scholarly journals The metabolism of nitrilotriacetate by a pseudomonad

1973 ◽  
Vol 136 (4) ◽  
pp. 1059-1068 ◽  
Author(s):  
Roger E. Cripps ◽  
Ann S. Noble

1. An organism that grows on nitrilotriacetate as sole source of carbon and energy was isolated in pure culture and was identified as a pseudomonad. 2. Cell-free extracts of the nitrilotriacetate-grown pseudomonad contain an enzyme that catalyses the NADH-and O2-dependent oxidation of nitrilotriacetate to iminodiacetate and glyoxalate. This enzyme is absent from extracts of glucose-grown cells. 3. Compared with growth on glucose, growth on nitrilotriacetate results in increased activities of enzymes of glycine and serine metabolism, namely serine hydroxymethyltransferase, glycine decarboxylase, serine–oxaloacetate aminotransferase and hydroxypyruvate reductase. 4. Cell-free extracts of the nitrilotriacetate-grown organism contain the enzyme glyoxalate carboligase and, when supplemented with NADH, Mg2+and thiamin pyrophosphate, can catalyse the anaerobic conversion of glyoxalate into glycerate. 5. These results are incorporated in a scheme which shows the oxidative metabolism of nitrilotriacetate by the successive removal of C2 units to form 2mol of glyoxalate and 1mol of glycine per mol of nitrilotriacetate degraded. The glyoxalate and glycine are then both metabolized to glycerate by separate pathways, via tartronic semialdehyde and serine respectively. The role of this scheme in the growth of the organism on nitrilotriacetate is discussed.

Author(s):  
Piero Ignazi

Chapter 3 investigates the process of party formation in France, Germany, Great Britain, and Italy, and demonstrates the important role of cultural and societal premises for the development of political parties in the nineteenth century. Particular attention is paid in this context to the conditions in which the two mass parties, socialists and Christian democrats, were established. A larger set of Western European countries included in this analysis is thoroughly scrutinized. Despite discontent among traditional liberal-conservative elites, full endorsement of the political party was achieved at the beginning of the twentieth century. Particular attention is paid to the emergence of the interwar totalitarian party, especially under the guise of Italian and German fascism, when ‘the party’ attained its most dominant influence as the sole source and locus of power. The chapter concludes by suggesting hidden and unaccounted heritages of that experience in post-war politics.


2007 ◽  
Vol 293 (5) ◽  
pp. R2059-R2069 ◽  
Author(s):  
Steven D. Mason ◽  
Helene Rundqvist ◽  
Ioanna Papandreou ◽  
Roger Duh ◽  
Wayne J. McNulty ◽  
...  

During endurance training, exercising skeletal muscle experiences severe and repetitive oxygen stress. The primary transcriptional response factor for acclimation to hypoxic stress is hypoxia-inducible factor-1α (HIF-1α), which upregulates glycolysis and angiogenesis in response to low levels of tissue oxygenation. To examine the role of HIF-1α in endurance training, we have created mice specifically lacking skeletal muscle HIF-1α and subjected them to an endurance training protocol. We found that only wild-type mice improve their oxidative capacity, as measured by the respiratory exchange ratio; surprisingly, we found that HIF-1α null mice have already upregulated this parameter without training. Furthermore, untrained HIF-1α null mice have an increased capillary to fiber ratio and elevated oxidative enzyme activities. These changes correlate with constitutively activated AMP-activated protein kinase in the HIF-1α null muscles. Additionally, HIF-1α null muscles have decreased expression of pyruvate dehydrogenase kinase I, a HIF-1α target that inhibits oxidative metabolism. These data demonstrate that removal of HIF-1α causes an adaptive response in skeletal muscle akin to endurance training and provides evidence for the suppression of mitochondrial biogenesis by HIF-1α in normal tissue.


