The Mechanisms Involved in the Removal of Oxygen and Oxygen Radicals in the N2-Fixing Cyanobacterium Nostoc Muscorum

Author(s):  
Leah Karni ◽  
Elisha Tel-Or
Author(s):  
Tomoo Kawada ◽  
Michio Arakawa ◽  
Kenjiro Kambara ◽  
Takashi Segawa ◽  
Fumio Ando ◽  
...  

We know that alloxan causes increased-permeability pulmonary edema and that alloxan generates oxygen radicals (H2O2, O2−, ·OH) in blood. Therefore, we hypothesize that alloxan-generated oxygen radicals damage pulmonary capillary endothelial cells, and, possibly, alveolar epithelial cells as well. We examined whether oxygen radical scavengers, such as catalase or dimethylsulfoxide (DMSO), protected against alloxaninduced pulmonary edema.Five dogs in each following group were anesthetized: control group: physiological saline (20ml/kg/h); alloxan group: physiological saline + alloxan (75mg/kg) bolus injection at the beginning of the experiment; catalase group: physiological saline + catalase (150,000u/kg) bolus injection before injection of alloxan; DMSO group: physiological saline + DMSO (0.4mg/kg) bolus injection before alloxan. All dogs had 30-min baseline period and 3-h intervention period. Hemodynamics and circulating substances were measured at the specific points of time. At the end of intervention period, the dogs were killed and had the lungs removed for electron microscopic study and lung water measurement with direct destructive method.


2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  

2018 ◽  
Vol 69 (8) ◽  
pp. 2160-2166
Author(s):  
Elena Todirascu Ciornea ◽  
Gabriela Dumitru ◽  
Ion Sandu

The using of the pesticides of dinitrophenol type in agriculture has as consequence the major pollution of the environment, the plants taking these substances from the soil and once with these ones they reach in the human and animal organism where they product disequilibrium that are interpreted through the accumulation of free oxygen radicals with direct repercussions on the antioxidant enzyme�s synthesis intensification and on their activity�s increase. The apply of treatments on the barley seeds had significant effects regarding the seeds� germination, the young plants� growth, the oxidative stress enzymes� activity, but also regarding the content of photoassimilators and carotenoids pigments.


2020 ◽  
Vol 10 (3) ◽  
pp. 200-207
Author(s):  
Sabbir Ansari ◽  
Tasneem Fatma

Background: Poly-3-hydroxybutyrate (PHB) has attracted much consideration as biodegradable biocompatible polymer. This thermoplastic polymer has comparable material properties to polypropylene. Materials with more valuable properties may result from blending, a common practice in polymer science. Objective: In this paper, blends of PHB (extracted from cyanobacterium Nostoc muscorum NCCU- 442 with polyethylene glycol (PEG) were investigated for their thermal, tensile, hydrophilic and biodegradation properties. Methods: Blends were prepared in different proportions of PHB/PEG viz. 100/0, 98/2, 95/5, 90/10, 80/20, and 70/30 (wt %) using solvent casting technique. Morphological properties were investigated by using Scanning Electron Microscopy (SEM). Differential scanning calorimetry and thermogravimetric analysis were done for thermal properties determination whereas the mechanical and hydrophilic properties of the blends were studied by means of an automated material testing system and contact angle analyser respectively. Biodegradability potential of the blended films was tested as percent weight loss by mixed microbial culture within 60 days. Results: The blends showed good misciblity between PEG and PHB, however increasing concentrations of plasticizer caused morphological alteration as evidenced by SEM micrographs. PEG addition (10 % and above) showed significant alternations in the thermal properties of the blends. Increase in the PEG content increased the elongation at break ratio i.e enhanced the required plasticity of PHB. Rate of microbial facilitated degradation of the blends was greater with increasing PEG concentrations. Conclusion: Blending with PEG increased the crucial polymeric properties of cyanobacterial PHB.


Orinoquia ◽  
2020 ◽  
Vol 24 (1) ◽  
pp. 23-31
Author(s):  
Martha L. Ortiz-Moreno ◽  
Laura V. Solarte-Murillo ◽  
Karen X. Sandoval-Parra

