

  16. Tracking the formation of eumelanin from L-Dopa using coupled measurements

    Science.gov (United States)

    Yip, Philip; Sutter, Jens U.

    2018-04-01

    Melanin plays a crucial role as a pigment all through the animal kingdom. Being a macromolecule just on the divide between an ordered crystalline or a purely amorphous form melanin has proven a challenge to structure-function analysis. Melanin assembles from small molecules much like a jigsaw and much like in a jigsaw the fine detail quickly vanishes in the overall picture. With melanin being first and foremost a photo-active molecule we focus on spectral properties for the characterisation of its structure. We use absorption measurements to illustrate the complex nature of the formation process. To gain a better hold on the formation pathway we use coupled measurements of excitation and emission to identify ‘areas of interest’ in the excitation-emission matrix (EEM). We then probe one area for characteristic fluorescence lifetimes to track one melanin building block through the formation process. Comparison of the EEMs of L-Dopa derived melanin with natural Sepia melanin shows characteristic differences. We show how the presence of copper ions creates a melanin closer to its natural form.

  17. m-DOPA addition in MAPLE immobilization of lipase for biosensor applications

    Directory of Open Access Journals (Sweden)

    Valeria Califano

    2015-12-01

    Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique which uses a pulsed laser beam impinging, inside a high vacuum chamber, on a frozen target containing the guest molecules in a volatile matrix to induce fast “evaporation” of the matrix, and ejection of the guest molecules. Lipase, an enzyme acting as a catalyst in hydrolysis of lipids, is widely used in biosensors for detection of triglycerides in blood serum. A key action to this purpose is lipase immobilization on a substrate. In a recent paper, we have shown that MAPLE technique is able to deposit lipase on a substrate in an active form. Here we show that addition to the guest/matrix target of a small amount of m-DOPA (3-(3,4-dihydroxyphenyl-2-methyl-l-alanine in order to improve adhesion and protect lipase secondary structure, also allows the lowering the laser pulse energy required for matrix evaporation and therefore the risk of damaging the enzyme.

  18. Selective decrease in central nervous system serotonin turnover in children with dopa-nonresponsive dystonia.

    Science.gov (United States)

    Assmann, Birgit; Köhler, Martin; Hoffmann, Georg F; Heales, Simon; Surtees, Robert

    2002-07-01

    Childhood dystonia that does not respond to treatment with levodopa (dopa-nonresponsive dystonia, DND) has an unclear pathogenesis and is notoriously difficult to treat. To test the hypothesis that there may be abnormalities in serotonin turnover in DND we measured cerebrospinal fluid (CSF) concentrations of homovanillic (HVA) and 5-hydroxyindoleacetic (HIAA) acids, metabolites of dopamine and serotonin, respectively, in 18 children with dystonia not responsive to levodopa. These were combined with a reference population of 85 children with neurologic or metabolic disease known not to affect dopamine or serotonin metabolism. Because of the known natural age-related decrement in HVA and HIAA concentrations, the results were analyzed using multiple regression using age and DND as predictors of CSF HIAA and HVA concentrations. DND was a highly significant predictor of CSF HIAA concentration (p model, the geometric mean ratio of CSF HIAA in DND compared with the reference range was 0.53 whereas that for CSF HVA was 0.95. We also analyzed CSF HIAA/HVA ratios. After fitting a regression model, we found no dependence on age, and the mean of CSF HIAA/HVA in DND was 0.28 whereas that for the reference range was 0.49 (p < 0.001). We conclude that a significant number of children with DND have reduced CNS serotonin turnover. Treatment with drugs that increase serotonin concentration in the synaptic cleft should be considered in this group of patients.

  19. LC-MSdetermination of L-DOPA concentration in the leaf and flower tissues of six faba bean (Vicia fabaL. lines with common and rare flowercolors

    Directory of Open Access Journals (Sweden)

    Jinguo Hu

    2015-07-01

    Full Text Available Background: Parkinson’s disease (PD is the second most common neurodegenerative disorder characterized by the loss of muscle control, which causes trembling of the limbs and head as well as impaired balance. L-DOPA (L-3,4-dihydroxy phenylalanine is the major ingredient of several prescription drugs used to treat PD. Faba bean (Vicia faba L. is one of the few plant species that is known to produce L-DOPA and has the potential to be developed as a functional food crop for people suffering with PD. Objective: Aimed to provide needed information for people who want to use faba bean as a natural remedy or functional food to relieve PD symptoms, this study analyzed the variation of L-DOPA concentration in the leaf and flower tissues of six faba bean lines with common and rare flower colors. Methods: Leaf and flower samples were taken from field grown plants with different flower colors, namely, pink with purple lines and black dots, pure white, brown, and crimson. Samples were freeze-dried and L-DOPA was quantified by a LC-MS system consisting of an ACQUITY UPLC in line with a Synapt G2 HDMS quadrupole time-of-flight mass spectrometer. This experiment was carried out in two consecutive years (2012 and 2013 and the plants used in the second year were grown from the seeds harvested from the plants used in the first year. Results and Discussion: Our two-year study revealed a high level of variation in L-DOPA concentration for leaf and flower tissues among the six faba bean lines studied. The average L-DOPA concentration based on dry weight (DW in flowers ranged from 27.8 to 63.5 mg/g and 18.2 to 48.7 mg/g for leaf tissues. There was no significant correlation between L-DOPA concentrations in flowers and leaves. The L-DOPA concentration in flowers and in leaves of the same line varied but were not statistically significant between the two years. Ideally, the genotype with the highest average L-DOPA concentration in both flowers and leaves would be grown

  20. A retrospective comparison between 68Ga-DOTA-TOC PET/CT and 18F-DOPA PET/CT in patients with extra-adrenal paraganglioma

    International Nuclear Information System (INIS)

    Kroiss, Alexander; Putzer, Daniel; Decristoforo, Clemens; Uprimny, Christian; Virgolini, Irene Johanna; Frech, Andreas; Fraedrich, Gustav; Gasser, Rudolf Wolfgang; Shulkin, Barry Lynn; Url, Christoph; Widmann, Gerlig; Prommegger, Rupert; Sprinzl, Georg Mathias

    2013-01-01

    18 F-Fluoro-l-dihydroxyphenylalanine ( 18 F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by 68 Ga-DOTA-Tyr 3 -octreotide ( 68 Ga-DOTA-TOC) PET. Therefore, we compared 68 Ga-DOTA-TOC and 18 F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with 68 Ga-DOTA-TOC PET and 18 F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUV max ) of each functional imaging modality in concordant tumour lesions was measured. Compared with anatomical imaging, 68 Ga-DOTA-TOC PET and 18 F-DOPA PET each had a per-patient and per-lesion detection rate of 100 % in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of 68 Ga-DOTA-TOC was 100 % and that of 18 F-DOPA PET was 56.0 %. Overall, 68 Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and 18 F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of 68 Ga-DOTA-TOC PET was 100 % (McNemar, P 18 F-DOPA PET was 71.1 % (McNemar, P max (mean ± SD) of all 32 concordant lesions was 67.9 ± 61.5 for 68 Ga-DOTA-TOC PET and 11.8 ± 7.9 for 18 F-DOPA PET (Mann-Whitney U test, P 68 Ga-DOTA-TOC PET may be superior to 18 F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically

  1. The Role of Primary Motor Cortex (M1) Glutamate and GABA Signaling in l-DOPA-Induced Dyskinesia in Parkinsonian Rats.

    Science.gov (United States)

    Lindenbach, David; Conti, Melissa M; Ostock, Corinne Y; George, Jessica A; Goldenberg, Adam A; Melikhov-Sosin, Mitchell; Nuss, Emily E; Bishop, Christopher

    2016-09-21

    Long-term treatment of Parkinson's disease with l-DOPA almost always leads to the development of involuntary movements termed l-DOPA-induced dyskinesia. Whereas hyperdopaminergic signaling in the basal ganglia is thought to cause dyskinesia, alterations in primary motor cortex (M1) activity are also prominent during dyskinesia, suggesting that the cortex may represent a therapeutic target. The present study used the rat unilateral 6-hydroxydopamine lesion model of Parkinson's disease to characterize in vivo changes in GABA and glutamate neurotransmission within M1 and determine their contribution to behavioral output. 6-Hydroxydopamine lesion led to parkinsonian motor impairment that was partially reversed by l-DOPA. Among sham-lesioned rats, l-DOPA did not change glutamate or GABA efflux. Likewise, 6-hydroxydopamine lesion did not impact GABA or glutamate among rats chronically treated with saline. However, we observed an interaction of lesion and treatment whereby, among lesioned rats, l-DOPA given acutely (1 d) or chronically (14-16 d) reduced glutamate efflux and enhanced GABA efflux. Site-specific microinjections into M1 demonstrated that l-DOPA-induced dyskinesia was reduced by M1 infusion of a D1 antagonist, an AMPA antagonist, or a GABAA agonist. Overall, the present study demonstrates that l-DOPA-induced dyskinesia is associated with increased M1 inhibition and that exogenously enhancing M1 inhibition may attenuate dyskinesia, findings that are in agreement with functional imaging and transcranial magnetic stimulation studies in human Parkinson's disease patients. Together, our study suggests that increasing M1 inhibitory tone is an endogenous compensatory response designed to limit dyskinesia severity and that potentiating this response is a viable therapeutic strategy. Most Parkinson's disease patients will receive l-DOPA and eventually develop hyperkinetic involuntary movements termed dyskinesia. Such symptoms can be as debilitating as the disease

  2. Buspirone anti-dyskinetic effect is correlated with temporal normalization of dysregulated striatal DRD1 signalling in L-DOPA-treated rats.

    Science.gov (United States)

    Azkona, Garikoitz; Sagarduy, Ainhoa; Aristieta, Asier; Vazquez, Nerea; Zubillaga, Verónica; Ruíz-Ortega, José Angel; Pérez-Navarro, Esther; Ugedo, Luisa; Sánchez-Pernaute, Rosario

    2014-04-01

    Dopamine replacement with l-DOPA is the most effective therapy in Parkinson's disease. However, with chronic treatment, half of the patients develop an abnormal motor response including dyskinesias. The specific molecular mechanisms underlying dyskinesias are not fully understood. In this study, we used a well-characterized animal model to first establish the molecular differences between rats that did and did not develop dyskinesias. We then investigated the molecular substrates implicated in the anti-dyskinetic effect of buspirone, a 5HT1A partial agonist. Striatal protein expression profile of dyskinetic animals revealed increased levels of the dopamine receptor (DR)D3, ΔFosB and phospho (p)CREB, as well as an over-activation of the DRD1 signalling pathway, reflected by elevated ratios of phosphorylated DARPP32 and ERK2. Buspirone reduced the abnormal involuntary motor response in dyskinetic rats in a dose-dependent fashion. Buspirone (4 mg/kg) dramatically reduced the presence and severity of dyskinesias (by 83%) and normalized DARPP32 and ERK2 phosphorylation ratios, while the increases in DRD3, ΔFosB and pCREB observed in dyskinetic rats were not modified. Pharmacological experiments combining buspirone with 5HT1A and DRD3 antagonists confirmed that normalization of both pDARPP32 and pERK2 is required, but not sufficient, for blocking dyskinesias. The correlation between pDARPP32 ratio and dyskinesias was significant but not strong, pointing to the involvement of convergent factors and signalling pathways. Our results suggest that in dyskinetic rats DRD3 striatal over-expression could be instrumental in the activation of DRD1-downstream signalling and demonstrate that the anti-dyskinetic effect of buspirone in this model is correlated with DRD1 pathway normalization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Study of pyruvate decarboxylase and thiamine kinase from brewer's yeast by SERS

    Science.gov (United States)

    Maskevich, Sergei A.; Chernikevich, Ivan P.; Gachko, Gennedy A.; Kivach, Leonid N.; Strekal, Nataliya D.

    1993-06-01

    The Surface Enhanced Raman Scattering (SERS) spectra of holopyruvate decarboxylase (PDC) and thiamine kinase (ThK) adsorbed on silver electrode were obtained. In contrast to the Raman, the SERS spectrum of PDC contained no modes of tryptophan residues, it indicates a removal of this moiety from the surface. In the SERS spectrum of ThK the bands belonging to ligands bound to the protein were observed. A correlation between the SERS signal intensity and the enzymatic activity of the ThK separate fraction and found. The influence of amino acids on SERS spectra of thiamine (Th) was studied to determine the possible composition on microsurrounding of coenzyme.

  4. Arginase and Arginine Decarboxylase - Where Do the Putative Gate Keepers of Polyamine Synthesis Reside in Rat Brain?

    Directory of Open Access Journals (Sweden)

    Daniela Peters

    Full Text Available Polyamines are important regulators of basal cellular functions but also subserve highly specific tasks in the mammalian brain. With this respect, polyamines and the synthesizing and degrading enzymes are clearly differentially distributed in neurons versus glial cells and also in different brain areas. The synthesis of the diamine putrescine may be driven via two different pathways. In the "classical" pathway urea and carbon dioxide are removed from arginine by arginase and ornithine decarboxylase. The alternative pathway, first removing carbon dioxide by arginine decarboxlyase and then urea by agmatinase, may serve the same purpose. Furthermore, the intermediate product of the alternative pathway, agmatine, is an endogenous ligand for imidazoline receptors and may serve as a neurotransmitter. In order to evaluate and compare the expression patterns of the two gate keeper enzymes arginase and arginine decarboxylase, we generated polyclonal, monospecific antibodies against arginase-1 and arginine decarboxylase. Using these tools, we immunocytochemically screened the rat brain and compared the expression patterns of both enzymes in several brain areas on the regional, cellular and subcellular level. In contrast to other enzymes of the polyamine pathway, arginine decarboxylase and arginase are both constitutively and widely expressed in rat brain neurons. In cerebral cortex and hippocampus, principal neurons and putative interneurons were clearly labeled for both enzymes. Labeling, however, was strikingly different in these neurons with respect to the subcellular localization of the enzymes. While with antibodies against arginine decarboxylase the immunosignal was distributed throughout the cytoplasm, arginase-like immunoreactivity was preferentially localized to Golgi stacks. Given the apparent congruence of arginase and arginine decarboxylase distribution with respect to certain cell populations, it seems likely that the synthesis of agmatine

  5. OCCURRENCE OF L-DOPA AND DOPAMINE IN PLANTS AND CELL-CULTURES OF MUCUNA-PRURIENS AND EFFECTS OF 2,4-D AND NACL ON THESE COMPOUNDS

    NARCIS (Netherlands)

    WICHERS, HJ; VISSER, JF; HUIZING, HJ; PRAS, N

    The development of the L-DOPA-content of roots, stems and leaves of Mucuna pruriens during growth of the plants is described. Besides L-DOPA, the leaves, but not the stems and the roots, also contain the related catechol dopamine. The time course of dopamine accumulation is compared to that of

  6. Characterization of glial tumors in PET/CT 18F-dopa and in perfusion MRI

    International Nuclear Information System (INIS)

    Nioche, Christophe

    2011-01-01

    MRI provides morphological information about a tumour, as well as information regarding its micro-vascularisation of the tumour. In PET/CT, accumulation of 18 F-Dopa in tumour cells results from the metabolic activity greater than that of healthy tissues.We studied 28 gliomas for which we analysed data from MRI and PET/CT. A registration method has been developed to combine information from both PET and MRI and to extract volumes of interest consistent with the information included in the two modalities. In these volumes, the tumour compartment and normal tissue compartment were identified using a Gaussian mixture model. Parameters from PET or MRI data were then calculated in these compartments. ROC analyses combined with linear discriminant analyses were used to assess whether joint observation of standardized uptake value (SUVmax) and relative Cerebral Blood Volume (rCBV) or of relative rk1 and rCBV could distinguish between low grade and high grade tumours. We found that using this joint analysis, 82% of high-grade tumors and 70% of low grade tumors were correctly classified (AUC of 0.88 for [SUVmax, rCBV] and of 0.92 for [rk1, rCBV]). Considering the combined information from [SUVmax, rCBV], the sensitivity for detecting high-grade tumors was 95% with a specificity of 60%. The negative predictive value was 52% for a positive predictive value of 95%. Similarly, considering the combined information from [rk1, rCBV], we also obtain a specificity of 60% associated with a 95% sensitivity for detecting high-grade tumors, with a negative predictive value of 60% and positive predictive value of 95%. Our work shows that joint analysis of information from microvascular and metabolic is possible by combining PET and MR imaging data. However, we found that, in our patient population, the microvascular information obtained through MR did not achieve better discrimination than the metabolic information derived from PET only. (author)

  7. Effects of bis(guanylhydrazones) on the activity and expression of ornithine decarboxylase.

    Science.gov (United States)

    Nikula, P; Alhonen-Hongisto, L; Jänne, J

    1985-01-01

    Derivatives of glyoxal bis(guanylhydrazone) (GBG), such as methylglyoxal bis(guanylhydrazone) and ethylglyoxal bis(guanylhydrazone), are potent inhibitors of S-adenosylmethionine decarboxylase (EC 4.1.1.50), the key enzyme required for the synthesis of spermidine and spermine. These compounds, but not the parent compound, induce a massive accumulation of putrescine, partly by blocking the conversion of putrescine into spermidine, but also by strikingly stimulating ornithine decarboxylase (ODC; EC 4.1.1.17) activity. The mechanism of the stimulation of ODC activity and enhanced accumulation of the enzyme protein apparently involved a distinct stabilization of the enzyme against intracellular degradation. However, although the parent compound GBG also stabilized ODC, it powerfully inhibited the enzyme activity and the accumulation of immunoreactive protein in cultured L1210 leukaemia cells. Kinetic considerations indicated that, in addition to the stabilization, all three compounds, GBG in particular, inhibited the expression of ODC. It is unlikely that the decreased rate of synthesis of ODC was attributable to almost unaltered amounts of mRNA in drug-treated cells, thus supporting the view that especially GBG apparently depressed the expression of ODC at some post-transcriptional level. Images PMID:4062886

  8. Polyamine regulation of ornithine decarboxylase and its antizyme in intestinal epithelial cells.

    Science.gov (United States)

    Yuan, Q; Ray, R M; Viar, M J; Johnson, L R

    2001-01-01

    Ornithine decarboxylase (ODC) is feedback regulated by polyamines. ODC antizyme mediates this process by forming a complex with ODC and enhancing its degradation. It has been reported that polyamines induce ODC antizyme and inhibit ODC activity. Since exogenous polyamines can be converted to each other after they are taken up into cells, we used an inhibitor of S-adenosylmethionine decarboxylase, diethylglyoxal bis(guanylhydrazone) (DEGBG), to block the synthesis of spermidine and spermine from putrescine and investigated the specific roles of individual polyamines in the regulation of ODC in intestinal epithelial crypt (IEC-6) cells. We found that putrescine, spermidine, and spermine inhibited ODC activity stimulated by serum to 85, 46, and 0% of control, respectively, in the presence of DEGBG. ODC activity increased in DEGBG-treated cells, despite high intracellular putrescine levels. Although exogenous spermidine and spermine reduced ODC activity of DEGBG-treated cells close to control levels, spermine was more effective than spermidine. Exogenous putrescine was much less effective in inducing antizyme than spermidine or spermine. High putrescine levels in DEGBG-treated cells did not induce ODC antizyme when intracellular spermidine and spermine levels were low. The decay of ODC activity and reduction of ODC protein levels were not accompanied by induction of antizyme in the presence of DEGBG. Our results indicate that spermine is the most, and putrescine the least, effective polyamine in regulating ODC activity, and upregulation of antizyme is not required for the degradation of ODC protein.

  9. A coenzyme-independent decarboxylase/oxygenase cascade for the efficient synthesis of vanillin.

    Science.gov (United States)

    Furuya, Toshiki; Miura, Misa; Kino, Kuniki

    2014-10-13

    Vanillin is one of the most widely used flavor compounds in the world as well as a promising versatile building block. The biotechnological production of vanillin from plant-derived ferulic acid has attracted much attention as a new alternative to chemical synthesis. One limitation of the known metabolic pathway to vanillin is its requirement for expensive coenzymes. Here, we developed a novel route to vanillin from ferulic acid that does not require any coenzymes. This artificial pathway consists of a coenzyme-independent decarboxylase and a coenzyme-independent oxygenase. When Escherichia coli cells harboring the decarboxylase/oxygenase cascade were incubated with ferulic acid, the cells efficiently synthesized vanillin (8.0 mM, 1.2 g L(-1) ) via 4-vinylguaiacol in one pot, without the generation of any detectable aromatic by-products. The efficient method described here might be applicable to the synthesis of other high-value chemicals from plant-derived aromatics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Molecular cloning and expression of gene encoding aromatic amino acid decarboxylase in 'Vidal blanc' grape berries.

    Science.gov (United States)

    Pan, Qiu-Hong; Chen, Fang; Zhu, Bao-Qing; Ma, Li-Yan; Li, Li; Li, Jing-Ming

    2012-04-01

    The pleasantly fruity and floral 2-phenylethanol are a dominant aroma compound in post-ripening 'Vidal blanc' grapes. However, to date little has been reported about its synthetic pathway in grapevine. In the present study, a full-length cDNA of VvAADC (encoding aromatic amino acid decarboxylase) was firstly cloned from the berries of 'Vidal blanc', an interspecific hybrid variety of Vitis vinifera × Vitis riparia. This sequence encodes a complete open reading frame of 482 amino acids with a calculated molecular mass of 54 kDa and isoelectric point value (pI) of 5.73. The amino acid sequence deduced shared about 79% identity with that of aromatic L: -amino acid decarboxylases (AADCs) from tomato. Real-time PCR analysis indicated that VvAADC transcript abundance presented a small peak at 110 days after full bloom and then a continuous increase at the berry post-ripening stage, which was consistent with the accumulation of 2-phenylethanol, but did not correspond to the trends of two potential intermediates, phenethylamine and 2-phenylacetaldehyde. Furthermore, phenylalanine still exhibited a continuous increase even in post-ripening period. It is thus suggested that 2-phenylethanol biosynthetic pathway mediated by AADC exists in grape berries, but it has possibly little contribution to a considerable accumulation of 2-phenylethanol in post-ripening 'Vidal blanc' grapes.

  11. Identification of the orotidine-5'-monophosphate decarboxylase gene of the oleaginous yeast Rhodosporidium toruloides.

    Science.gov (United States)

    Yang, Fan; Zhang, Sufang; Tang, Wei; Zhao, Zongbao K

    2008-09-01

    Oleaginous yeast Rhodosporidium toruloides is an excellent microbial lipid producer of great industrial potential, yet there is no effective genetic tool for rationally engineering this microorganism. To develop a marker recycling system, the orotidine-5'-monophosphate (OMP) decarboxylase gene of R. toruloides (RtURA3) was isolated using methods of degenerate polymerase chain reaction (PCR) together with rapid amplification of cDNA ends. The results showed that RtURA3 contains four extrons and three introns, and that the encoded polypeptide holds a sequence of 279 amino acid residues with significant homology to those of OMP decarboxylases from other yeasts. A shuttle vector pYES2/CT-RtURA3 was constructed via site-specific insertion of RtURA3 into the commercial vector pYES2/CT. Transformation of the shuttle vector into Saccharomyces cerevisiae BY4741, a URA3-deficient yeast strain, ensured the viability of the strain on synthetic dextrose agar plate without uracil, suggesting that the isolated RtURA3 was functionally equivalent to the URA3 gene from S. cerevisiae.

  12. Crystal Structure and Substrate Specificity of Drosophila 3,4-Dihydroxyphenylalanine Decarboxylase

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Ding, H; Robinson, H; Christensen, B; Li, J

    2010-01-01

    3,4-Dihydroxyphenylalanine decarboxylase (DDC), also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses. In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82 and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine. The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins.

  13. Glutamic acid decarboxylase 67 expression by a distinct population of mouse vestibular supporting cells.

    Science.gov (United States)

    Tavazzani, Elisa; Tritto, Simona; Spaiardi, Paolo; Botta, Laura; Manca, Marco; Prigioni, Ivo; Masetto, Sergio; Russo, Giancarlo

    2014-01-01

    The function of the enzyme glutamate decarboxylase (GAD) is to convert glutamate in γ-aminobutyric acid (GABA). Glutamate decarboxylase exists as two major isoforms, termed GAD65 and GAD67, that are usually expressed in GABA-containing neurons in the central nervous system. GAD65 has been proposed to be associated with GABA exocytosis whereas GAD67 with GABA metabolism. In the present immunofluorescence study, we have investigated the presence of the two GAD isoforms in the semicircular canal cristae of wild type and GAD67-GFP knock-in mice. While no evidence for GAD65 expression was found, GAD67 was detected in a distinct population of peripherally-located supporting cells, but not in hair cells or in centrally-located supporting cells. GABA, on the other hand, was found in all supporting cells. The present result indicate that only a discrete population of supporting cells use GAD67 to synthesize GABA. This is the first report of a marker that allows to distinguish two populations of supporting cells in the vestibular epithelium. On the other hand, the lack of GABA and GAD enzymes in hair cells excludes its involvement in afferent transmission.

  14. Pyruvate Decarboxylase Activity Assay in situ of Different Industrial Yeast Strains

    Directory of Open Access Journals (Sweden)

    Dorota Kręgiel

    2009-01-01

    Full Text Available Cytoplasmic pyruvate decarboxylase (PDC, EC 4.1.1.1 is one of the key enzymes of yeast fermentative metabolism. PDC is the first enzyme which, under anaerobic conditions, leads to decarboxylation of pyruvate with acetaldehyde as the end product. The aim of this study is to develop a suitable method for PDC activity assay in situ for different industrial yeast strains. Saccharomyces sp. and Debaryomyces sp. yeast strains grew in fermentative medium with 12 % of glucose. Enzymatic assay was conducted in cell suspension treated with digitonin as permeabilisation agent, and with sodium pyruvate as a substrate, at temperature of 30 °C. Metabolites of PDC pathway were detected using gas chromatographic (GC technique. Various parameters like type and molar concentration of the substrate, minimal effective mass fraction of digitonin, cell concentration, reaction time and effect of pyrazole (alcohol dehydrogenase inhibitor were monitored to optimize PDC enzymatic assay in situ. In the concentration range of yeast cells from 1⋅10^7 to 1⋅10^8 per mL, linear correlation between the produced acetaldehyde and cell density was noticed. Only pyruvate was the specific substrate for pyruvate decarboxylase. In the presence of 0.05 M sodium pyruvate and 0.05 % digitonin, the enzymatic reaction was linear up to 20 min of the assay. During incubation, there was no formation of ethanol and, therefore, pyrazole was not necessary for the assay.

  15. Crystallization and preliminary X-ray analysis of the inducible lysine decarboxylase from Escherichia coli

    International Nuclear Information System (INIS)

    Alexopoulos, Eftichia; Kanjee, Usheer; Snider, Jamie; Houry, Walid A.; Pai, Emil F.

    2008-01-01

    The structure of the decameric inducible lysine decarboxylase from E. coli was determined by SIRAS using a hexatantalum dodecabromide (Ta 6 Br 12 2+ ) derivative. Model building and refinement are under way. The decameric inducible lysine decarboxylase (LdcI) from Escherichia coli has been crystallized in space groups C2 and C222 1 ; the Ta 6 Br 12 2+ cluster was used to derivatize the C2 crystals. The method of single isomorphous replacement with anomalous scattering (SIRAS) as implemented in SHELXD was used to solve the Ta 6 Br 12 2+ -derivatized structure to 5 Å resolution. Many of the Ta 6 Br 12 2+ -binding sites had twofold and fivefold noncrystallographic symmetry. Taking advantage of this feature, phase modification was performed in DM. The electron-density map of LdcI displays many features in agreement with the low-resolution negative-stain electron-density map [Snider et al. (2006 ▶), J. Biol. Chem.281, 1532–1546

  16. Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme

    International Nuclear Information System (INIS)

    Matte, Allan; Grosse, Stephan; Bergeron, Hélène; Abokitse, Kofi; Lau, Peter C. K.

    2010-01-01

    The crystal structure of phenolic acid decarboxylase from B. pumilus strain UI-670 has been determined and refined at 1.69 Å resolution. The enzyme is a dimer, with each subunit adopting a β-barrel structure belonging to the lipocalin fold. The decarboxylation of phenolic acids, including ferulic and p-coumaric acids, to their corresponding vinyl derivatives is of importance in the flavouring and polymer industries. Here, the crystal structure of phenolic acid decarboxylase (PAD) from Bacillus pumilus strain UI-670 is reported. The enzyme is a 161-residue polypeptide that forms dimers both in the crystal and in solution. The structure of PAD as determined by X-ray crystallography revealed a β-barrel structure and two α-helices, with a cleft formed at one edge of the barrel. The PAD structure resembles those of the lipocalin-fold proteins, which often bind hydrophobic ligands. Superposition of structurally related proteins bound to their cognate ligands shows that they and PAD bind their ligands in a conserved location within the β-barrel. Analysis of the residue-conservation pattern for PAD-related sequences mapped onto the PAD structure reveals that the conservation mainly includes residues found within the hydrophobic core of the protein, defining a common lipocalin-like fold for this enzyme family. A narrow cleft containing several conserved amino acids was observed as a structural feature and a potential ligand-binding site

  17. Benzoylformate analogues exhibit differential rate-determining steps in the benzoylformate decarboxylase reaction

    International Nuclear Information System (INIS)

    Garcia, G.A.; Weiss, P.M.; Cook, P.F.; Kenyon, G.L.; Cleland, W.W.

    1987-01-01

    Benzoylformate decarboxylase from Pseudomonas putida is a thiamine pyrophosphate (TPP)-dependent enzyme which converts benzoylformate to benzaldehyde and CO 2 . The rate-determining step(s) in the benzoylformate decarboxylase reaction for a series of substituted benzoylformates (p-CH 3 O, p-CH 3 , p-Cl, and m-F) were studied using solvent deuterium and 13 C kinetic isotope effects. The normal substrate was found to have two partially rate-determining steps; initial tetrahedral adduct formation (D 2 O-sensitive) and decarboxylation ( 13 C-sensitive). D 2 O and 13 C isotope effects indicate that electron-withdrawing substituents (p-Cl and m-F) remove the rate dependence upon decarboxylation such that only a D 2 O effect on (V/K) is observed. Conversely, electron-donating substituents increase the rate-dependence upon decarboxylation such that a larger 13 (V/K) is seen while the D 2 O effects on (V) and (V/K) are not dramatically different from those for benzoylformate. All of the data are consistent with substituent stabilization or destabilization of the carbanionic intermediate formed upon decarboxylation

  18. Crystal structure and substrate specificity of Drosophila 3,4-dihydroxyphenylalanine decarboxylase.

    Directory of Open Access Journals (Sweden)

    Qian Han

    2010-01-01

    Full Text Available 3,4-Dihydroxyphenylalanine decarboxylase (DDC, also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses.In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82 and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine.The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins.

  19. Evolutionary Trails of Plant Group II Pyridoxal Phosphate-Dependent Decarboxylase Genes.

    Science.gov (United States)

    Kumar, Rahul

    2016-01-01

    Type II pyridoxal phosphate-dependent decarboxylase (PLP_deC) enzymes play important metabolic roles during nitrogen metabolism. Recent evolutionary profiling of these genes revealed a sharp expansion of histidine decarboxylase genes in the members of Solanaceae family. In spite of the high sequence homology shared by PLP_deC orthologs, these enzymes display remarkable differences in their substrate specificities. Currently, limited information is available on the gene repertoires and substrate specificities of PLP_deCs which renders their precise annotation challenging and offers technical challenges in the immediate identification and biochemical characterization of their full gene complements in plants. Herein, we explored their evolutionary trails in a comprehensive manner by taking advantage of high-throughput data accessibility and computational approaches. We discussed the premise that has enabled an improved reconstruction of their evolutionary lineage and evaluated the factors offering constraints in their rapid functional characterization, till date. We envisage that the synthesized information herein would act as a catalyst for the rapid exploration of their biochemical specificity and physiological roles in more plant species.

  20. Plateau potentials in alpha‐motoneurones induced by intravenous injection of L‐dopa and clonidine in the spinal cat

    DEFF Research Database (Denmark)

    Conway, B. A.; Hultborn, H.; Kiehn, O.

    1988-01-01

    1. Intracellular recordings were made from lumbar alpha‐motoneurones in unanaesthetized decerebrate acute spinal cats. The response of motoneurones to direct current pulse injection or synaptic excitation was investigated following intravenous injection of L‐beta‐3,4‐dihydroxyphenylalanine (L....... It is demonstrated that plateau potentials in the motoneurones contribute to the late long‐lasting reflexes observed in L‐DOPA‐treated spinal cats. 7. It is concluded that L‐DOPA (and clonidine) change the response properties of the motoneurones in an analogous way to 5‐hydroxy‐DL‐tryptophan (5‐HTP...

  1. Differential effects of gaseous versus injectable anesthetics on changes in regional cerebral blood flow and metabolism induced by l-DOPA in a rat model of Parkinson's disease.

    Science.gov (United States)

    Bimpisidis, Zisis; Öberg, Carl M; Maslava, Natallia; Cenci, M Angela; Lundblad, Cornelia

    2017-06-01

    Preclinical imaging of brain activity requires the use of anesthesia. In this study, we have compared the effects of two widely used anesthetics, inhaled isoflurane and ketamine/xylazine cocktail, on cerebral blood flow and metabolism in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia. Specific tracers were used to estimate regional cerebral blood flow (rCBF - [ 14 C]-iodoantipyrine) and regional cerebral metabolic rate (rCMR - [ 14 C]-2-deoxyglucose) with a highly sensitive autoradiographic method. The two types of anesthetics had quite distinct effects on l-DOPA-induced changes in rCBF and rCMR. Isoflurane did not affect either the absolute rCBF values or the increases in rCBF in the basal ganglia after l-DOPA administration. On the contrary, rats anesthetized with ketamine/xylazine showed lower absolute rCBF values, and the rCBF increases induced by l-DOPA were masked. We developed a novel improved model to calculate rCMR, and found lower metabolic activities in rats anesthetized with isoflurane compared to animals anesthetized with ketamine/xylazine. Both anesthetics prevented changes in rCMR upon l-DOPA administration. Pharmacological challenges in isoflurane-anesthetized rats indicated that drugs mimicking the actions of ketamine/xylazine on adrenergic or glutamate receptors reproduced distinct effects of the injectable anesthetics on rCBF and rCMR. Our results highlight the importance of anesthesia in studies of cerebral flow and metabolism, and provide novel insights into mechanisms mediating abnormal neurovascular responses to l-DOPA in Parkinson's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Ibuprofen or piroxicam protects nigral neurons and delays the development of l-dopa induced dyskinesia in rats with experimental Parkinsonism: Influence on angiogenesis.

    Science.gov (United States)

    Teema, Asmaa M; Zaitone, Sawsan A; Moustafa, Yasser M

    2016-08-01

    Neuroinflammation and angiogenesis have been involved in the pathogenesis of Parkinson's disease (PD). This study investigated the effect of ibuprofen or piroxicam on the motor response to l-dopa and development of dyskinesia in Parkinsonian rats focusing on the anti-angiogenic role of the two non-steroidal anti-inflammatory drugs (NSAIDs). Rats were divided into nine groups as follows: Group I: the vehicle group, Group II: rotenone group, rats were injected with nine doses of rotenone (1 mg/kg/48 h), group III&IV: rats received rotenone + ibuprofen (10 or 30 mg/kg), Group V-VI: rats received rotenone + piroxicam (1 or 3 mg/kg), Group VII: rats received rotenone + l-dopa/carbidopa (100/10 mg/kg), Group VIII-IX: rats received rotenone + l-dopa/carbidopa + ibuprofen (30 mg/kg) or piroxicam (3 mg/kg). In general, drugs were administered daily for ten weeks. Rotenone-treated rats showed motor dysfunction, lower striatal dopamine, lower staining for nigral tyrosine hydroxylase but higher level of striatal cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) compared to vehicle-treated rats (P piroxicam in combination with l-dopa preserved the effect of l-dopa at the end of week 10, delayed the development of dyskinesia and decreased striatal COX-2 and VEGF levels. In conclusion, the current study suggests that ibuprofen and piroxicam are promising candidates for neuroprotection in PD and may have utility in conjunction with l-dopa in order to ensure the longevity of its action and to delay the development of dyskinesia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The added value of [{sup 18}F]fluoro-L-DOPA PET in the diagnosis of hyperinsulinism of infancy: a retrospective study involving 49 children

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Maria-Joao; Bourgeois, Sandrine; Delzescaux, Thierry [Frederic Joliot Hospital, Biomedical Imaging Institute, Life Sciences Division, CEA, Orsay (France); Boddaert, Nathalie; Brunelle, Francis [Necker-Enfants Malades Hospital, AP-HP, Department of Radiology, Paris (France); Bellanne-Chantelot, Christine [Saint-Antoine Hospital, AP-HP, Department of Cytogenetics, Paris (France); Valayannopoulos, Vassili; Lonlay, Pascale de [Necker-Enfants Malades Hospital, AP-HP, Department of Pediatrics, Paris (France); Jaubert, Francis [Necker-Enfants Malades Hospital, AP-HP, Department of Pathology, Paris (France); Nihoul-Fekete, Claire [Necker-Enfants Malades Hospital, AP-HP, Department of Surgery, Paris (France)

    2007-12-15

    Neuroendocrine diseases are a heterogeneous group of entities with the ability to take up amine precursors, such as L-DOPA, and convert them into biogenic amines, such as dopamine. Congenital hyperinsulinism of infancy (HI) is a neuroendocrine disease secondary to either focal adenomatous hyperplasia or a diffuse abnormal pancreatic insulin secretion. While focal hyperinsulinism may be reversed by selective surgical resection, diffuse forms require near-total pancreatectomy when resistant to medical treatment. Here, we report the diagnostic value of PET with [{sup 18}F]fluoro-L-DOPA in distinguishing focal from diffuse HI. Forty-nine children were studied with [{sup 18}F]fluoro-L-DOPA. A thoraco-abdominal scan was acquired 45-65 min after the injection of 4.2 {+-} 1.0 MBq/kg of [{sup 18}F]fluoro-L-DOPA. Additionally, 12 of the 49 children were submitted to pancreatic venous catheterisation for blood samples (PVS) and 31 were also investigated using MRI. We identified abnormal focal pancreatic uptake of [{sup 18}F]fluoro-L-DOPA in 15 children, whereas diffuse radiotracer uptake was observed in the pancreatic area in the other 34 patients. In children studied with both PET and PVS, the results were concordant in 11/12 cases. All patients with focal radiotracer uptake and nine of the patients with diffuse pancreatic radiotracer accumulation, unresponsive to medical treatment, were submitted to surgery. In 21 of these 24 patients, the histopathological results confirmed the PET findings. In focal forms, selective surgery was followed by clinical remission without carbohydrate intolerance. These data demonstrate that PET with [{sup 18}F]fluoro-L-DOPA is an accurate non-invasive technique allowing differential diagnosis between focal and diffuse forms of HI. (orig.)

