scholarly journals Arginine metabolism in Trichomonas vaginalis infected with Mycoplasma hominis

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3734-3743 ◽  
Author(s):  
Mary Morada ◽  
Mafruha Manzur ◽  
Brian Lam ◽  
Cho Tan ◽  
Jan Tachezy ◽  
...  
Keyword(s):  
Energy Source ◽  
Trichomonas Vaginalis ◽  
Potential Benefit ◽  
Flow Analysis ◽  
Mycoplasma Hominis ◽  
Fold Increase ◽  
Arginine Metabolism ◽  
Threefold Increase ◽  
Arginine Dihydrolase ◽  
Activity Of Enzymes

Both Mycoplasma hominis and Trichomonas vaginalis utilize arginine as an energy source via the arginine dihydrolase (ADH) pathway. It has been previously demonstrated that M. hominis forms a stable intracellular relationship with T. vaginalis; hence, in this study we examined the interaction of two localized ADH pathways by comparing T. vaginalis strain SS22 with the laboratory-generated T. vaginalis strain SS22-MOZ2 infected with M. hominis MOZ2. The presence of M. hominis resulted in an approximately 16-fold increase in intracellular ornithine and a threefold increase in putrescine, compared with control T. vaginalis cultures. No change in the activity of enzymes of the ADH pathway could be demonstrated in SS22-MOZ2 compared with the parent SS22, and the increased production of ornithine could be attributed to the presence of M. hominis. Using metabolic flow analysis it was determined that the elasticity of enzymes of the ADH pathway in SS22-MOZ2 was unchanged compared with the parent SS22; however, the elasticity of ornithine decarboxylase (ODC) in SS22 was small, and it was doubled in SS22-MOZ2 cells. The potential benefit of this relationship to both T. vaginalis and M. hominis is discussed.

scholarly journals Efficiency stagnation in global steel production urges joint supply- and demand-side mitigation efforts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peng Wang ◽  
Morten Ryberg ◽  
Yi Yang ◽  
Kuishuang Feng ◽  
Sami Kara ◽  
...  
Keyword(s):  
Supply And Demand ◽  
Flow Analysis ◽  
Steel Production ◽  
Fold Increase ◽  
Process Efficiency ◽  
Mitigation Measures ◽  
Carbon Intensity ◽  
Climate Mitigation ◽  
Past Century ◽  
Demand Side

AbstractSteel production is a difficult-to-mitigate sector that challenges climate mitigation commitments. Efforts for future decarbonization can benefit from understanding its progress to date. Here we report on greenhouse gas emissions from global steel production over the past century (1900-2015) by combining material flow analysis and life cycle assessment. We find that ~45 Gt steel was produced in this period leading to emissions of ~147 Gt CO2-eq. Significant improvement in process efficiency (~67%) was achieved, but was offset by a 44-fold increase in annual steel production, resulting in a 17-fold net increase in annual emissions. Despite some regional technical improvements, the industry’s decarbonization progress at the global scale has largely stagnated since 1995 mainly due to expanded production in emerging countries with high carbon intensity. Our analysis of future scenarios indicates that the expected demand expansion in these countries may jeopardize steel industry’s prospects for following 1.5 °C emission reduction pathways. To achieve the Paris climate goals, there is an urgent need for rapid implementation of joint supply- and demand-side mitigation measures around the world in consideration of regional conditions.

scholarly journals The Generation of Energy by the Arginine Dihydrolase Pathway in Mycoplasma hominis 07

1966 ◽  
Vol 241 (10) ◽  
pp. 2228-2236
Author(s):  
Robert T. Schimke ◽  
C.M. Berlin ◽  
E.W. Sweeney ◽  
William R. Carroll
Keyword(s):  
Mycoplasma Hominis ◽  
Arginine Dihydrolase

Endothelium, vasopressin receptors, and resistance to DOCA-salt hypertension

1993 ◽  
Vol 265 (1) ◽  
pp. H15-H21 ◽  
Author(s):  
C. S. Bockman ◽  
W. B. Jeffries ◽  
W. A. Pettinger ◽  
P. W. Abel
Keyword(s):  
Mesenteric Artery ◽  
Wistar Rats ◽  
Fold Increase ◽  
Vasopressin Receptor ◽  
Receptor Function ◽  
Salt Treatment ◽  
Threefold Increase ◽  
Lysine Vasopressin ◽  
Salt Hypertension ◽  
Vasopressin Receptors

Mesenteric artery rings from Wistar and Wistar-Furth rats subcutaneously treated with deoxycorticosterone acetate (DOCA) and 1% NaCl drinking water were used to measure endothelial modulation of contractile sensitivity and vasopressin receptor function and affinity. DOCA-salt hypertension reduced contractile sensitivity to arginine vasopressin (AVP) and did not affect contractile sensitivity to norepinephrine in arteries from Wistar rats. Endothelial removal caused a threefold increase in contractile sensitivity to AVP and norepinephrine in DOCA-salt hypertensive Wistar rats. In Wistar-Furth rats, DOCA-salt treatment did not affect contractile sensitivity to AVP, lysine vasopressin, oxytocin, and norepinephrine or the affinity of the vasopressin receptor for agonists or antagonists. Removal of endothelium did not affect vasopressin contractile sensitivity but caused a 15-fold increase in contractile sensitivity to norepinephrine in untreated or DOCA-salt-treated Wistar-Furth rats. These data show that reduced vasopressin receptor function and increased endothelial function that compensate for increased contractile sensitivity in arteries from DOCA-salt hypertensive Wistar rats are not the cause of resistance of DOCA-salt-treated Wistar-Furth rats to the development of enhanced contractile sensitivity and hypertension.