Author(s):  
Thamer Y. Mutter ◽  
Gerben J. Zylstra

Sphingomonas wittichii RW1 grows on the two related compounds dibenzofuran (DBF) and dibenzo- p -dioxin (DXN) as the sole source of carbon. Previous work by others (P.V. Bunz, R. Falchetto, and A.M. Cook. Biodegradation 4:171-8, 1993, doi: 10.1007/BF00695119) identified two upper pathway meta cleavage product hydrolases (DxnB1 and DxnB2) active on the DBF upper pathway metabolite 2-hydroxy-6-oxo-6-(2-hydroxyphenyl)-hexa-2,4-dienoate. We took a physiological approach to determine the role of these two enzymes in the degradation of DBF and DXN by RW1. Single knockouts of either plasmid located dbfB1 or chromosome located dbfB2 had no effect on RW1 growth on either DBF or DXN. However, a double knockout lost the ability to grow on DBF but still grew normally on DXN demonstrating that DbfB1 and DbfB2 are the only hydrolases involved in the DBF upper pathway. Using a transcriptomic-guided approach we identified a constitutively expressed third hydrolase encoded by the chromosomally located SWIT0910 gene. Knockout of SWIT0910 resulted in a strain that no longer grows on DXN but still grows normally on DBF. Thus the DbfB1 and DbfB2 hydrolases function in the DBF but not the DXN catabolic pathway and the SWIT0190 hydrolase functions in the DXN but not the DBF catabolic pathway. Importance S. wittichii RW1 is one of only a few strains known to grow on DXN as the sole course of carbon. Much of the work deciphering the related RW1 DXN and DBF catabolic pathways has involved genome gazing, transcriptomics, proteomics, heterologous expression, and enzyme purification and characterization. Very little research has utilized physiological techniques to precisely dissect the genes and enzymes involved in DBF and DXN degradation. Previous work by others identified and extensively characterized two RW1 upper pathway hydrolases. Our present work demonstrates that these two enzymes are involved in DBF but not DXN degradation. In addition, our work identified a third constitutively expressed hydrolase that is involved in DXN but not DBF degradation. Combined with our previous work, this means that the RW1 DXN upper pathway involves genes from three very different locations in the genome: an initial plasmid-encoded dioxygenase and a ring cleavage enzyme and hydrolase encoded on opposite sides of the chromosome.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Claudia Pileggi ◽  
Valentina Mascaro ◽  
Aida Bianco ◽  
Maria Pavia

The use of nonprescription medicines (NPDs) for children illnesses without a doctor’s suggestion can lead to unnecessary medication use and is not free of risks. The aim of our study was to examine attitudes and practice of parents towards NPDs use for their children. We also investigated the conditions that may predict NPDs use. A cross-sectional survey was conducted on parents of children attending Community Based Pediatrician (CBP) consultation and data were collected through structured interviews. Positive attitude on NPDs use was reported by 71.4% of parents, and 61.5% of them had administered NPDs in the previous 6 months. Antipyretic drugs were the most frequently used medication class without the supervision of the CBP. A positive attitude towards NPDs was significantly more frequent in parents who did not use the CBP as the sole source of information about drugs. The study demonstrated a widespread use of NPDs in children in our context, supported by a substantial positive attitude towards their safety. However, considering potential harms related to some NPDs and the finding that most parents rely on CBP advice, role of CBP on appropriate use of NPDs by parents should be emphasized.


2012 ◽  
Vol 129 (2) ◽  
pp. 280-292 ◽  
Author(s):  
Claudio A. Erratico ◽  
András Szeitz ◽  
Stelvio M. Bandiera

1983 ◽  
Vol 29 (3) ◽  
pp. 513-515 ◽  
Author(s):  
M S Cohen ◽  
P S Shirley ◽  
L R DeChatelet

Abstract Chemiluminescence can be used to identify defects in the oxidative metabolism of granulocytes. This procedure has recently been adopted for use with microliter quantities of whole blood, appropriate for prenatal or neonatal study. Although the contribution of myeloperoxidase to the chemiluminescence assay has been noted, the possible diagnostic confusion between chronic granulomatous disease of childhood (which is rare and severe) and myeloperoxidase deficiency (which is common and of little clinical consequence) has not been stressed. We report a father and his infant daughter whose cells emitted no light in the luminol-enhanced luminescence assay; both patients are totally peroxidase deficient. These results emphasize the hereditary nature of myeloperoxidase deficiency, and the possibility for erroneous diagnosis of chronic granulomatous disease of childhood based on the luminol-enhanced luminescence test.