  4. A retrospective comparison between 68Ga-DOTA-TOC PET/CT and 18F-DOPA PET/CT in patients with extra-adrenal paraganglioma.

    Science.gov (United States)

    Kroiss, Alexander; Putzer, Daniel; Frech, Andreas; Decristoforo, Clemens; Uprimny, Christian; Gasser, Rudolf Wolfgang; Shulkin, Barry Lynn; Url, Christoph; Widmann, Gerlig; Prommegger, Rupert; Sprinzl, Georg Mathias; Fraedrich, Gustav; Virgolini, Irene Johanna

    2013-12-01

    (18)F-Fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by (68)Ga-DOTA-Tyr(3)-octreotide ((68)Ga-DOTA-TOC) PET. Therefore, we compared (68)Ga-DOTA-TOC and (18)F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with (68)Ga-DOTA-TOC PET and (18)F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. Compared with anatomical imaging, (68)Ga-DOTA-TOC PET and (18)F-DOPA PET each had a per-patient and per-lesion detection rate of 100% in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of (68)Ga-DOTA-TOC was 100% and that of (18)F-DOPA PET was 56.0%. Overall, (68)Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and (18)F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of (68)Ga-DOTA-TOC PET was 100% (McNemar, P TOC PET and 11.8 ± 7.9 for (18)F-DOPA PET (Mann-Whitney U test, P TOC PET may be superior to (18)F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically inoperable tumours and metastatic or multifocal disease.

  5. Grading and outcome prediction of pediatric diffuse astrocytic tumors with diffusion and arterial spin labeling perfusion MRI in comparison with 18F-DOPA PET

    Energy Technology Data Exchange (ETDEWEB)

    Morana, Giovanni; Tortora, Domenico; Severino, Mariasavina; Rossi, Andrea [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Piccardo, Arnoldo; Cabria, Manlio [Ente Ospedaliero Ospedali Galliera, Nuclear Medicine Unit, Genoa (Italy); Puntoni, Matteo [Ente Ospedaliero Ospedali Galliera, Clinical Trial Unit, Scientific Directorate, Genoa (Italy); Nozza, Paolo [Istituto Giannina Gaslini, Pathology Unit, Genoa (Italy); Ravegnani, Marcello; Consales, Alessandro; Mascelli, Samantha; Raso, Alessandro [Istituto Giannina Gaslini, Neurosurgery Unit, Genoa (Italy); Verrico, Antonio; Milanaccio, Claudia [Istituto Giannina Gaslini, Neuro-oncology Unit, Genoa (Italy)

    2017-11-15

    The aim of this study was to investigate MRI-derived diffusion weighted imaging (DWI) and arterial spin labeling (ASL) perfusion imaging in comparison with {sup 18}F-dihydroxyphenylalanine (DOPA) PET with respect to diagnostic performance in tumor grading and outcome prediction in pediatric patients with diffuse astrocytic tumors (DAT). We retrospectively analyzed 26 children with histologically proven treatment naive low and high grade DAT who underwent ASL and DWI performed within 2 weeks of {sup 18}F-DOPA PET. Relative ASL-derived cerebral blood flow max (rCBF max) and DWI-derived minimum apparent diffusion coefficient (rADC min) were compared with {sup 18}F-DOPA uptake tumor/normal tissue (T/N) and tumor/striatum (T/S) ratios, and correlated with World Health Organization (WHO) tumor grade and progression-free survival (PFS). Statistics included Pearson's chi-square and Mann-Whitney U tests, Spearman's rank correlation, receiver operating characteristic (ROC) analysis, discriminant function analysis (DFA), Kaplan-Meier survival curve, and Cox analysis. A significant correlation was demonstrated between rCBF max, rADC min, and {sup 18}F-DOPA PET data (p < 0.001). Significant differences in terms of rCBF max, rADC min, and {sup 18}F-DOPA uptake were found between low- and high-grade DAT (p ≤ 0.001). ROC analysis and DFA demonstrated that T/S and T/N values were the best parameters for predicting tumor progression (AUC 0.93, p < 0.001). On univariate analysis, all diagnostic tools correlated with PFS (p ≤ 0.001); however, on multivariate analysis, only {sup 18}F-DOPA uptake remained significantly associated with outcome (p ≤ 0.03), while a trend emerged for rCBF max (p = 0.09) and rADC min (p = 0.08). The combination of MRI and PET data increased the predictive power for prognosticating tumor progression (AUC 0.97, p < 0.001). DWI, ASL and {sup 18}F-DOPA PET provide useful complementary information for pediatric DAT grading. {sup 18}F-DOPA uptake

  6. Prognostic value of {sup 18}F-DOPA PET/CT at the time of recurrence in patients affected by neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Piccardo, Arnoldo [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); E.O. Ospedali Galliera, Department of Nuclear Medicine, Genoa (Italy); Puntoni, Matteo [Galliera Hospital, Clinical Trial Research Unit, Genoa (Italy); Lopci, Egesta; Fanti, Stefano [Sant' Orsola-Malpighi Hospital, Nuclear Medicine Unit, Bologna (Italy); Conte, Massimo; Sorrentino, Stefania; Garaventa, Alberto [G. Gaslini Children' s Hospital, Department of Hematology-Oncology, Genoa (Italy); Foppiani, Luca [Galliera Hospital, Internal Medicine, Genoa (Italy); Morana, Giovanni [G. Gaslini Children' s Hospital, Department of Pathology and Radiology, Genoa (Italy); Naseri, Mehrdad; Villavecchia, Giampiero [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); Cistaro, Angelina [IRMET, PET Centre, Turin (Italy)

    2014-06-15

    The aim of this study was to investigate the relationship between {sup 123}I-metaiodobenzylguanidine (MIBG) scan semi-quantification and a new {sup 18}F-DOPA positron emission tomography (PET)/CT score in patients with suspected or documented neuroblastoma (NB) relapse and to assess the association between these two parameters and progression-free survival (PFS)/overall survival (OS). We analysed 24 NB patients who had undergone {sup 123}I-MIBG and {sup 18}F-DOPA PET/CT scans at the time of suspected relapse, after applying a proper scoring system for each scan. In time-to-event analyses, the score distributions were regarded as continuous and were categorized in tertiles and medians. We used Kaplan-Meier curves and Cox proportional hazard models for PFS and OS in order to estimate the independent prognostic impact of {sup 123}I-MIBG and {sup 18}F-DOPA PET/CT scans. The {sup 123}I-MIBG and {sup 18}F-DOPA scores were highly and positively correlated (Spearman's rho = 0.8, p < 0.001). Over a median follow-up of 14 months (range 6-82), 12 cases of disease progression and 6 deaths occurred. Multivariate Cox models showed a higher risk of disease progression [hazard ratio (HR) 17.0, 95 % confidence interval (CI) 2.7-109] in NB patients with {sup 123}I-MIBG score > 3 (3rd tertile) and an even higher risk (HR:37.2, 95 % CI 2.4-574) in those with {sup 18}F-DOPA whole-body metabolic burden (WBMB) >7.5 (median), after adjustment for all main clinical/pathological factors considered. Kaplan-Meier analyses showed a significant association with OS (log-rank p = 0.01 and p = 0.03 for {sup 123}I-MIBG and {sup 18}F-DOPA WBMB, respectively). Our results confirm the good agreement between {sup 18}F-DOPA PET/CT and {sup 123}I-MIBG scan in patients affected by NB relapse. In time-to-event analyses, {sup 123}I-MIBG scan and {sup 18}F-DOPA PET/CT scores were independently and significantly associated with disease progression. (orig.)

  7. Evaluation of blood-brain barrier transport and CNS drug metabolism in diseased and control brain after intravenous L-DOPA in a unilateral rat model of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Ravenstijn Paulien GM

    2012-02-01

    Full Text Available Abstract Background Changes in blood-brain barrier (BBB functionality have been implicated in Parkinson's disease. This study aimed to investigate BBB transport of L-DOPA transport in conjunction with its intra-brain conversion, in both control and diseased cerebral hemispheres in the unilateral rat rotenone model of Parkinson's disease. Methods In Lewis rats, at 14 days after unilateral infusion of rotenone into the medial forebrain bundle, L-DOPA was administered intravenously (10, 25 or 50 mg/kg. Serial blood samples and brain striatal microdialysates were analysed for L-DOPA, and the dopamine metabolites DOPAC and HVA. Ex-vivo brain tissue was analyzed for changes in tyrosine hydroxylase staining as a biomarker for Parkinson's disease severity. Data were analysed by population pharmacokinetic analysis (NONMEM to compare BBB transport of L-DOPA in conjunction with the conversion of L-DOPA into DOPAC and HVA, in control and diseased cerebral hemisphere. Results Plasma pharmacokinetics of L-DOPA could be described by a 3-compartmental model. In rotenone responders (71%, no difference in L-DOPA BBB transport was found between diseased and control cerebral hemisphere. However, in the diseased compared with the control side, basal microdialysate levels of DOPAC and HVA were substantially lower, whereas following L-DOPA administration their elimination rates were higher. Conclusions Parkinson's disease-like pathology, indicated by a huge reduction of tyrosine hydroxylase as well as by substantially reduced levels and higher elimination rates of DOPAC and HVA, does not result in changes in BBB transport of L-DOPA. Taking the results of this study and that of previous ones, it can be concluded that changes in BBB functionality are not a specific characteristic of Parkinson's disease, and cannot account for the decreased benefit of L-DOPA at later stages of Parkinson's disease.

  8. The function of glycine decarboxylase complex is optimized to maintain high photorespiratory flux via buffering of its reaction products

    DEFF Research Database (Denmark)

    Bykova, Natalia V; Møller, Ian Max; Gardeström, Per

    2014-01-01

    oxidase. We discuss here possible mechanisms of high photorespiratory flux maintenance in mitochondria and suggest that it is fulfilled under conditions where the concentrations of glycine decarboxylase reaction products NADH and CO2 achieve an equilibrium provided by malate dehydrogenase and carbonic...

  9. Effects of polyamine biosynthesis inhibitors on S-adenosylmethionine synthetase and S-adenosylmethionine decarboxylase activities in carrot cell cultures

    Science.gov (United States)

    S.C. Minocha; R. Minocha; A. Komamine

    1991-01-01

    Changes in the activites of S-adcnosylmethionine (SAM) synthetase (methionine adenosyltransferase, EC 2.5.1.6.) and SAM decarboxylase (EC 4.1.1.50) were studied in carrot (Daucus carota) cell cultures in response to 2,4-dichlorophenoxyacetic acid (2,4-D) and several inhibitors of polyamine biosynthesis. Activity of SAM synthetase increased...

  10. An internal deletion in MTH1 enables growth on glucose of pyruvate-decarboxylase negative, non-fermentative Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Oud, B.; Flores, C.L.; Gancedo, C.; Zhang, X.; Trueheart, J.; Daran, J.M.; Pronk, J.T.; Van Maris, A.J.A.

    2012-01-01

    Background Pyruvate-decarboxylase negative (Pdc-) strains of Saccharomyces cerevisiae combine the robustness and high glycolytic capacity of this yeast with the absence of alcoholic fermentation. This makes Pdc-S. cerevisiae an interesting platform for efficient conversion of glucose towards

  11. National Elevation Dataset (NED)

    Data.gov (United States)

    Kansas Data Access and Support Center — The U.S. Geological Survey has developed a National Elevation Database (NED). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation...

  12. Elevated Liver Enzymes

    Science.gov (United States)

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  13. Dopa-responsive dystonia: functional analysis of single nucleotide substitutions within the 5' untranslated GCH1 region.

    Directory of Open Access Journals (Sweden)

    Ioanna A Armata

    Full Text Available BACKGROUND: Mutations in the GCH1 gene are associated with childhood onset, dopa-responsive dystonia (DRD. Correct diagnosis of DRD is crucial, given the potential for complete recovery once treated with L-dopa. The majority of DRD associated mutations lie within the coding region of the GCH1 gene, but three additional single nucleotide sequence substitutions have been reported within the 5' untranslated (5'UTR region of the mRNA. The biologic significance of these 5'UTR GCH1 sequence substitutions has not been analyzed. METHODOLOGY/PRINCIPAL FINDINGS: Luciferase reporter assays, quantitative real time PCR and RNA decay assays, combined with bioinformatics, revealed a pathogenic 5'UTR GCH1 substitution. The +142C>T single nucleotide 5'UTR substitution that segregates with affected status in DRD patients, substantially attenuates translation without altering RNA expression levels or stability. The +142C>T substitution disrupts translation most likely by creating an upstream initiation start codon (uAUG and an upstream open reading frame (uORF. CONCLUSIONS/SIGNIFICANCE: This is the first GCH1 regulatory substitution reported to act at a post-transcriptional level, increasing the list of genetic diseases caused by abnormal translation and reaffirming the importance of investigating potential regulatory substitutions in genetic diseases.

  14. Singlet oxygen generation during the oxidation of L-tyrosine and L-dopa with mushroom tyrosinase

    Energy Technology Data Exchange (ETDEWEB)

    Miyaji, Akimitsu [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259-G1-14, Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kohno, Masahiro [Department of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-G1-25 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Inoue, Yoshihiro [Showa Pharmaceutical University, 3-3165 Higashi-tamagawagakuen, Machida, Tokyo 194-8543 (Japan); Baba, Toshihide, E-mail: tbaba@chemenv.titech.ac.jp [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259-G1-14, Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

    2016-03-18

    The generation of singlet oxygen during the oxidation of tyrosine and L-dopa using mushroom tyrosinase in a phosphate buffer (pH 7.4), the model of melanin synthesis in melanocytes, was examined. The reaction was performed in the presence of 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP), an acceptor of singlet oxygen and the electron spin resonance (ESR) of the spin adduct, 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy (4-oxo-TEMPO), was measured. An increase in the ESR signal attributable to 4-oxo-TEMPO was observed during the oxidation of tyrosine and L-dopa with tyrosinase, indicating the generation of singlet oxygen. The results suggest that {sup 1}O{sub 2} generation via tyrosinase-catalyzed melanin synthesis occurs in melanocyte. - Highlights: • Generation of singlet oxygen was observed during tyrosinase-catalyzed tyrosine oxidation. • The singlet oxygen generated when tyrosine was converted into dopachrome. • The amount of singlet oxygen is not sufficient for cell toxicity. • It decreased when the hydroxyl radicals and/or superoxide anions were trapped.

  15. Contribution of glutamate decarboxylase in Lactobacillus reuteri to acid resistance and persistence in sourdough fermentation.

    Science.gov (United States)

    Su, Marcia S; Schlicht, Sabine; Gänzle, Michael G

    2011-08-30

    Acid stress impacts the persistence of lactobacilli in industrial sourdough fermentations, and in intestinal ecosystems. However, the contribution of glutamate to acid resistance in lactobacilli has not been demonstrated experimentally, and evidence for the contribution of acid resistance to the competitiveness of lactobacilli in sourdough is lacking. It was therefore the aim of this study to investigate the ecological role of glutamate decarboxylase in L. reuteri. A gene coding for a putative glutamate decarboxylase, gadB, was identified in the genome of L. reuteri 100-23. Different from the organization of genetic loci coding for glutamate decarboxylase in other lactic acid bacteria, gadB was located adjacent to a putative glutaminase gene, gls3. An isogenic deletion mutant, L. reuteri ∆gadB, was generated by a double crossover method. L. reuteri 100-23 but not L. reuteri ∆gadB converted glutamate to γ-aminobutyrate (GABA) in phosphate butter (pH 2.5). In sourdough, both strains converted glutamine to glutamate but only L. reuteri 100-23 accumulated GABA. Glutamate addition to phosphate buffer, pH 2.5, improved survival of L. reuteri 100-23 100-fold. However, survival of L. reuteri ∆gadB remained essentially unchanged. The disruption of gadB did not affect growth of L. reuteri in mMRS or in sourdough. However, the wild type strain L. reuteri 100-23 displaced L. reuteri ∆gadB after 5 cycles of fermentation in back-slopped sourdough fermentations. The conversion of glutamate to GABA by L. reuteri 100-23 contributes to acid resistance and to competitiveness in industrial sourdough fermentations. The organization of the gene cluster for glutamate conversion, and the availability of amino acids in cereals imply that glutamine rather than glutamate functions as the substrate for GABA formation. The exceptional coupling of glutamine deamidation to glutamate decarboxylation in L. reuteri likely reflects adaptation to cereal substrates.

  16. Expression and functional analysis of the lysine decarboxylase and copper amine oxidase genes from the endophytic fungus Colletotrichum gloeosporioides ES026.

    Science.gov (United States)

    Zhang, Xiangmei; Wang, Zhangqian; Jan, Saad; Yang, Qian; Wang, Mo

    2017-06-05

    Huperzine A (HupA) isolated from Huperzia serrata is an important compound used to treat Alzheimer's disease (AD). Recently, HupA was reported in various endophytic fungi, with Colletotrichum gloeosporioides ES026 previously isolated from H. serrata shown to produce HupA. In this study, we performed next-generation sequencing and de novo RNA sequencing of C. gloeosporioides ES026 to elucidate the molecular functions, biological processes, and biochemical pathways of these unique sequences. Gene ontology and Kyoto Encyclopedia of Genes and Genomes assignments allowed annotation of lysine decarboxylase (LDC) and copper amine oxidase (CAO) for their conversion of L-lysine to 5-aminopentanal during HupA biosynthesis. Additionally, we constructed a stable, high-yielding HupA-expression system resulting from the overexpression of CgLDC and CgCAO from the HupA-producing endophytic fungus C. gloeosporioides ES026 in Escherichia coli. Quantitative reverse transcription polymerase chain reaction analysis confirmed CgLDC and CgCAO expression, and quantitative determination of HupA levels was assessed by liquid chromatography high-resolution mass spectrometry, which revealed that elevated expression of CgLDC and CgCAO produced higher yields of HupA than those derived from C. gloeosporioides ES026. These results revealed CgLDC and CgCAO involvement in HupA biosynthesis and their key role in regulating HupA content in C. gloeosporioides ES026.

  17. Adaptive mutations in sugar metabolism restore growth on glucose in a pyruvate decarboxylase negative yeast strain

    DEFF Research Database (Denmark)

    Zhang, Yiming; Liu, Guodong; Engqvist, Martin K. M.

    2015-01-01

    Background: A Saccharomyces cerevisiae strain carrying deletions in all three pyruvate decarboxylase (PDC) genes (also called Pdc negative yeast) represents a non-ethanol producing platform strain for the production of pyruvate derived biochemicals. However, it cannot grow on glucose as the sole...... DNA sequencing. Among these genetic changes, 4 genes were found to carry point mutations in at least two of the evolved strains: MTH1 encoding a negative regulator of the glucose-sensing signal transduction pathway, HXT2 encoding a hexose transporter, CIT1 encoding a mitochondrial citrate synthase...... further increased the maximum specific growth rate to 0.069 h-1. Conclusions: In this study, possible evolving mechanisms of Pdc negative strains on glucose were investigated by genome sequencing and reverse engineering. The non-synonymous mutations in MTH1 alleviated the glucose repression by repressing...

  18. Discovery and characterization of gut microbiota decarboxylases that can produce the neurotransmitter tryptamine.

    Science.gov (United States)

    Williams, Brianna B; Van Benschoten, Andrew H; Cimermancic, Peter; Donia, Mohamed S; Zimmermann, Michael; Taketani, Mao; Ishihara, Atsushi; Kashyap, Purna C; Fraser, James S; Fischbach, Michael A

    2014-10-08

    Several recent studies describe the influence of the gut microbiota on host brain and behavior. However, the mechanisms responsible for microbiota-nervous system interactions are largely unknown. Using a combination of genetics, biochemistry, and crystallography, we identify and characterize two phylogenetically distinct enzymes found in the human microbiome that decarboxylate tryptophan to form the β-arylamine neurotransmitter tryptamine. Although this enzymatic activity is exceedingly rare among bacteria more broadly, analysis of the Human Microbiome Project data demonstrate that at least 10% of the human population harbors at least one bacterium encoding a tryptophan decarboxylase in their gut community. Our results uncover a previously unrecognized enzymatic activity that can give rise to host-modulatory compounds and suggests a potential direct mechanism by which gut microbiota can influence host physiology, including behavior. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. MUCUNA PRURIENS - IMPROVEMENT OF THE BIOTECHNOLOGICAL PRODUCTION OF THE ANTI-PARKINSON DRUG L-DOPA BY PLANT-CELL SELECTION

    NARCIS (Netherlands)

    PRAS, N; WOERDENBAG, HJ; BATTERMAN, S; VISSER, JF; VANUDEN, W

    1993-01-01

    Routinely grown cell suspension cultures of Mucuna pruriens L. (Fabaceae) were able to endogenously accumulate the anti-Parkinson drug L-dihydroxyphenylalanine (L-dopa) in the range between 0.2 and 2% on a dry weight (DW) basis. The green colour that developed in light-exposed cultures, appeared to

  20. Single or combined treatment with L-DOPA and quinpirole differentially modulate expression and phosphorylation of key regulatory kinases in neuroblastoma cells.

    Science.gov (United States)

    Fuzzati-Armentero, Marie Therese; Ghezzi, Cristina; Nisticò, Robert; Oda, Adriano; Blandini, Fabio

    2013-09-27

    In the past decades, the clinical use of dopamine agonists has expanded from adjunct therapy in patients with a deteriorating response to L-3,4-dihydroxyphenylalanine (L-DOPA) to monotherapy for the treatment of early PD. Dopamine agonists provide their antiparkinsonian benefit through stimulation of brain postsynaptic type 2 dopamine receptors that exert their effect through classical cAMP-dependent mechanisms, as well as cAMP-independent cellular signaling cascades, including the Akt/glycogen synthase kinase 3 (GSK3) pathway. Alterations of Akt/GSK3 have been observed and may contribute to the neurodegenerative processes and the development of L-DOPA-induced dyskinesia. The effects L-DOPA and quinpirole, a dopamine agonist, on the two key regulatory kinases, Akt and GSK3, were evaluated in neuroblastoma cell line. L-DOPA and dopamine agonist dose-dependently and differentially modulated Akt and GSK3 expression and phosphorylation when added alone or combined. The combined treatment inverted or potentiated the modulatory properties of the single compound. The drug- and concentration-dependent balance of dopamine receptor stimulation over auto-oxidation may distinctively modulate GSK3 isoforms and Akt. Our results indicate that particular attention must be given to drug concentration and combination when multiple therapies are applied for the clinical treatment of PD patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. In vivo trypanocidal activities of new S-adenosylmethionine decarboxylase inhibitors.

    Science.gov (United States)

    Bacchi, C J; Brun, R; Croft, S L; Alicea, K; Bühler, Y

    1996-01-01

    A series of novel aromatic derivatives based on the structure of methylglyoxal bis(guanylhydrazone) (MGBG) was examined for trypanocidal activities in human and veterinary trypanosomes of African origin. One agent, CGP 40215A, a bicyclic analog of MGBG which also resembles the diamidines diminazene (Berenil) and pentamidine, was curative of infections by 19 isolates of Trypanosoma brucei subspecies as well as a Trypanosoma congolense isolate. Several of these isolates were resistant to standard trypanocides. Curative doses were < or = 25 mg/kg of body weight/day for 3 days in these acute laboratory model infections. In addition, CGP 40215A also cured a model central nervous system infection in combination with the ornithine decarboxylase inhibitor DL-alpha-difluoromethylornithine (DFMO; Ornidyl, eflornithine). Curative combinations were 14 days of oral 2% DFMO (approximately 5 g/kg/day) plus 5, 10, or 25 mg/kg/day for 3 or 7 days given by intraperitoneal injection or with a miniosmotic pump. Combinations were most effective if CGP 40215A was given in the second half or at the end of the DFMO regimen. MGBG has modest activity as an inhibitor of trypanosome S-adenosylmethionine decarboxylase (50% inhibitory concentration [IC50]. 130 microM), while CGP 40215A was a more active inhibitor (IC50, 20 microM). Preincubation of trypanosomes with CGP 40215A for 1 h caused a reduction in spermidine content (36%) and an increase in putrescine content (20%), indicating that one possible mechanism of its action may be inhibition of polyamine biosynthesis. PMID:8726018

  2. 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism. A blinded evaluation

    International Nuclear Information System (INIS)

    Dahl Christiansen, Charlotte; Helleskov Rasmussen, Annett; Petersen, Henrik; Lerberg Nielsen, Anne; Detlefsen, Soenke; Brusgaard, Klaus; Rasmussen, Lars; Hovendal, Claus; Melikyan, Maria; Ekstroem, Klas; Globa, Evgenia; Christesen, Henrik Thybo

    2018-01-01

    Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3 -octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV max ) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUV max ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV max cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively. 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged. (orig.)

  3. Comparison between 68Ga-DOTA-NOC and 18F-DOPA PET for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours

    International Nuclear Information System (INIS)

    Ambrosini, Valentina; Tomassetti, Paola; Castellucci, Paolo; Campana, Davide; Montini, Giancarlo; Rubello, Domenico; Nanni, Cristina; Rizzello, Anna; Franchi, Roberto; Fanti, Stefano

    2008-01-01

    18 F-FDG positron emission tomography (PET) value for the assessment of neuro-endocrine tumours (NET) is limited. Preliminary studies indicate that 18 F-DOPA and 68 Ga-DOTA-NOC are more accurate for disease assessment and 68 Ga-DOTA peptides provide additional data on receptor status that are crucial for targeted radionuclide therapy. At present, there are no comparative studies investigating their role in NET. The aim of this study was to compare 68 Ga-DOTA-NOC and 18 F-DOPA for the evaluation of gastro-entero-pancreatic and lung neuro-endocrine tumours. Thirteen patients with biopsy-proven NET (gastro-entero-pancreatic or pulmonary) were prospectively enrolled and scheduled for 18 F-DOPA and 68 Ga-DOTA-NOC PET. PET results obtained with both tracers were compared with each other, with other conventional diagnostic procedures (CT, ultrasound) and with follow-up (clinical, imaging). The most common primary tumour site was the pancreas (8/13) followed by the ileum (2/13), the lung (2/13) and the duodenum (1/13). The carcinoma was well differentiated in 10/13 and poorly differentiated in 3/13 cases. 68 Ga-DOTA-NOC PET was positive, showing at least one lesion, in 13/13 cases while 18 F-DOPA PET was positive in 9/13. On a lesions basis, 68 Ga-DOTA-NOC identified more lesions than 18 F-DOPA (71 vs 45), especially at liver, lung and lymph node level. 68 Ga-DOTA-NOC correctly identified the primary site in six of eight non-operated cases (in five cases, the primary was surgically removed before PET), while 18 F-DOPA identified the primary only in two of eight cases. Although the patients studied are few and heterogeneous, our data show that 68 Ga-DOTA-NOC is accurate for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours in either the primary or metastatic site and that it offers several advantages over 18 F-DOPA. (orig.)

  4. Comparison between 68Ga-DOTA-NOC and 18F-DOPA PET for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours.

    Science.gov (United States)

    Ambrosini, Valentina; Tomassetti, Paola; Castellucci, Paolo; Campana, Davide; Montini, Giancarlo; Rubello, Domenico; Nanni, Cristina; Rizzello, Anna; Franchi, Roberto; Fanti, Stefano

    2008-08-01

    (18)F-FDG positron emission tomography (PET) value for the assessment of neuro-endocrine tumours (NET) is limited. Preliminary studies indicate that (18)F-DOPA and (68)Ga-DOTA-NOC are more accurate for disease assessment and (68)Ga-DOTA peptides provide additional data on receptor status that are crucial for targeted radionuclide therapy. At present, there are no comparative studies investigating their role in NET. The aim of this study was to compare (68)Ga-DOTA-NOC and (18)F-DOPA for the evaluation of gastro-entero-pancreatic and lung neuro-endocrine tumours. Thirteen patients with biopsy-proven NET (gastro-entero-pancreatic or pulmonary) were prospectively enrolled and scheduled for (18)F-DOPA and (68)Ga-DOTA-NOC PET. PET results obtained with both tracers were compared with each other, with other conventional diagnostic procedures (CT, ultrasound) and with follow-up (clinical, imaging). The most common primary tumour site was the pancreas (8/13) followed by the ileum (2/13), the lung (2/13) and the duodenum (1/13). The carcinoma was well differentiated in 10/13 and poorly differentiated in 3/13 cases. (68)Ga-DOTA-NOC PET was positive, showing at least one lesion, in 13/13 cases while (18)F-DOPA PET was positive in 9/13. On a lesions basis, (68)Ga-DOTA-NOC identified more lesions than (18)F-DOPA (71 vs 45), especially at liver, lung and lymph node level. (68)Ga-DOTA-NOC correctly identified the primary site in six of eight non-operated cases (in five cases, the primary was surgically removed before PET), while (18)F-DOPA identified the primary only in two of eight cases. Although the patients studied are few and heterogeneous, our data show that (68)Ga-DOTA-NOC is accurate for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours in either the primary or metastatic site and that it offers several advantages over (18)F-DOPA.

  5. 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism. A blinded evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Dahl Christiansen, Charlotte; Helleskov Rasmussen, Annett [Hans Christian Andersen Children' s Hospital, Odense University Hospital, Odense (Denmark); University of Southern Denmark, Department of Clinical Research, Odense (Denmark); Petersen, Henrik; Lerberg Nielsen, Anne [Odense University Hospital, Department of Nuclear Medicine, Odense (Denmark); Detlefsen, Soenke [University of Southern Denmark, Department of Clinical Research, Odense (Denmark); Odense University Hospital, Department of Pathology, Odense (Denmark); Brusgaard, Klaus [Odense University Hospital, Department of Clinical Genetics, Odense (Denmark); Rasmussen, Lars; Hovendal, Claus [Odense University Hospital, Department of Abdominal Surgery, Odense (Denmark); Melikyan, Maria [Endocrine Research Centre, Moscow (Russian Federation); Ekstroem, Klas [Karolinska Hospital, Astrid Lindgren Children' s Hospital, Stockholm (Sweden); Globa, Evgenia [MOH of Ukraine, Ukrainian Center of Endocrine Surgery, Endocrine Organs and Tissue Transplantation, Kyiv (Ukraine); Christesen, Henrik Thybo [Hans Christian Andersen Children' s Hospital, Odense University Hospital, Odense (Denmark); University of Southern Denmark, Department of Clinical Research, Odense (Denmark); Odense University Hospital, Odense Pancreas Center (OPAC), Odense (Denmark); Odense University Hospital, Department of Paediatrics, Odense C (Denmark)

    2018-02-15

    Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3 -octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV{sub max}) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUV{sub max} ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV{sub max} cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively. 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged. (orig.)

  6. Transgenic Centipedegrass (Eremochloa ophiuroides [Munro] Hack. Overexpressing S-Adenosylmethionine Decarboxylase (SAMDC Gene for Improved Cold Tolerance Through Involvement of H2O2 and NO Signaling

    Directory of Open Access Journals (Sweden)

    Jianhao Luo

    2017-09-01

    Full Text Available Centipedegrass (Eremochloa ophiuroides [Munro] Hack. is an important warm-season turfgrass species. Transgenic centipedgrass plants overexpressing S-adenosylmethionine decarboxylase from bermudagrass (CdSAMDC1 that was induced in response to cold were generated in this study. Higher levels of CdSAMDC1 transcript and sperimidine (Spd and spermin (Spm concentrations and enhanced freezing and chilling tolerance were observed in transgenic plants as compared with the wild type (WT. Transgenic plants had higher levels of polyamine oxidase (PAO activity and H2O2 than WT, which were blocked by pretreatment with methylglyoxal bis (guanylhydrazone or MGBG, inhibitor of SAMDC, indicating that the increased PAO and H2O2 were a result of expression of CdSAMDC1. In addition, transgenic plants had higher levels of nitrate reductase (NR activity and nitric oxide (NO concentration. The increased NR activity were blocked by pretreatment with MGBG and ascorbic acid (AsA, scavenger of H2O2, while the increased NO level was blocked by MGBG, AsA, and inhibitors of NR, indicating that the enhanced NR-derived NO was dependent upon H2O2, as a result of expression CdSAMDC1. Elevated superoxide dismutase (SOD and catalase (CAT activities were observed in transgenic plants than in WT, which were blocked by pretreatment with MGBG, AsA, inhibitors of NR and scavenger of NO, indicating that the increased activities of SOD and CAT depends on expression of CdSAMDC1, H2O2, and NR-derived NO. Our results suggest that the elevated cold tolerance was associated with PAO catalyzed production of H2O2, which in turn led to NR-derived NO production and induced antioxidant enzyme activities in transgenic plants.

  7. Cardiac dysfunction and peri-weaning mortality in malonyl-coenzyme A decarboxylase (MCD) knockout mice as a consequence of restricting substrate plasticity.

    Science.gov (United States)

    Aksentijević, Dunja; McAndrew, Debra J; Karlstädt, Anja; Zervou, Sevasti; Sebag-Montefiore, Liam; Cross, Rebecca; Douglas, Gillian; Regitz-Zagrosek, Vera; Lopaschuk, Gary D; Neubauer, Stefan; Lygate, Craig A

    2014-10-01

    Inhibition of malonyl-coenzyme A decarboxylase (MCD) shifts metabolism from fatty acid towards glucose oxidation, which has therapeutic potential for obesity and myocardial ischemic injury. However, ~40% of patients with MCD deficiency are diagnosed with cardiomyopathy during infancy. To clarify the link between MCD deficiency and cardiac dysfunction in early life and to determine the contributing systemic and cardiac metabolic perturbations. MCD knockout mice ((-/-)) exhibited non-Mendelian genotype ratios (31% fewer MCD(-/-)) with deaths clustered around weaning. Immediately prior to weaning (18days) MCD(-/-) mice had lower body weights, elevated body fat, hepatic steatosis and glycogen depletion compared to wild-type littermates. MCD(-/-) plasma was hyperketonemic, hyperlipidemic, had 60% lower lactate levels and markers of cellular damage were elevated. MCD(-/-) hearts exhibited hypertrophy, impaired ejection fraction and were energetically compromised (32% lower total adenine nucleotide pool). However differences between WT and MCD(-/-) converged with age, suggesting that, in surviving MCD(-/-) mice, early cardiac dysfunction resolves over time. These observations were corroborated by in silico modelling of cardiomyocyte metabolism, which indicated improvement of the MCD(-/-) metabolic phenotype and improved cardiac efficiency when switched from a high-fat diet (representative of suckling) to a standard post-weaning diet, independent of any developmental changes. MCD(-/-) mice consistently exhibited cardiac dysfunction and severe metabolic perturbations while on a high-fat, low carbohydrate diet of maternal milk and these gradually resolved post-weaning. This suggests that dysfunction is a common feature of MCD deficiency during early development, but that severity is dependent on composition of dietary substrates. Copyright © 2014. Published by Elsevier Ltd.

  8. Transgenic Centipedegrass (Eremochloa ophiuroides [Munro] Hack.) Overexpressing S-Adenosylmethionine Decarboxylase (SAMDC) Gene for Improved Cold Tolerance Through Involvement of H2O2 and NO Signaling.