The contribution of the arginine dihydrolase pathway to energy metabolism by Trichomonas vaginalis

1996 ◽  
Vol 78 (1-2) ◽  
pp. 117-125 ◽  
Author(s):  
Nigel Yarlett ◽  
Martha P. Martinez ◽  
M. Ali Moharrami ◽  
Jan Tachezy
Keyword(s):  
Energy Metabolism ◽  
Trichomonas Vaginalis ◽  
Arginine Dihydrolase

scholarly journals Transgenic Approaches for Cyanogen Reduction in Cassava

2007 ◽  
Vol 90 (5) ◽  
pp. 1450-1455 ◽  
Author(s):  
Dimuth Siritunga ◽  
Richard Sayre
Keyword(s):  
Gene Expression ◽  
Potential Benefit ◽  
Fold Increase ◽  
Selective Inhibition ◽  
Alternative Strategy ◽  
Specific Inhibition ◽  
Cyanogenic Glycoside ◽  
Wild Type ◽  
Hydroxynitrile Lyase ◽  
Tissue Specific

Abstract For cassava to become a safe and acceptable crop, it is necessary to reduce the cyanogen levels in cassava foods. While this objective can be achieved by processing procedures, recent findings have shown that it is also possible to achieve it by suppression of cyanogen synthesis or by accelerating cyanogen turnover and volatilization. In 2003, cyanogen-free cultivars were generated by selective inhibition CYP79D1/D2 gene expression. The CYP79D1/D2 enzymes catalyze the first-dedicated step in cyanogen synthesis. Tissue-specific inhibition of CYP79D1/D2 expression in leaves lead to a 99 reduction in root cyanogen levels, indicating that the cyanogenic glycoside, linamarin, is synthesized in leaves and transported to roots. An alternative strategy to the reduce cyanogen content is to enhance cyanogen detoxification and cyanide volatilization during processing. This strategy has the advantage that cyanogen levels in unprocessed roots are not altered, potentially providing protection against herbivory and/or theft. To produce cultivars that promote rapid cyanide volatilization, hydroxynitrile lyase (HNL), which catalyzes the last step in cyanogenesis, was overexpressed in roots. Elevated HNL activity resulted in a 3-fold increase in the rate of cyanogen turnover. Importantly, the cyanogen content of the transformed and wild-type plants was identical, a potential benefit for farmers.

scholarly journals XMAP from Xenopus eggs promotes rapid plus end assembly of microtubules and rapid microtubule polymer turnover.

1994 ◽  
Vol 127 (4) ◽  
pp. 985-993 ◽  
Author(s):  
R J Vasquez ◽  
D L Gard ◽  
L Cassimeris
Keyword(s):  
Dynamic Instability ◽  
Fold Increase ◽  
Nucleation Site ◽  
Microtubule Assembly ◽  
Shortening Velocity ◽  
Threefold Increase ◽  
Cell Biol ◽  
Dic Microscopy

We have used video-enhanced DIC microscopy to examine the effects of XMAP, a Mr 215,000 microtubule-associated protein from Xenopus eggs (Gard, D.L., and M. W. Kirschner. 1987. J. Cell Biol. 105:2203-2215), on the dynamic instability of microtubules nucleated from axoneme fragments in vitro. Our results indicate that XMAP substantially alters the parameters of microtubule assembly at plus ends. Specifically, addition of 0.2 microM XMAP resulted in (a) 7-10-fold increase in elongation velocity, (b) approximately threefold increase in shortening velocity, and (c) near elimination of rescue (the switch from rapid shortening to elongation). Thus, addition of XMAP resulted in the assembly of longer, but more dynamic, microtubules from the plus ends of axonemes which upon catastrophe disassembled back to the axoneme nucleation site. In agreement with previous observations (Gard, D.L., and M. W. Kirschner. 1987. J. Cell Biol. 105:2203-2215), the effects of XMAP on the minus end were much less dramatic, with only a 1.5-3-fold increase in elongation velocity. These results indicate that XMAP, unlike brain MAPs, promotes both polymer assembly and turnover, and suggests that the interaction of XMAP with tubulin and the function of XMAP in vivo may differ from previously characterized MAPs.

Transmembrane K+, Na+, and Cl− permeability and conductance changes in the frog sartorius fibres following ouabain and zero [K+]o treatment

1987 ◽  
Vol 65 (5) ◽  
pp. 949-953 ◽  
Author(s):  
J. A. M. Hinke
Keyword(s):  
Fold Increase ◽  
Resting Potential ◽  
Small Decrease ◽  
Threefold Increase ◽  
Fibre Membrane ◽  
Ionic Fluxes ◽  
Conductance Changes ◽  
Whole Muscle ◽  
Frog Sartorius ◽  
Cl Permeability

Changes in the K+, Na+, and Cl− permeabilities (P) and conductances (g) of the intact frog sartorius fibre membrane following ouabain or zero [K+]o treatment were calculated from intrafibre activity and whole muscle electrolyte changes. Conventional equations relating ionic fluxes to resting potential (E), ionic gradient potential, and internal and external ionic activities were used. Both treatments produced a three- to five-fold increase in PNa and gNa. In addition, ouabain produced a fivefold increase in PK (and gK) and a small decrease in PCl (and gCl), whereas zero [K+]o produced a 60% reduction in PK, a 90% reduction in gK, and a threefold increase in PCl (and gCl). When the two treatments were combined, the P and g changes were paradoxical, suggesting that the ouabain-induced increase in gK and the zero [K+]o-induced decrease in gK were occurring but in different channels (or carriers). During ouabain treatment, E reflects mainly the transmembrane K+ gradient potential; during zero [K+]o treatment, E reflects mainly the Cl− gradient potential. Despite channel (or carrier) specificity, it appears that all three ionic permeabilities are altered during the perturbations.

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