2014 ◽  
Vol 20 (47) ◽  
pp. 17756-17772 ◽  
Author(s):  
Elisabetta Ceni ◽  
Tommaso Mello ◽  
Andrea Galli

2000 ◽  
Vol 89 (4) ◽  
pp. 1293-1301 ◽  
Author(s):  
Bruno Grassi ◽  
Michael C. Hogan ◽  
Kevin M. Kelley ◽  
William G. Aschenbach ◽  
Jason J. Hamann ◽  
...  

A previous study (Grassi B, Gladden LB, Samaja M, Stary CM, and Hogan MC, J Appl Physiol 85: 1394–1403, 1998) showed that convective O2 delivery to muscle did not limit O2 uptake (V˙o 2) on-kinetics during transitions from rest to contractions at ∼60% of peakV˙o 2. The present study aimed to determine whether this finding is also true for transitions involving contractions of higher metabolic intensities.V˙o 2 on-kinetics were determined in isolated canine gastrocnemius muscles in situ ( n = 5) during transitions from rest to 4 min of electrically stimulated isometric tetanic contractions corresponding to the muscle peakV˙o 2. Two conditions were compared: 1) spontaneous adjustment of muscle blood flow (Q˙) (Control) and 2) pump-perfused Q˙, adjusted ∼15–30 s before contractions at a constant level corresponding to the steady-state value during contractions in Control (Fast O2 Delivery). In Fast O2 Delivery, adenosine was infused intra-arterially. Q˙ was measured continuously in the popliteal vein; arterial and popliteal venous O2 contents were measured at rest and at 5- to 7-s intervals during the transition. Muscle V˙o 2 was determined as Q˙times the arteriovenous blood O2 content difference. The time to reach 63% of the V˙o 2 difference between resting baseline and steady-state values during contractions was 24.9 ± 1.6 (SE) s in Control and 18.5 ± 1.8 s in Fast O2 Delivery ( P < 0.05). FasterV˙o 2 on-kinetics in Fast O2Delivery was associated with an ∼30% reduction in the calculated O2 deficit and with less muscle fatigue. During transitions involving contractions at peak V˙o 2, convective O2 delivery to muscle, together with an inertia of oxidative metabolism, contributes in determining theV˙o 2 on-kinetics.


2011 ◽  
Vol 51 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Paweł Węgorek ◽  
Joanna Zamojska ◽  
Marek Mrówczyński

Susceptibility Level of the Colorado Potato Beetle (Leptinotarsa DecemlineataSay) to Chlorpyrifos and Acetamiprid in Poland and Resistance Mechanisms of the Pest to ChlorpyrifosNowadays, neonicotinoids play an essential role in the control of the Colorado potato beetle (CPB) in Poland. Taking into consideration that CPB shows some resistance to pyrethroids and the main role of oxidative metabolism in this resistance, research was conducted to estimate CPB susceptibility level to chlorpyrifos and acetamiprid. The results pointed to a lack of CPB resistance to acetamiprid and a weak susceptibility level to chlorpyrifos by the CPB. For this reason, the second part of the experiment was aimed at detecting the resistance mechanisms of the CPB to chlorpyrifos. Results showed that none of the tested enzyme groups (oxidases, esterases and glutathione transferases) are the reason for CPB resistance to chlorpyrifos. The experiments revealed an increase in the beetles survival after adding oxidative enzyme blocker to chlorpyrifos.


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