    Science.gov (United States)

    Luo, Jianhao; Liu, Mingxi; Zhang, Chendong; Zhang, Peipei; Chen, Jingjing; Guo, Zhenfei; Lu, Shaoyun

    2017-01-01

    Centipedegrass ( Eremochloa ophiuroides [Munro] Hack.) is an important warm-season turfgrass species. Transgenic centipedgrass plants overexpressing S-adenosylmethionine decarboxylase from bermudagrass ( CdSAMDC1 ) that was induced in response to cold were generated in this study. Higher levels of CdSAMDC1 transcript and sperimidine (Spd) and spermin (Spm) concentrations and enhanced freezing and chilling tolerance were observed in transgenic plants as compared with the wild type (WT). Transgenic plants had higher levels of polyamine oxidase (PAO) activity and H 2 O 2 than WT, which were blocked by pretreatment with methylglyoxal bis (guanylhydrazone) or MGBG, inhibitor of SAMDC, indicating that the increased PAO and H 2 O 2 were a result of expression of CdSAMDC1 . In addition, transgenic plants had higher levels of nitrate reductase (NR) activity and nitric oxide (NO) concentration. The increased NR activity were blocked by pretreatment with MGBG and ascorbic acid (AsA), scavenger of H 2 O 2 , while the increased NO level was blocked by MGBG, AsA, and inhibitors of NR, indicating that the enhanced NR-derived NO was dependent upon H 2 O 2 , as a result of expression CdSAMDC1 . Elevated superoxide dismutase (SOD) and catalase (CAT) activities were observed in transgenic plants than in WT, which were blocked by pretreatment with MGBG, AsA, inhibitors of NR and scavenger of NO, indicating that the increased activities of SOD and CAT depends on expression of CdSAMDC1 , H 2 O 2 , and NR-derived NO. Our results suggest that the elevated cold tolerance was associated with PAO catalyzed production of H 2 O 2 , which in turn led to NR-derived NO production and induced antioxidant enzyme activities in transgenic plants.

  9. Rapid screening for cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L. using liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Xing, Jie; Yang, Zijuan; Lv, Beibei; Xiang, Lan

    2008-05-01

    A simple and rapid qualitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for screening cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L. at sub-ppm levels. An electrospray ionization orbitrap mass spectrometer, which provides accurate full scan MS and MS/MS data, was used in this study. After simple extraction with ethanol and purification by AB-8 resin, the extracts were subjected to LC/MS/MS analysis. A high mass tolerance (10 ppm) was used in the initial screening to filter the full scan MS data. The cyclo-dopa and diketopiperazine alkaloid standards gave limits of detection (LODs) at or below 5 ng/mL. The results also indicated that the method had an acceptable precision for day-to-day use in the identification of compounds. The alkaloids could be identified based on their MS/MS data, elemental compositions, and retention behavior. This system was used to assay trace amounts of cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L., leading to the identification of 5/2 confirmed/unconfirmed cyclo-dopa and 7/6 confirmed/unconfirmed diketopiperazine alkaloids, respectively. The screening method considerably reduces the time and cost involved in the identification of cyclo-dopa and diketopiperazine alkaloids in Portulaca oleracea L., as well as being a simple and convenient approach to the identification of other structural families of natural products. Copyright (c) 2008 John Wiley & Sons, Ltd.

  10. Do the metabolites of 6-[F-18]fluoro-L-dopa and of [F-18]fluoro-meta-L-tyrosine contribute to the F-18 accumulation in the human brain?

    International Nuclear Information System (INIS)

    Firnau, G.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

    1990-01-01

    The purpose of this study was to determine if the metabolites of 6-[F-18]fluoro-L-dopa (F-dopa) and of [F-18]fluoro-meta-L-tyrosine (FmLtyr) contribute to the accumulation of fluorine-18 in the brain through unspecific retention. PET studies were conducted on a healthy human subject who was treated with both of the radiopharmaceuticals and their labelled metabolites. Results indicated that in contrast to F-dopa, the metabolite of FmLtyr does not 'contaminate' the brain with extraneous fluorine-18

  11. Directed evolution of pyruvate decarboxylase-negative Saccharomyces cerevisiae, yielding a C2-independent, glucose-tolerant, and pyruvate-hyperproducing yeast

    NARCIS (Netherlands)

    A.J. van Maris; J.M. Geertman; A. Vermeulen; M.K. Groothuizen; A.A. Winkler; M.D. Piper; J.P. van Dijken; J.T. Pronk

    2004-01-01

    textabstractThe absence of alcoholic fermentation makes pyruvate decarboxylase-negative (Pdc(-)) strains of Saccharomyces cerevisiae an interesting platform for further metabolic engineering of central metabolism. However, Pdc(-) S. cerevisiae strains have two growth defects:

  12. A novel missense mutation pattern of the GCH1 gene in dopa-responsive dystonia Novo padrão de mutação missense no gene GCH1 na distonia dopa-responsiva

    Directory of Open Access Journals (Sweden)

    Rosana H. Scola

    2007-12-01

    Full Text Available Dopa-responsive dystonia (DRD is an inherited metabolic disorder now classified as DYT5 with two different biochemical defects: autosomal dominant GTP cyclohydrolase 1 (GCH1 deficiency or autosomal recessive tyrosine hydroxylase deficiency. We report the case of a 10-years-old girl with progressive generalized dystonia and gait disorder who presented dramatic response to levodopa. The phenylalanine to tyrosine ratio was significantly higher after phenylalanine loading test. This condition had two different heterozygous mutations in the GCH1 gene: the previously reported P23L mutation and a new Q182E mutation. The characteristics of the DRD and the molecular genetic findings are discussed.Distonia dopa-responsiva (DRD, classificada como DYT5, é um erro inato do metabolismo que pode ser causado por dois diferentes tipos de defeito bioquímico: deficiência de GTP ciclo-hidrolase 1 (GCH1 (autossômica dominante ou de tirosina hidroxilase (autossômica recessiva. Descrevemos o caso de menina de 10 anos com distonia generalizada progressiva e alteração da marcha com importante melhora após uso de levodopa. A relação fenilalanina/tirosina estava aumentada após teste de sobrecarga com fenilalanina. O estudo molecular mostrou que o paciente apresenta uma combinação hererozigótica de mutação no gene GCH1: a já conhecida mutação P23L e uma nova mutação Q182E. Discutem-se as características da DRD e as alterações genéticas possíveis.

  13. Danish children born with glutamic acid decarboxylase-65 and islet antigen-2 autoantibodies at birth had an increased risk to develop type 1 diabetes

    DEFF Research Database (Denmark)

    Eising, Stefanie; Nilsson, Anita; Carstensen, Bendix

    2011-01-01

    A large, population-based case-control cohort was used to test the hypothesis that glutamic acid decarboxylase-65 (GAD65) and islet antigen-2 autoantibodies (IA-2A) at birth predict type 1 diabetes.......A large, population-based case-control cohort was used to test the hypothesis that glutamic acid decarboxylase-65 (GAD65) and islet antigen-2 autoantibodies (IA-2A) at birth predict type 1 diabetes....

  14. Polyamine and amino acid content, and activity of polyamine-synthesizing decarboxylases, in liver of streptozotocin-induced diabetic and insulin-treated diabetic rats

    OpenAIRE

    Brosnan, Margaret E.; Roebothan, Barbara V.; Hall, Douglas E.

    1980-01-01

    1. Concentrations of polyamines, amino acids, glycogen, nucleic acids and protein, and activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, were measured in livers from control, streptozotocin-diabetic and insulin-treated diabetic rats. 2. Total DNA per liver and protein per mg of DNA were unaffected by diabetes, whereas RNA per mg of DNA and glycogen per g of liver were decreased. Insulin treatment of diabetic rats induced both hypertrophy and hyperplasia, as indicat...

  15. Nature or Nurture? Determining the Heritability of Human Striatal Dopamine Function: an [18F]-DOPA PET Study

    Science.gov (United States)

    Stokes, Paul R A; Shotbolt, Paul; Mehta, Mitul A; Turkheimer, Eric; Benecke, Aaf; Copeland, Caroline; Turkheimer, Federico E; Lingford-Hughes, Anne R; Howes, Oliver D

    2013-01-01

    Striatal dopamine function is important for normal personality, cognitive processes and behavior, and abnormalities are linked to a number of neuropsychiatric disorders. However, no studies have examined the relative influence of genetic inheritance and environmental factors in determining striatal dopamine function. Using [18F]-DOPA positron emission tomography (PET), we sought to determine the heritability of presynaptic striatal dopamine function by comparing variability in uptake values in same sex monozygotic (MZ) twins to dizygotic (DZ) twins. Nine MZ and 10 DZ twin pairs underwent high-resolution [18F]-DOPA PET to assess presynaptic striatal dopamine function. Uptake values for the overall striatum and functional striatal subdivisions were determined by a Patlak analysis using a cerebellar reference region. Heritability, shared environmental effects and non-shared individual-specific effects were estimated using a region of interest (ROI) analysis and a confirmatory parametric analysis. Overall striatal heritability estimates from the ROI and parametric analyses were 0.44 and 0.33, respectively. We found a distinction between striatal heritability in the functional subdivisions, with the greatest heritability estimates occurring in the sensorimotor striatum and the greatest effect of individual-specific environmental factors in the limbic striatum. Our results indicate that variation in overall presynaptic striatal dopamine function is determined by a combination of genetic factors and individual-specific environmental factors, with familial environmental effects having no effect. These findings underline the importance of individual-specific environmental factors for striatal dopaminergic function, particularly in the limbic striatum, with implications for understanding neuropsychiatric disorders such as schizophrenia and addictions. PMID:23093224

  16. Antileishmanial activity of berenil and methylglyoxal bis (guanylhydrazone) and its correlation with S-adenosylmethionine decarboxylase and polyamines.

    Science.gov (United States)

    Mukhopadhyay, R; Madhubala, R

    1995-01-01

    Leishmania donovani S-adenosyl-L-methionine (AdoMet) decarboxylase was found to show a growth related pattern. Methylglyoxal bis (guanylhydrazone) (MGBG) and Berenil inhibited the growth of Leishmania donovani promastigotes (strain UR6) in a dose dependent manner. The concentrations of MGBG and Berenil required for 50% inhibition of rate of growth were 67 and 47 microM, respectively. The growth inhibition of MGBG was partially reversed by spermidine (100 microM) and spermine (100 microM). Berenil inhibition of promastigote growth was partially reversed by 100 microM spermidine whereas 100 microM spermine did not result in any reversal of growth. The reduction in parasitemia in vitro by these inhibitors was accompanied by inhibition of AdoMet decarboxylase activity and spermidine levels.

  17. Local anesthetics inhibit induction of ornithine decarboxylase by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate.

    OpenAIRE

    Yuspa, S H; Lichti, U; Ben, T

    1980-01-01

    The induction of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) activity in mouse epidermal cells in vivo and in vitro occurs rapidly after exposure to the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). This induction has characteristics of a cell surface receptor-mediated process. Local anesthetics modify a variety of cellular responses mediated by membrane receptors. When cultured mouse epidermal cells were exposed to the local anesthetics lidocaine, tetracaine...

  18. Enhancement of protocatechuate decarboxylase activity for the effective production of muconate from lignin-related aromatic compounds.

    Science.gov (United States)

    Sonoki, Tomonori; Morooka, Miyuki; Sakamoto, Kimitoshi; Otsuka, Yuichiro; Nakamura, Masaya; Jellison, Jody; Goodell, Barry

    2014-12-20

    The decarboxylation reaction of protocatechuate has been described as a bottleneck and a rate-limiting step in cis,cis-muconate (ccMA) bioproduction from renewable feedstocks such as sugar. Because sugars are already in high demand in the development of many bio-based products, our work focuses on improving protocatechuate decarboxylase (Pdc) activity and ccMA production in particular, from lignin-related aromatic compounds. We previously had transformed an Escherichia coli strain using aroY, which had been used as a protocatechuate decarboxylase encoding gene from Klebsiella pneumoniae subsp. pneumoniae A170-40, and inserted other required genes from Pseudomonas putida KT2440, to allow the production of ccMA from vanillin. This recombinant strain produced ccMA from vanillin, however the Pdc reaction step remained a bottleneck during incubation. In the current study, we identify a way to increase protocatechuate decarboxylase activity in E. coli through enzyme production involving both aroY and kpdB; the latter which encodes for the B subunit of 4-hydroxybenzoate decarboxylase. This permits expression of Pdc activity at a level approximately 14-fold greater than the strain with aroY only. The expression level of AroY increased, apparently as a function of the co-expression of AroY and KpdB. Our results also imply that ccMA may inhibit vanillate demethylation, a reaction step that is rate limiting for efficient ccMA production from lignin-related aromatic compounds, so even though ccMA production may be enhanced, other challenges to overcome vanilate demethylation inhibition still remain.

  19. Iowa Bedrock Surface Elevation

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This Digital Elevation Model (DEM) of the bedrock surface elevation in Iowa was compiled using all available data, principally information from GEOSAM, supplemented...

  20. Acid Evolution of Escherichia coli K-12 Eliminates Amino Acid Decarboxylases and Reregulates Catabolism.

    Science.gov (United States)

    He, Amanda; Penix, Stephanie R; Basting, Preston J; Griffith, Jessie M; Creamer, Kaitlin E; Camperchioli, Dominic; Clark, Michelle W; Gonzales, Alexandra S; Chávez Erazo, Jorge Sebastian; George, Nadja S; Bhagwat, Arvind A; Slonczewski, Joan L

    2017-06-15

    Acid-adapted strains of Escherichia coli K-12 W3110 were obtained by serial culture in medium buffered at pH 4.6 (M. M. Harden, A. He, K. Creamer, M. W. Clark, I. Hamdallah, K. A. Martinez, R. L. Kresslein, S. P. Bush, and J. L. Slonczewski, Appl Environ Microbiol 81:1932-1941, 2015, https://doi.org/10.1128/AEM.03494-14). Revised genomic analysis of these strains revealed insertion sequence (IS)-driven insertions and deletions that knocked out regulators CadC (acid induction of lysine decarboxylase), GadX (acid induction of glutamate decarboxylase), and FNR (anaerobic regulator). Each acid-evolved strain showed loss of one or more amino acid decarboxylase systems, which normally help neutralize external acid (pH 5 to 6) and increase survival in extreme acid (pH 2). Strains from populations B11, H9, and F11 had an IS 5 insertion or IS-mediated deletion in cadC , while population B11 had a point mutation affecting the arginine activator adiY The cadC and adiY mutants failed to neutralize acid in the presence of exogenous lysine or arginine. In strain B11-1, reversion of an rpoC (RNA polymerase) mutation partly restored arginine-dependent neutralization. All eight strains showed deletion or downregulation of the Gad acid fitness island. Strains with the Gad deletion lost the ability to produce GABA (gamma-aminobutyric acid) and failed to survive extreme acid. Transcriptome sequencing (RNA-seq) of strain B11-1 showed upregulated genes for catabolism of diverse substrates but downregulated acid stress genes (the biofilm regulator ariR , yhiM , and Gad). Other strains showed downregulation of H 2 consumption mediated by hydrogenases ( hya and hyb ) which release acid. Strains F9-2 and F9-3 had a deletion of fnr and showed downregulation of FNR-dependent genes ( dmsABC , frdABCD , hybABO , nikABCDE , and nrfAC ). Overall, strains that had evolved in buffered acid showed loss or downregulation of systems that neutralize unbuffered acid and showed altered regulation of

  1. Involvement of the ornithine decarboxylase gene in acid stress response in probiotic Lactobacillus delbrueckii UFV H2b20.

    Science.gov (United States)

    Ferreira, A B; Oliveira, M N V de; Freitas, F S; Paiva, A D; Alfenas-Zerbini, P; Silva, D F da; Queiroz, M V de; Borges, A C; Moraes, C A de

    2015-01-01

    Amino acid decarboxylation is important for the maintenance of intracellular pH under acid stress. This study aims to carry out phylogenetic and expression analysis by real-time PCR of two genes that encode proteins involved in ornithine decarboxylation in Lactobacillus delbrueckii UFV H2b20 exposed to acid stress. Sequencing and phylogeny analysis of genes encoding ornithine decarboxylase and amino acid permease in L. delbrueckii UFV H2b20 showed their high sequence identity (99%) and grouping with those of L. delbrueckii subsp. bulgaricus ATCC 11842. Exposure of L. delbrueckii UFV H2b20 cells in MRS pH 3.5 for 30 and 60 min caused a significant increase in expression of the gene encoding ornithine decarboxylase (up to 8.1 times higher when compared to the control treatment). Increased expression of the ornithine decarboxylase gene demonstrates its involvement in acid stress response in L. delbrueckii UFV H2b20, evidencing that the protein encoded by that gene could be involved in intracellular pH regulation. The results obtained show ornithine decarboxylation as a possible mechanism of adaptation to an acidic environmental condition, a desirable and necessary characteristic for probiotic cultures and certainly important to the survival and persistence of the L. delbrueckii UFV H2b20 in the human gastrointestinal tract.

  2. Characterisation of a thiamine diphosphate-dependent alpha-keto acid decarboxylase from Proteus mirabilis JN458.

    Science.gov (United States)

    Wang, Biying; Bai, Yajun; Fan, Taiping; Zheng, Xiaohui; Cai, Yujie

    2017-10-01

    Alpha-keto acid decarboxylases can convert keto acids to their corresponding aldehydes, which are often volatile aroma compounds. The gene encoding α-keto acid decarboxylase in Proteus mirabilis JN458 was cloned, and the enzyme overexpressed in Escherichia coli BL21 (DE3), purified in high yield, and characterised. The molecular weight is 62.291kDa by MALDI-TOF MS, and optimum activity at pH 6.0 and 40-50°C. The enzyme is a typical decarboxylase, dependent on thiamine diphosphate and Mg 2+ as cofactors. For the decarboxylation reaction, the enzyme displayed a broad substrate range. Kinetic parameters were determined using 4-methyl-2-oxopentanoic acid, phenyl pyruvate and 3-methyl-2-oxopentanoic acid as substrates. K m and k cat values for phenyl pyruvate were 0.62mM and 77.38s -1 , respectively, and the k cat /K m value was 124.81mM -1 s -1 . The enzyme properties suggest it may act effectively under cheese ripening conditions. Copyright © 2017. Published by Elsevier Ltd.

  3. 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism: a blinded evaluation.

    Science.gov (United States)

    Christiansen, Charlotte Dahl; Petersen, Henrik; Nielsen, Anne Lerberg; Detlefsen, Sönke; Brusgaard, Klaus; Rasmussen, Lars; Melikyan, Maria; Ekström, Klas; Globa, Evgenia; Rasmussen, Annett Helleskov; Hovendal, Claus; Christesen, Henrik Thybo

    2018-02-01

    Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3-octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV max ) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUV max ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV max cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p PET/CT and 68Ga-DOTANOC PET/CT, respectively. 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged.

  4. Levodopa/benserazide microsphere (LBM) prevents L-dopa induced dyskinesia by inactivation of the DR1/PKA/P-tau pathway in 6-OHDA-lesioned Parkinson's rats.

    Science.gov (United States)

    Xie, Cheng-long; Wang, Wen-Wen; Zhang, Su-fang; Yuan, Ming-Lu; Che, Jun-Yi; Gan, Jing; Song, Lu; Yuan, Wei-En; Liu, Zhen-Guo

    2014-12-16

    L-3, 4-dihydroxyphenylalanine (L-dopa) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of L-dopa-induced dyskinesia (LID). In the present study, L-dopa and benserazide were loaded by poly (lactic-co-glycolic acid) microspheres (LBM), which can release levodopa and benserazide in a sustained manner in order to continuous stimulate dopaminergic receptors. We investigated the role of striatal DR1/PKA/P-tau signal transduction in the molecular event underlying LID in the 6-OHDA-lesioned rat model of PD. We found that animals rendered dyskinetic by L-dopa treatment, administration of LBM prevented the severity of AIM score, as well as improvement in motor function. Moreover, we also showed L-dopa elicits profound alterations in the activity of three LID molecular markers, namely DR1/PKA/P-tau (ser396). These modifications are totally prevented by LBM treatment, a similar way to achieve continuous dopaminergic delivery (CDD). In conclusion, our experiments provided evidence that intermittent administration of L-dopa, but not continuous delivery, and DR1/PKA/p-tau (ser396) activation played a critical role in the molecular and behavioural induction of LID in 6-OHDA-lesioned rats. In addition, LBM treatment prevented the development of LID by inhibiting the expression of DR1/PKA/p-tau, as well as PPEB mRNA in dyskintic rats.

  5. Rapid adaptation of the stimulatory effect of CO2 on brain norepinephrine metabolism.

    Science.gov (United States)

    Stone, E A

    1983-12-01

    The present study examined the effects of exposure of rats to elevated environmental levels of CO2 on norepinephrine metabolism in the hypothalamus and other regions of the brain. In confirmation of previous findings by others CO2 at 10 or 15% was found to elevate both dopa accumulation after dopa decarboxylase inhibition and norepinephrine utilization after tyrosine hydroxylase inhibition. These effects however were found to be transient occurring only during the first 30 min of 2.5 h exposure. In this regard CO2 differs from another form of stress, restraint which produces a sustained 2.5 h increase of dopa accumulation and NE accumulation. Restraint was also more effective than CO2 in depleting endogenous stores of hypothalamic NE. The factor responsible for the adaptation of the catecholamine response to CO2 was not identified although it was shown not to be hypothermia and it was reversed by a 2 h CO2-free recovery period.

  6. Uroporphyrinogen decarboxylase is a radiosensitizing target for head and neck cancer.

    Science.gov (United States)

    Ito, Emma; Yue, Shijun; Moriyama, Eduardo H; Hui, Angela B; Kim, Inki; Shi, Wei; Alajez, Nehad M; Bhogal, Nirmal; Li, Guohua; Datti, Alessandro; Schimmer, Aaron D; Wilson, Brian C; Liu, Peter P; Durocher, Daniel; Neel, Benjamin G; O'Sullivan, Brian; Cummings, Bernard; Bristow, Rob; Wrana, Jeff; Liu, Fei-Fei

    2011-01-26

    Head and neck cancer (HNC) is the eighth most common malignancy worldwide, comprising a diverse group of cancers affecting the head and neck region. Despite advances in therapeutic options over the last few decades, treatment toxicities and overall clinical outcomes have remained disappointing, thereby underscoring a need to develop novel therapeutic approaches in HNC treatment. Uroporphyrinogen decarboxylase (UROD), a key regulator of heme biosynthesis, was identified from an RNA interference-based high-throughput screen as a tumor-selective radiosensitizing target for HNC. UROD knockdown plus radiation induced caspase-mediated apoptosis and cell cycle arrest in HNC cells in vitro and suppressed the in vivo tumor-forming capacity of HNC cells, as well as delayed the growth of established tumor xenografts in mice. This radiosensitization appeared to be mediated by alterations in iron homeostasis and increased production of reactive oxygen species, resulting in enhanced tumor oxidative stress. Moreover, UROD was significantly overexpressed in HNC patient biopsies. Lower preradiation UROD mRNA expression correlated with improved disease-free survival, suggesting that UROD could potentially be used to predict radiation response. UROD down-regulation also radiosensitized several different models of human cancer, as well as sensitized tumors to chemotherapeutic agents, including 5-fluorouracil, cisplatin, and paclitaxel. Thus, our study has revealed UROD as a potent tumor-selective sensitizer for both radiation and chemotherapy, with potential relevance to many human malignancies.

  7. Benchmarking pKa prediction methods for Lys115 in acetoacetate decarboxylase.

    Science.gov (United States)

    Liu, Yuli; Patel, Anand H G; Burger, Steven K; Ayers, Paul W

    2017-05-01

    Three different pK a prediction methods were used to calculate the pK a of Lys115 in acetoacetate decarboxylase (AADase): the empirical method PROPKA, the multiconformation continuum electrostatics (MCCE) method, and the molecular dynamics/thermodynamic integration (MD/TI) method with implicit solvent. As expected, accurate pK a prediction of Lys115 depends on the protonation patterns of other ionizable groups, especially the nearby Glu76. However, since the prediction methods do not explicitly sample the protonation patterns of nearby residues, this must be done manually. When Glu76 is deprotonated, all three methods give an incorrect pK a value for Lys115. If protonated, Glu76 is used in an MD/TI calculation, the pK a of Lys115 is predicted to be 5.3, which agrees well with the experimental value of 5.9. This result agrees with previous site-directed mutagenesis studies, where the mutation of Glu76 (negative charge when deprotonated) to Gln (neutral) causes no change in K m , suggesting that Glu76 has no effect on the pK a shift of Lys115. Thus, we postulate that the pK a of Glu76 is also shifted so that Glu76 is protonated (neutral) in AADase. Graphical abstract Simulated abundances of protonated species as pH is varied.

  8. S-adenosylmethionine decarboxylase inhibitors: new aryl and heteroaryl analogues of methylglyoxal bis(guanylhydrazone).

    Science.gov (United States)

    Stanek, J; Caravatti, G; Capraro, H G; Furet, P; Mett, H; Schneider, P; Regenass, U

    1993-01-08

    A series of 3-acylbenzamidine (amidino)hydrazones 7a-h, the corresponding (hetero)aromatic congeners 7i-p, and 3,3'-bis-amidino-biaryls 25a-e were synthesized. The hydrazones 7a-p were prepared by conversion of the corresponding acyl nitriles 1a,c-d,i,n-p to the imido esters 3a,c-d,i and the amidines 5a,c-d,h-i, followed by a reaction with aminoguanidine, or vice versa. Similarly, the biaryl 3,3'-dinitriles 23a-e were converted, via the imino esters 24a-c or the imino thioesters 27d-e, to the diamidines 25a-e. These new products are conformationally constrained analogues of methylglyoxal bis(guanylhydrazone) (MGBG). They are up to 100 times more potent as inhibitors of rat liver S-adenosylmethionine decarboxylase (SMDC) and generally less potent inhibitors of rat small intestine diamine oxidase (DAO) than MGBG. Some of these SAMDC inhibitors, e.g., compounds 7a, 7e, 7i, 25a, and 25d, have shown antiproliferative effects against T24 human bladder carcinoma cells. These products, whose structure-activity relationships are discussed, are of interest as potential anticancer agents and drugs for the treatment of protozoal and Pneumocystis carinii infections.

  9. Pyruvate decarboxylase provides growing pollen tubes with a competitive advantage in petunia.

    Science.gov (United States)

    Gass, Nathalie; Glagotskaia, Tatiana; Mellema, Stefan; Stuurman, Jeroen; Barone, Mario; Mandel, Therese; Roessner-Tunali, Ute; Kuhlemeier, Cris

    2005-08-01

    Rapid pollen tube growth places unique demands on energy production and biosynthetic capacity. The aim of this work is to understand how primary metabolism meets the demands of such rapid growth. Aerobically grown pollen produce ethanol in large quantities. The ethanolic fermentation pathway consists of two committed enzymes: pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH). Because adh mutations do not affect male gametophyte function, the obvious question is why pollen synthesize an abundant enzyme if they could do just as well without. Using transposon tagging in Petunia hybrida, we isolated a null mutant in pollen-specific Pdc2. Growth of the mutant pollen tubes through the style is reduced, and the mutant allele shows reduced transmission through the male, when in competition with wild-type pollen. We propose that not ADH but rather PDC is the critical enzyme in a novel, pollen-specific pathway. This pathway serves to bypass pyruvate dehydrogenase enzymes and thereby maintain biosynthetic capacity and energy production under the unique conditions prevailing during pollen-pistil interaction.

  10. Measurement of activity for S-adenosylmethionine decarboxylase using radioisotope {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Kyong Cheol; Park, Sang Hyun [Radiation Research Center for Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kamio, Yoshiyuku [Division of Bioscience and Biotechnology for Future Bioindustries, Graduate School of Agricultural Science, Tohoku University (Japan)

    2007-05-15

    Polyamines are essential for normal cell growth and have important physiological function. They are polycationic compounds that are present in all biological materials. Also, they have been implicated in a wide variety of biological reactions. Generally, putrescine and spermidine are contained high amount in prokaryote, but spermidine and spermine are in eukaryote, respectively. However, S. ruminantium cells contain the polyamins such as spermidine and spermine. Addition of an aminopropyl group to putrescine conducts to the synthesis of spermidine. Aminopropyl group is derived from the dcSAM, a decarboxylation of S-adenosylmethionine, through action of S-adenosylmethionine decarboxylase (SAMDC). We suggested that S. ruminantium has a different pathway compare with prokaryote for polyamine synthesis. Assay for SAMDC activity was used {sup 14}C labeled substrate. Key enzyme in the biosynthesis of polyamines, SAMDC, was purified from S. ruminantium and characterized. The enzyme was purified about 1,259-fold to electrophoretic homogeneity with a specific activity of 1.89×10{sup -5} kat kg'-{sup 1} of protein.

  11. Measurement of activity for S-adenosylmethionine decarboxylase using radioisotope 14C

    International Nuclear Information System (INIS)

    Ko, Kyong Cheol; Park, Sang Hyun; Kamio, Yoshiyuku

    2007-01-01

    Polyamines are essential for normal cell growth and have important physiological function. They are polycationic compounds that are present in all biological materials. Also, they have been implicated in a wide variety of biological reactions. Generally, putrescine and spermidine are contained high amount in prokaryote, but spermidine and spermine are in eukaryote, respectively. However, S. ruminantium cells contain the polyamins such as spermidine and spermine. Addition of an aminopropyl group to putrescine conducts to the synthesis of spermidine. Aminopropyl group is derived from the dcSAM, a decarboxylation of S-adenosylmethionine, through action of S-adenosylmethionine decarboxylase (SAMDC). We suggested that S. ruminantium has a different pathway compare with prokaryote for polyamine synthesis. Assay for SAMDC activity was used 14 C labeled substrate. Key enzyme in the biosynthesis of polyamines, SAMDC, was purified from S. ruminantium and characterized. The enzyme was purified about 1,259-fold to electrophoretic homogeneity with a specific activity of 1.89×10 -5 kat kg'- 1 of protein

  12. Renal ornithine decarboxylase activity, polyamines, and compensatory renal hypertrophy in the rat

    International Nuclear Information System (INIS)

    Humphreys, M.H.; Etheredge, S.B.; Lin, Shanyan; Ribstein, J.; Marton, L.J.

    1988-01-01

    The authors determined the role of ornithine decarboxylase (ODC) in compensatory renal hypertrophy (CRH) by relating renal ODC activity and polyamine content to kidney size, expressed as a percent of body weight, 1 wk after unilateral nephrectomy (UN). In normal rats, renal ODC activity increased after UN; 1 wk later the remaining kidney weight had increased. Renal concentration of putrescine, the product of ODC's decarboxylation of ornithine, was increased 3, 8, and 48 h after UN, but concentrations of polyamines synthesized later in the pathway, spermidine and spermine, were not appreciably affected. Pretreatment with difluoromethylornithine (DFMO), an irreversible inhibitor of ODC inhibited both base-line renal ODC activity and putrescine concentration as well as increases stimulated by UN, although concentrations of spermidine and spermine were not decreased. In hypophysectomized rats, both increased renal ODC activity and CRH occurred as well, indicating that these two consequences of UN do not require intact pituitary function. Thus stimulation of renal ODC activity and putrescine content do not appear critical to the process of CRH after UN

  13. Insights on ornithine decarboxylase silencing as a potential strategy for targeting retinoblastoma.

    Science.gov (United States)

    Muthukumaran, Sivashanmugam; Bhuvanasundar, Renganathan; Umashankar, Vetrivel; Sulochana, K N

    2018-02-01

    Ornithine Decarboxylase (ODC) is a key enzyme involved in polyamine synthesis and is reported to be up regulated in several cancers. However, the effect of ODC gene silencing in retinoblastoma is to be understood for utilization in therapeutic applications. Hence, in this study, a novel siRNA (small interference RNA) targeting ODC was designed and validated in Human Y79 retinoblastoma cells for its effects on intracellular polyamine levels, Matrix Metalloproteinase 2 & 9 activity and Cell cycle. The designed siRNA showed efficient silencing of ODC mRNA expression and protein levels in Y79 cells. It also showed significant reduction of intracellular polyamine levels and altered levels of oncogenic LIN28b expression. By this study, a regulatory loop is proposed, wherein, ODC silencing in Y79 cells to result in decreased polyamine levels, thereby, leading to altered protein levels of Lin28b, MMP-2 and MMP-9, which falls in line with earlier studies in neuroblastoma. Thus, by this study, we propose ODC silencing as a prospective strategy for targeting retinoblastoma. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Screening and kinetics of glutaminase and glutamate decarboxylase producing lactic acid bacteria from fermented Thai foods

    Directory of Open Access Journals (Sweden)

    Sasimar Woraharn

    2014-12-01

    Full Text Available L-glutaminase and glutamic acid decarboxylase (GAD catalyzes the hydrolysis of L-glutamine and glutamate, respectively. L-glutaminase widely used in cancer therapy along with a combination of other enzymes and most importantly these enzymes were used in food industries, as a major catalyst of bioconversion. The current investigation was aimed to screen and select L-glutaminase, and GAD producing lactic acid bacteria (LAB. A total of 338 LAB were isolated from fermented meat, fermented fish, fermented soya bean, fermented vegetables and fruits. Among 338 isolates, 22 and 237 LAB has been found to be positive for L-glutaminase and GAD, respectively. We found that 30 days of incubation at 35 ºC and pH 6.0 was the optimum condition for glutaminase activity by G507/1. G254/2 was found to be the best for GAD activity with the optimum condition of pH 6.5, temperature 40 ºC and ten days of incubation. These LAB strains, G507/1 and G254/2, were identified as close relative of Lactobacillus brevis ATCC 14869 and Lactobacillus fermentum NBRC 3956, respectively by 16S rRNA sequencing. Further, improvements in up-stream of the fermentation process with these LAB strains are currently under development.

  15. The Relationship among Tyrosine Decarboxylase and Agmatine Deiminase Pathways in Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Marta Perez

    2017-11-01

    Full Text Available Enterococci are considered mainly responsible for the undesirable accumulation of the biogenic amines tyramine and putrescine in cheeses. The biosynthesis of tyramine and putrescine has been described as a species trait in Enterococcus faecalis. Tyramine is formed by the decarboxylation of the amino acid tyrosine, by the tyrosine decarboxylase (TDC route encoded in the tdc cluster. Putrescine is formed from agmatine by the agmatine deiminase (AGDI pathway encoded in the agdi cluster. These biosynthesis routes have been independently studied, tyrosine and agmatine transcriptionally regulate the tdc and agdi clusters. The objective of the present work is to study the possible co-regulation among TDC and AGDI pathways in E. faecalis. In the presence of agmatine, a positive correlation between putrescine biosynthesis and the tyrosine concentration was found. Transcriptome studies showed that tyrosine induces the transcription of putrescine biosynthesis genes and up-regulates pathways involved in cell growth. The tyrosine modulation over AGDI route was not observed in the mutant Δtdc strain. Fluorescence analyses using gfp as reporter protein revealed PaguB (the promoter of agdi catabolic genes was induced by tyrosine in the wild-type but not in the mutant strain, confirming that tdc cluster was involved in the tyrosine induction of putrescine biosynthesis. This study also suggests that AguR (the transcriptional regulator of agdi was implicated in interaction among the two clusters.

  16. Histidine Decarboxylase Knockout Mice as a Model of the Pathophysiology of Tourette Syndrome and Related Conditions.

    Science.gov (United States)

    Pittenger, Christopher

    2017-01-01

    While the normal functions of histamine (HA) in the central nervous system have gradually come into focus over the past 30 years, the relationship of abnormalities in neurotransmitter HA to human disease has been slower to emerge. New insight came with the 2010 description of a rare nonsense mutation in the biosynthetic enzyme histidine decarboxylase (Hdc) that was associated with Tourette syndrome (TS) and related conditions in a single family pedigree. Subsequent genetic work has provided further support for abnormalities of HA signaling in sporadic TS. As a result of this genetic work, Hdc knockout mice, which were generated more than 15 years ago, have been reexamined as a model of the pathophysiology of TS and related conditions. Parallel work in these KO mice and in human carriers of the Hdc mutation has revealed abnormalities in the basal ganglia system and its modulation by dopamine (DA) and has confirmed the etiologic, face, and predictive validity of the model. The Hdc-KO model thus serves as a unique platform to probe the pathophysiology of TS and related conditions, and to generate specific hypotheses for subsequent testing in humans. This chapter summarizes the development and validation of this model and recent and ongoing work using it to further investigate pathophysiological changes that may contribute to these disorders.

  17. Transcriptional response to deletion of the phosphatidylserine decarboxylase Psd1p in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Gsell, Martina; Mascher, Gerald; Schuiki, Irmgard; Ploier, Birgit; Hrastnik, Claudia; Daum, Günther

    2013-01-01

    In the yeast, Saccharomyces cerevisiae, the synthesis of the essential phospholipid phosphatidylethanolamine (PE) is accomplished by a network of reactions which comprises four different pathways. The enzyme contributing most to PE formation is the mitochondrial phosphatidylserine decarboxylase 1 (Psd1p) which catalyzes conversion of phosphatidylserine (PS) to PE. To study the genome wide effect of an unbalanced cellular and mitochondrial PE level and in particular the contribution of Psd1p to this depletion we performed a DNA microarray analysis with a ∆psd1 deletion mutant. This approach revealed that 54 yeast genes were significantly up-regulated in the absence of PSD1 compared to wild type. Surprisingly, marked down-regulation of genes was not observed. A number of different cellular processes in different subcellular compartments were affected in a ∆psd1 mutant. Deletion mutants bearing defects in all 54 candidate genes, respectively, were analyzed for their growth phenotype and their phospholipid profile. Only three mutants, namely ∆gpm2, ∆gph1 and ∆rsb1, were affected in one of these parameters. The possible link of these mutations to PE deficiency and PSD1 deletion is discussed.