Nostoc es un género de cianobacterias filamentosas con aplicaciones biotecnológicas en nutrición humana, biomedicina, biofertilización y producción comercial de biocombustibles. Sin embargo, su baja tasa de crecimiento en medio líquido por su naturaleza perifítica y su tendencia a formar biofilms, limita su producción a gran escala. Por lo tanto, el objetivo de este estudio fue analizar la producción de biomasa de Nostoc muscorum en un sistema hidropónico modificado. Para ello, se realizaron cultivos de N. muscorum por triplicado, en un sistema hidropónico bajo condiciones semicontroladas de temperatura (29 ± 13°C), intensidad lumínica (32 ± 54 μmol/m2/s) y fotoperiodo (12 horas), durante 23 días en un invernadero. La temperatura, el pH, la conductividad eléctrica y la producción de biomasa seca, fueron monitoreados en días alternados. Los resultados arrojaron que la producción máxima de biomasa seca fue de 0.2276 ± 0.0114 g/m2/día, y la productividad promedio fue de 0.4149 ± 0.0207 g/m2/día. A su vez, la producción máxima de biomasa de N. muscorum se obtuvo el día trece con 0.3185 ± 0.0159 g/m2/día. El análisis estadístico de correlación de variables ambientales no arrojó diferencias significativas, por lo que la temperatura, el pH y la conductividad eléctrica no afectaron la producción de biomasa de N. muscorum. Consecuentemente, el crecimiento algal fue influenciado por la fisiología de la especie. El soporte empleado en el sistema hidropónico permitió la adherencia y el desarrollo de la capa mucilaginosa de la cianobacteria sin requerir períodos de desecación como en los cultivos convencionales. El sistema hidropónico proporcionó un flujo continuo de nutrientes que podría prevenir el ataque de bacterias y hongos oportunistas, generando una alta tasa de crecimiento. De este modo, este sistema hidropónico representa una alternativa viable para la producción de biomasa de N. muscorum en condiciones de invernadero a gran escala.


2002 ◽  
Vol 282 (5) ◽  
pp. H1778-H1786 ◽  
Author(s):  
Haiying Fan ◽  
Baogui Sun ◽  
Qiuping Gu ◽  
Anne Lafond-Walker ◽  
Suyi Cao ◽  
...  

We investigated whether oxygen radicals generated during ischemia-reperfusion trigger postischemic inflammation in the heart. Closed-chest dogs underwent 90-min coronary artery occlusion, followed by 1- or 3-h reperfusion: 10 dogs received the cell-permeant oxygen radical scavenger N-(2-mercaptopropionyl)-glycine (MPG; 8 mg · kg−1 · h−1intracoronary) beginning 5 min before reperfusion, and 9 dogs received vehicle. Blood flow (microspheres), intercellular adhesion molecule (ICAM)-1 protein expression (immunohistochemistry), ICAM-1 gene activation (Northern blotting), nuclear DNA binding activity of nuclear factor (NF)-κb and AP-1 (electrophoretic mobility shift assays), and neutrophil (PMN) accumulation (myeloperoxidase activity) were assessed in myocardial tissue samples. ICAM-1 protein expression was high in vascular endothelium after ischemia-reperfusion but was markedly reduced by MPG. MPG treatment also markedly decreased expression of ICAM-1 mRNA and tissue PMN accumulation. Nuclear DNA binding activities of NF-κB and AP-1, increased by ischemia-reperfusion, were both markedly decreased by MPG at 1 h of reperfusion. However, by 3 h, AP-1 activity was only modestly reduced by MPG and NF-κB activity was not significantly different from ischemic-reperfused controls. These results suggest that oxygen radicals generated in vivo during reperfusion trigger early activation of NF-κb and AP-1, resulting in upregulation of the ICAM-1 gene in vascular endothelium and subsequent tissue accumulation of activated PMNs.


1983 ◽  
Vol 258 (11) ◽  
pp. 6855-6857 ◽  
Author(s):  
L Taylor ◽  
M J Menconi ◽  
P Polgar

1992 ◽  
Vol 267 (1) ◽  
pp. 597-601
Author(s):  
M A Shatos ◽  
J M Doherty ◽  
T Orfeo ◽  
J C Hoak ◽  
D Collen ◽  
...  

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 437
Author(s):  
Pavlína Hemerková ◽  
Martin Vališ

Amyotrophic lateral sclerosis (ALS) affects motor neurons in the cerebral cortex, brainstem and spinal cord and leads to death due to respiratory failure within three to five years. Although the clinical symptoms of this disease were first described in 1869 and it is the most common motor neuron disease and the most common neurodegenerative disease in middle-aged individuals, the exact etiopathogenesis of ALS remains unclear and it remains incurable. However, free oxygen radicals (i.e., molecules containing one or more free electrons) are known to contribute to the pathogenesis of this disease as they very readily bind intracellular structures, leading to functional impairment. Antioxidant enzymes, which are often metalloenzymes, inactivate free oxygen radicals by converting them into a less harmful substance. One of the most important antioxidant enzymes is Cu2+Zn2+ superoxide dismutase (SOD1), which is mutated in 20% of cases of the familial form of ALS (fALS) and up to 7% of sporadic ALS (sALS) cases. In addition, the proper functioning of catalase and glutathione peroxidase (GPx) is essential for antioxidant protection. In this review article, we focus on the mechanisms through which these enzymes are involved in the antioxidant response to oxidative stress and thus the pathogenesis of ALS and their potential as therapeutic targets.


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