  18. Aspartate beta-decarboxylase from Alcaligenes faecalis: carbon-13 kinetic isotope effect and deuterium exchange experiments

    International Nuclear Information System (INIS)

    Rosenberg, R.M.; O'Leary, M.H.

    1985-01-01

    The authors have measured the 13 C kinetic isotope effect at pH 4.0, 5.0, 6.0, and 6.5 and in D 2 O at pH 5.0 and the rate of D-H exchange of the alpha and beta protons of aspartic acid in D 2 O at pH 5.0 for the reaction catalyzed by the enzyme aspartate beta-decarboxylase from Alcaligenes faecalis. The 13 C kinetic isotope effect, with a value of 1.0099 +/- 0.0002 at pH 5.0, is less than the intrinsic isotope effect for the decarboxylation step, indicating that the decarboxylation step is not entirely rate limiting. The authors have been able to estimate probable values of the relative free energies of the transition states of the enzymatic reaction up to and including the decarboxylation step from the 13 C kinetic isotope effect and the rate of D-H exchange of alpha-H. The pH dependence of the kinetic isotope effect reflects the pKa of the pyridine nitrogen of the coenzyme pyridoxal 5'-phosphate but not that of the imine nitrogen. A mechanism is proposed for the exchange of aspartate beta-H that is consistent with the stereochemistry suggested earlier

  19. Ornithine decarboxylase and extracellular polyamines regulate microvascular sprouting and actin cytoskeleton dynamics in endothelial cells

    International Nuclear Information System (INIS)

    Kucharzewska, Paulina; Welch, Johanna E.; Svensson, Katrin J.; Belting, Mattias

    2010-01-01

    The polyamines are essential for cancer cell proliferation during tumorigenesis. Targeted inhibition of ornithine decarboxylase (ODC), i.e. a key enzyme of polyamine biosynthesis, by α-difluoromethylornithine (DFMO) has shown anti-neoplastic activity in various experimental models. This activity has mainly been attributed to the anti-proliferative effect of DFMO in cancer cells. Here, we provide evidence that unperturbed ODC activity is a requirement for proper microvessel sprouting ex vivo as well as the migration of primary human endothelial cells. DFMO-mediated ODC inhibition was reversed by extracellular polyamine supplementation, showing that anti-angiogenic effects of DFMO were specifically related to polyamine levels. ODC inhibition was associated with an abnormal morphology of the actin cytoskeleton during cell spreading and migration. Moreover, our data suggest that de-regulated actin cytoskeleton dynamics in DFMO treated endothelial cells may be related to constitutive activation of the small GTPase CDC42, i.e. a well-known regulator of cell motility and actin cytoskeleton remodeling. These insights into the potential role of polyamines in angiogenesis should stimulate further studies testing the combined anti-tumor effect of polyamine inhibition and established anti-angiogenic therapies in vivo.

  20. Functional Characterization of Waterlogging and Heat Stresses Tolerance Gene Pyruvate decarboxylase 2 from Actinidia deliciosa

    Directory of Open Access Journals (Sweden)

    Hui-Ting Luo

    2017-11-01

    Full Text Available A previous report showed that both Pyruvate decarboxylase (PDC genes were significantly upregulated in kiwifruit after waterlogging treatment using Illumina sequencing technology, and that the kiwifruit AdPDC1 gene was required during waterlogging, but might not be required during other environmental stresses. Here, the function of another PDC gene, named AdPDC2, was analyzed. The expression of the AdPDC2 gene was determined using qRT-PCR, and the results showed that the expression levels of AdPDC2 in the reproductive organs were much higher than those in the nutritive organs. Waterlogging, NaCl, and heat could induce the expression of AdPDC2. Overexpression of kiwifruit AdPDC2 in transgenic Arabidopsis enhanced resistance to waterlogging and heat stresses in five-week-old seedlings, but could not enhance resistance to NaCl and mannitol stresses at the seed germination stage and in early seedlings. These results suggested that the kiwifruit AdPDC2 gene may play an important role in waterlogging resistance and heat stresses in kiwifruit.

  1. Syndromic intellectual disability: a new phenotype caused by an aromatic amino acid decarboxylase gene (DDC) variant.

    Science.gov (United States)

    Graziano, Claudio; Wischmeijer, Anita; Pippucci, Tommaso; Fusco, Carlo; Diquigiovanni, Chiara; Nõukas, Margit; Sauk, Martin; Kurg, Ants; Rivieri, Francesca; Blau, Nenad; Hoffmann, Georg F; Chaubey, Alka; Schwartz, Charles E; Romeo, Giovanni; Bonora, Elena; Garavelli, Livia; Seri, Marco

    2015-04-01

    The causative variant in a consanguineous family in which the three patients (two siblings and a cousin) presented with intellectual disability, Marfanoid habitus, craniofacial dysmorphisms, chronic diarrhea and progressive kyphoscoliosis, has been identified through whole exome sequencing (WES) analysis. WES study identified a homozygous DDC variant in the patients, c.1123C>T, resulting in p.Arg375Cys missense substitution. Mutations in DDC cause a recessive metabolic disorder (aromatic amino acid decarboxylase, AADC, deficiency, OMIM #608643) characterized by hypotonia, oculogyric crises, excessive sweating, temperature instability, dystonia, severe neurologic dysfunction in infancy, and specific abnormalities of neurotransmitters and their metabolites in the cerebrospinal fluid (CSF). In our family, analysis of neurotransmitters and their metabolites in patient's CSF shows a pattern compatible with AADC deficiency, although the clinical signs are different from the classic form. Our work expands the phenotypic spectrum associated with DDC variants, which therefore can cause an additional novel syndrome without typical movement abnormalities. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Simultaneous silencing of two arginine decarboxylase genes alters development in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Diana eSánchez-Rangel

    2016-03-01

    Full Text Available Polyamines (PAs are small aliphatic polycations that are found ubiquitously in all organisms. In plants, PAs are involved in diverse biological processes such as growth, development, and stress responses. In Arabidopsis thaliana, the arginine decarboxylase enzymes (ADC1 and 2 catalyze the first step of PA biosynthesis. For a better understanding of PA biological functions, mutants in PA biosynthesis have been generated; however, the double adc1/adc2 mutant is not viable in A. thaliana. In this study, we generated non-lethal A. thaliana lines through an artificial microRNA that simultaneously silenced the two ADC genes (amiR:ADC. The generated transgenic lines (amiR:ADC-L1 and -L2 showed reduced AtADC1 and AtADC2 transcript levels. For further analyses the amiR:ADC-L2 line was selected. We found that the amiR:ADC-L2 line showed a significant decrease of their PA levels. The co-silencing revealed a stunted growth in A. thaliana seedlings, plantlets and delay in its flowering rate; these phenotypes were reverted with PA treatment. In addition, amiR:ADC-L2 plants displayed two seed phenotypes, such as yellow and brownish seeds. The yellow mutant seeds were smaller than adc1, adc2 mutants and wild type seeds; however, the brownish were the smallest seeds with arrested embryos at the torpedo stage. These data reinforce the importance of PA homeostasis in the plant development processes.

  3. Histidine decarboxylase knockout mice, a genetic model of Tourette syndrome, show repetitive grooming after induced fear.

    Science.gov (United States)

    Xu, Meiyu; Li, Lina; Ohtsu, Hiroshi; Pittenger, Christopher

    2015-05-19

    Tics, such as are seen in Tourette syndrome (TS), are common and can cause profound morbidity, but they are poorly understood. Tics are potentiated by psychostimulants, stress, and sleep deprivation. Mutations in the gene histidine decarboxylase (Hdc) have been implicated as a rare genetic cause of TS, and Hdc knockout mice have been validated as a genetic model that recapitulates phenomenological and pathophysiological aspects of the disorder. Tic-like stereotypies in this model have not been observed at baseline but emerge after acute challenge with the psychostimulant d-amphetamine. We tested the ability of an acute stressor to stimulate stereotypies in this model, using tone fear conditioning. Hdc knockout mice acquired conditioned fear normally, as manifested by freezing during the presentation of a tone 48h after it had been paired with a shock. During the 30min following tone presentation, knockout mice showed increased grooming. Heterozygotes exhibited normal freezing and intermediate grooming. These data validate a new paradigm for the examination of tic-like stereotypies in animals without pharmacological challenge and enhance the face validity of the Hdc knockout mouse as a pathophysiologically grounded model of tic disorders. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Glutamic acid decarboxylase 67 expression by a distinct population of mouse vestibular supporting cells

    Directory of Open Access Journals (Sweden)

    Giancarlo eRusso

    2014-12-01

    Full Text Available The function of the enzyme glutamate decarboxylase (GAD is to convert glutamate in -aminobutyric acid (GABA.GAD exists as two major isoforms, termed GAD65 and GAD67,.that are usually expressed in GABA-containing neurons in the central nervous system. GAD65 has been proposed to be associated with GABA exocytosis whereas GAD67 with GABA metabolism. In the present immunofluorescence study, we have investigated the presence of the two GAD isoforms in the semicircular canal cristae of wild type and GAD67-GFP knock-in mice. While no evidence for GAD65 expression was found, GAD67 was detected in a distinct population of peripherally-located supporting cells, but not in hair cells or in centrally-located supporting cells. GABA, on the other hand, was found in all supporting cells. The present result indicate that only a discrete population of supporting cells use GAD67 to synthesize GABA. This is the first report of a marker that allows to distinguish two populations of supporting cells in the vestibular epithelium. On the other hand, the lack of GABA and GAD enzymes in hair cells excludes its involvement in afferent transmission.

  5. Modulating effect of new potential antimelanomic agents, spin-labeled triazenes and nitrosoureas on the DOPA-oxidase activity of tyrosinase.

    Science.gov (United States)

    Gadjeva, V; Zheleva, A; Raikova, E

    1999-07-01

    The modulating effect of newly synthesized alkylating spin labeled triazene and spin labeled nitrosourea derivatives on the DOPA-oxidase activity of mushroom tyrosinase has been investigated by Bumett's spectrophotometric method (Burnett et al., 1967). All spin labeled triazenes have exhibited activating effect on DOPA-oxidase activity of tyrosinase, whereas clinically used triazene (DTIC), which does not contain nitroxide moiety, have showed inhibiting effect. At the same experimental conditions the spin labeled aminoacid nitrosoureas have showed dual effect - activating, in the beginning of the enzyme reaction and inhibiting later on. It is deduced that the activating effect of the spin labeled compounds is due to the nitroxide moiety and the inhibiting effect of all compounds depends on their half-life time. This study might contribute to make more clear the mechanism of action of the new compounds and on the other hand would come in quite useful as a preliminary prognosis for their antimelanomic activity.

  6. A Role for Mitogen- and Stress-Activated Kinase 1 in L-DOPA-Induced Dyskinesia and ∆FosB Expression

    DEFF Research Database (Denmark)

    Feyder, Michael; Södersten, Erik; Santini, Emanuela

    2014-01-01

    BACKGROUND: Abnormal regulation of extracellular signal-regulated kinases 1 and 2 has been implicated in 3,4-dihydroxy-l-phenylalanine (L-DOPA)-induced dyskinesia (LID), a motor complication affecting Parkinson's disease patients subjected to standard pharmacotherapy. We examined the involvement...... of mitogen- and stress-activated kinase 1 (MSK1), a downstream target of extracellular signal-regulated kinases 1 and 2, and an important regulator of transcription in LID. METHODS: 6-Hydroxydopamine was used to produce a model of Parkinson's disease in MSK1 knockout mice and in ∆FosB- or ∆c......Jun-overexpressing transgenic mice, which were assessed for LID following long-term L-DOPA administration. Biochemical processes were evaluated by Western blotting or immunofluorescence. Histone H3 phosphorylation was analyzed by chromatin immunoprecipitation followed by promotor-specific quantitative polymerase chain reaction...

  7. 18F-DOPA PET/CT for assessment of response to induction chemotherapy in a child with high-risk neuroblastoma

    International Nuclear Information System (INIS)

    Piccardo, Arnoldo; Lopci, Egesta; Foppiani, Luca; Morana, Giovanni; Conte, Massimo

    2014-01-01

    Functional imaging plays a crucial role in the assessment of neuroblastoma. The evaluation of response to induction chemotherapy is a cornerstone in scheduling proper treatment management in patients affected by high-risk neuroblastoma. 123 I-metaiodobenzylguanidine has been recognized as the radiopharmaceutical of choice in neuroblastoma assessment. To date, the clinical role of PET/CT in pediatric malignancy is not well established. 18 F-DOPA-PET/CT has been recently used in neuroblastoma, and compared with 123 I-MIBG-scan. Scant new data are available about the role of this tool in the evaluation of treatment response after induction chemotherapy. We investigate the role of 18 F-DOPA-PET/CT in characterizing the response to induction chemotherapy in a child affected by high-risk-neuroblastoma, in whom the rare association of 123 I-MIBG-negative primary tumor and MIBG-positive bone marrow metastases was observed. (orig.)

  8. {sup 18}F-DOPA PET/CT for assessment of response to induction chemotherapy in a child with high-risk neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Piccardo, Arnoldo [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); E.O. Ospedali Galliera, Department of Nuclear Medicine, Genoa (Italy); Lopci, Egesta [Humanitas Clinical and Research Center, Nuclear Medicine Department, Rozzano, MI (Italy); Foppiani, Luca [Galliera Hospital, Internal Medicine and Endocrinology, Genoa (Italy); Morana, Giovanni [G. Gaslini Children' s Hospital, Department of Pathology and Radiology, Genoa (Italy); Conte, Massimo [G. Gaslini Children' s Hospital, Department of Hematology-Oncology, Genoa (Italy)

    2014-03-15

    Functional imaging plays a crucial role in the assessment of neuroblastoma. The evaluation of response to induction chemotherapy is a cornerstone in scheduling proper treatment management in patients affected by high-risk neuroblastoma. {sup 123}I-metaiodobenzylguanidine has been recognized as the radiopharmaceutical of choice in neuroblastoma assessment. To date, the clinical role of PET/CT in pediatric malignancy is not well established.{sup 18}F-DOPA-PET/CT has been recently used in neuroblastoma, and compared with {sup 123}I-MIBG-scan. Scant new data are available about the role of this tool in the evaluation of treatment response after induction chemotherapy. We investigate the role of {sup 18}F-DOPA-PET/CT in characterizing the response to induction chemotherapy in a child affected by high-risk-neuroblastoma, in whom the rare association of {sup 123}I-MIBG-negative primary tumor and MIBG-positive bone marrow metastases was observed. (orig.)

  9. 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Dahl; Petersen, Henrik; Nielsen, Anne Lerberg

    2018-01-01

    (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. Methods: PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUVmax) by two independent examiners......, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Results: Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed...... in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut...

  10. Influence of basal ganglia on upper limb locomotor synergies. Evidence from deep brain stimulation and L-DOPA treatment in Parkinson's disease.

    Science.gov (United States)

    Crenna, P; Carpinella, I; Lopiano, L; Marzegan, A; Rabuffetti, M; Rizzone, M; Lanotte, M; Ferrarin, M

    2008-12-01

    Clinical evidence of impaired arm swing while walking in patients with Parkinson's disease suggests that basal ganglia and related systems play an important part in the control of upper limb locomotor automatism. To gain more information on this supraspinal influence, we measured arm and thigh kinematics during walking in 10 Parkinson's disease patients, under four conditions: (i) baseline (no treatment), (ii) therapeutic stimulation of the subthalamic nucleus (STN), (iii)L-DOPA medication and (iv) combined STN stimulation and L-DOPA. Ten age-matched controls provided reference data. Under baseline conditions the range of patients' arm motion was severely restricted, with no correlation with the excursion of the thigh. In addition, the arm swing was abnormally coupled in time with oscillation of the ipsilateral thigh. STN stimulation significantly increased the gait speed and improved the spatio-temporal parameters of arm and thigh motion. The kinematic changes as a function of gait speed changes, however, were significantly smaller for the upper than the lower limb, in contrast to healthy controls. Arm motion was also less responsive after L-DOPA. Simultaneous deep brain stimulation and L-DOPA had additive effects on thigh motion, but not on arm motion and arm-thigh coupling. The evidence that locomotor automatisms of the upper and lower limbs display uncorrelated impairment upon dysfunction of the basal ganglia, as well as different susceptibility to electrophysiological and pharmacological interventions, points to the presence of heterogeneously distributed, possibly partially independent, supraspinal control channels, whereby STN and dopaminergic systems have relatively weaker influence on the executive structures involved in the arm swing and preferential action on those for lower limb movements. These findings might be considered in the light of phylogenetic changes in supraspinal control of limb motion related to primate bipedalism.

  11. Efficacy and safety of extended- versus immediate-release pramipexole in Japanese patients with advanced and L-dopa-undertreated Parkinson disease: a double-blind, randomized trial.

    Science.gov (United States)

    Mizuno, Yoshikuni; Yamamoto, Mitsutoshi; Kuno, Sadako; Hasegawa, Kazuko; Hattori, Nobutaka; Kagimura, Tatsuro; Sarashina, Akiko; Rascol, Olivier; Schapira, Anthony H V; Barone, Paolo; Hauser, Robert A; Poewe, Werner

    2012-01-01

    To compare the efficacy, safety, tolerability, and trough plasma levels of pramipexole extended-release (ER) and pramipexole immediate-release (IR), and to assess the effects of overnight switching from an IR to an ER formulation, in L-dopa-treated patients with Parkinson disease (PD). After a 1- to 4-week screening/enrollment, 112 patients who had exhibited L-dopa-related problems or were receiving suboptimal L-dopa dosage were randomized in double-blind, double-dummy, 1:1 fashion to pramipexole ER once daily or pramipexole IR 2 to 3 times daily for 12 weeks, both titrated to a maximum daily dose of 4.5 mg. Successful completers of double-blind treatment were switched to open-label pramipexole ER, beginning with a 4-week dose-adjustment phase. Among the double-blind treatment patients (n = 56 in each group), Unified Parkinson's Disease Rating Scale Parts II+III total scores decreased significantly from baseline and to a similar degree with pramipexole ER and IR formulations. In each group, 47 double-blind patients (83.9%) reported adverse events (AEs), requiring withdrawal of 3 ER patients (5.4%) and 2 IR patients (3.6%). Trough plasma levels at steady state (at the same doses and dose-normalized concentrations) were also similar with both formulations. Among open-label treatment patients (n = 53 from IR to ER), 83% were successfully switched (no worsening of PD symptoms) to pramipexole ER. In L-dopa-treated patients, pramipexole ER and pramipexole IR demonstrated similar efficacy, safety, tolerability, and trough plasma levels. Patients can be safely switched overnight from pramipexole IR to pramipexole ER with no impact on efficacy.

  12. Disturbed neural circuits in a subtype of chronic catatonic schizophrenia demonstrated by F-18-FDG-PET and F-18-DOPA-PET

    International Nuclear Information System (INIS)

    Lauer, M.; Beckmann, H.; Stoeber, G.; Schirrmeister, H.; Gerhard, A.; Ellitok, E.; Reske, S.N.

    2001-01-01

    Permanent verbal, visual scenic and coenaestetic hallucinations are the most prominent psychopathological symptoms aside from psychomotor disorders in speech-sluggish catatonia, a subtype of chronic catatonic schizophrenia according to Karl Leonhard. These continuous hallucinations serve as an excellent paradigm for the investigation of the assumed functional disturbances of cortical circuits in schizophrenia. Data from positron emission tomography (F-18-FDG-PET and F-18-DOPA-PET) from three patients with this rare phenotype were available (two cases of simple speech-sluggish catatonia, one case of a combined speech-prompt/speech-sluggish subtype) and were compared with a control collective. During their permanent hallucinations, all catatonic patients showed a clear bitemporal hypometabolism in the F-18-FDG-PET. Both patients with the simple speech-sluggish catatonia showed an additional bilateral thalamic hypermetabolism and an additional bilateral hypometabolism of the frontal cortex, especially on the left side. In contrast, the patient with the combined speech-prompt/speech-sluggish catatonia showed a bilateral thalamic hypo-metabolism combined with a bifrontal cortical hypermetabolism. However, the left/right ratio of the frontal cortex also showed a lateralization effect with a clear relative hypometabolism of the left frontal cortex. The F-18-DOPA-PET of both schizophrenic patients with simple speech-sluggish catatonia showed a normal F-18-DOPA storage in the striatum, whereas in the right putamen of the patient with the combined form a higher right/left ratio in F-DOPA storage was discernible, indicating an additional lateralized influence of the dopaminergic system in this subtype of chronic catatonic schizophrenia. (author)

  13. Effects of chronic fructose overload on renal dopaminergic system: alteration of urinary L-dopa/dopamine index correlates to hypertension and precedes kidney structural damage.

    Science.gov (United States)

    Rukavina Mikusic, Natalia L; Kouyoumdzian, Nicolás M; Del Mauro, Julieta S; Cao, Gabriel; Trida, Verónica; Gironacci, Mariela M; Puyó, Ana M; Toblli, Jorge E; Fernández, Belisario E; Choi, Marcelo R

    2018-01-01

    Insulin resistance induced by a high-fructose diet has been associated to hypertension and renal damage. The aim of this work was to assess alterations in the urinary L-dopa/dopamine ratio over three time periods in rats with insulin resistance induced by fructose overload and its correlation with blood pressure levels and the presence of microalbuminuria and reduced nephrin expression as markers of renal structural damage. Male Sprague-Dawley rats were randomly divided into six groups: control (C) (C4, C8 and C12) with tap water to drink and fructose-overloaded (FO) rats (FO4, FO8 and FO12) with a fructose solution (10% w/v) to drink for 4, 8 and 12 weeks. A significant increase of the urinary L-dopa/dopamine ratio was found in FO rats since week 4, which positively correlated to the development of hypertension and preceded in time the onset of microalbuminuria and reduced nephrin expression observed on week 12 of treatment. The alteration of this ratio was associated to an impairment of the renal dopaminergic system, evidenced by a reduction in renal dopamine transporters and dopamine D1 receptor expression, leading to an overexpression and overactivation of the enzyme Na + , K + -ATPase with sodium retention. In conclusion, urinary L-dopa/dopamine ratio alteration in rats with fructose overload positively correlated to the development of hypertension and preceded in time the onset of renal structural damage. This is the first study to propose the use of the urinary L-dopa/dopamine index as marker of renal dysfunction that temporarily precedes kidney structural damage induced by fructose overload. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Striatal kinetics of [11C]-(+)-nomifensine and 6-[18F]fluoro-L-dopa in Parkinson's disease measured with positron emission tomography

    International Nuclear Information System (INIS)

    Tedroff, J.; Aquilonius, S.-M.; Laihinen, A.; Rinne, U.; Hartvig, P.; Anderson, J.; Lundqvist, H.; Haaparanta, M.; Solin, O.; Antoni, G.; Gee, A.D.; Ulin, J.; Laangstroem, B.

    1990-01-01

    The kinetics in brain of the dopamine reuptake blocking agent [ 11 C]-(+)-nomifensine and the L-dopa analogue 6-[ 18 F]fluoro-L-dopa were compared in 3 patients with idopathic Parkinson's disease and agematched healthy volunteers using positron emission tomography. Regional uptake was analyzed and quantified according to a 3-compartment model. Retention of both tracers in striatal regions of the parkinsonian patients were reduced compared with the healthy volunteers mainly in the putamen, while the caudate nuclleus was only mildly affected. The reductions were considerably less than the decrease previously reported postmortem for striatal dopamine content in the basal ganglia of patients with Parkinson's disease. A fairly constant ratio between 6-[ 18 F]fluoro-L-dopa utilization and [ 11 C]-(+)-nomifensine binding in the caudate nucleus and the putamen were found in both groups unrelated to the size of the estimated parameters. This indicates that a limiting factor for the utilization of exogenous levodopa in Parkinsons's disease may be a reduced transport capacity for the amino acid into the dopaminergic terminals. (author)

  15. Striatal kinetics of ( sup 11 C)-(+)-nomifensine and 6-( sup 18 F)fluoro-L-dopa in Parkinson's disease measured with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tedroff, J; Aquilonius, S -M [Department of Neurology, University Hospital (Sweden); Laihinen, A; Rinne, U [Department of Neurology, University of Turku (Finland); Hartvig, P [Department of Hospital Pharmacy, University Hospital (Sweden); Anderson, J [Department of Radiation Sciences, University Hospital (Sweden); Lundqvist, H [Svenberg Laboratory, Uppsala University (Sweden); Haaparanta, M; Solin, O [Medical Cyclotron Laboratory, University of Turku (Finland); Antoni, G; Gee, A D; Ulin, J; Laangstroem, B [Department of Organic Chemistry, University Hospital (Sweden)

    1990-01-01

    The kinetics in brain of the dopamine reuptake blocking agent ({sup 11}C)-(+)-nomifensine and the L-dopa analogue 6-({sup 18}F)fluoro-L-dopa were compared in 3 patients with idopathic Parkinson's disease and agematched healthy volunteers using positron emission tomography. Regional uptake was analyzed and quantified according to a 3-compartment model. Retention of both tracers in striatal regions of the parkinsonian patients were reduced compared with the healthy volunteers mainly in the putamen, while the caudate nuclleus was only mildly affected. The reductions were considerably less than the decrease previously reported postmortem for striatal dopamine content in the basal ganglia of patients with Parkinson's disease. A fairly constant ratio between 6-({sup 18}F)fluoro-L-dopa utilization and ({sup 11}C)-(+)-nomifensine binding in the caudate nucleus and the putamen were found in both groups unrelated to the size of the estimated parameters. This indicates that a limiting factor for the utilization of exogenous levodopa in Parkinsons's disease may be a reduced transport capacity for the amino acid into the dopaminergic terminals. (author).

  16. Work and power reduced in L-dopa naïve patients in the early-stages of Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Lidiane Oliveira Lima

    2016-04-01

    Full Text Available ABSTRACT Studies which have investigated muscular performance during the initial stages of Parkinson´s disease (PD without L-dopa treatments were not found. Objective to assess whether muscular performance, work and power, of the trunk and lower limbs in L-dopa naïve patients in the early stages of PD was lower than those of healthy subjects and to compare muscular performance between the lower limbs. Method Ten subjects with PD, Hoehn and Yahr (HY I-II, L-dopa naïve and 10 subjects in the control group were assessed with the isokinetic dynamometer. Results ANOVAs revealed that work and power measures of the trunk, hip, knee, and ankle muscular groups were lower in PD compared with the control group (p < 0.05. There were no significant differences in muscular performance between the lower limbs. Conclusion The results suggested the use of specific exercises, as rehabilitation strategies, to improve the ability to produce work and power with this population.

  17. Mutation of Aspergillus oryzae for improved production of 3, 4-dihydroxy phenyl-L-alanine (L-DOPA from L-tyrosine Mutação de Aspergillus orizae para produção melhorada de 3,4-dihidroxi fenil-L-alanina (L-DOPA a partir de L-tirosina

    Directory of Open Access Journals (Sweden)

    Ikram-ul Haq

    2006-03-01

    Full Text Available Aspergillus oryzae mutant strain UV-7 was further improved for the production of L-DOPA from L-tyrosine using chemical mutation. Different putative mutant strains of organism were tested for the production of L-DOPA in submerged fermentation. Among these putative mutant strains, mutant designated SI-12 gave maximum production of L-DOPA (300 mg L-DOPA.g-1 cells. The production of L-DOPA from different carbon source solutions (So= 30 g.l-1 by mutant culture was investigated at different nitrogen sources, initial pH and temperature values. At optimum pH (pHo= 5.0, and temperature (t=30ºC, 100% sugars were utilized for production and cell mass formation, corresponding to final L-DOPA product yield of 150 mg.g-1 substrate utilized, and maximum volumetric and specific productivities of 125 mg.l-1.h-1, and 150 mg.g-1 cells. h-1, respectively. There was up to 3-fold enhancement in product formation rate. This enhancement is the highest reported in literature. To explain the kinetic mechanism of L-DOPA formation and thermal inactivation of tyrosinase, the thermodynamic parameters were determined with the application of Arrhenius model: activation enthalpy and entropy for product formation, in case of mutant derivative, were 40 k j/mol and 0.076 k j/mol. K for L-DOPA production and 116 k j/mol and 0.590 k j/mol. K for thermal inactivation, respectively. The respective values for product formation were lower while those for product deactivation were higher than the respective values for the parental culture. Therefore, the mutant strain was thermodynamically more resistant to thermal denaturation.A produção de L-DOPA a partir de tirosina pela cepa mutante de Aspergillus orizae UV-7 foi melhorada através de mutação química. Diferentes cepas foram testadas quanto a produção de L-DOPA por fermentação submersa, observando-se que a cepa denominada SI-12 foi a melhor produtora (300 mg de L-DOPA por g de células. A produção de L-DOPA pela cepa

  18. De stille elever

    DEFF Research Database (Denmark)

    Winther-Lindqvist, Ditte Alexandra

    2012-01-01

    Det er blevet en afgørende samværskompetence i uddannelsessystemet at stå aktivt frem og deltage verbalt i skoleklassens liv både fagligt og socialt. Men ikke alle elever deltager lige villigt verbalt i plenum. Artiklen handler om de stille elever og konsekvenserne af stillehed i skolen. Det...... foreslås at skolesystemet sanktionerer ældre elever hårdere for stillehed end yngre elever og det forklares med at skolelivet også er en kultivering henimod elevhed som social identitet og denne er der forventning om at eleverne mestrer i udskolingen....

  19. Characterization of Trypanosoma brucei brucei S-adenosyl-L-methionine decarboxylase and its inhibition by Berenil, pentamidine and methylglyoxal bis(guanylhydrazone).

    Science.gov (United States)

    Bitonti, A J; Dumont, J A; McCann, P P

    1986-01-01

    Trypanosoma brucei brucei S-adenosyl-L-methionine (AdoMet) decarboxylase was found to be relatively insensitive to activation by putrescine as compared with the mammalian enzyme, being stimulated by only 50% over a 10,000-fold range of putrescine concentrations. The enzyme was not stimulated by up to 10 mM-Mg2+. The Km for AdoMet was 30 microM, similar to that of other eukaryotic AdoMet decarboxylases. T.b. brucei AdoMet decarboxylase activity was apparently irreversibly inhibited in vitro by Berenil and reversibly by pentamidine and methylglyoxal bis(guanylhydrazone). Berenil also inhibited trypanosomal AdoMet decarboxylase by 70% within 4 h after administration to infected rats and markedly increased the concentration of putrescine in trypanosomes that were exposed to the drug in vivo. Spermidine and spermine blocked the curative effect of Berenil on model mouse T.b. brucei infections. This effect of the polyamines was probably not due to reversal of Berenil's inhibitory effects on the AdoMet decarboxylase. PMID:3800910

  20. Antihistamines suppress upregulation of histidine decarboxylase gene expression with potencies different from their binding affinities for histamine H1 receptor in toluene 2,4-diisocyanate-sensitized rats

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    Hiroyuki Mizuguchi

    2016-04-01

    Full Text Available Antihistamines inhibit histamine signaling by blocking histamine H1 receptor (H1R or suppressing H1R signaling as inverse agonists. The H1R gene is upregulated in patients with pollinosis, and its expression level is correlated with the severity of nasal symptoms. Here, we show that antihistamine suppressed upregulation of histidine decarboxylase (HDC mRNA expression in patients with pollinosis, and its expression level was correlated with that of H1R mRNA. Certain antihistamines, including mepyramine and diphenhydramine, suppress toluene-2,4-diisocyanate (TDI-induced upregulation of HDC gene expression and increase HDC activity in TDI-sensitized rats. However, d-chlorpheniramine did not demonstrate any effect. The potencies of antihistamine suppressive effects on HDC mRNA elevation were different from their H1R receptor binding affinities. In TDI-sensitized rats, the potencies of antihistamine inhibitory effects on sneezing in the early phase were related to H1R binding. In contrast, the potencies of their inhibitory effects on sneezing in the late phase were correlated with those of suppressive effects on HDC mRNA elevation. Data suggest that in addition to the antihistaminic and inverse agonistic activities, certain antihistamines possess additional properties unrelated to receptor binding and alleviate nasal symptoms in the late phase by inhibiting synthesis and release of histamine by suppressing HDC gene transcription.

  1. Electrochemiluminescence assays for insulin and glutamic acid decarboxylase autoantibodies improve prediction of type 1 diabetes risk.

    Science.gov (United States)

    Miao, Dongmei; Steck, Andrea K; Zhang, Li; Guyer, K Michelle; Jiang, Ling; Armstrong, Taylor; Muller, Sarah M; Krischer, Jeffrey; Rewers, Marian; Yu, Liping

    2015-02-01

    We recently developed new electrochemiluminescence (ECL) insulin autoantibody (IAA) and glutamic acid decarboxylase 65 autoantibody (GADA) assays that discriminate high-affinity, high-risk diabetes-specific autoantibodies from low-affinity, low-risk islet autoantibodies (iAbs) detected by radioassay (RAD). Here, we report a further validation of the ECL-IAA and -GADA assays in 3,484 TrialNet study participants. The ECL assay and RAD were congruent in those with prediabetes and in subjects with multiple autoantibodies, but only 24% (P<0.0001) of single RAD-IAA-positive and 46% (P<0.0001) of single RAD-GADA-positive were confirmed by the ECL-IAA and -GADA assays, respectively. During a follow-up (mean, 2.4 years), 51% of RAD-IAA-positive and 63% of RAD-GADA-positive subjects not confirmed by ECL became iAb negative, compared with only 17% of RAD-IAA-positive (P<0.0001) and 15% of RAD-GADA-positive (P<0.0001) subjects confirmed by ECL assays. Among subjects with multiple iAbs, diabetes-free survival was significantly shorter if IAA or GADA was positive by ECL and negative by RAD than if IAA or GADA was negative by ECL and positive by RAD (P<0.019 and P<0.0001, respectively). Both positive and negative predictive values in terms of progression to type 1 diabetes mellitus were superior for ECL-IAA and ECL-GADA, compared with RADs. The prevalence of the high-risk human leukocyte antigen-DR3/4, DQB1*0302 genotype was significantly higher in subjects with RAD-IAA or RAD-GADA confirmed by ECL. In conclusion, both ECL-IAA and -GADA are more disease-specific and better able to predict the risk of progression to type 1 diabetes mellitus than the current standard RADs.

  2. Catalytic properties of the archaeal S-adenosylmethionine decarboxylase from Methanococcus jannaschii.

    Science.gov (United States)

    Lu, Zichun J; Markham, George D

    2004-01-02

    S-Adenosylmethionine decarboxylase (AdoMetDC) is a pyruvoyl cofactor-dependent enzyme that participates in polyamine biosynthesis. AdoMetDC from the Archaea Methanococcus jannaschii is a prototype for a recently discovered class that is not homologous to the eucaryotic enzymes or to a distinct group of microbial enzymes. M. jannaschii AdoMetDC has a Km of 95 microm and the turnover number (kcat) of 0.0075 s(-1) at pH 7.5 and 22 degrees C. The turnover number increased approximately 38-fold at a more physiological temperature of 80 degrees C. AdoMetDC was inactivated by treatment with the imine reductant NaCNBH3 only in the presence of substrate. Mass spectrometry of the inactivated protein showed modification solely of the pyruvoyl-containing subunit, with a mass increase corresponding to reduction of a Schiff base adduct with decarboxylated AdoMet. The presteady state time course of the AdoMetDC reaction revealed a burst of product formation; thus, a step after CO2 formation is rate-limiting in turnover. Comparable D2O kinetic isotope effects of were seen on the first turnover (1.9) and on kcat/Km (1.6); there was not a significant D2O isotope effect on kcat, suggesting that product release is rate-limiting in turnover. The pH dependence of the steady state rate showed participation of acid and basic groups with pK values of 5.3 and 8.2 for kcat and 6.5 and 8.3 for kcat/Km, respectively. The competitive inhibitor methylglyoxal bis(guanylhydrazone) binds at a single site per (alphabeta) heterodimer. UV spectroscopic studies show that methylglyoxal bis(guanylhydrazone) binds as the dication with a 23 microm dissociation constant. Studies with substrate analogs show a high specificity for AdoMet.

  3. Mesomere-derived glutamate decarboxylase-expressing blastocoelar mesenchyme cells of sea urchin larvae

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    Hideki Katow

    2013-12-01

    The ontogenetic origin of blastocoelar glutamate decarboxylase (GAD-expressing cells (GADCs in larvae of the sea urchin Hemicentrotus pulcherrimus was elucidated. Whole-mount in situ hybridisation (WISH detected transcription of the gene that encodes GAD in H. pulcherrimus (Hp-gad in unfertilised eggs and all blastomeres in morulae. However, at and after the swimming blastula stage, the transcript accumulation was particularly prominent in clumps of ectodermal cells throughout the embryonic surface. During the gastrula stage, the transcripts also accumulated in the endomesoderm and certain blastocoelar cells. Consistent with the increasing number of Hp-gad transcribing cells, immunoblot analysis indicated that the relative abundance of Hp-Gad increased considerably from the early gastrula stage until the prism stage. The expression pattern of GADCs determined by immunohistochemistry was identical to the pattern of Hp-gad transcript accumulation determined using WISH. In early gastrulae, GADCs formed blastocoelar cell aggregates around the blastopore with primary mesenchyme cells. The increase in the number of blastocoelar GADCs was inversely proportional to the number of ectodermal GADCs ranging from a few percent of total GADCs in early gastrulae to 80% in late prism larvae; this depended on ingression of ectodermal GADCs into the blastocoel. Some of the blastocoelar GADCs were fluorescein-positive in the larvae that developed from the 16-cell stage chimeric embryos; these comprised fluorescein-labeled mesomeres and unlabelled macromeres and micromeres. Our finding indicates that some of the blastocoelar GADCs are derived from the mesomeres and thus they are the new group of mesenchyme cells, the tertiary mesenchyme cells.

  4. Cloning and Expression Vector Construction of Glutamate Decarboxylase Gene from Lactobacillus Plantarum

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    B Arabpour

    2016-06-01

    Full Text Available BACKGROUND AND OBJECTIVE: Gamma-aminobutyric acid (GABA is a four-carbon non-protein amino acid used in the treatment of hypertension, diabetes, inflammation, and depression. GABA is synthesized by glutamic acid decarboxylase (GAD enzyme in many organisms, including bacteria. Therefore, cloning of this enzyme is essential to the optimization of GABA production. This study aimed to clone and construct the expression vector of GAD gene from Lactobacillus plantarum PTCC 1058 bacterium. METHODS: In this experimental study, we investigated the morphological, biochemical, genetic and 16s rDNA sequencing of L. plantarum PTCC 1058 strain. Genomic DNA of the bacterium was isolated and amplified using the GAD gene via polymerase chain reaction (PCR. Afterwards, the gene was inserted into the pJET1.2/blunt cloning vector and subcloned in vector pET32a. Plasmid pET32a-gad expression vector was transformed in Escherichia coli BL21 strain, and protein expression was assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE. FINDINGS: Morphological, biochemical and genetic analyses of 16s rDNA sequencing indicated that the studied substrain was of the L. plantarum strain. In addition, results of nucleotide sequencing of the fragmented segment via PCR showed the presence of GAD gene. Results of colony PCR and SDS-PAGE analysis confirmed the accuracy of the cloning and gene expression of the recombinant Escherichia coli BL21 strain. CONCLUSION: According to the results of this study, cloning of GAD gene from L. plantarum PTCC 1058 was successful. These cloned genes could grow rapidly in prokaryotic and eukaryotic systems and be used in cost-effective culture media and even non-recyclable waste.

  5. Ornithine decarboxylase activity in rat organs and tissues under artificial hypobiosis.

    Science.gov (United States)

    Aksyonova, G E; Logvinovich, O S; Fialkovskaya, L A; Afanasyev, V N; Ignat'ev, D A; Kolomiytseva, I K

    2010-09-01

    The influence of hypothermia-hypoxia-hypercapnia on ornithine decarboxylase (ODC, EC 4.1.1.17) activities in rat organs and tissues and also on the thymocyte distribution throughout the cell cycle stages was studied. The state of artificial hypobiosis in rats on decrease in the body temperature to 14.4-18.0°C during 3.0-3.5 h was accompanied by drops in the ODC activities in the neocortex and liver by 50-60% and in rapidly proliferating tissues (thymus, spleen, and small intestine mucosa) by 80% of the control value. In kidneys the ODC activity raised to 200% of the control level. Twenty-four hours after termination of the cooling and replacing the rats under the standard conditions, the ODC activities in the neocortex, liver, kidneys, spleen, and intestinal mucosa returned to the control values, but remained decreased in the thymus. Forty-eight hours later the ODC activities in the thymus and spleen exceeded the normal level. The distribution of thymocytes throughout the cell cycle stages did not change in rats in the state of hypothermia (hypobiosis); 24 and 48 h after termination of the cooling the fraction of thymocytes in the S stage was decreased and the fraction of the cells in the G(0)+G(1) stage was increased. The normal distribution of thymocytes throughout the cell cycle stages recovered in 72 h. Thus, in the thymus the diminution of the ODC activity preceded the suppression of the cell proliferation rate. The tissue-specific changes in the ODC activity are suggested to reflect adaptive changes in the functional and proliferative activities of organs and tissues during the development of hypobiosis under conditions of hypothermia-hypoxia-hypercapnia.

  6. [Ornithine decarboxylase in mammalian organs and tissues at hibernation and artificial hypobiosis].

    Science.gov (United States)

    Logvinovich, O S; Aksenova, G E

    2013-01-01

    Ornithine decarboxylase (ODC, EC 4.1.1.17.) is a short-lived and dynamically regulated enzyme of polyamines biosynthesis. Regulation of functional, metabolic and proliferative state of organs and tissues involves the modifications of the ODC enzymatic activity. The organ-specific changes in ODC activity were revealed in organs and tissues (liver, spleen, bone marrow, kidney, and intestinal mucosa) of hibernating mammals - squirrels Spermophilus undulates - during the hibernating season. At that, a positive correlation was detected between the decline and recovery of the specialized functions of organs and tissues and the respective modifications of ODC activity during hibernation bouts. Investigation of changes in ODC activity in organs and tissues of non-hibernating mammals under artificial hypobiosis showed that in Wistar rats immediately after exposure to hypothermia-hypoxia-hypercapnia (hypobiosis) the level of ODC activity was low in thymus, spleen, small intestine mucosa, neocortex, and liver. The most marked reduction in enzyme activity was observed in actively proliferating tissues: thymus, spleen, small intestine mucosa. In bone marrow of squirrels, while in a state of torpor, as well as in thymus of rats after exposure to hypothermia-hypoxia-hypercapnia, changes in the ODC activity correlated with changes in the rate of cell proliferation (by the criterion of cells distribution over cell cycle). The results obtained, along with the critical analysis of published data, indicate that the ODC enzyme is involved in biochemical adaptation of mammals to natural and artificial hypobiosis. A decline in the ODC enzymatic activity indicates a decline in proliferative, functional, and metabolic activity of organs and tissues of mammals (bone marrow, mucosa of small intestine, thymus, spleen, neocortex, liver, kidneys) when entering the state of hypobiosis.

  7. The Arginine Decarboxylase Pathways of Host and Pathogen Interact to Impact Inflammatory Pathways in the Lung

    Science.gov (United States)

    Dalluge, Joseph J.; Welchlin, Cole W.; Hughes, John; Han, Wei; Blackwell, Timothy S.; Laguna, Theresa A.; Williams, Bryan J.

    2014-01-01

    The arginine decarboxylase pathway, which converts arginine to agmatine, is present in both humans and most bacterial pathogens. In humans agmatine is a neurotransmitter with affinities towards α2-adrenoreceptors, serotonin receptors, and may inhibit nitric oxide synthase. In bacteria agmatine serves as a precursor to polyamine synthesis and was recently shown to enhance biofilm development in some strains of the respiratory pathogen Pseudomonas aeruginosa. We determined agmatine is at the center of a competing metabolism in the human lung during airways infections and is influenced by the metabolic phenotypes of the infecting pathogens. Ultra performance liquid chromatography with mass spectrometry detection was used to measure agmatine in human sputum samples from patients with cystic fibrosis, spent supernatant from clinical sputum isolates, and from bronchoalvelolar lavage fluid from mice infected with P. aeruginosa agmatine mutants. Agmatine in human sputum peaks during illness, decreased with treatment and is positively correlated with inflammatory cytokines. Analysis of the agmatine metabolic phenotype in clinical sputum isolates revealed most deplete agmatine when grown in its presence; however a minority appeared to generate large amounts of agmatine presumably driving sputum agmatine to high levels. Agmatine exposure to inflammatory cells and in mice demonstrated its role as a direct immune activator with effects on TNF-α production, likely through NF-κB activation. P. aeruginosa mutants for agmatine detection and metabolism were constructed and show the real-time evolution of host-derived agmatine in the airways during acute lung infection. These experiments also demonstrated pathogen agmatine production can upregulate the inflammatory response. As some clinical isolates have adapted to hypersecrete agmatine, these combined data would suggest agmatine is a novel target for immune modulation in the host-pathogen dynamic. PMID:25350753

  8. The arginine decarboxylase pathways of host and pathogen interact to impact inflammatory pathways in the lung.

    Directory of Open Access Journals (Sweden)

    Nick B Paulson

    Full Text Available The arginine decarboxylase pathway, which converts arginine to agmatine, is present in both humans and most bacterial pathogens. In humans agmatine is a neurotransmitter with affinities towards α2-adrenoreceptors, serotonin receptors, and may inhibit nitric oxide synthase. In bacteria agmatine serves as a precursor to polyamine synthesis and was recently shown to enhance biofilm development in some strains of the respiratory pathogen Pseudomonas aeruginosa. We determined agmatine is at the center of a competing metabolism in the human lung during airways infections and is influenced by the metabolic phenotypes of the infecting pathogens. Ultra performance liquid chromatography with mass spectrometry detection was used to measure agmatine in human sputum samples from patients with cystic fibrosis, spent supernatant from clinical sputum isolates, and from bronchoalvelolar lavage fluid from mice infected with P. aeruginosa agmatine mutants. Agmatine in human sputum peaks during illness, decreased with treatment and is positively correlated with inflammatory cytokines. Analysis of the agmatine metabolic phenotype in clinical sputum isolates revealed most deplete agmatine when grown in its presence; however a minority appeared to generate large amounts of agmatine presumably driving sputum agmatine to high levels. Agmatine exposure to inflammatory cells and in mice demonstrated its role as a direct immune activator with effects on TNF-α production, likely through NF-κB activation. P. aeruginosa mutants for agmatine detection and metabolism were constructed and show the real-time evolution of host-derived agmatine in the airways during acute lung infection. These experiments also demonstrated pathogen agmatine production can upregulate the inflammatory response. As some clinical isolates have adapted to hypersecrete agmatine, these combined data would suggest agmatine is a novel target for immune modulation in the host-pathogen dynamic.

  9. Developmental PCB Exposure Increases Audiogenic Seizures and Decreases Glutamic Acid Decarboxylase in the Inferior Colliculus.

    Science.gov (United States)

    Bandara, Suren B; Eubig, Paul A; Sadowski, Renee N; Schantz, Susan L

    2016-02-01

    Previously, we observed that developmental polychlorinated biphenyl (PCB) exposure resulted in an increase in audiogenic seizures (AGSs) in rats. However, the rats were exposed to loud noise in adulthood, and were not tested for AGS until after 1 year of age, either of which could have interacted with early PCB exposure to increase AGS susceptibility. This study assessed susceptibility to AGS in young adult rats following developmental PCB exposure alone (without loud noise exposure) and investigated whether there was a decrease in GABA inhibitory neurotransmission in the inferior colliculus (IC) that could potentially explain this effect. Female Long-Evans rats were dosed orally with 0 or 6 mg/kg/day of an environmentally relevant PCB mixture from 28 days prior to breeding until the pups were weaned at postnatal day 21. One male-female pair from each litter was retained for the AGS study whilst another was retained for Western blot analysis of glutamic acid decarboxylase (GAD) and GABAAα1 receptor in the IC, the site in the auditory midbrain where AGS are initiated. There was a significant increase in the number and severity of AGSs in the PCB groups, with females somewhat more affected than males. GAD65 was decreased but there was no change in GAD67 or GABAAα1 in the IC indicating decreased inhibitory regulation in the PCB group. These results confirm that developmental PCB exposure alone is sufficient to increase susceptibility to AGS, and provide the first evidence for a possible mechanism of action at the level of the IC. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

    Science.gov (United States)

    Persson, H; Pelto-Huikko, M; Metsis, M; Söder, O; Brene, S; Skog, S; Hökfelt, T; Ritzén, E M

    1990-09-01

    The gene encoding glutamic acid decarboxylase (GAD), the key enzyme in the synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid, is shown to be expressed in the testis of several different species. Nucleotide sequence analysis of a cDNA clone isolated from the human testis confirmed the presence of GAD mRNA in the testis. The major GAD mRNA in the testis was 2.5 kilobases. Smaller amounts of a 3.7-kilobase mRNA with the same size as GAD mRNA in the brain was also detected in the testis. In situ hybridization using a GAD-specific probe revealed GAD mRNA expressing spermatocytes and spermatids located in the middle part of rat seminiferous tubules. Studies on the ontogeny of GAD mRNA expression showed low levels of GAD mRNA in testes of prepubertal rats, with increasing levels as sexual maturation is reached, compatible with GAD mRNA expression in germ cells. In agreement with this, fractionation of cells from the rat seminiferous epithelium followed by Northern (RNA) blot analysis showed the highest levels of GAD mRNA associated with spermatocytes and spermatids. Evidence for the presence of GAD protein in the rat testis was obtained from the demonstration of GAD-like immunoreactivity in seminiferous tubules, predominantly at a position where spermatids and spermatozoa are found. Furthermore, GAD-like immunoreactivity was seen in the midpiece of ejaculated human spermatozoa, the part that is responsible for generating energy for spermatozoan motility.

  11. Enzyme architecture: deconstruction of the enzyme-activating phosphodianion interactions of orotidine 5'-monophosphate decarboxylase.

    Science.gov (United States)

    Goldman, Lawrence M; Amyes, Tina L; Goryanova, Bogdana; Gerlt, John A; Richard, John P

    2014-07-16

    The mechanism for activation of orotidine 5'-monophosphate decarboxylase (OMPDC) by interactions of side chains from Gln215 and Try217 at a gripper loop and R235, adjacent to this loop, with the phosphodianion of OMP was probed by determining the kinetic parameters k(cat) and K(m) for all combinations of single, double, and triple Q215A, Y217F, and R235A mutations. The 12 kcal/mol intrinsic binding energy of the phosphodianion is shown to be equal to the sum of the binding energies of the side chains of R235 (6 kcal/mol), Q215 (2 kcal/mol), Y217 (2 kcal/mol), and hydrogen bonds to the G234 and R235 backbone amides (2 kcal/mol). Analysis of a triple mutant cube shows small (ca. 1 kcal/mol) interactions between phosphodianion gripper side chains, which are consistent with steric crowding of the side chains around the phosphodianion at wild-type OMPDC. These mutations result in the same change in the activation barrier to the OMPDC-catalyzed reactions of the whole substrate OMP and the substrate pieces (1-β-D-erythrofuranosyl)orotic acid (EO) and phosphite dianion. This shows that the transition states for these reactions are stabilized by similar interactions with the protein catalyst. The 12 kcal/mol intrinsic phosphodianion binding energy of OMP is divided between the 8 kcal/mol of binding energy, which is utilized to drive a thermodynamically unfavorable conformational change of the free enzyme, resulting in an increase in (k(cat))(obs) for OMPDC-catalyzed decarboxylation of OMP, and the 4 kcal/mol of binding energy, which is utilized to stabilize the Michaelis complex, resulting in a decrease in (K(m))(obs).

  12. Markedly Lower Glutamic Acid Decarboxylase 67 Protein Levels in a Subset of Boutons in Schizophrenia.

    Science.gov (United States)

    Rocco, Brad R; Lewis, David A; Fish, Kenneth N

    2016-06-15

    Convergent findings indicate that cortical gamma-aminobutyric acid (GABA)ergic circuitry is altered in schizophrenia. Postmortem studies have consistently found lower levels of glutamic acid decarboxylase 67 (GAD67) messenger RNA (mRNA) in the prefrontal cortex (PFC) of subjects with schizophrenia. At the cellular level, the density of GABA neurons with detectable levels of GAD67 mRNA is ~30% lower across cortical layers. Knowing how this transcript deficit translates to GAD67 protein levels in axonal boutons is important for understanding the impact it might have on GABA synthesis. In addition, because reductions in GAD67 expression before, but not after, the maturation of GABAergic boutons results in a lower density of GABAergic boutons in mouse cortical cultures, knowing if GABAergic bouton density is altered in schizophrenia would provide insight into the timing of the GAD67 deficit. PFC tissue sections from 20 matched pairs of schizophrenia and comparison subjects were immunolabeled for the vesicular GABA transporter (vGAT) and GAD67. vGAT+ bouton density did not differ between subject groups, consistent with findings that vGAT mRNA levels are unaltered in the illness and confirming that the number of cortical GABAergic boutons is not lower in schizophrenia. In contrast, in schizophrenia subjects, the proportion of vGAT+ boutons with detectable GAD67 levels (vGAT+/GAD67+ boutons) was 16% lower and mean GAD67 levels were 14% lower in the remaining vGAT+/GAD67+ boutons. Our findings suggest that GABA production is markedly reduced in a subset of boutons in the PFC of schizophrenia subjects and that this reduction likely occurs after the maturation of GABAergic boutons. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  13. Structural Basis for Nucleotide Binding and Reaction Catalysis in Mevalonate Diphosphate Decarboxylase

    Energy Technology Data Exchange (ETDEWEB)

    Barta, Michael L.; McWhorter, William J.; Miziorko, Henry M.; Geisbrecht, Brian V. (UMKC)

    2012-09-17

    Mevalonate diphosphate decarboxylase (MDD) catalyzes the final step of the mevalonate pathway, the Mg{sup 2+}-ATP dependent decarboxylation of mevalonate 5-diphosphate (MVAPP), producing isopentenyl diphosphate (IPP). Synthesis of IPP, an isoprenoid precursor molecule that is a critical intermediate in peptidoglycan and polyisoprenoid biosynthesis, is essential in Gram-positive bacteria (e.g., Staphylococcus, Streptococcus, and Enterococcus spp.), and thus the enzymes of the mevalonate pathway are ideal antimicrobial targets. MDD belongs to the GHMP superfamily of metabolite kinases that have been extensively studied for the past 50 years, yet the crystallization of GHMP kinase ternary complexes has proven to be difficult. To further our understanding of the catalytic mechanism of GHMP kinases with the purpose of developing broad spectrum antimicrobial agents that target the substrate and nucleotide binding sites, we report the crystal structures of wild-type and mutant (S192A and D283A) ternary complexes of Staphylococcus epidermidis MDD. Comparison of apo, MVAPP-bound, and ternary complex wild-type MDD provides structural information about the mode of substrate binding and the catalytic mechanism. Structural characterization of ternary complexes of catalytically deficient MDD S192A and D283A (k{sub cat} decreased 10{sup 3}- and 10{sup 5}-fold, respectively) provides insight into MDD function. The carboxylate side chain of invariant Asp{sup 283} functions as a catalytic base and is essential for the proper orientation of the MVAPP C3-hydroxyl group within the active site funnel. Several MDD amino acids within the conserved phosphate binding loop ('P-loop') provide key interactions, stabilizing the nucleotide triphosphoryl moiety. The crystal structures presented here provide a useful foundation for structure-based drug design.

  14. Gamma radiation inhibits the appearance of induced ornithine decarboxylase activity in Chinese hamster cells

    International Nuclear Information System (INIS)

    Ben-Hur, E.; Heimer, Y.M.; Riklis, E.

    1981-01-01

    Ornithine decarboxylase activity of Chinese hamster cells (ODC, EC 4.1.1.17) can be induced in plateau phase by change of medium. Exposure of the cells to gamma radiation before induction reduces the amount of ODC activity induced. The dose-response curve is exponential with a D 0 of 106 krad. Exposure of BUdR-substituted cells is more effective in reducing ODC induction at high doses, with a D 0 of 38 krad. Cells can recover from the reduction incurred by 74 krad if enzyme induction is delayed for 2 hours after exposure. Treatment of the cells with psoralen-plus-light completely inhibits RNA synthesis without affecting protein synthesis (Heimer, Ben-Hur and Riklis 1977, 1978). Using this procedure it is shown that the effect of gamma radiation on inducible ODC activity is due not only to DNA damage but also involves a post-transcriptional effect. This conclusion is supported by employing a heat shock to inhibit protein synthesis prior to gamma-irradiation of log-phase cells. In such cells the increased activity of ODC upon transfer to 37 0 C is due primarily to enzyme synthesis using pre-existing RNA species during the first few hours. A low concentration of actinomycin D, which inhibits rRNA synthesis, applied during the recovery period, prevents the recovery of the cells' capacity for maximal ODC induction. This may indicate that, in order to recover, the cells have to repair damage to the ribosomes as well as to DNA. (author)

  15. Role of Arginine decarboxylase (ADC) in Arabidopsis thaliana defence against the pathogenic bacterium Pseudomonas viridiflava.

    Science.gov (United States)

    Rossi, F R; Marina, M; Pieckenstain, F L

    2015-07-01

    Polyamine biosynthesis starts with putrescine production through the decarboxylation of arginine or ornithine. In Arabidopsis thaliana, putrescine is synthesised exclusively by arginine decarboxylase (ADC), which exists as two isoforms (ADC1 and 2) that are differentially regulated by abiotic stimuli, but their role in defence against pathogens has not been studied in depth. This work analysed the participation of ADC in Arabidopsis defence against Pseudomonas viridiflava. ADC activity and expression, polyamine levels and bacterial resistance were analysed in null mutants of each ADC isoform. In non-infected wild-type (WT) plants, ADC2 expression was much higher than ADC1. Analysis of adc mutants demonstrated that ADC2 contributes to a much higher extent than ADC1 to basal ADC activity and putrescine biosynthesis. In addition, adc2 mutants showed increased basal expression of salicylic acid- and jasmonic acid-dependent PR genes. Bacterial infection induced putrescine accumulation and ADC1 expression in WT plants, but pathogen-induced putrescine accumulation was blocked in adc1 mutants. Results suggest a specific participation of ADC1 in defence, although basal resistance was not decreased by dysfunction of either of the two ADC genes. In addition, and as opposed to WT plants, bacterial infection increased ADC2 expression and ADC activity in adc1 mutants, which could counterbalance the lack of ADC1. Results demonstrate a major contribution of ADC2 to total ADC activity and the specific induction of ADC1 in response to infection. A certain degree of functional redundancy between the two isoforms in relation to their contribution to basal resistance is also evident. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Spermidine mediates degradation of ornithine decarboxylase by a non-lysosomal, ubiquitin-independent mechanism

    International Nuclear Information System (INIS)

    Glass, J.R.; Gerner, E.W.

    1987-01-01

    The mechanism of spermidine-induced ornithine decarboxylase (OCD, E.C. 4.1.1.17) inactivation was investigated using Chinese hamster ovary (CHO) cells, maintained in serum-free medium, which display a stabilization of ODC owing to the lack of accumulation of putrescine and spermidine. Treatment of cells with 10 μM exogenous spermidine leads to rapid decay of ODC activity accompanied by a parallel decrease in enzyme protein. Analysis of the decay of [ 35 S]methionine-labeled ODC and separation by two-dimensional electrophoresis revealed no detectable modification in ODC structure during enhanced degradation. Spermidine-mediated inactivation of ODC occurred in a temperature-dependent manner exhibiting pseudo-first-order kinetics over a temperature range of 22-37 0 C. In cultures treated continuously, an initial lag was observed after treatment with spermidine, followed by a rapid decline in activity as an apparent critical concentration of intracellular spermidine was achieved. Treating cells at 22 0 C for 3 hours with 10 μ M spermidine, followed by removal of exogenous polyamine, and then shifting to varying temperatures, resulted in rates of ODC inactivation identical with that determined with a continuous treatment. Arrhenius analysis showed that polyamine mediated inactivation of ODC occurred with an activation energy of approximately 16 kcal/mol. Treatment of cells with lysosomotrophic agents had no effect of ODC degradation. ODC turnover was not dependent on ubiquitin-dependent proteolysis. These data support the hypothesis that spermidine regulates ODC degradation via a mechanism requiring new protein synthesis, and that this occurs via a non-lysosomal, ubiquitin-independent pathway

  17. Development of a sensor for L-Dopa based on Co(DMG)(2)ClPy/multi-walled carbon nanotubes composite immobilized on basal plane pyrolytic graphite electrode.

    Science.gov (United States)

    Leite, Fernando Roberto Figueirêdo; Maroneze, Camila Marchetti; de Oliveira, Adriano Bof; dos Santos, Wallans Torres Pio; Damos, Flavio Santos; Silva Luz, Rita de Cássia

    2012-08-01

    L-Dopa is the immediate precursor of the neurotransmitter dopamine, being the most widely prescribed drug in the treatment of Parkinson's disease. A sensitive and selective method is presented for the voltammetric determination of L-Dopa in pharmaceutical formulations using a basal plane pyrolytic graphite (BPPG) electrode modified with chloro(pyridine)bis(dimethylglyoximato)cobalt(III) (Co(DMG)(2)ClPy) absorbed in a multi-walled carbon nanotube (MWCNT). Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy were used to characterize the materials. The electrocatalytical oxidation of L-Dopa using the Co(DMG)(2)ClPy/MWCNT/BPPG electrode was investigated by cyclic voltammetry and square wave voltammetry. The parameters that influence the electrode response (the amount of Co(DMG)(2)ClPy and of MWCNT, buffer solution, buffer concentration, buffer pH, frequency and potential pulse amplitude) were investigated. Voltammetric peak currents showed a linear response for L-Dopa concentration in the range of 3 to 100 μM, with a sensitivity of 4.43 μAcm(-2)/μM and a detection limit of 0.86 μM. The related standard deviation for 10 determinations of 50 μM L-Dopa was 1.6%. The results obtained for L-Dopa determination in pharmaceutical formulations (tablets) were in agreement with the compared official method. The sensor was successfully applied for L-Dopa selective determination in pharmaceutical formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Undervisning af tosprogede elever

    DEFF Research Database (Denmark)

    Horst, Christian

    2003-01-01

    Artiklen fremdrager hovedresultaterne fra Virginia P. Collier's og Wayne P. Thomas's længdeundersøgelser af tosprogede elever i USA, som formentlig er de mest omfattende undersøgelser af undervisningen af tosprogede elever overhovedet. Resultaterne diskuteres i relation til udviklingen af en...

  19. Effects of elevated CO

    NARCIS (Netherlands)

    Xue, Sha; Yang, Xiaomei; Liu, Guobin; Gai, Lingtong; Zhang, Changsheng; Ritsema, Coen J.; Geissen, Violette

    2017-01-01

    Elevated CO2 and drought are key consequences of climate change and affect soil processes and plant growth. This study investigated the effects of elevated CO2 and drought on the microbial biomass and enzymatic activities in the rhizospheres of Bothriochloa ischaemum and

  20. Human Monoclonal Islet Cell Antibodies From a Patient with Insulin- Dependent Diabetes Mellitus Reveal Glutamate Decarboxylase as the Target Antigen

    Science.gov (United States)

    Richter, Wiltrud; Endl, Josef; Eiermann, Thomas H.; Brandt, Michael; Kientsch-Engel, Rosemarie; Thivolet, Charles; Jungfer, Herbert; Scherbaum, Werner A.

    1992-09-01

    The autoimmune phenomena associated with destruction of the β cell in pancreatic islets and development of type 1 (insulin-dependent) diabetes mellitus (IDDM) include circulating islet cell antibodies. We have immortalized peripheral blood lymphocytes from prediabetic individuals and patients with newly diagnosed IDDM by Epstein-Barr virus transformation. IgG-positive cells were selected by anti-human IgG-coupled magnetic beads and expanded in cell culture. Supernatants were screened for cytoplasmic islet cell antibodies using the conventional indirect immunofluorescence test on cryostat sections of human pancreas. Six islet cell-specific B-cell lines, originating from a patient with newly diagnosed IDDM, could be stabilized on a monoclonal level. All six monoclonal islet cell antibodies (MICA 1-6) were of the IgG class. None of the MICA reacted with human thyroid, adrenal gland, anterior pituitary, liver, lung, stomach, and intestine tissues but all six reacted with pancreatic islets of different mammalian species and, in addition, with neurons of rat cerebellar cortex. MICA 1-6 were shown to recognize four distinct antigenic epitopes in islets. Islet cell antibody-positive diabetic sera but not normal human sera blocked the binding of the monoclonal antibodies to their target epitopes. Immunoprecipitation of 35S-labeled human islet cell extracts revealed that a protein of identical size to the enzyme glutamate decarboxylase (EC 4.1.1.15) was a target of all MICA. Furthermore, antigen immunotrapped by the MICA from brain homogenates showed glutamate decarboxylase enzyme activity. MICA 1-6 therefore reveal glutamate decarboxylase as the predominant target antigen of cytoplasmic islet cell autoantibodies in a patient with newly diagnosed IDDM.

  1. Swit_4259, an acetoacetate decarboxylase-like enzyme from Sphingomonas wittichii RW1

    Energy Technology Data Exchange (ETDEWEB)

    Mydy, Lisa S.; Mashhadi, Zahra; Knight, T. William; Fenske, Tyler; Hagemann, Trevor; Hoppe, Robert W.; Han, Lanlan; Miller, Todd R.; Schwabacher, Alan W.; Silvaggi, Nicholas R. (UW); (Vanderbilt)

    2017-11-14

    The Gram-negative bacteriumSphingomonas wittichiiRW1 is notable for its ability to metabolize a variety of aromatic hydrocarbons. Not surprisingly, theS. wittichiigenome contains a number of putative aromatic hydrocarbon-degrading gene clusters. One of these includes an enzyme of unknown function, Swit_4259, which belongs to the acetoacetate decarboxylase-like superfamily (ADCSF). Here, it is reported that Swit_4259 is a small (28.8 kDa) tetrameric ADCSF enzyme that, unlike the prototypical members of the superfamily, does not have acetoacetate decarboxylase activity. Structural characterization shows that the tertiary structure of Swit_4259 is nearly identical to that of the true decarboxylases, but there are important differences in the fine structure of the Swit_4259 active site that lead to a divergence in function. In addition, it is shown that while it is a poor substrate, Swit_4259 can catalyze the hydration of 2-oxo-hex-3-enedioate to yield 2-oxo-4-hydroxyhexanedioate. It is also demonstrated that Swit_4259 has pyruvate aldolase-dehydratase activity, a feature that is common to all of the family V ADCSF enzymes studied to date. The enzymatic activity, together with the genomic context, suggests that Swit_4259 may be a hydratase with a role in the metabolism of an as-yet-unknown hydrocarbon. These data have implications for engineering bioremediation pathways to degrade specific pollutants, as well as structure–function relationships within the ADCSF in general.

  2. Cloning of affecting pyruvate decarboxylase gene in the production bioethanol of agricultural waste in the E.coli bacteria

    Directory of Open Access Journals (Sweden)

    Masome Zeinali

    2016-09-01

    Full Text Available Introduction: Ethanol made by a biomass is one of the useful strategies in terms of economic and environmental and as a clean and safe energy to replace fossil fuels considered and examined. Materials and methods: In this study, key enzyme in the production of ethanol (Pyruvate decarboxylase from Zymomonas mobilis bacteria was isolated and cloned at E. coli bacteria by freeze and thaw method. For gene cloning, we used specific primers of pdc and PCR reaction and then pdc gene isolated and pET 28a plasmid double digested with (Sal I and Xho I enzymes. Digestion Products were ligated by T4 DNA ligase in 16 °C for 16 hours. Results: Results of bacteria culture showed that a few colonies containing pET 28a plasmid could grow. Result of colony pcr of pdc gene with specific primers revealed 1700 bp bands in 1% agarose gel electrophoresis. The results of PCR with T7 promotor forward primer and pdc revers primer have proved the accurate direction of integration of pdc gene into plasmid and revealed 1885 bp band. Double digestion of recombinant plasmid with SalI and XhoI enzymes revealed same bands. Finally, RT showed the expected band of 1700 bp that implies the desired gene expression in the samples. Discussion and conclusion: Due to the increased production of ethanol via pyruvate decarboxylase gene cloning in expression plasmids with a strong promoter upstream of the cloning site can conclude that, pyruvate decarboxylase cloning as a key gene would be useful and according to beneficial properties of E. coli bacteria, transfering the gene to bacteria appears to be reasonable.

  3. Elevator and hydraulics; Elevator to yuatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, I. [Hitachi, Ltd., Tokyo (Japan)

    1994-07-15

    A hydraulic type elevator is installed in relatively lower buildings as compared with a rope type elevator, but the ratio in the number of installation of the former elevator is increasing. This paper explains from its construction and features to especially various control systems for the riding comfort and safety. A direct push-up system with hydraulic jacks arranged beneath a car, and an indirect push-up system that has hydraulic jacks arranged on flank of a car and transmits the movement of a plunger via a rope are available. The latter system eliminates the need of large holes to embed hydraulic jacks. While the speed is controlled by controlling flow rates of high-pressure oil, the speed, position, acceleration and even time differential calculus of the acceleration must be controlled severely. The system uses two-step control for the through-speed and the landing speed. Different systems that have been realized may include compensation for temperatures in flow rate control valves, load pressures, and oil viscosity, from learning control to fuzzy control for psychological effects, or control of inverters in motors. 13 refs., 12 figs., 1 tab.

  4. Case Reports Showing a Long-Term Effect of Subanesthetic Ketamine Infusion in Reducing L-DOPA-Induced Dyskinesias

    Directory of Open Access Journals (Sweden)

    Scott J. Sherman

    2016-02-01

    Full Text Available Ketamine is an FDA-approved drug with a known safety profile. Low-dose subanesthetic intravenous ketamine infusion treatment has led to long-term reduction of treatment-resistant depression and of chronic pain states. We report on low-dose subanesthetic intravenous ketamine infusion treatment in Parkinson's disease (PD patients by 5 case studies and show a long-lasting therapeutic benefit to reduce L-DOPA-induced dyskinesia (LID, improve on time, and reduce depression. Based on the literature we hypothesize that low-dose ketamine may act as a ‘chemical deep brain stimulation', by desynchronizing hypersynchronous oscillatory brain activity, including in the basal ganglia and the motor cortex. The presented PD case reports indicate tolerability, safety and long-term beneficial effects of low-dose ketamine infusion that should be further investigated in a properly controlled prospective clinical trial for treatment of LID, as well as the prevalent nonmotor features pain and depression in PD patients.

  5. Biodistribution and human dosimetry estimation of fluoro-L-DOPA as PET imaging agent of dopaminergic nerve transmitter systems

    International Nuclear Information System (INIS)

    Tang Ganghua; Wang Mingfang; Luo Lei; Gan Manquan; Tang Xiaolan; Zhang Lan; Wang Yongxian

    2002-01-01

    Objective: To investigate the biodistribution and human dosimetry estimation of 6-[ 18 F] Fluoro-L-DOPA (FDOPA). Methods: Biodistribution of FDOPA in normal rats and brain of hemi-Parkinsonism rats were determined. Human dosimetry estimation was performed by MIRD method based on the rats biodistribution data. Results: Biodistributions in normal rats showed high uptake in kidney, blood, striatum and hippocampi, fast clearance of radioactivity from kidney and blood, longer retain time in striatum and hippocampi, and higher striatum to cerebellum and striatum to cortex ratio. FDOPA uptake, striatum to cerebellum and striatum to cortex ratio in the lesioned side of hemi-Parkinsonism rats (P 2 to 2.3 x 10 -2 mGy/MBq and the effective dose in humans was estimated to be 2.05 x 10 -2 mSv/MBq after injection of FDOPA based on rats biodistribution data, which were consistent with those reported by literature on the whole. Conclusion: Human radiation dosimetry of FDOPA and other PET tracers can be estimated based on animals biodistribution data. The synthetic FDOPA is safe and efficient and can be used in animals, human and PD patients PET studies

  6. Agdc1p - a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans.

    Science.gov (United States)

    Meier, Anna K; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

    2017-01-01

    Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (K m -0.7 ± 0.2 mM, k cat -42.0 ± 8.2 s -1 ) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (K m -3.2 ± 0.2 mM, k cat -44.0 ± 3.2 s -1 ). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δ agdc1 ] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis -muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be

  7. Effects of methylglyoxal bis(guanylhydrazone) and two phenylated analogues on S-adenosylmethionine decarboxylase activity from Eimeria stiedai (Apicomplexa).

    Science.gov (United States)

    San-Martín Núñez, B; Alunda, J M; Balaña-Fouce, R; Ordóñez Escudero, D

    1987-01-01

    1. Activity of S-adenosylmethionine decarboxylase, one of the rate-limiting enzymes of polyamine biosynthesis, was determined in oocysts of Eimeria stiedai, a coccidian parasite of the rabbit. 2. Several properties of the enzyme were compared to the mammalian enzyme. It showed considerably less substrate affinity than the analog enzyme from the rabbit. 3. The E. stiedai enzyme showed a low sensitivity to methylglyoxal bis(guanylhydrazone), a frequently used inhibitor of the enzyme in mammals, and two phenylated derivatives. 4. Results with the inhibitors are discussed in view of their potential use in chemotherapy.

  8. Elevators or stairs?

    Science.gov (United States)

    Shah, Sachin; O’Byrne, Michael; Wilson, Merne; Wilson, Thomas

    2011-01-01

    Background: Staff in hospitals frequently travel between floors and choose between taking the stairs or elevator. We compared the time savings with these two options. Methods: Four people aged 26–67 years completed 14 trips ranging from one to six floors, both ascending and descending. We compared the amount of time per floor travelled by stairs and by two banks of elevators. Participants reported their fatigue levels using a modified Borg scale. We performed two-way analysis of variance to compare the log-transformed data, with participant and time of day as independent variables. Results: The mean time taken to travel between each floor was 13.1 (standard deviation [SD] 1.7) seconds by stairs and 37.5 (SD 19.0) and 35.6 (SD 23.1) seconds by the two elevators (F = 8.61, p elevator equaled about 15 minutes a day. Self-reported fatigue was less than 13 (out of 20) on the Borg scale for all participants, and they all stated that they were able to continue their duties without resting. The extra time associated with elevator use was because of waiting for its arrival. There was a difference in the amount of time taken to travel by elevator depending on the time of day and day of the week. Interpretation: Taking the stairs rather than the elevator saved about 15 minutes each workday. This 3% savings per workday could translate into improved productivity as well as increased fitness. PMID:22159365

  9. A retrospective comparison between {sup 68}Ga-DOTA-TOC PET/CT and {sup 18}F-DOPA PET/CT in patients with extra-adrenal paraganglioma

    Energy Technology Data Exchange (ETDEWEB)

    Kroiss, Alexander; Putzer, Daniel; Decristoforo, Clemens; Uprimny, Christian; Virgolini, Irene Johanna [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria); Frech, Andreas; Fraedrich, Gustav [Innsbruck Medical University, Department of Vascular Surgery, Innsbruck (Austria); Gasser, Rudolf Wolfgang [Innsbruck Medical University, Department of Internal Medicine I, Innsbruck (Austria); Shulkin, Barry Lynn [St. Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); Url, Christoph [Innsbruck Medical University, Department of Otorhinolaryngology, Innsbruck (Austria); Widmann, Gerlig [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Prommegger, Rupert [Sanatorium Kettenbruecke, Department of Surgery, Innsbruck (Austria); Sprinzl, Georg Mathias [State Clinic St. Poelten, Department of Otorhinolaryngology, St. Poelten (Austria)

    2013-12-15

    {sup 18}F-Fluoro-l-dihydroxyphenylalanine ({sup 18}F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by {sup 68}Ga-DOTA-Tyr{sup 3}-octreotide ({sup 68}Ga-DOTA-TOC) PET. Therefore, we compared {sup 68}Ga-DOTA-TOC and {sup 18}F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with {sup 68}Ga-DOTA-TOC PET and {sup 18}F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUV{sub max}) of each functional imaging modality in concordant tumour lesions was measured. Compared with anatomical imaging, {sup 68}Ga-DOTA-TOC PET and {sup 18}F-DOPA PET each had a per-patient and per-lesion detection rate of 100 % in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of {sup 68}Ga-DOTA-TOC was 100 % and that of {sup 18}F-DOPA PET was 56.0 %. Overall, {sup 68}Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and {sup 18}F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of {sup 68}Ga-DOTA-TOC PET was 100 % (McNemar, P < 0.5), and that of {sup 18}F-DOPA PET was 71.1 % (McNemar, P < 0.001). The SUV{sub max} (mean {+-} SD) of all 32 concordant lesions was 67.9 {+-} 61.5 for {sup 68}Ga-DOTA-TOC PET and 11.8 {+-} 7.9 for {sup 18}F-DOPA PET (Mann-Whitney U test, P < 0.0001). {sup 68}Ga-DOTA-TOC PET

  10. Elevated temperature fracture mechanics

    International Nuclear Information System (INIS)

    Tomkins, B.

    1979-01-01

    The application of fracture mechanics concepts to cracks at elevated temperatures is examined. Particular consideration is given to the characterisation of crack tip stress-strain fields and parameters controlling crack extension under static and cyclic loads. (author)

  11. Structural Characterization of the Molecular Events during a Slow Substrate-Product Transition in Orotidine 5'-Monophosphate Decarboxylase

    Energy Technology Data Exchange (ETDEWEB)

    Fujihashi, Masahiro; Wei, Lianhu; Kotra, Lakshmi P; Pai, Emil F; (TGRI); (Toronto); (Kyoto)

    2009-04-06

    Crystal structures of substrate-product complexes of Methanobacterium thermoautotrophicum orotidine 5'-monophosphate decarboxylase, obtained at various steps in its catalysis of the unusual transformation of 6-cyano-uridine 5'-monophosphate (UMP) into barbituric acid ribosyl monophosphate, show that the cyano substituent of the substrate, when bound to the active site, is first bent significantly from the plane of the pyrimidine ring and then replaced by an oxygen atom. Although the K72A and D70A/K72A mutants are either catalytically impaired or even completely inactive, they still display bending of the C6 substituent. Interestingly, high-resolution structures of the D70A and D75N mutants revealed a covalent bond between C6 of UMP and the Lys72 side chain after the -CN moiety's release. The same covalent bond was observed when the native enzyme was incubated with 6-azido-UMP and 6-iodo-UMP; in contrast, the K72A mutant transformed 6-iodo-UMP to barbituric acid ribosyl 5'-monophosphate. These results demonstrate that, given a suitable environment, native orotidine 5'-monophosphate decarboxylase and several of its mutants are not restricted to the physiologically relevant decarboxylation; they are able to catalyze even nucleophilic substitution reactions but consistently maintain distortion on the C6 substituent as an important feature of catalysis.

  12. Crystallization and preliminary crystallographic analysis of orotidine 5′-monophosphate decarboxylase from the human malaria parasite Plasmodium falciparum

    International Nuclear Information System (INIS)

    Krungkrai, Sudaratana R.; Tokuoka, Keiji; Kusakari, Yukiko; Inoue, Tsuyoshi; Adachi, Hiroaki; Matsumura, Hiroyoshi; Takano, Kazufumi; Murakami, Satoshi; Mori, Yusuke; Kai, Yasushi; Krungkrai, Jerapan; Horii, Toshihiro

    2006-01-01

    Orotidine 5′-monophosphate decarboxylase of human malaria parasite P. falciparum was crystallized by the seeding method in a hanging drop using PEG 3000 as a precipitant. A complete set of diffraction data from a native crystal was collected to 2.7 Å resolution at 100 K using synchrotron radiation. Orotidine 5′-monophosphate (OMP) decarboxylase (OMPDC; EC 4.1.1.23) catalyzes the final step in the de novo synthesis of uridine 5′-monophosphate (UMP) and defects in the enzyme are lethal in the malaria parasite Plasmodium falciparum. Active recombinant P. falciparum OMPDC (PfOMPDC) was crystallized by the seeding method in a hanging drop using PEG 3000 as a precipitant. A complete set of diffraction data from a native crystal was collected to 2.7 Å resolution at 100 K using synchrotron radiation at the Swiss Light Source. The crystal exhibits trigonal symmetry (space group R3), with hexagonal unit-cell parameters a = b = 201.81, c = 44.03 Å. With a dimer in the asymmetric unit, the solvent content is 46% (V M = 2.3 Å 3 Da −1 )

  13. Structural basis of enzymatic activity for the ferulic acid decarboxylase (FADase from Enterobacter sp. Px6-4.

    Directory of Open Access Journals (Sweden)

    Wen Gu

    Full Text Available Microbial ferulic acid decarboxylase (FADase catalyzes the transformation of ferulic acid to 4-hydroxy-3-methoxystyrene (4-vinylguaiacol via non-oxidative decarboxylation. Here we report the crystal structures of the Enterobacter sp. Px6-4 FADase and the enzyme in complex with substrate analogues. Our analyses revealed that FADase possessed a half-opened bottom β-barrel with the catalytic pocket located between the middle of the core β-barrel and the helical bottom. Its structure shared a high degree of similarity with members of the phenolic acid decarboxylase (PAD superfamily. Structural analysis revealed that FADase catalyzed reactions by an "open-closed" mechanism involving a pocket of 8 × 8 × 15 Å dimension on the surface of the enzyme. The active pocket could directly contact the solvent and allow the substrate to enter when induced by substrate analogues. Site-directed mutagenesis showed that the E134A mutation decreased the enzyme activity by more than 60%, and Y21A and Y27A mutations abolished the enzyme activity completely. The combined structural and mutagenesis results suggest that during decarboxylation of ferulic acid by FADase, Trp25 and Tyr27 are required for the entering and proper orientation of the substrate while Glu134 and Asn23 participate in proton transfer.

  14. Reactions of Ferrous Coproheme Decarboxylase (HemQ) with O2 and H2O2 Yield Ferric Heme b.

    Science.gov (United States)

    Streit, Bennett R; Celis, Arianna I; Shisler, Krista; Rodgers, Kenton R; Lukat-Rodgers, Gudrun S; DuBois, Jennifer L

    2017-01-10

    A recently discovered pathway for the biosynthesis of heme b ends in an unusual reaction catalyzed by coproheme decarboxylase (HemQ), where the Fe(II)-containing coproheme acts as both substrate and cofactor. Because both O 2 and H 2 O 2 are available as cellular oxidants, pathways for the reaction involving either can be proposed. Analysis of reaction kinetics and products showed that, under aerobic conditions, the ferrous coproheme-decarboxylase complex is rapidly and selectively oxidized by O 2 to the ferric state. The subsequent second-order reaction between the ferric complex and H 2 O 2 is slow, pH-dependent, and further decelerated by D 2 O 2 (average kinetic isotope effect of 2.2). The observation of rapid reactivity with peracetic acid suggested the possible involvement of Compound I (ferryl porphyrin cation radical), consistent with coproheme and harderoheme reduction potentials in the range of heme proteins that heterolytically cleave H 2 O 2 . Resonance Raman spectroscopy nonetheless indicated a remarkably weak Fe-His interaction; how the active site structure may support heterolytic H 2 O 2 cleavage is therefore unclear. From a cellular perspective, the use of H 2 O 2 as an oxidant in a catalase-positive organism is intriguing, as is the unusual generation of heme b in the Fe(III) rather than Fe(II) state as the end product of heme synthesis.

  15. Tryptophan decarboxylase plays an important role in ajmalicine biosynthesis in Rauvolfia verticillata.

    Science.gov (United States)

    Liu, Wanhong; Chen, Rong; Chen, Min; Zhang, Haoxing; Peng, Meifang; Yang, Chunxian; Ming, Xingjia; Lan, Xiaozhong; Liao, Zhihua

    2012-07-01

    Tryptophan decarboxylase (TDC) converts tryptophan into tryptamine that is the indole moiety of ajmalicine. The full-length cDNA of Rauvolfia verticillata (RvTDC) was 1,772 bps that contained a 1,500-bp ORF encoding a 499-amino-acid polypeptide. Recombinant 55.5 kDa RvTDC converted tryptophan into tryptamine. The K (m) of RvTDC for tryptophan was 2.89 mM, higher than those reported in other TIAs-producing plants. It demonstrated that RvTDC had lower affinity to tryptophan than other plant TDCs. The K (m) of RvTDC was also much higher than that of strictosidine synthase and strictosidine glucosidase in Rauvolfia. This suggested that TDC might be the committed-step enzyme involved in ajmalicine biosynthesis in R. verticillata. The expression of RvTDC was slightly upregulated by MeJA; the five MEP pathway genes and SGD showed no positive response to MeJA; and STR was sharply downregulated by MeJA. MeJA-treated hairy roots produced higher level of ajmalicine (0.270 mg g(-1) DW) than the EtOH control (0.183 mg g(-1) DW). Highest RvTDC expression level was detected in hairy root, about respectively 11, 19, 65, and 109-fold higher than in bark, young leaf, old leaf, and root. Highest ajmalicine content was also found in hairy root (0.249 mg g(-1) DW) followed by in bark (0.161 mg g(-1) DW) and young leaf (0.130 mg g(-1) DW), and least in root (0.014 mg g(-1) DW). Generally, the expression level of RvTDC was positively consistent with the accumulation of ajmalicine. Therefore, it could be deduced that TDC might be the key enzyme involved in ajmalicine biosynthesis in Rauvolfia.

  16. The UDP-glucuronate decarboxylase gene family in Populus: structure, expression, and association genetics.

    Directory of Open Access Journals (Sweden)

    Qingzhang Du

    Full Text Available In woody crop plants, the oligosaccharide components of the cell wall are essential for important traits such as bioenergy content, growth, and structural wood properties. UDP-glucuronate decarboxylase (UXS is a key enzyme in the synthesis of UDP-xylose for the formation of xylans during cell wall biosynthesis. Here, we isolated a multigene family of seven members (PtUXS1-7 encoding UXS from Populus tomentosa, the first investigation of UXSs in a tree species. Analysis of gene structure and phylogeny showed that the PtUXS family could be divided into three groups (PtUXS1/4, PtUXS2/5, and PtUXS3/6/7, consistent with the tissue-specific expression patterns of each PtUXS. We further evaluated the functional consequences of nucleotide polymorphisms in PtUXS1. In total, 243 single-nucleotide polymorphisms (SNPs were identified, with a high frequency of SNPs (1/18 bp and nucleotide diversity (πT = 0.01033, θw = 0.01280. Linkage disequilibrium (LD analysis showed that LD did not extend over the entire gene (r (2<0.1, P<0.001, within 700 bp. SNP- and haplotype-based association analysis showed that nine SNPs (Q <0.10 and 12 haplotypes (P<0.05 were significantly associated with growth and wood property traits in the association population (426 individuals, with 2.70% to 12.37% of the phenotypic variation explained. Four significant single-marker associations (Q <0.10 were validated in a linkage mapping population of 1200 individuals. Also, RNA transcript accumulation varies among genotypic classes of SNP10 was further confirmed in the association population. This is the first comprehensive study of the UXS gene family in woody plants, and lays the foundation for genetic improvements of wood properties and growth in trees using genetic engineering or marker-assisted breeding.

  17. Indsatser for tosprogede elever

    DEFF Research Database (Denmark)

    Andersen, Dines; Jakobsen, Vibeke; Jensen, Vibeke Myrup

    Fagligt set klarer tosprogede elever sig dårligere i skolen og det videre uddannelsessystem end ’danske’ elever. Kommuner og folkeskoler har derfor sat en række tiltag i værk, som sigter mod at forbedre de tosprogede elevers skole- og uddannelsessituation. Rapporten kortlægger og analyserer...... af klasseundervisningen. Analysen viser, at de elever, der bliver taget ud af klassen for at få ekstra undervisning i dansk som andetsprog, klarer sig dårligere end elever, der modtager ekstraundervisningen i klassen eller uden for skoletid. Undersøgelsen er baseret på spørgeskemaundersøgelser blandt...... kommunale forvaltningschefer, skoleledere, lærere og forældre til børn i 2. klasse samt lærere til og elever i 9. klasse, SFI’s forløbsundersøgelse af årgang 1995 og registerdata. Undersøgelsen er via Ministeriet for Børn og Undervisning betalt med midler fra satspuljeaftalen 2009 om integration....

  18. On the synthesis of radiofluorinated amino acids by isotope exchange based on the example of 6-[18F]Fluor-L-DOPA

    International Nuclear Information System (INIS)

    Wagner, F.M.

    2008-06-01

    In nuclear medical diagnosis, 6-[ 18 F]fluoro-L-3,4-dihydroxyphenylalanine (6-[ 18 F]fluoro-LDOPA), an analogue of L-DOPA, is one of the few established radiopharmaceuticals used for the in vivo investigation of the presynaptic dopaminergic metabolism and of some kind of tumours via Positron Emission Tomography (PET). The presently used method of preparation of the radiotracer by electrophilic labelling is limited to low amounts of activity at high costs. Known nucleophilic syntheses, however, result either in insufficient enantiomeric purity or the known multi-step syntheses are hard to automate, due to their complexity. During this work a novel, easy to automate alternative for the preparation of 6-[ 18 F]fluoro-L-DOPA, was developed and evaluated, using a direct nucleophilic 18 F-fluorination of a protected amino acid derivative. The resulting product has a very high enantiomeric purity. At first, the general suitability of the (S)-BOC-BMI-derivatives for the synthesis of 18 F-labelled amino acids, used in this work, was investigated using a less complex precursor, which resulted in the amino acid 6-[ 18 F]fluoro-L-m-tyrosin via acidic hydrolysis. The preparation of a useful precursor for the nucleophilic 18 F-isotope substitution, namely the (2S,5S)-tert.-butyl- 5-(2-fluoro-5-formylbenzyl)-2-tert. -butyl-3-methyl-4-oxoimidazolidine-1-carbox= yl ate, was investigated in three general different ways. At first it was tried to obtain this product via formylation after coupling with the BOC-BMI, secondly via α,β-dehydro amino acid derivatives and finally via a systematic multi-step synthesis. Only the last mentioned way resulted in a precursor with sufficient purity that could be labelled. The radiochemical yield of the isotopic exchange was about 60 %. In the next step, the presented concept was modified to synthesize a precursor for the preparation of 6-[ 18 F]fluoro-L-DOPA. Only a combination of the protecting groups benzyl and THP resulted in the useful

  19. Excessive sensitivity to uncertain visual input in L-dopa induced dyskinesias in Parkinson’s disease: further implications for cerebellar involvement

    Directory of Open Access Journals (Sweden)

    James eStevenson

    2014-02-01

    Full Text Available When faced with visual uncertainty during motor performance, humans rely more on predictive forward models and proprioception and attribute lesser importance to the ambiguous visual feedback. Though disrupted predictive control is typical of patients with cerebellar disease, sensorimotor deficits associated with the involuntary and often unconscious nature of L-dopa-induced dyskinesias in Parkinson’s disease (PD suggests dyskinetic subjects may also demonstrate impaired predictive motor control. Methods: We investigated the motor performance of 9 dyskinetic and 10 non-dyskinetic PD subjects on and off L-dopa, and of 10 age-matched control subjects, during a large-amplitude, overlearned, visually-guided tracking task. Ambiguous visual feedback was introduced by adding ‘jitter’ to a moving target that followed a Lissajous pattern. Root mean square (RMS tracking error was calculated, and ANOVA, robust multivariate linear regression and linear dynamical system analyses were used to determine the contribution of speed and ambiguity to tracking performance. Results: Increasing target ambiguity and speed contributed significantly more to the RMS error of dyskinetic subjects off medication. L-dopa improved the RMS tracking performance of both PD groups. At higher speeds, controls and PDs without dyskinesia were able to effectively de-weight ambiguous visual information. Conclusions: PDs’ visually-guided motor performance degrades with visual jitter and speed of movement to a greater degree compared to age-matched controls. However, there are fundamental differences in PDs with and without dyskinesia: subjects without dyskinesia are generally slow, and less responsive to dynamic changes in motor task requirements but, PDs with dyskinesia there was a trade-off between overall performance and inappropriate reliance on ambiguous visual feedback. This is likely associated with functional changes in posterior parietal-ponto-cerebellar pathways.

  20. The effects of dopamine on regional cerebral blood flow in patients with Parkinson's disease before and after L-dopa. Measurement by Xe-enhanced CT

    International Nuclear Information System (INIS)

    Aiba, Ikuko; Indo, Toshikatsu; Takahashi, Akira.

    1994-01-01

    Regional cerebral blood flow (rCBF) was measured using the stable xenon enhanced CT method in previously untreated 13 patients with Parkinson's disease to evaluate CBF abnormality related to dysfunction of the nigrostriatal dopaminergic neurons. The patients comprised 5 men and 8 women with Hoehn-Yahr stage II-III. Age at onset ranged from 51 to 73 years (mean±SD, 61.8±8.9) and the duration of illness ranged from 1 to 96 months (15.1±24.1 months). In this series, there was no clinical evidence of hypertension, diabetes mellitus and cognitive impairment. rCBF was measured during 4-5-minutes inhalation, of 33% stable xenon gas-67% oxygen. The first measurement of rCBF was performed in all of the patients before L-dopa treatment. After initiation of L-dopa treatment (333.3±47.1 mg/day), the second measurement was carried out in 6 patients (1 man and 5 women) who had shown symptomatic improvement. The interval between both measurements was 57.7±16.9 days. The following results were obtained. 1) No significant CBF asymmetry was noted in any of the striatum, pallidum, thalamus, cerebrum, cerebellum and frontal lobe in untreated patients with Parkinson's disease. 2) After L-dopa treatment, rCBF was significantly increased only in the striatum as compared with the pretreatment level (51.9±9.3→63.1±9.9 ml/100g/min, p<0.01). 3) This increase was significantly greater on the more severely affected side (contralateral to the predominantly symptomatic limb) (p<0.05). These results suggest that the increase of rCBF in the striatum is closely related to functional improvement of the nigrostriatal dopaminergic neurons. (author)

  1. Influence of O-methylated metabolite penetrating the blood-brain barrier to estimation of dopamine synthesis capacity in human L-[β-(11)C]DOPA PET.

    Science.gov (United States)

    Matsubara, Keisuke; Ikoma, Yoko; Okada, Maki; Ibaraki, Masanobu; Suhara, Tetsuya; Kinoshita, Toshibumi; Ito, Hiroshi

    2014-02-01

    O-methyl metabolite (L-[β-(11)C]OMD) of (11)C-labeled L-3,4-dihydroxyphenylalanine (L-[β-(11)C]DOPA) can penetrate into brain tissue through the blood-brain barrier, and can complicate the estimation of dopamine synthesis capacity by positron emission tomography (PET) study with L-[β-(11)C]DOPA. We evaluated the impact of L-[β-(11)C]OMD on the estimation of the dopamine synthesis capacity in a human L-[β-(11)C]DOPA PET study. The metabolite correction with mathematical modeling of L-[β-(11)C]OMD kinetics in a reference region without decarboxylation and further metabolism, proposed by a previous [(18)F]FDOPA PET study, were implemented to estimate radioactivity of tissue L-[β-(11)C]OMD in 10 normal volunteers. The component of L-[β-(11)C]OMD in tissue time-activity curves (TACs) in 10 regions were subtracted by the estimated radioactivity of L-[β-(11)C]OMD. To evaluate the influence of omitting blood sampling and metabolite correction, relative dopamine synthesis rate (kref) was estimated by Gjedde-Patlak analysis with reference tissue input function, as well as the net dopamine synthesis rate (Ki) by Gjedde-Patlak analysis with the arterial input function and TAC without and with metabolite correction. Overestimation of Ki was observed without metabolite correction. However, the kref and Ki with metabolite correction were significantly correlated. These data suggest that the influence of L-[β-(11)C]OMD is minimal for the estimation of kref as dopamine synthesis capacity.

  2. Targeting the D1-N-methyl-D-aspartate receptor complex reduces L-dopa-induced dyskinesia in 6-hydroxydopamine-lesioned Parkinson’s rats

    Directory of Open Access Journals (Sweden)

    Song L

    2016-02-01

    Full Text Available Lu Song,1,* Zhanzhao Zhang,2,* Rongguo Hu,1 Jie Cheng,1 Lin Li,1 Qinyi Fan,1 Na Wu,1 Jing Gan,1 Mingzhu Zhou,1 Zhenguo Liu11Department of Neurology, Xinhua Hospital, 2Department of Plastic and Reconstructive Surgery, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China*These authors contributed equally to this workAbstract: L-3,4-dihydroxyphenylalanine (L-dopa remains the most effective therapy for Parkinson’s disease (PD, but its long-term administration is associated with the development of debilitating motor complications known as L-dopa-induced dyskinesia (LID. Enhanced function of dopamine D1 receptor (D1R and N-methyl-d-aspartate receptor (NMDAR is believed to participate in the pathogenesis of LID. Given the existence of physical and functional interactions between D1R and NMDAR, we explored the effects of uncoupling D1R and NMDA GluN1 (GluN1 interaction on LID by using the Tat-conjugated interfering peptide (Tat-D1-t2. In this study, we demonstrated in 6-hydroxydopamine (6-OHDA-lesioned PD rat model that intrastriatal injection of Tat-D1-t2 alleviated dyskinetic behaviors and downregulated the phosphorylation of DARPP-32 at Thr34 induced by levodopa. Moreover, we also showed intrastriatal administration of Tat-D1-t2 elicited alterations in membranous GluN1 and D1R expression. These findings indicate that D1R/GluN1 complexes may be a molecular target with therapeutic potential for the treatment of dyskinesia in Parkinson’s patients.Keywords: 6-hydroxydopamine, Parkinson’s disease, dyskinesia, L-dopa, D1 receptor, NMDA, protein–protein interaction

  3. Overexpression of blood microRNAs 103a, 30b, and 29a in L-dopa-treated patients with PD.

    Science.gov (United States)

    Serafin, Alice; Foco, Luisa; Zanigni, Stefano; Blankenburg, Hagen; Picard, Anne; Zanon, Alessandra; Giannini, Giulia; Pichler, Irene; Facheris, Maurizio F; Cortelli, Pietro; Pramstaller, Peter P; Hicks, Andrew A; Domingues, Francisco S; Schwienbacher, Christine

    2015-02-17

    The aims of the present study were to profile the expression of several candidate microRNAs (miRNAs) in blood from L-dopa-treated and drug-naive patients with Parkinson disease (PD) vs unaffected controls and to interpret the miRNA expression data in a biological context. We analyzed RNAs from peripheral blood of 36 L-dopa-treated, 10 drug-naive patients with PD and unaffected controls matched 1:1 by sex and age. We evaluated expression by reverse transcription-quantitative real-time PCR, and we analyzed data using a 2-tailed paired t test. To detect miRNA targets, several miRNA resources were combined to generate an overall score for each candidate gene using weighted rank aggregation. Significant overexpression of miR-103a-3p (p < 0.0001), miR-30b-5p (p = 0.002), and miR-29a-3p (p = 0.005) in treated patients with PD was observed, and promising candidate target genes for these were revealed by an integrated in silico analysis. We revealed 3 candidate biomarkers for PD. miRNAs 30b-5p and 29a-3p replicated a documented deregulation in PD albeit opposite to published data, while for miR-103a-3p, we demonstrated for the first time an overexpression in treated patients with PD. Expression studies in patients and/or in isolated peripheral blood mononuclear cells before and after L-dopa administration are necessary to define the involvement of L-dopa treatment in the observed overexpression. Our in silico analysis to prioritize targets of deregulated miRNAs identified candidate target genes, including genes related to neurodegeneration and PD. Despite the preliminary character of our study, the results provide a rationale for further clarifying the role of the identified miRNAs in the pathogenesis of PD and for validating their diagnostic potential. © 2015 American Academy of Neurology.

  4. Guideline for PET/CT imaging of neuroendocrine neoplasms withGa-DOTA-conjugated somatostatin receptor targeting peptides andF-DOPA

    DEFF Research Database (Denmark)

    Bozkurt, Murat Fani; Virgolini, Irene; Balogova, Sona

    2017-01-01

    PURPOSE & METHODS: Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing......, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using68Ga-DOTA-conjugated peptides, as well as18F-DOPA imaging for various neuroendocrine neoplasms. RESULTS & CONCLUSION: The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with68Ga...

  5. Prospective trial evaluating the sensitivity and specificity of 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (18F-DOPA) PET and MRI in patients with recurrent gliomas.

    Science.gov (United States)

    Youland, Ryan S; Pafundi, Deanna H; Brinkmann, Debra H; Lowe, Val J; Morris, Jonathan M; Kemp, Bradley J; Hunt, Christopher H; Giannini, Caterina; Parney, Ian F; Laack, Nadia N

    2018-05-01

    Treatment-related changes can be difficult to differentiate from progressive glioma using MRI with contrast (CE). The purpose of this study is to compare the sensitivity and specificity of 18F-DOPA-PET and MRI in patients with recurrent glioma. Thirteen patients with MRI findings suspicious for recurrent glioma were prospectively enrolled and underwent 18F-DOPA-PET and MRI for neurosurgical planning. Stereotactic biopsies were obtained from regions of concordant and discordant PET and MRI CE, all within regions of T2/FLAIR signal hyperintensity. The sensitivity and specificity of 18F-DOPA-PET and CE were calculated based on histopathologic analysis. Receiver operating characteristic curve analysis revealed optimal tumor to normal (T/N) and SUVmax thresholds. In the 37 specimens obtained, 51% exhibited MRI contrast enhancement (M+) and 78% demonstrated 18F-DOPA-PET avidity (P+). Imaging characteristics included M-P- in 16%, M-P+ in 32%, M+P+ in 46% and M+P- in 5%. Histopathologic review of biopsies revealed grade II components in 16%, grade III in 43%, grade IV in 30% and no tumor in 11%. MRI CE sensitivity for recurrent tumor was 52% and specificity was 50%. PET sensitivity for tumor was 82% and specificity was 50%. A T/N threshold > 2.0 altered sensitivity to 76% and specificity to 100% and SUVmax > 1.36 improved sensitivity and specificity to 94 and 75%, respectively. 18F-DOPA-PET can provide increased sensitivity and specificity compared with MRI CE for visualizing the spatial distribution of recurrent gliomas. Future studies will incorporate 18F-DOPA-PET into re-irradiation target volume delineation for RT planning.

  6. 4-Amidinoindan-1-one 2'-amidinohydrazone (CGP 48664A) exerts in vitro growth inhibitory effects that are not only related to S-adenosylmethionine decarboxylase (SAMdc) inhibition

    NARCIS (Netherlands)

    Dorhout, B; Odink, MFG; deHoog, E; Kingma, AW; vanderVeer, E; Muskiet, FAJ

    1997-01-01

    The competitive S-adenosylmethionine decarboxylase (SAMdc; EC 4.1.1.50) inhibitor 4-amidinoindan-1-one 2'-amidinohydrazone (CGP 48664A) inhibits growth more effectively than the irreversible SAMdc inhibitor 5'-{[(Z)-4-amino-2-butenyl]methylamino}-5'-deoxyadenosine (AbeAdo), while having similar

  7. Harmonization of Glutamic Acid Decarboxylase and Islet Antigen-2 Autoantibody Assays for National Institute of Diabetes and Digestive and Kidney Diseases Consortia

    OpenAIRE

    Bonifacio, Ezio; Yu, Liping; Williams, Alastair K.; Eisenbarth, George S.; Bingley, Polly J.; Marcovina, Santica M.; Adler, Kerstin; Ziegler, Anette G.; Mueller, Patricia W.; Schatz, Desmond A.; Krischer, Jeffrey P.; Steffes, Michael W.; Akolkar, Beena

    2010-01-01

    Background/Rationale: Autoantibodies to islet antigen-2 (IA-2A) and glutamic acid decarboxylase (GADA) are markers for diagnosis, screening, and measuring outcomes in National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) consortia studies. A harmonization program was established to increase comparability of results within and among these studies.

  8. Requirement of a Functional Flavin Mononucleotide Prenyltransferase for the Activity of a Bacterial Decarboxylase in a Heterologous Muconic Acid Pathway in Saccharomyces cerevisiae.

    Science.gov (United States)

    Weber, Heike E; Gottardi, Manuela; Brückner, Christine; Oreb, Mislav; Boles, Eckhard; Tripp, Joanna

    2017-05-15

    Biotechnological production of cis , cis -muconic acid from renewable feedstocks is an environmentally sustainable alternative to conventional, petroleum-based methods. Even though a heterologous production pathway for cis , cis -muconic acid has already been established in the host organism Saccharomyces cerevisiae , the generation of industrially relevant amounts of cis , cis -muconic acid is hampered by the low activity of the bacterial protocatechuic acid (PCA) decarboxylase AroY isomeric subunit C iso (AroY-C iso ), leading to secretion of large amounts of the intermediate PCA into the medium. In the present study, we show that the activity of AroY-C iso in S. cerevisiae strongly depends on the strain background. We could demonstrate that the strain dependency is caused by the presence or absence of an intact genomic copy of PAD1 , which encodes a mitochondrial enzyme responsible for the biosynthesis of a prenylated form of the cofactor flavin mononucleotide (prFMN). The inactivity of AroY-C iso in strain CEN.PK2-1 could be overcome by plasmid-borne expression of Pad1 or its bacterial homologue AroY subunit B (AroY-B). Our data reveal that the two enzymes perform the same function in decarboxylation of PCA by AroY-C iso , although coexpression of Pad1 led to higher decarboxylase activity. Conversely, AroY-B can replace Pad1 in its function in decarboxylation of phenylacrylic acids by ferulic acid decarboxylase Fdc1. Targeting of the majority of AroY-B to mitochondria by fusion to a heterologous mitochondrial targeting signal did not improve decarboxylase activity of AroY-C iso , suggesting that mitochondrial localization has no major impact on cofactor biosynthesis. IMPORTANCE In Saccharomyces cerevisiae , the decarboxylation of protocatechuic acid (PCA) to catechol is the bottleneck reaction in the heterologous biosynthetic pathway for production of cis , cis -muconic acid, a valuable precursor for the production of bulk chemicals. In our work, we demonstrate

  9. National Elevation Dataset

    Science.gov (United States)

    ,

    2002-01-01

    The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. NED has a resolution of one arc-second (approximately 30 meters) for the conterminous United States, Hawaii, Puerto Rico and the island territories and a resolution of two arc-seconds for Alaska. NED data sources have a variety of elevation units, horizontal datums, and map projections. In the NED assembly process the elevation values are converted to decimal meters as a consistent unit of measure, NAD83 is consistently used as horizontal datum, and all the data are recast in a geographic projection. Older DEM's produced by methods that are now obsolete have been filtered during the NED assembly process to minimize artifacts that are commonly found in data produced by these methods. Artifact removal greatly improves the quality of the slope, shaded-relief, and synthetic drainage information that can be derived from the elevation data. Figure 2 illustrates the results of this artifact removal filtering. NED processing also includes steps to adjust values where adjacent DEM's do not match well, and to fill sliver areas of missing data between DEM's. These processing steps ensure that NED has no void areas and artificial discontinuities have been minimized. The artifact removal filtering process does not eliminate all of the artifacts. In areas where the only available DEM is produced by older methods, then "striping" may still occur.

  10. Micro-plate radiobinding assay of autoantibody to glutamic acid decarboxylase

    International Nuclear Information System (INIS)

    Huang Gan; Jin Helai; Wang Xia; Li Hui; Zhang Song; Zhou Zhiguang

    2008-01-01

    Objective: The purpose of this study was to develop a high-throughput micro-plate radiobinding assay (RBA) of glutamic acid decarboxylase antibody (CAD-Ab) and to evaluate its clinical application. Methods: 35 S labeled GAD 65 antigen was incubated with sera for 24 h on a 96-well plate, and then transferred to the Millipore plate coated with protein A, which was washed with 4 degree C PBS buffer, and then counted by a liquid scintillation counter. The CAD-Ab results were expressed by WHO standard unit (U/ml). A total of 224 healthy controls, 162 patients with type 1 diabetes mellitus (T1DM) and 210 patients with newly diagnosed type 2 diabetes (T2DM) were recruited. A total of 119 T1DM and healthy eases with gradually changing GAD-Ab levels were selected to compare the consistency of micro-plate RBA with conventional radioligand assay (RLA). Blood samples were obtained from the peripheral vein and finger tip in 32 healthy controls, 35 T1DM and 24 T2DM patients, and tested with micro-plate RBA and then compared with the conventional RLA to investigate the reliability of finger tip sampling. Linear correlation, student's t-test, variance analysis and receiver operating characteristic (ROC) curve were performed using SPSS 11.5. Results: (1) The optimized conditions of micro-plate RBA included 2 μl serum incubated with 3 x 10 4 counts/min 35 S-CAD for 24 h under slow vibration, antigen-antibody compounds washed 10 times by 4 degree C PBS buffer, and radioactivity counted with Optiphase Supermix scintillation liquid. (2)The intra-batch CV of the micro-plate RBA was 3.8%-10.2%, and the inter-batch CV was 5.6%-11.9%. The linearity analysis showed a good correlation when the GAD-Ab in serum samples ranged from 40.3 to 664 U/ml and the detection limit of measurement was 3.6 U/ml. The results from Diabetes Autoantibody Standardization Program (DASP) 2005 showed that the sensitivity and specificity for GAD-Ab were 78% (39 positive among 50 new-onset T1DM) and 98% (2 positive

  11. Physiological relation between respiration activity and heterologous expression of selected benzoylformate decarboxylase variants in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Pohl Martina

    2010-10-01

    Full Text Available Abstract Background The benzoylformate decarboxylase (BFD from Pseudomonas putida is a biotechnologically interesting biocatalyst. It catalyses the formation of chiral 2-hydroxy ketones, which are important building blocks for stereoselective syntheses. To optimise the enzyme function often the amino acid composition is modified to improve the performance of the enzyme. So far it was assumed that a relatively small modification of the amino acid composition of a protein does not significantly influence the level of expression or media requirements. To determine, which effects these modifications might have on cultivation and product formation, six different BFD-variants with one or two altered amino acids and the wild type BFD were expressed in Escherichia coli SG13009 pKK233-2. The oxygen transfer rate (OTR as parameter for growth and metabolic activity of the different E. coli clones was monitored on-line in LB, TB and modified PanG mineral medium with the Respiratory Activity MOnitoring System (RAMOS. Results Although the E. coli clones were genetically nearly identical, the kinetics of their metabolic activity surprisingly differed in the standard media applied. Three different types of OTR curves could be distinguished. Whereas the first type (clones expressing Leu476Pro-Ser181Thr or Leu476Pro had typical OTR curves, the second type (clones expressing the wild type BFD, Ser181Thr or His281Ala showed an early drop of OTR in LB and TB medium and a drastically reduced maximum OTR in modified PanG mineral medium. The third type (clone expressing Leu476Gln behaved variable. Depending on the cultivation conditions, its OTR curve was similar to the first or the second type. It was shown, that the kinetics of the metabolic activity of the first type depended on the concentration of thiamine, which is a cofactor of BFD, in the medium. It was demonstrated that the cofactor binding strength of the different BFD-variants correlated with the differences

  12. Interaktive tavler - interaktive elever

    DEFF Research Database (Denmark)

    Reusch, Charlotte F.; Otzen, Elsebeth

    Abstract, Poster-præsentation 13.-14. juni 2012, Pilotprojekt: Interaktive tavler – interaktive elever Lektor, cand. pæd., Elsebeth Otzen og Lektor, cand. mag., Charlotte Reusch, Institut for Skole og Læring, Læreruddannelsen, Professionshøjskolen Metropol, København Hvordan motiverer en interaktiv...... tavle lærere og elever? Hvad sker der mellem elev, stof og lærer, når læreren bliver i stand til at billedliggøre og dynamisere sine oplæg på tavlen? Bliver læreroplæg prioriteret? Bliver eleverne aktive, eller ender den interaktive tavle med blot at understøtte lærerens envejskommunikation til klassen......? Og hvad sker der mellem eleverne? Disse spørgsmål var igangsættende for arbejdet med pilotprojektet Interaktive tavler – interaktive elever, som blev afviklet i skoleåret 2010-2011. Projektet blev udført af en tværfaglig gruppe, bestående af lektorer i matematik, biologi og dansk i læreruddannelsen...

  13. Udeskole og elevers handlekompetence

    DEFF Research Database (Denmark)

    Breiting, Søren

    2011-01-01

    Elever elsker at komme væk fra undervisningen i skolen. Er det positivt eller negativt? Og hvad har betydning for, at eleverne får mest muligt ud af oplevelserne uden for skolen? Forskellige former for udeskole giver nogle oplagte muligheder, så eleverne udvikler sig som engagerede borgere i et...

  14. Interaktive tavler - interaktive elever

    DEFF Research Database (Denmark)

    Reusch, Charlotte; Otzen, Elsebeth

    Abstract, Poster-præsentation 13.-14. juni 2012, Pilotprojekt: Interaktive tavler ? interaktive elever Lektor, cand. pæd., Elsebeth Otzen og Lektor, cand. mag., Charlotte Reusch, Institut for Skole og Læring, Læreruddannelsen, Professionshøjskolen Metropol, København Hvordan motiverer en interaktiv...... tavle lærere og elever? Hvad sker der mellem elev, stof og lærer, når læreren bliver i stand til at billedliggøre og dynamisere sine oplæg på tavlen? Bliver læreroplæg prioriteret? Bliver eleverne aktive, eller ender den interaktive tavle med blot at understøtte lærerens envejskommunikation til klassen......? Og hvad sker der mellem eleverne? Disse spørgsmål var igangsættende for arbejdet med pilotprojektet Interaktive tavler ? interaktive elever, som blev afviklet i skoleåret 2010-2011. Projektet blev udført af en tværfaglig gruppe, bestående af lektorer i matematik, biologi og dansk i læreruddannelsen...

  15. Antibacterial activity of oregano and sage plant extracts against decarboxylase-positive enterococci isolated from rabbit meat

    Directory of Open Access Journals (Sweden)

    Ľubica Chrastinová

    2013-02-01

    Full Text Available The effect of plant extracts (sage, oregano against decarboxylase-positive enterococci from rabbit back limb meat  was reported in this study. Oregano plant extract inhibited the growth of all 34 tested enterococci (the inhibitory zones: 12 to 45 mm. The growth of the majority of strains  (n=23 was inhibited by oregano plant extract (the high size inhibitory zones (higher than 25 mm. The growth of 11 strains  was inhibited by oregano extract reaching medium size inhibitory zones (10 to 25mm. The most sensitive strain to oregano extract was E. faecium M7bA (45 mm. Sage extract was less active against tested enterococci (n=16  reaching lower inhibitory zones (up to 10 mm. doi:10.5219/239 Normal 0 21 false false false SK X-NONE X-NONE

  16. Involvement of a putative substrate binding site in the biogenesis and assembly of phosphatidylserine decarboxylase 1 from Saccharomyces cerevisiae.

    Science.gov (United States)

    Di Bartolomeo, Francesca; Doan, Kim Nguyen; Athenstaedt, Karin; Becker, Thomas; Daum, Günther

    2017-07-01

    In the yeast Saccharomyces cerevisiae, the mitochondrial phosphatidylserine decarboxylase 1 (Psd1p) produces the largest amount of cellular phosphatidylethanolamine (PE). Psd1p is synthesized as a larger precursor on cytosolic ribosomes and then imported into mitochondria in a three-step processing event leading to the formation of an α-subunit and a β-subunit. The α-subunit harbors a highly conserved motif, which was proposed to be involved in phosphatidylserine (PS) binding. Here, we present a molecular analysis of this consensus motif for the function of Psd1p by using Psd1p variants bearing either deletions or point mutations in this region. Our data show that mutations in this motif affect processing and stability of Psd1p, and consequently the enzyme's activity. Thus, we conclude that this consensus motif is essential for structural integrity and processing of Psd1p. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Differential retinoic acid inhibition of ornithine decarboxylase induction by 12-O-tetradecanoylphorbol-13-acetate and by germicidal ultraviolet light

    International Nuclear Information System (INIS)

    Lichti, U.; Patterson, E.; Hennings, H.; Yuspa, S.H.

    1981-01-01

    Several retinoids including retinoic acid effectively inhibit phorbol ester-mediated tumor promotion and ornithine decarboxylase (ODC) induction in mouse epidermis. To understand better the possible cellular site of action of retinoids, the inhibitory action of retinoic acid on the induction of ODC was compared for two distinctly different inducers, namely, 12-O-tetradecanoylphorbol-13-acetate (TPA) and germicidal ultraviolet light (uv), in primary mouse epidermal cell cultures. It was found that the induction of ODC by TPA is almost completely prevented by retinoic acid while the induction by uv is only moderately inhibited. The differential inhibition of enzyme induction cannot be accounted for by selective retinoid inhibition of DNA, RNA, or protein synthesis either alone or in concert with TPA or uv. These agents possibly act at transcription or translation, both of which are required for ODC induction by TPA or uv

  18. Biotic and abiotic stress tolerance in transgenic tomatoes by constitutive expression of S-adenosylmethionine decarboxylase gene.

    Science.gov (United States)

    Hazarika, Pranjal; Rajam, Manchikatla Venkat

    2011-04-01

    Recent findings have implicated the role of polyamines (putrescine, spermidine and spermine) in stress tolerance. Therefore, the present work was carried out with the goal of generating transgenic tomato plants with human S-adenosylmethionine decarboxylase (samdc) gene, a key gene involved in biosynthesis of polyamines, viz. spermidine and spermine and evaluating the transgenic plants for tolerance to both biotic and abiotic stresses. Several putative transgenic tomato plants with normal phenotype were obtained, and the transgene integration and expression was validated by PCR, Southern blot analysis and RT-PCR analysis, respectively. The transgenic plants exhibited high levels of polyamines as compared to the untransformed control plants. They also showed increased resistance against two important fungal pathogens of tomato, the wilt causing Fusarium oxysporum and the early blight causing Alternaria solani and tolerance to multiple abiotic stresses such as salinity, drought, cold and high temperature. These results suggest that engineering polyamine accumulation can confer tolerance to both biotic and abiotic stresses in plants.

  19. Aromatic Amino Acid Decarboxylase Deficiency Not Responding to Pyridoxine and Bromocriptine Therapy: Case Report and Review of Response to Treatment

    Directory of Open Access Journals (Sweden)

    Majid Alfadhel

    2014-01-01

    Full Text Available Aromatic L-amino acid decarboxylase (AADC deficiency (MIM #608643 is an autosomal recessive inborn error of monoamines. It is caused by a mutation in the DDC gene that leads to a deficiency in the AADC enzyme. The clinical features of this condition include a combination of dopamine, noradrenaline, and serotonin deficiencies, and a patient may present with hypotonia, oculogyric crises, sweating, hypersalivation, autonomic dysfunction, and progressive encephalopathy with severe developmental delay. We report the case of an 8-month-old boy who presented with the abovementioned symptoms and who was diagnosed with AADC deficiency based on clinical, biochemical, and molecular investigations. Treatment with bromocriptine and pyridoxine showed no improvement. These data support the findings observed among previously reported cohorts that showed poor response of this disease to current regimens. Alternative therapies are needed to ameliorate the clinical complications associated with this disorder.

  20. Cloning and characterization of the ddc homolog encoding L-2,4-diaminobutyrate decarboxylase in Enterobacter aerogenes.

    Science.gov (United States)

    Yamamoto, S; Mutoh, N; Tsuzuki, D; Ikai, H; Nakao, H; Shinoda, S; Narimatsu, S; Miyoshi, S I

    2000-05-01

    L-2,4-diaminobutyrate decarboxylase (DABA DC) catalyzes the formation of 1,3-diaminopropane (DAP) from DABA. In the present study, the ddc gene encoding DABA DC from Enterobacter aerogenes ATCC 13048 was cloned and characterized. Determination of the nucleotide sequence revealed an open reading frame of 1470 bp encoding a 53659-Da protein of 490 amino acids, whose deduced NH2-terminal sequence was identical to that of purified DABA DC from E. aerogenes. The deduced amino acid sequence was highly similar to those of Acinetobacter baumannii and Haemophilus influenzae DABA DCs encoded by the ddc genes. The lysine-307 of the E. aerogenes DABA DC was identified as the pyridoxal 5'-phosphate binding residue by site-directed mutagenesis. Furthermore, PCR analysis revealed the distribution of E. aerogenes ddc homologs in some other species of Enterobacteriaceae. Such a relatively wide occurrence of the ddc homologs implies biological significance of DABA DC and its product DAP.

  1. The Parkinsonian Subthalamic Network: Measures of Power, Linear, and Non-linear Synchronization and their Relationship to L-DOPA Treatment and OFF State Motor Severity.

    Science.gov (United States)

    West, Timothy; Farmer, Simon; Berthouze, Luc; Jha, Ashwani; Beudel, Martijn; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Brown, Peter; Litvak, Vladimir

    2016-01-01

    In this paper we investigated the dopaminergic modulation of neuronal interactions occurring in the subthalamic nucleus (STN) during Parkinson's disease (PD). We utilized linear measures of local and long range synchrony such as power and coherence, as well as Detrended Fluctuation Analysis for Phase Synchrony (DFA-PS)- a recently developed non-linear method that computes the extent of long tailed autocorrelations present in the phase interactions between two coupled signals. Through analysis of local field potentials (LFPs) taken from the STN we seek to determine changes in the neurodynamics that may underpin the pathophysiology of PD in a group of 12 patients who had undergone surgery for deep brain stimulation. We demonstrate up modulation of alpha-theta (5-12 Hz) band power in response to L-DOPA treatment, whilst low beta band power (15-20 Hz) band-power is suppressed. We also find evidence for significant local connectivity within the region surrounding STN although there was evidence for its modulation via administration of L-DOPA. Further to this we present evidence for a positive correlation between the phase ordering of bilateral STN interactions and the severity of bradykinetic and rigidity symptoms in PD. Although, the ability of non-linear measures to predict clinical state did not exceed standard measures such as beta power, these measures may help identify the connections which play a role in pathological dynamics.

  2. Trypanosoma cruzi has not lost its S-adenosylmethionine decarboxylase: characterization of the gene and the encoded enzyme.

    Science.gov (United States)

    Persson, K; Aslund, L; Grahn, B; Hanke, J; Heby, O

    1998-01-01

    All attempts to identify ornithine decarboxylase in the human pathogen Trypanosoma cruzi have failed. The parasites have instead been assumed to depend on putrescine uptake and S-adenosylmethionine decarboxylase (AdoMetDC) for their synthesis of the polyamines spermidine and spermine. We have now identified the gene encoding AdoMetDC in T. cruzi by PCR cloning, with degenerate primers corresponding to conserved amino acid sequences in AdoMetDC proteins of other trypanosomatids. The amplified DNA fragment was used as a probe to isolate the complete AdoMetDC gene from a T. cruzi genomic library. The AdoMetDC gene was located on chromosomes with a size of approx. 1.4 Mbp, and contained a coding region of 1110 bp, specifying a sequence of 370 amino acid residues. The protein showed a sequence identity of only 25% with human AdoMetDC, the major differences being additional amino acids present in the terminal regions of the T. cruzi enzyme. As expected, a higher sequence identity (68-72%) was found in comparison with trypanosomatid AdoMetDCs. When the coding region was expressed in Escherichia coli, the recombinant protein underwent autocatalytic cleavage, generating a 33-34 kDa alpha subunit and a 9 kDa beta subunit. The encoded protein catalysed the decarboxylation of AdoMet (Km 0.21 mM) and was stimulated by putrescine but inhibited by the polyamines, weakly by spermidine and strongly by spermine. Methylglyoxal-bis(guanylhydrazone) (MGBG), a potent inhibitor of human AdoMetDC, was a poor inhibitor of the T. cruzi enzyme. This differential sensitivity to MGBG suggests that the two enzymes are sufficiently different to warrant the search for compounds that might interfere with the progression of Chagas' disease by selectively inhibiting T. cruzi AdoMetDC. PMID:9677309

  3. Redox Cycling, pH Dependence, and Ligand Effects of Mn(III) in Oxalate Decarboxylase from Bacillus subtilis.

    Science.gov (United States)

    Twahir, Umar T; Ozarowski, Andrew; Angerhofer, Alexander

    2016-11-29

    This contribution describes electron paramagnetic resonance (EPR) experiments on Mn(III) in oxalate decarboxylase of Bacillus subtilis, an interesting enzyme that catalyzes the redox-neutral dissociation of oxalate into formate and carbon dioxide. Chemical redox cycling provides strong evidence that both Mn centers can be oxidized, although the N-terminal Mn(II) appears to have the lower reduction potential and is most likely the carrier of the +3 oxidation state under moderate oxidative conditions, in agreement with the general view that it represents the active site. Significantly, Mn(III) was observed in untreated OxDC in succinate and acetate buffers, while it could not be directly observed in citrate buffer. Quantitative analysis showed that up to 16% of the EPR-visible Mn is in the +3 oxidation state at low pH in the presence of succinate buffer. The fine structure and hyperfine structure parameters of Mn(III) are affected by small carboxylate ligands that can enter the active site and have been recorded for formate, acetate, and succinate. The results from a previous report [Zhu, W., et al. (2016) Biochemistry 55, 429-434] could therefore be reinterpreted as evidence of formate-bound Mn(III) after the enzyme is allowed to turn over oxalate. The pH dependence of the Mn(III) EPR signal compares very well with that of enzymatic activity, providing strong evidence that the catalytic reaction of oxalate decarboxylase is driven by Mn(III), which is generated in the presence of dioxygen.

  4. Cortical Gene Expression After a Conditional Knockout of 67 kDa Glutamic Acid Decarboxylase in Parvalbumin Neurons.

    Science.gov (United States)

    Georgiev, Danko; Yoshihara, Toru; Kawabata, Rika; Matsubara, Takurou; Tsubomoto, Makoto; Minabe, Yoshio; Lewis, David A; Hashimoto, Takanori

    2016-07-01

    In the cortex of subjects with schizophrenia, expression of glutamic acid decarboxylase 67 (GAD67), the enzyme primarily responsible for cortical GABA synthesis, is reduced in the subset of GABA neurons that express parvalbumin (PV). This GAD67 deficit is accompanied by lower cortical levels of other GABA-associated transcripts, including GABA transporter-1, PV, brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B, somatostatin, GABAA receptor α1 subunit, and KCNS3 potassium channel subunit mRNAs. In contrast, messenger RNA (mRNA) levels for glutamic acid decarboxylase 65 (GAD65), another enzyme for GABA synthesis, are not altered. We tested the hypothesis that this pattern of GABA-associated transcript levels is secondary to the GAD67 deficit in PV neurons by analyzing cortical levels of these GABA-associated mRNAs in mice with a PV neuron-specific GAD67 knockout. Using in situ hybridization, we found that none of the examined GABA-associated transcripts had lower cortical expression in the knockout mice. In contrast, PV, BDNF, KCNS3, and GAD65 mRNA levels were higher in the homozygous mice. In addition, our behavioral test battery failed to detect a change in sensorimotor gating or working memory, although the homozygous mice exhibited increased spontaneous activities. These findings suggest that reduced GAD67 expression in PV neurons is not an upstream cause of the lower levels of GABA-associated transcripts, or of the characteristic behaviors, in schizophrenia. In PV neuron-specific GAD67 knockout mice, increased levels of PV, BDNF, and KCNS3 mRNAs might be the consequence of increased neuronal activity secondary to lower GABA synthesis, whereas increased GAD65 mRNA might represent a compensatory response to increase GABA synthesis. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. P04.02 Analysis of 18F-DOPA PET imaging for target volume definition in patients with recurrent glioblastoma treated with proton therapy

    Science.gov (United States)

    Amelio, D.; Scartoni, D.; Palucci, A.; Vennarini, S.; Giacomelli, I.; Lemoine, S.; Donner, D.; Farace, P.; Chierichetti, F.; Amichetti, M.

    2017-01-01

    Abstract Introduction: Target volume definition is of critical relevance when re-irradiation is delivered and steep dose gradient irradiation techniques, such as proton therapy (PT), are employed. Aim of the study is to investigate the impact of 18F-DOPA on target volume contouring in recurrent glioblastoma (rGBM) patients (pts) undergoing re-irradiation with PT. MATERIAL AND METHODS: We investigated the differences in volume and relationship of magnetic resonance imaging (MRI)- vs. DOPA PET-derived gross tumor volumes (GTVs) of 14 rGBM pts re-irradiated with PT between January and November 2016. All pts had been previously treated with photon radiotherapy (60 Gy) with concomitant and adjuvant temozolomide. All the pts received morphological MRI with contrast enhancement medium administration and 18F-DOPA PET-CT study. We used the pathological distribution of 18F-DOPA in brain tissue to identify the so-called Biological Tumor Volume (BTV). Such areas were assessed using a tumor to normal brain ratio > 2. Moreover, any area of contrast enhancement on MRI was used to identify the MRI-based GTV (MRGTV). Definitive GTV included MRGTV plus BTV. Clinical target volume was generated by adding to GTV a 3-mm uniform margin manually corrected in proximity of anatomical barriers. CTV was expanded by 4 mm to create planning target volume. All pts received 36 GyRBE in 18 fractions. Mean values of differently delineated GTVs were compared each other by paired Student’s t-test; p < 0.05 was considered significant. To further compare MRGTV and BTV, the overlapping (MRGTV ^ BTV) and the composite (MRGTV U BTV) volumes were calculated, and a concordance index (CI) was defined as the ratio between the overlap and composite volumes. Results: MRGTV (mean 14.9 ± 14.5 cc) was larger than BTV (mean 10.9 ± 9.8 cc) although this difference was not statistically significant. The composite volume (mean 20.9 ± 14.7 cc) was significantly larger than each single volume (p < 0

  6. Mutual augmentation of the induction of the histamine-forming enzyme, histidine decarboxylase, between alendronate and immuno-stimulants (IL-1, TNF, and LPS), and its prevention by clodronate

    International Nuclear Information System (INIS)

    Deng Xue; Yu Zhiqian; Funayama, Hiromi; Shoji, Noriaki; Sasano, Takashi; Iwakura, Yoichiro; Sugawara, Shunji; Endo, Yasuo

    2006-01-01

    Nitrogen-containing bisphosphonates (N-BPs), powerful anti-bone-resorptive drugs, have inflammatory side effects, while histamine is not only an inflammatory mediator, but also an immuno-modifier. In murine models, a single intraperitoneal injection of an N-BP induces various inflammatory reactions, including the induction of the histamine-forming enzyme histidine decarboxylase (HDC) in tissues important in immune responses (such as liver, lungs, spleen, and bone marrow). Lipopolysaccharide (LPS) and the proinflammatory cytokines IL-1 and TNF are also capable of inducing HDC. We reported previously that in mice (i) the inflammatory actions of N-BPs depend on IL-1 (ii) N-BP pretreatment augments both LPS-stimulated IL-1 production and HDC induction, and (iii) the co-administration of clodronate (a non-N-BP) with an N-BP inhibits the latter's inflammatory actions (including HDC induction). Here, we add the new findings that (a) pretreatment with alendronate (a typical N-BP) augments both IL-1- and TNF-induced HDC elevations, (b) LPS pretreatment augments the alendronate-induced HDC elevation, (c) co-administration of clodronate with alendronate abolishes these augmentations, (d) alendronate does not induce HDC in IL-1-deficient mice even if they are pretreated with LPS, and (e) alendronate increases IL-1β in all tissues tested, but not in the serum. These results suggest that (1) there are mutual augmentations between alendronate and immuno-stimulants (IL-1, TNF, and LPS) in HDC induction, (2) tissue IL-1β is important in alendronate-stimulated HDC induction, and (3) combination use of clodronate may have the potential to reduce the inflammatory effects of alendronate (we previously found that clodronate, conveniently, does not inhibit the anti-bone-resorptive activity of alendronate)

  7. Skuldertesten "Kombineret Elevation"

    DEFF Research Database (Denmark)

    Clausen, Mikkel Bek; Overkær, Brian

    2010-01-01

    Formål: At udarbejde en testprotokol for testen Kombineret Elevation (KE) og undersøge test-retest variationen ved test af elite svømmere, samt diskutere testens relevans og validitet. Materiale og Metode: 9 elite og 10 sub-elite svømmere, heraf var 11 mænd og 8 kvinder, gennemførte testen KE 2...

  8. Comparison of 18F-fluoro-L-DOPA, 18F-fluoro-deoxyglucose, and 18F-fluorodopamine PET and 123I-MIBG scintigraphy in the localization of pheochromocytoma and paraganglioma.

    NARCIS (Netherlands)

    Timmers, H.J.L.M.; Chen, C.C.; Carrasquillo, J.A.; Whatley, M.; Ling, A.; Havekes, B.; Eisenhofer, G.; Martiniova, L.; Adams, K.T.; Pacak, K.

    2009-01-01

    CONTEXT: Besides (123)I-metaiodobenzylguanidine (MIBG), positron emission tomography (PET) agents are available for the localization of paraganglioma (PGL), including (18)F-3,4-dihydroxyphenylalanine (DOPA), (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG), and (18)F-fluorodopamine ((18)F-FDA). OBJECTIVE:

  9. Protective effect of two essential oils isolated from Rosa damascena Mill. and Lavandula angustifolia Mill, and two classic antioxidants against L-dopa oxidative toxicity induced in healthy mice.

    Science.gov (United States)

    Nikolova, Galina; Karamalakova, Yanka; Kovacheva, Natasha; Stanev, Stanko; Zheleva, Antoaneta; Gadjeva, Veselina

    2016-11-01

    Levodopa (L-dopa) is a "gold standard" and most effective symptomatic agent in the Parkinson's disease (PD) treatment. The several treatments have been developed in an attempt to improve PD treatment, but most patients were still levodopa dependent. The issue of toxicity was raised in vitro studies, and suggests that L-dopa can be toxic to dopaminergic neurons, but it is not yet entirely proven. L-dopa prolonged treatment is associated with motor complications and some limitations. Combining the L-dopa therapy with antioxidants can reduce related sideeffects and provide symptomatic relief. The natural antioxidants can be isolated from any plant parts such as seeds, leaves, roots, bark, etc., and their extracts riched in phenols can retard the oxidative degradation of the lipids, proteins and DNA. Thus, study suggests that combination of essential oils (Rose oil and Lavender oil), Vitamin C and Trolox with Ldopa can reduce oxidative toxicity, and may play a key role in ROS/RNS disarm. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. A six-month multicentre, double-blind, bromocriptine-controlled study of the safety and efficacy of ropinirole in the treatment of patients with Parkinson's disease not optimally controlled by L-dopa

    NARCIS (Netherlands)

    Brunt, ER; Brooks, DJ; Korczyn, AD; Montastruc, JL; Stocchi, F

    2002-01-01

    Objectives. To compare the safety and efficacy of ropinirole and bromocriptine as adjunct therapy in patients with Parkinson's disease (PD) not optimally controlled by L-dopa. Methods. A randomised, double-blind trial in which 555 patients were assigned to three treatment groups according to the

  11. Agmatine Production by Aspergillus oryzae is Elevated by Low pH During Solid-State Cultivation.

    Science.gov (United States)

    Akasaka, Naoki; Kato, Saori; Kato, Saya; Hidese, Ryota; Wagu, Yutaka; Sakoda, Hisao; Fujiwara, Shinsuke

    2018-05-25

    Sake (rice wine) produced by multiple parallel fermentation (MPF) involving Aspergillus oryzae (strain RW) and Saccharomyces cerevisiae under solid-state cultivation conditions contained 3.5 mM agmatine, while that produced from enzymatically saccharified rice syrup by S. cerevisiae contained oryzae under solid-state cultivation (3.1 mM) but not under submerged cultivation, demonstrating that A. oryzae in solid-state culture produces agmatine. The effect of cultivation conditions on agmatine production was examined. Agmatine production was boosted at 30°C and reached the highest level (6.3 mM) at pH 5.3. The addition of l-lactic, succinic, and citric acids reduced the initial culture pH to 3.0, 3.5, and 3.2, respectively, resulting in further increase in agmatine accumulation (8.2, 8.7, and 8.3 mM, respectively). Homogenate from a solid-state culture exhibited a maximum l-arginine decarboxylase (ADC) activity (74 pmol min -1 μg -1 ) at pH 3.0 at 30°C; that from a submerged culture exhibited an extremely low activity (oryzae , even though A. oryzae lacks ADC orthologs and, instead, possesses four ornithine decarboxylases (ODC1-4). Recombinant ODC1 and ODC2 exhibited no ADC activity at acidic pH (pH 4.0>), suggesting that other decarboxylases or an unidentified ADC is involved in agmatine production. IMPORTANCE It has been speculated that, in general, fungi do not synthesize agmatine from l-arginine because they do not possess genes encoding for arginine decarboxylase. Numerous preclinical studies have shown that agmatine exerts pleiotropic effects on various molecular targets, leading to an improved quality of life. In the present study, we first demonstrated that l-arginine was a feasible substrate for agmatine production by the fungus Aspergillus oryzae RW. We observed that the productivity of agmatine by A. oryzae RW was elevated at low pH only during solid-state cultivation. A. oryzae is utilized in the production of various oriental fermented foods. The

  12. On the synthesis of radiofluorinated amino acids by isotope exchange based on the example of 6-[{sup 18}F]Fluor-L-DOPA; Zur Synthese radiofluorierter aromatischer Aminosaeuren mittels Isotopenaustausch am Beispiel von 6-[{sup 18}F]Fluor-L-DOPA

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, F M

    2008-06-15

    In nuclear medical diagnosis, 6-[{sup 18}F]fluoro-L-3,4-dihydroxyphenylalanine (6-[{sup 18}F]fluoro-LDOPA), an analogue of L-DOPA, is one of the few established radiopharmaceuticals used for the in vivo investigation of the presynaptic dopaminergic metabolism and of some kind of tumours via Positron Emission Tomography (PET). The presently used method of preparation of the radiotracer by electrophilic labelling is limited to low amounts of activity at high costs. Known nucleophilic syntheses, however, result either in insufficient enantiomeric purity or the known multi-step syntheses are hard to automate, due to their complexity. During this work a novel, easy to automate alternative for the preparation of 6-[{sup 18}F]fluoro-L-DOPA, was developed and evaluated, using a direct nucleophilic {sup 18}F-fluorination of a protected amino acid derivative. The resulting product has a very high enantiomeric purity. At first, the general suitability of the (S)-BOC-BMI-derivatives for the synthesis of {sup 18}F-labelled amino acids, used in this work, was investigated using a less complex precursor, which resulted in the amino acid 6-[{sup 18}F]fluoro-L-m-tyrosin via acidic hydrolysis. The preparation of a useful precursor for the nucleophilic {sup 18}F-isotope substitution, namely the (2S,5S)-tert.-butyl- 5-(2-fluoro-5-formylbenzyl)-2-tert.-butyl-3-methyl-4-oxoimidazolidine-1-carboxylate, was investigated in three general different ways. At first it was tried to obtain this product via formylation after coupling with the BOC-BMI, secondly via {alpha},{beta}-dehydro amino acid derivatives and finally via a systematic multi-step synthesis. Only the last mentioned way resulted in a precursor with sufficient purity that could be labelled. The radiochemical yield of the isotopic exchange was about 60 %. In the next step, the presented concept was modified to synthesize a precursor for the preparation of 6-[{sup 18}F]fluoro-L-DOPA. Only a combination of the protecting groups

  13. Utilization of fluoro dopa in nuclear medicine method for determination of radiochemical purity: study of irradiation during the manipulation; Utilisation de la FDOPA dans un service de medecine nucleaire: mise au point d'une methode de controle de purete radiochimique, etude de poste sur l'irradiation de l'operateur lors de la manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Bizien, V

    2007-10-15

    As a first step is a bibliographic reminder done on the use of two main fluorine molecules, FDG and F DOPA. The objective of the work then acted to develop a chromatographic method for determining the radiochemical purity of F DOPA response to the alteration of its stability after neutralization. Finally, the optimization of a technique of TLC will determine a period of stability in order to offset the risks that may delay examinations (breakdowns of cameras). The preparation of product requires handling, a study of post will then determine radiation doses on ends of members and on the whole-body when preparing the F DOPA. (N.C.)

  14. A spider elevator

    Energy Technology Data Exchange (ETDEWEB)

    Butylkin, A.V.; Butylkin, V.A.; Izosimov, A.M.

    1983-01-01

    A spider elevator is proposed which contains a body, a wedge clamp with wedges hinged to each other, a subassembly for holding the wedge clamp in the open and closed positions and a mechanism for changing the wedge clamp, which is made in the form of levers with ears for cleats and installed in the body with the capability of turning. To increase reliability in the operational mode through using the external force for clamping the pipe, the free ends of the levers are hinged with the body by a power cylinder.

  15. Elevator Control Strategies

    OpenAIRE

    Ceder, Frederick; Nordin, Alexandra

    2013-01-01

    The purpose of this essay is to investigate if it is eective to switch strategies for elevators during one day in an oce building. This essay describes some of the strategies in use today, followed by a comparison and analysis of two of the strategies described. We have also implemented optimizations to one of these strategies. From our test results we can conclude that our optimized strategy worked and produced better results on average waiting time and total traveling time than the two stra...

  16. Adversity in childhood linked to elevated striatal dopamine function in adulthood.

    Science.gov (United States)

    Egerton, Alice; Valmaggia, Lucia R; Howes, Oliver D; Day, Fern; Chaddock, Christopher A; Allen, Paul; Winton-Brown, Toby T; Bloomfield, Michael A P; Bhattacharyya, Sagnik; Chilcott, Jack; Lappin, Julia M; Murray, Robin M; McGuire, Philip

    2016-10-01

    Childhood adversity increases the risk of psychosis in adulthood. Theoretical and animal models suggest that this effect may be mediated by increased striatal dopamine neurotransmission. The primary objective of this study was to examine the relationship between adversity in childhood and striatal dopamine function in early adulthood. Secondary objectives were to compare exposure to childhood adversity and striatal dopamine function in young people at ultra high risk (UHR) of psychosis and healthy volunteers. Sixty-seven young adults, comprising 47 individuals at UHR for psychosis and 20 healthy volunteers were recruited from the same geographic area and were matched for age, gender and substance use. Presynaptic dopamine function in the associative striatum was assessed using 18F-DOPA positron emission tomography. Childhood adversity was assessed using the Childhood Experience of Care and Abuse questionnaire. Within the sample as a whole, both severe physical or sexual abuse (T63=2.92; P=0.005), and unstable family arrangements (T57=2.80; P=0.007) in childhood were associated with elevated dopamine function in the associative striatum in adulthood. Comparison of the UHR and volunteer subgroups revealed similar incidence of childhood adverse experiences, and there was no significant group difference in dopamine function. This study provides evidence that childhood adversity is linked to elevated striatal dopamine function in adulthood. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Inhibition of S-adenosylmethionine decarboxylase and diamine oxidase activities by analogues of methylglyoxal bis(guanylhydrazone) and their cellular uptake during lymphocyte activation.

    Science.gov (United States)

    Jänne, J; Morris, D R

    1984-03-15

    Several congeners of methylglyoxal bis(guanylhydrazone) were tested for their ability to inhibit eukaryotic putrescine-activated S-adenosylmethionine decarboxylase (EC 4.1.1.50) and intestinal diamine oxidase (EC 1.4.3.6). All the compounds tested, namely methylglyoxal bis(guanylhydrazone), ethylglyoxal bis(guanylhydrazone), dimethylglyoxal bis(guanylhydrazone) and the di-N"-methyl derivative of methylglyoxal bis(guanylhydrazone), were strong inhibitors of both yeast and mouse liver adenosylmethionine decarboxylase activity in vitro. The enzyme from both sources was most powerfully inhibited by ethylglyoxal bis(guanylhydrazone). All the diguanidines likewise inhibited diamine oxidase activity in vitro. The maximum intracellular concentrations of the ethyl and dimethylated analogues achieved in activated lymphocytes were only about one-fifth of that of the parent compound. However, both derivatives appeared to utilize the polyamine-carrier system, as indicated by competition experiments with spermidine.

  18. Inhibition of S-adenosylmethionine decarboxylase and diamine oxidase activities by analogues of methylglyoxal bis(guanylhydrazone) and their cellular uptake during lymphocyte activation.

    OpenAIRE

    Jänne, J; Morris, D R

    1984-01-01

    Several congeners of methylglyoxal bis(guanylhydrazone) were tested for their ability to inhibit eukaryotic putrescine-activated S-adenosylmethionine decarboxylase (EC 4.1.1.50) and intestinal diamine oxidase (EC 1.4.3.6). All the compounds tested, namely methylglyoxal bis(guanylhydrazone), ethylglyoxal bis(guanylhydrazone), dimethylglyoxal bis(guanylhydrazone) and the di-N"-methyl derivative of methylglyoxal bis(guanylhydrazone), were strong inhibitors of both yeast and mouse liver adenosylm...

  19. Autoantibodies against voltage-gated potassium channel and glutamic acid decarboxylase in psychosis: A systematic review, meta-analysis, and case series.

    OpenAIRE

    Grain, Rosemary; Lally, John; Stubbs, Brendon; Malik, Steffi; LeMince, Anne; Nicholson, Timothy R; Murray, Robin M; Gaughran, Fiona

    2017-01-01

    Antibodies to the voltage-gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the first systematic review and meta-analysis to investigate their prevalence in people with psychosis and report a case series of VGKC-complex antibodies in refractory psychosis. Only five studies presenting prevalence rates of VGKC seropositivity in psychosis were identified, in addition to our case series, with an overall prevale...

  20. Autoantibodies against voltage-gated potassium channel (VGKC) and glutamic acid decarboxylase (GAD) in psychosis: A systematic review, meta-analysis and case series.

    OpenAIRE

    Lally*, John; Grain*, Rosemary; Stubbs, Brendon; Malik, Steffi; LeMince, Anne; Nicholson, Timothy RJ; Murray, Robin MacGregor; Gaughran, Fiona Patricia

    2017-01-01

    Antibodies to the voltage-gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the first systematic review and meta-analysis to investigate their prevalence in people with psychosis and report a case series of VGKC-complex antibodies in refractory psychosis. Only five studies presenting prevalence rates of VGKC seropositivity in psychosis were identified, in addition to our case series, with an overall prevale...

  1. Automatic pipe elevator

    Energy Technology Data Exchange (ETDEWEB)

    Haney, K.M.; Willis, C.A.

    1987-03-17

    This patent describes an elevator adapted for use with a power swivel for supporting a drilling or production tubular, the elevator comprising: at least two jaws, each jaw having a clamping surface; a connector member for supporting the jaws, the connector member comprising an upper end, a lower end, means for coupling the upper end to the power swivel, means for coupling the lower end to a tubular. The member also comprises means for defining a passageway extending from the upper end to the lower end through the connector member to allow drilling mud to be passed from the power swivel through the bore, into the tubular; and linkage means mounted between the connector member and the jaws for coupling the jaws to the connector member and for maintaining the clamping surfaces of the jaws in clamping engagement with the tubular when the connector member and the tubular are urged apart relative to one another. The linkage means is configured such that the force by which the clamping surfaces clamp the tubular increases as the force urging the connector member and the tubular apart increases.

  2. Elevation data for floodplain mapping

    National Research Council Canada - National Science Library

    Committee on Floodplain Mapping Technologies; National Research Council; Division on Earth and Life Studies; National Research Council

    2007-01-01

    .... Elevation Data for Floodplain Mapping shows that there is sufficient two-dimensional base map imagery to meet FEMA's flood map modernization goals, but that the three-dimensional base elevation data...

  3. The effect of different doses of epidermal growth factor on liver ornithine decarboxylase and Na-K ATPase activities in newborn rats.

    Science.gov (United States)

    Bilgihan, A; Turkozkan, N; Isman, F; Kilinc, M; Demirsoy, S

    1998-08-01

    1. Ornithine decarboxylase and Na-K ATPase activities were studied in rat livers that were treated with different doses of epidermal growth factor (EGF). 2. The ornithine decarboxylase activities were studied with spectrophotometry, and results were expressed as micromoles of putrescine per hour per milligram of protein. Na-K ATPase activities were studied on the basis of the principle of measuring the amount of inorganic phosphates released by the hydrolysis of ATP, and the results were expressed as micromoles of inorganic phosphate per hour per milligram of protein. 3. When compared with the controls, although the Na-K ATPase activities were decreased at low doses of EGF, their activities were found to be increased at high doses of EGF. On the other hand, there was a positive correlation between ornithine decarboxylase activities and EGF doses. 4. The results of this study suggest that, whereas the decrease in Na-K ATPase activities at low doses of EGF can be due to the utilization of the enzyme, the increase in Na-K ATPase activities at high doses of EGF can be attributed to its enhanced synthesis.

  4. Guideline for PET/CT imaging of neuroendocrine neoplasms with {sup 68}Ga-DOTA-conjugated somatostatin receptor targeting peptides and {sup 18}F-DOPA

    Energy Technology Data Exchange (ETDEWEB)

    Bozkurt, Murat Fani [Hacettepe University Faculty of Medicine Department of Nuclear Medicine, Ankara (Turkey); Virgolini, Irene; Decristoforo, Clemens [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Balogova, Sona [Comenius University and St. Elisabeth Oncology Institute, Department of Nuclear Medicine, Bratislava (Slovakia); Tenon Hospital AP-HP and Universite Pierre et Marie Curie, Department of Nuclear Medicine, Paris (France); Beheshti, Mohsen [St. Vincent' s Hospital, PET-CT Center, Department of Nuclear Medicine and Endocrinology, Linz (Austria); Paracelsus Medical University, Department of Nuclear Medicine, Salzburg (Austria); Rubello, Domenico [Santa Maria della Misericordia Hospital, Department of Nuclear Medicine, PET Center and Medical Physics and Radiology, Rovigo (Italy); Ambrosini, Valentina; Fanti, Stefano [University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Bologna (Italy); Kjaer, Andreas [National University Hospital and University of Copenhagen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Delgado-Bolton, Roberto [San Pedro Hospital and Centre for Biomedical Research of La Rioja (CIBIR), Department of Diagnostic Imaging (Radiology) and Nuclear Medicine, Logrono (Spain); Kunikowska, Jolanta [Medical University of Warsaw, Nuclear Medicine, Warsaw (Poland); Oyen, Wim J.G. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London (United Kingdom); Chiti, Arturo [Humanitas University, Nuclear Medicine Department, Rozzano, MI (Italy); Giammarile, Francesco [University of Lyon, Nuclear Medicine, Lyon (France)

    2017-08-15

    Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using {sup 68}Ga-DOTA-conjugated peptides, as well as {sup 18}F-DOPA imaging for various neuroendocrine neoplasms. The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with {sup 68}Ga-conjugated peptides has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts. (orig.)

  5. Structure-function relations in oxaloacetate decarboxylase complex. Fluorescence and infrared approaches to monitor oxomalonate and Na(+ binding effect.

    Directory of Open Access Journals (Sweden)

    Thierry Granjon

    Full Text Available BACKGROUND: Oxaloacetate decarboxylase (OAD is a member of the Na(+ transport decarboxylase enzyme family found exclusively in anaerobic bacteria. OAD of Vibrio cholerae catalyses a key step in citrate fermentation, converting the chemical energy of the decarboxylation reaction into an electrochemical gradient of Na(+ ions across the membrane, which drives endergonic membrane reactions such as ATP synthesis, transport and motility. OAD is a membrane-bound enzyme composed of alpha, beta and gamma subunits. The alpha subunit contains the carboxyltransferase catalytic site. METHODOLOGY/PRINCIPAL FINDINGS: In this report, spectroscopic techniques were used to probe oxomalonate (a competitive inhibitor of OAD with respect to oxaloacetate and Na(+ effects on the enzyme tryptophan environment and on the secondary structure of the OAD complex, as well as the importance of each subunit in the catalytic mechanism. An intrinsic fluorescence approach, Red Edge Excitation Shift (REES, indicated that solvent molecule mobility in the vicinity of OAD tryptophans was more restricted in the presence of oxomalonate. It also demonstrated that, although the structure of OAD is sensitive to the presence of NaCl, oxomalonate was able to bind to the enzyme even in the absence of Na(+. REES changes due to oxomalonate binding were also observed with the alphagamma and alpha subunits. Infrared spectra showed that OAD, alphagamma and alpha subunits have a main component band centered between 1655 and 1650 cm(-1 characteristic of a high content of alpha helix structures. Addition of oxomalonate induced a shift of the amide-I band of OAD toward higher wavenumbers, interpreted as a slight decrease of beta sheet structures and a concomitant increase of alpha helix structures. Oxomalonate binding to alphagamma and alpha subunits also provoked secondary structure variations, but these effects were negligible compared to OAD complex. CONCLUSION: Oxomalonate binding affects the

  6. Mucuna pruriens and its major constituent L-DOPA recover spermatogenic loss by combating ROS, loss of mitochondrial membrane potential and apoptosis.

    Directory of Open Access Journals (Sweden)

    Akhand Pratap Singh

    Full Text Available BACKGROUND: The Ayurvedic medicinal system claims Mucuna pruriens (MP to possess pro-male fertility, aphrodisiac and adaptogenic properties. Some scientific evidence also supports its pro-male fertility properties; however, the mechanism of its action is not yet clear. The present study aimed at demonstrating spermatogenic restorative efficacy of MP and its major constituent L-DOPA (LD, and finding the possible mechanism of action thereof in a rat model. METHODOLOGY/FINDINGS: Ethinyl estradiol (EE was administered at a rate of 3 mg/kg body weight (BW/day for a period of 14 days to generate a rat model with compromised spermatogenesis. MP and LD were administered in two separate groups of these animals starting 15(th day for a period of 56 days, and the results were compared with an auto-recovery (AR group. Sperm count and motility, testis histo-architecture, level of reactive oxygen species (ROS, mitochondrial membrane potential (MMP, apoptosis, peripheral hormone levels and testicular germ cell populations were analysed, in all experimental groups. We observed efficient and quick recovery of spermatogenesis in MP and LD groups in comparison to the auto-recovery group. The treatment regulated ROS level, apoptosis, and mitochondrial membrane potential (MMP, recovered the hypothalamic-pituitary-gonadal axis and the number of testicular germ cells, ultimately leading to increased sperm count and motility. CONCLUSION/SIGNIFICANCE: M. pruriens efficiently recovers the spermatogenic loss induced due to EE administration. The recovery is mediated by reduction in ROS level, restoration of MMP, regulation of apoptosis and eventual increase in the number of germ cells and regulation of apoptosis. The present study simplified the complexity of mechanism involved and provided meaningful insights into MP/LD mediated correction of spermatogenic impairment caused by estrogens exposure. This is the first study demonstrating that L-DOPA largely accounts for pro

  7. Mucuna pruriens and its major constituent L-DOPA recover spermatogenic loss by combating ROS, loss of mitochondrial membrane potential and apoptosis.

    Science.gov (United States)

    Singh, Akhand Pratap; Sarkar, Saumya; Tripathi, Muktanand; Rajender, Singh

    2013-01-01

    The Ayurvedic medicinal system claims Mucuna pruriens (MP) to possess pro-male fertility, aphrodisiac and adaptogenic properties. Some scientific evidence also supports its pro-male fertility properties; however, the mechanism of its action is not yet clear. The present study aimed at demonstrating spermatogenic restorative efficacy of MP and its major constituent L-DOPA (LD), and finding the possible mechanism of action thereof in a rat model. Ethinyl estradiol (EE) was administered at a rate of 3 mg/kg body weight (BW)/day for a period of 14 days to generate a rat model with compromised spermatogenesis. MP and LD were administered in two separate groups of these animals starting 15(th) day for a period of 56 days, and the results were compared with an auto-recovery (AR) group. Sperm count and motility, testis histo-architecture, level of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis, peripheral hormone levels and testicular germ cell populations were analysed, in all experimental groups. We observed efficient and quick recovery of spermatogenesis in MP and LD groups in comparison to the auto-recovery group. The treatment regulated ROS level, apoptosis, and mitochondrial membrane potential (MMP), recovered the hypothalamic-pituitary-gonadal axis and the number of testicular germ cells, ultimately leading to increased sperm count and motility. M. pruriens efficiently recovers the spermatogenic loss induced due to EE administration. The recovery is mediated by reduction in ROS level, restoration of MMP, regulation of apoptosis and eventual increase in the number of germ cells and regulation of apoptosis. The present study simplified the complexity of mechanism involved and provided meaningful insights into MP/LD mediated correction of spermatogenic impairment caused by estrogens exposure. This is the first study demonstrating that L-DOPA largely accounts for pro-spermatogenic properties of M. pruriens. The manuscript bears CDRI

  8. Motor cortex plasticity can indicate vulnerability to motor fluctuation and high L-DOPA need in drug-naïve Parkinson's disease.

    Science.gov (United States)

    Kishore, Asha; James, Praveen; Krishnan, Syam; Yahia-Cherif, Lydia; Meunier, Sabine; Popa, Traian

    2017-02-01

    Motor cortex plasticity is reported to be decreased in Parkinson's disease in studies which pooled patients in various stages of the disease. Whether the early decrease in plasticity is related to the motor signs or is linked to the future development of motor complications of treatment is unclear. The aim of the study was to test if motor cortex plasticity and its cerebellar modulation are impaired in treatment-naïve Parkinson's disease, are related to the motor signs of the disease and predict occurrence of motor complications of treatment. Twenty-nine denovo patients with Parkinson's disease were longitudinally assessed for motor complications for four years. Using transcranial magnetic stimulation, the plasticity of the motor cortex and its cerebellar modulation were measured (response to paired-associative stimulation alone or preceded by 2 active cerebellar stimulation protocols), both in the untreated state and after a single dose of L-DOPA. Twenty-six matched, healthy volunteers were tested, only without L-DOPA. Patients and healthy controls had similar proportions of responders and non-responders to plasticity induction. In the untreated state, the more efficient was the cerebellar modulation of motor cortex plasticity, the lower were the bradykinesia and rigidity scores. The extent of the individual plastic response to paired associative stimulation could indicate a vulnerability to develop early motor fluctuation but not dyskinesia. Measuring motor cortex plasticity in denovo Parkinson's disease could be a neurophysiological parameter that may help identify patients with greater propensity for early motor fluctuations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Influence of ornithine decarboxylase antizymes and antizyme inhibitors on agmatine uptake by mammalian cells

    DEFF Research Database (Denmark)

    Ramos-Molina, Bruno; López-Contreras, Andrés J; Lambertos, Ana

    2015-01-01

    Agmatine (4-aminobutylguanidine), a dicationic molecule at physiological pH, exerts relevant modulatory actions at many different molecular target sites in mammalian cells, having been suggested that the administration of this compound may have therapeutic interest. Several plasma membrane...... transporters have been implicated in agmatine uptake by mammalian cells. Here we report that in kidney-derived COS-7cell line, at physiological agmatine levels, the general polyamine transporter participates in the plasma membrane translocation of agmatine, with an apparent Km of 44 ± 7 µM and V max of 17.......3 ± 3.3 nmol h(-1) mg(-1) protein, but that at elevated concentrations, agmatine can be also taken up by other transport systems. In the first case, the physiological polyamines (putrescine, spermidine and spermine), several diguanidines and bis(2-aminoimidazolines) and the polyamine transport inhibitor...

  10. An elevator wheel

    Energy Technology Data Exchange (ETDEWEB)

    Zhornik, V.I.; Cherkov, Ye.M.; Simonov, A.A.

    1982-01-01

    This invention deals with mineral enrichment and is primarily for unloading submerged products of enrichment during separation in heavy mediums. An elevator wheel is proposed for unloading the submerged product from the bath of a heavy to medium separator which includes ladle disks with internal walls and overlapping sheets hinged to the ends. In order to increase the degree of dehydration of the unloaded product, the internal wall of each ladle is made of sheets installed in stages with clearances relative to each other. The advantages of the proposed device include an improvement in the degree of dehydration of the submerged product in the ladles and a reduction in the carry away of the heavy medium with the enrichment products.

  11. Selective loss of bi-directional synaptic plasticity in the direct and indirect striatal output pathways accompanies generation of parkinsonism and l-DOPA induced dyskinesia in mouse models.

    Science.gov (United States)

    Thiele, Sherri L; Chen, Betty; Lo, Charlotte; Gertler, Tracey S; Warre, Ruth; Surmeier, James D; Brotchie, Jonathan M; Nash, Joanne E

    2014-11-01

    Parkinsonian symptoms arise due to over-activity of the indirect striatal output pathway, and under-activity of the direct striatal output pathway. l-DOPA-induced dyskinesia (LID) is caused when the opposite circuitry problems are established, with the indirect pathway becoming underactive, and the direct pathway becoming over-active. Here, we define synaptic plasticity abnormalities in these pathways associated with parkinsonism, symptomatic benefits of l-DOPA, and LID. We applied spike-timing dependent plasticity protocols to cortico-striatal synapses in slices from 6-OHDA-lesioned mouse models of parkinsonism and LID, generated in BAC transgenic mice with eGFP targeting the direct or indirect output pathways, with and without l-DOPA present. In naïve mice, bidirectional synaptic plasticity, i.e. LTP and LTD, was induced, resulting in an EPSP amplitude change of approximately 50% in each direction in both striatal output pathways, as shown previously. In parkinsonism and dyskinesia, both pathways exhibited unidirectional plasticity, irrespective of stimulation paradigm. In parkinsonian animals, the indirect pathway only exhibited LTP (LTP protocol: 143.5±14.6%; LTD protocol 177.7±22.3% of baseline), whereas the direct pathway only showed LTD (LTP protocol: 74.3±4.0% and LTD protocol: 63.3±8.7%). A symptomatic dose of l-DOPA restored bidirectional plasticity on both pathways to levels comparable to naïve animals (Indirect pathway: LTP protocol: 124.4±22.0% and LTD protocol: 52.1±18.5% of baseline. Direct pathway: LTP protocol: 140.7±7.3% and LTD protocol: 58.4±6.0% of baseline). In dyskinesia, in the presence of l-DOPA, the indirect pathway exhibited only LTD (LTP protocol: 68.9±21.3% and LTD protocol 52.0±14.2% of baseline), whereas in the direct pathway, only LTP could be induced (LTP protocol: 156.6±13.2% and LTD protocol 166.7±15.8% of baseline). We conclude that normal motor control requires bidirectional plasticity of both striatal outputs

  12. Molecular identification and characterization of the pyruvate decarboxylase gene family associated with latex regeneration and stress response in rubber tree.

    Science.gov (United States)

    Long, Xiangyu; He, Bin; Wang, Chuang; Fang, Yongjun; Qi, Jiyan; Tang, Chaorong

    2015-02-01

    In plants, ethanolic fermentation occurs not only under anaerobic conditions but also under aerobic conditions, and involves carbohydrate and energy metabolism. Pyruvate decarboxylase (PDC) is the first and the key enzyme of ethanolic fermentation, which branches off the main glycolytic pathway at pyruvate. Here, four PDC genes were isolated and identified in a rubber tree, and the protein sequences they encode are very similar. The expression patterns of HbPDC4 correlated well with tapping-simulated rubber productivity in virgin rubber trees, indicating it plays an important role in regulating glycometabolism during latex regeneration. HbPDC1, HbPDC2 and HbPDC3 had striking expressional responses in leaves and bark to drought, low temperature and high temperature stresses, indicating that the HbPDC genes are involve in self-protection and defense in response to various abiotic and biotic stresses during rubber tree growth and development. To understand ethanolic fermentation in rubber trees, it will be necessary to perform an in-depth study of the regulatory pathways controlling the HbPDCs in the future. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Biochemical properties and crystal structure of ethylmethylglyoxal bis(guanylhydrazone) sulfate--an extremely powerful novel inhibitor of adenosylmethionine decarboxylase.

    Science.gov (United States)

    Elo, H; Mutikainen, I; Alhonen-Hongisto, L; Laine, R; Jänne, J; Lumme, P

    1986-01-01

    Ethylmethylglyoxal bis(guanylhydrazone) (EMGBG) sulfate, an analog of the well-known anti-leukemic drug methylglyoxal bis(guanylhydrazone), was synthesized. It was shown to be an extremely powerful competitive inhibitor of eukaryotic S-adenosylmethionine decarboxylase, with an apparent Ki value 12 nM. Thus, it appears to be the most powerful known inhibitor of the enzyme, being almost an order of magnitude more powerful than the corresponding ethylglyoxal derivative. It neither inhibited the proliferation of mouse L1210 leukemia cells in vitro, nor did it potentiate the growth inhibition produced by alpha-difluoromethyl ornithine. In this respect, its properties are closely related to those of dimethylglyoxal, ethylglyoxal and propylglyoxal bis(guanylhydrazones), while in striking contrast to those of the antiproliferative glyoxal and methylglyoxal analogs. EMGBG also inhibited intestinal diamine oxidase activity (Ki 0.7 microM). EMGBG sulfate was crystallized from water, giving orthorhombic crystals (space group Pbcn). Their crystal and molecular structure was determined by X-ray diffraction methods. The carbon-nitrogen double bonds between the ethylmethylglyoxal part and the aminoguanidine moieties were found to have the same configuration as they are known to have in the salts of glyoxal, methylglyoxal and propylglyoxal bis(guanylhydrazones). The glyoxal bis(guanylhydrazone) chain of the EMGBG cation deviated strongly from planarity, thus differing dramatically from the corresponding chains of the glyoxal, methylglyoxal and propylglyoxal analogs.

  14. Recovery from inhibition by UV-irradiation of ornithine decarboxylase induction in human cells: implication of excision repair

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Hur, E.; Prager, A. (Nuclear Research Centre-Negev, Beer-Sheva (Israel)); Buonaguro, F. (Argonne National Lab., IL (USA))

    1982-05-01

    Exposure of stationary-phase human breast carcinoma (T-47D) cells to far-UV light (254nm) inhibited the appearance of induced ornithine decarboxylase (ODC) activity. The fluence response curve had a shoulder (Dsub(q)=2Jm/sup -2/) followed by an exponential decline (D/sub 0/=4.2Jm/sup -2/). The cells could recover from this inhibition when the stimulus of induction of ODC was delayed for 20-24h after irradiation. Hydroxyurea (HU) when present at 3mM during the recovery period eliminated completely the ability of the cells to recover. This effect of HU on ODC induction was partially reversed by 50..mu..M of the four deoxyribonucleosides required for DNA synthesis. Neither HU nor the deoxyribonucleosides by themselves affected ODC induction in unirradiated cells. Since HU inhibited the recovery from potentially lethal UV damage and is a known inhibitor of excision repair, it is suggested that recovery from UV-induced inhibition of ODC induction depends on excision-repair of DNA damage. This interpretation is strongly supported by the finding that specific photolysis of 5-bromodeoxyuridine, incorporated into DNA during the recovery period, inhibited recovery of ODC induction from inhibition by UV light.

  15. Investigation of the enzymatic mechanism of yeast orotidine-5'-monophosphate decarboxylase using 13C kinetic isotope effects

    International Nuclear Information System (INIS)

    Smiley, J.A.; Bell, J.B.; Jones, M.E.; Paneth, P.; O'Leary, M.H.

    1991-01-01

    Orotidine-5'-monophosphate decarboxylase (ODCase) from Saccharomyces cerevisiae displays an observed 13 C kinetic isotope effect of 1.0247 ± 0.0008 at 25 C, pH 6.8. The observed isotope effect is sensitive to changes in the reaction medium, such as pH, temperature, or glycerol content. The value of 1.0494 ± 0.0006 measured at pH 4.0, 25 C, is not altered significantly by temperature or glycerol, and thus the intrinsic isotope effect for the reaction is apparently being observed under these conditions and decarboxylation is almost entirely rate-determining. These data require a catalytic mechanism with freely reversible binding and one in which a very limited contribution to the overall rate is made by chemical steps preceding decarboxylation; the zwitterion mechanism of Beak and Siegel, which involves only protonation of the pyrimidine ring, is such a mechanism. With use of an intrinsic isotope effect of 1.05, a partitioning factor of less than unity is calculated for ODCase at pH 6.0, 25 C. A quantitative kinetic analysis using this result excludes the possibility of an enzymatic mechanism involving covalent attachment of an enzyme nucleophile to C-5 of the pyrimidine ring. These data fit a kinetic model in which an enzyme proton necessary for catalysis is titrated at high pH, thus providing evidence for the catalytic mechanism of Beak and Siegal

  16. Improving nutritional quality and fungal tolerance in soya bean and grass pea by expressing an oxalate decarboxylase.

    Science.gov (United States)

    Kumar, Vinay; Chattopadhyay, Arnab; Ghosh, Sumit; Irfan, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

    2016-06-01

    Soya bean (Glycine max) and grass pea (Lathyrus sativus) seeds are important sources of dietary proteins; however, they also contain antinutritional metabolite oxalic acid (OA). Excess dietary intake of OA leads to nephrolithiasis due to the formation of calcium oxalate crystals in kidneys. Besides, OA is also a known precursor of β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), a neurotoxin found in grass pea. Here, we report the reduction in OA level in soya bean (up to 73%) and grass pea (up to 75%) seeds by constitutive and/or seed-specific expression of an oxalate-degrading enzyme, oxalate decarboxylase (FvOXDC) of Flammulina velutipes. In addition, β-ODAP level of grass pea seeds was also reduced up to 73%. Reduced OA content was interrelated with the associated increase in seeds micronutrients such as calcium, iron and zinc. Moreover, constitutive expression of FvOXDC led to improved tolerance to the fungal pathogen Sclerotinia sclerotiorum that requires OA during host colonization. Importantly, FvOXDC-expressing soya bean and grass pea plants were similar to the wild type with respect to the morphology and photosynthetic rates, and seed protein pool remained unaltered as revealed by the comparative proteomic analysis. Taken together, these results demonstrated improved seed quality and tolerance to the fungal pathogen in two important legume crops, by the expression of an oxalate-degrading enzyme. © 2016 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  17. Cyclobutane-type pyrimidine photodimer formation and induction of ornithine decarboxylase in human skin fibroblasts after UV irradiation

    International Nuclear Information System (INIS)

    Niggli, H.J.; Roethlisberger, R.

    1988-01-01

    Cyclobutane-type pyrimidine photodimers as well as the induction of ornithine decarboxylase (ODC) may serve as biochemical markers of the mutagenic and carcinogenic effects of ultraviolet light (UV). For this reason, it is important to compare the formation of pyrimidine dimers with the induction of ODC in human skin fibroblasts after irradiation with UVC (200-290 nm) and UVB (290-320 nm). In our studies we determined cytosine-thymine (C-T) as well as thymine-thymine dimer yields (T-T) by high-pressure liquid chromatography in cultures of neonatal normal human foreskin-derived fibroblasts after irradiation with UVC and UVB light. It was found that the yield of dimerization and the ratio of T-T/C-T decreased from the UVC to the UVB region. Time-course studies of ODC-induction in the same cells indicated that the maximal activity after UVB irradiation was retarded compared to UVC exposure. For the UV-induced ODC-levels, however, no significant difference in maximal induction could be measured after UVC and UVB irradiation at fluences where comparable yields of thymine dimerization are produced. Similar ODC-maxima were obtained with strains from children, while cells from adults showed significantly less pronounced ODC induction, indicating that ODC-response decreases with age and may therefore be used as a marker of aging

  18. Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid.

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    Yan Huang

    Full Text Available Glutamate decarboxylase (GAD catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA. In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C. Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C, superior thermostability (2.8-fold greater than that of GAD-C, and higher kcat/Km (1.6-fold higher than that of GAD-C. Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA.

  19. Thiol Redox Sensitivity of Two Key Enzymes of Heme Biosynthesis and Pentose Phosphate Pathways: Uroporphyrinogen Decarboxylase and Transketolase

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    Brian McDonagh

    2013-01-01

    Full Text Available Uroporphyrinogen decarboxylase (Hem12p and transketolase (Tkl1p are key mediators of two critical processes within the cell, heme biosynthesis, and the nonoxidative part of the pentose phosphate pathway (PPP. The redox properties of both Hem12p and Tkl1p from Saccharomyces cerevisiae were investigated using proteomic techniques (SRM and label-free quantification and biochemical assays in cell extracts and in vitro with recombinant proteins. The in vivo analysis revealed an increase in oxidized Cys-peptides in the absence of Grx2p, and also after treatment with H2O2 in the case of Tkl1p, without corresponding changes in total protein, demonstrating a true redox response. Out of three detectable Cys residues in Hem12p, only the conserved residue Cys52 could be modified by glutathione and efficiently deglutathionylated by Grx2p, suggesting a possible redox control mechanism for heme biosynthesis. On the other hand, Tkl1p activity was sensitive to thiol redox modification and although Cys622 could be glutathionylated to a limited extent, it was not a natural substrate of Grx2p. The human orthologues of both enzymes have been involved in certain cancers and possess Cys residues equivalent to those identified as redox sensitive in yeast. The possible implication for redox regulation in the context of tumour progression is put forward.

  20. Evaluation of Brachypodium distachyon L-Tyrosine Decarboxylase Using L-Tyrosine Over-Producing Saccharomyces cerevisiae.

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    Shuhei Noda

    Full Text Available To demonstrate that herbaceous biomass is a versatile gene resource, we focused on the model plant Brachypodium distachyon, and screened the B. distachyon for homologs of tyrosine decarboxylase (TDC, which is involved in the modification of aromatic compounds. A total of 5 candidate genes were identified in cDNA libraries of B. distachyon and were introduced into Saccharomyces cerevisiae to evaluate TDC expression and tyramine production. It is suggested that two TDCs encoded in the transcripts Bradi2g51120.1 and Bradi2g51170.1 have L-tyrosine decarboxylation activity. Bradi2g51170.1 was introduced into the L-tyrosine over-producing strain of S. cerevisiae that was constructed by the introduction of mutant genes that promote deregulated feedback inhibition. The amount of tyramine produced by the resulting transformant was 6.6-fold higher (approximately 200 mg/L than the control strain, indicating that B. distachyon TDC effectively converts L-tyrosine to tyramine. Our results suggest that B. distachyon possesses enzymes that are capable of modifying aromatic residues, and that S. cerevisiae is a suitable host for the production of L-tyrosine derivatives.

  1. IGF2BP2 alternative variants associated with glutamic acid decarboxylase antibodies negative diabetes in Malaysian subjects.

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    Sameer D Salem

    Full Text Available BACKGROUND: The association of Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2 common variants (rs4402960 and rs1470579 with type 2 diabetes (T2D has been performed in different populations. The aim of this study was to evaluate the association of alternative variants of IGF2BP2; rs6777038, rs16860234 and rs7651090 with glutamic acid decarboxylase antibodies (GADA negative diabetes in Malaysian Subjects. METHODS/PRINCIPAL FINDINGS: IGF2BP2; rs6777038, rs16860234 and rs7651090 single nucleotide polymorphisms (SNPs were genotyped in 1107 GADA negative diabetic patients and 620 control subjects of Asian from Malaysia. The additive genetic model adjusted for age, race, gender and BMI showed that alternative variants; rs6777038, rs16860234 and rs7651090 of IGF2BP2 associated with GADA negative diabetes (OR = 1.21; 1.36; 1.35, P = 0.03; 0.0004; 0.0002, respectively. In addition, the CCG haplotype and diplotype CCG-TCG increased the risk of diabetes (OR = 1.51, P = 0.01; OR = 2.36, P = 0.009, respectively. CONCLUSIONS/SIGNIFICANCE: IGF2BP2 alternative variants were associated with GADA negative diabetes. The IGF2BP2 haplotypes and diplotypes increased the risk of diabetes in Malaysian subject.

  2. The clinical significance of detecting serum glutamic acid decarboxylase antibody (GAD), C-peptide and insulin in diabetics

    International Nuclear Information System (INIS)

    Zheng Tingliang; Zhang Jinchi; Yao Yingfei; Chen Linxing; Huang Hua

    2005-01-01

    Objective: To explore the clinical significance of detecting serum glutamic acid decarboxylase (GAD) antibody, C-peptide (CP) and insulin (INS) in the classification of diabetic patients. Methods: Serum GAD antibody, CP and INS concentration were determined with RIA in 27 patients with type 1 diabetes mellitus (DM1) and 49 patients with type 2 diabetes mellitus (DM2). Sugar-electrode-method was used to detect the concentrations of fasting plasma glucose (FPG) in these patients. Results: The positive rate of GAD antibody in DM1 patients (66.7%) were significantly higher than that in DM2 group (8.2%) (P<0.01), The levels of CP and INS were lower in DM1 group than those in DM2 group as well (P<0.01). Conclusion: GAD antibody is a valuable marker to predict the impairment of β-cell GAD antibody levels, together with CP /FPG and INS/FPG ratios, might be useful in determining the type of DM and guiding the therapy. (authors)

  3. Knocking out Ornithine Decarboxylase Antizyme 1 (OAZ1 Improves Recombinant Protein Expression in the HEK293 Cell Line

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    Laura Abaandou

    2018-06-01

    Full Text Available Creating efficient cell lines is a priority for the biopharmaceutical industry, which produces biologicals for various uses. A recent approach to achieving this goal is the use of non-coding RNAs, microRNA (miRNA and small interfering RNA (siRNA, to identify key genes that can potentially improve production or growth. The ornithine decarboxylase antizyme 1 (OAZ1 gene, a negative regulator of polyamine biosynthesis, was identified in a genome-wide siRNA screen as a potential engineering target, because its knock down by siRNA increased recombinant protein expression from human embryonic kidney 293 (HEK293 cells by two-fold. To investigate this further, the OAZ1 gene in HEK293 cells was knocked out using CRISPR genome editing. The OAZ1 knockout cell lines displayed up to four-fold higher expression of both stably and transiently expressed proteins, with comparable growth and metabolic activity to the parental cell line; and an approximately three-fold increase in intracellular polyamine content. The results indicate that genetic inactivation of OAZ1 in HEK293 cells is an effective strategy to improve recombinant protein expression in HEK293 cells.

  4. Comparison of the effects of an ornithine decarboxylase inhibitor on the intestinal epithelium and on intestinal tumors.

    Science.gov (United States)

    Tutton, P J; Barkla, D H

    1986-12-01

    Ornithine decarboxylase (ODC) catalyzes the rate-limiting step in the synthesis of polyamines, it has a short half-life, and its synthesis is under hormonal control. Recently, insight into the role of ODC and thus into the physiology of polyamines has been gained by the use of an inhibitor of ODC, difluoromethylornithine (DFMO). In the present report cell proliferation was measured by a stathmokinetic method in the crypt epithelium of the jejunum and colon of normal rats and in dimethylhydrazine-induced colonic tumors. Growth of human colon tumor xenografts in immunosuppressed mice and mouse colon tumor isografts was also assessed. Cell proliferation in primary colonic tumors was substantially suppressed by a single dose of DFMO at 100 mg/kg whereas the normal crypt epithelium of the small and large intestine required two doses at 400 mg/kg to produce a similar magnitude of inhibition of cell proliferation. DFMO was also found to suppress cell proliferation in, and the growth of, the transplantable colon cancers. Because of the apparent selectivity of the antimitotic activity of DFMO towards tumors, ODC inhibitors may prove to be useful anticancer drugs.

  5. High titers of autoantibodies to glutamate decarboxylase in Type 1 Diabetes Patients: Epitope Analysis and Inhibition of Enzyme Activity

    Science.gov (United States)

    Hampe, Christiane S.; Maitland, Murray E.; Gilliam, Lisa K.; Thi Phan, Thanh-H.; Sweet, Ian R.; Radtke, Jared R.; Bota, Vasile; Ransom, Bruce R.; Hirsch, Irl B.

    2014-01-01

    Objective Autoantibodies to glutamate decarboxylase (GAD65Ab) are found in patients with autoimmune neurological disorders and patients with type 1 diabetes. The correct diagnosis of GAD65Ab-associated neurological disorders is often delayed by the variability of symptoms and a lack of diagnostic markers. We hypothesize that the frequency of neurological disorders with high GAD65Ab titers is significantly higher than currently recognized. Methods We analyzed GAD65Ab titer, inhibition of GAD65 enzyme activity, and pattern of GAD65Ab epitopes in a cohort of type 1 diabetes patients (n=100) and correlated our findings with neurological symptoms and diseases. Results Fourty-three percent (43/100) of the patients had detectable GAD65Ab titers (median=400 U/ml, range: 142–250,000U/ml). The GAD65Ab titers in 10 type 1 diabetes patients exceeded the 90th percentile of the cohort (2,000–250,000 U/ml). Sera of these 10 patients were analyzed for their GAD65Ab epitope specificity and their ability to inhibit GAD65 enzyme activity in vitro. GAD65Ab of five patients inhibited the enzyme activity significantly (by 34–55%). Three of these patients complained of muscle stiffness and pain, which was documented in two of these patients. Conclusions Based on our findings we suggest that neurological disorders with high GAD65Ab titers are more frequent in type 1 diabetes patients than currently recognized. PMID:23512385

  6. Efficient Production of γ-GABA Using Recombinant E. coli Expressing Glutamate Decarboxylase (GAD) Derived from Eukaryote Saccharomyces cerevisiae.

    Science.gov (United States)

    Xiong, Qiang; Xu, Zheng; Xu, Lu; Yao, Zhong; Li, Sha; Xu, Hong

    2017-12-01

    γ-Aminobutyric acid (γ-GABA) is a non-proteinogenic amino acid, which acts as a major regulator in the central nervous system. Glutamate decarboxylase (namely GAD, EC 4.1.1.15) is known to be an ideal enzyme for γ-GABA production using L-glutamic acid as substrate. In this study, we cloned and expressed GAD gene from eukaryote Saccharomyces cerevisiae (ScGAD) in E. coli BL21(DE3). This enzyme was further purified and its optimal reaction temperature and pH were 37 °C and pH 4.2, respectively. The cofactor of ScGAD was verified to be either pyridoxal 5'-phosphate (PLP) or pyridoxal hydrochloride. The optimal concentration of either cofactor was 50 mg/L. The optimal medium for E. coli-ScGAD cultivation and expression were 10 g/L lactose, 5 g/L glycerol, 20 g/L yeast extract, and 10 g/L sodium chloride, resulting in an activity of 55 U/mL medium, three times higher than that of using Luria-Bertani (LB) medium. The maximal concentration of γ-GABA was 245 g/L whereas L-glutamic acid was near completely converted. These findings provided us a good example for bio-production of γ-GABA using recombinant E. coli expressing a GAD enzyme derived from eukaryote.

  7. Disruption of pknG enhances production of gamma-aminobutyric acid by Corynebacterium glutamicum expressing glutamate decarboxylase.

    Science.gov (United States)

    Okai, Naoko; Takahashi, Chihiro; Hatada, Kazuki; Ogino, Chiaki; Kondo, Akihiko

    2014-01-01

    Gamma-aminobutyric acid (GABA), a building block of the biodegradable plastic polyamide 4, is synthesized from glucose by Corynebacterium glutamicum that expresses Escherichia coli glutamate decarboxylase (GAD) B encoded by gadB. This strain was engineered to produce GABA more efficiently from biomass-derived sugars. To enhance GABA production further by increasing the intracellular concentration of its precursor glutamate, we focused on engineering pknG (encoding serine/threonine protein kinase G), which controls the activity of 2-oxoglutarate dehydrogenase (Odh) in the tricarboxylic acid cycle branch point leading to glutamate synthesis. We succeeded in expressing GadB in a C. glutamicum strain harboring a deletion of pknG. C. glutamicum strains GAD and GAD ∆pknG were cultured in GP2 medium containing 100 g L(-1) glucose and 0.1 mM pyridoxal 5'-phosphate. Strain GAD∆pknG produced 31.1 ± 0.41 g L(-1) (0.259 g L(-1) h(-1)) of GABA in 120 hours, representing a 2.29-fold higher level compared with GAD. The production yield of GABA from glucose by GAD∆pknG reached 0.893 mol mol(-1).

  8. Current concepts on the physiology and genetics of neurotransmitters-mediating enzyme-aromatic L-amino acid decarboxylase

    International Nuclear Information System (INIS)

    Rahman, M.K.

    1993-03-01

    Two most important neurotransmitters, dopamine and serotonin are mediated by the enzyme aromatic L-amino acid decarboxylase (AADC). Because of their importance in the regulation of neuronal functions, behaviour and emotion of higher animals, many researchers are working on this enzyme to elucidate its physiological properties, structure and genetic aspects. We have discovered this enzyme in the mammalian blood, we established sensitive assay methods for the assay of the activities of this enzyme. We have made systematic studies on this enzyme in the tissues and brains of rats, and human subjects. We have found an endogenous inhibitor of this enzyme in the monkey's blood. The amino acid sequences of human AADC has been compared to rat or bovine. A full-length cDNA clone encoding human AADC has been isolated. Very recently the structure of human AADC gene including 5'-flaking region has been characterized and the transcriptional starting point has been determined. The human AADC gene assigned to chromosome 7. Up-to-date research data have shown that AADC is encoded by a single gene. Recently two patients with AADC deficiency were reported. This paper describes the systematic up-to-date review studies on AADC. (author). 62 refs, 5 figs, 8 tabs