scholarly journals PARTICIPATION OF A NON-RESPIRATORY FERROUS COMPLEX DURING MITOSIS IN ROOTS

1962 ◽  
Vol 13 (3) ◽  
pp. 373-381 ◽  
Author(s):  
J. E. Amoore
Keyword(s):  
Carbon Monoxide ◽  
Cytochrome Oxidase ◽  
Hydrogen Cyanide ◽  
Iron Complex ◽  
Cent Oxygen ◽  
Root Tips ◽  
Systematic Survey ◽  
Divalent State ◽  
Pea Root ◽  
Ferrous Complex

A systematic survey was undertaken, of the effects of carbon monoxide and hydrogen cyanide (in the presence of 20 per cent oxygen), in darkness and light, on the relative rates of respiration, mitosis, and interphase in pea root tips. The inhibition of respiration by carbon monoxide was light-sensitive, but the inhibition by hydrogen cyanide was light-stable. The inhibitions were presumably due to combination of the inhibitor with the iron of cytochrome oxidase, in its divalent and trivalent forms respectively. In contrast, the inhibitions of mitosis by both poisons proved to be light-sensitive. The light-sensitive inhibition of mitosis by carbon monoxide shows that an iron complex is responsible for the process. That the inhibition of mitosis by hydrogen cyanide is also light-reversible shows that, in contrast with cytochrome oxidase, the mitotic iron complex remains always in the divalent state. The relative affinities of the mitotic ferrous complex, in molar units, were 0.68 for CO/O2, and 0.37 for HCN/O2. The properties of the complex are analogous to, yet distinct from, Gastrophilus haemoglobin and reduced cytochrome oxidase. It is considered that the arrest of mitosis by oxygen lack, carbon monoxide, and hydrogen cyanide is definitely due to interference with this unidentified, non-respiratory ferrous complex.

scholarly journals OXYGEN TENSION AND THE RATES OF MITOSIS AND INTERPHASE IN ROOTS

1962 ◽  
Vol 13 (3) ◽  
pp. 365-371 ◽  
Author(s):  
J. E. Amoore
Keyword(s):  
Oxygen Tension ◽  
Cent Oxygen ◽  
Low Oxygen ◽  
Root Tips ◽  
Pea Root ◽  
Wide Range ◽  
Oxygen Tensions ◽  
Mitotic Figures

The object of this work was to determine the influence of a wide range of oxygen tensions upon the relative rates of respiration, mitosis, and interphase in pea root tips, compared with the normal rates of these processes in air. From the rates of disappearance of mitotic figures in excised tips kept in various oxygen tensions, the relative rates of mitosis were found to decrease gradually from 122 per cent in 100 per cent oxygen to 24 per cent in 0.0007 per cent oxygen. From the mitotic indices of intact seedlings, the relative rates of interphase were found to decrease sharply from 82 per cent in 10 per cent oxygen to 6 per cent in 5 per cent oxygen. The data on relative rates of respiration, mitosis, and interphase in root tips were compared, and it was shown that the three processes are perfectly distinct in their quantitative relationships to low oxygen tensions.

scholarly journals Analysis of Cytosine Methylation Pattern in Response to Water Deficit in Pea Root Tips

Plant Biology ◽  
2002 ◽  
Vol 4 (6) ◽  
pp. 694-699 ◽  
Author(s):  
M. Labra ◽  
A. Ghiani ◽  
S. Citterio ◽  
S. Sgorbati ◽  
F. Sala ◽  
...  
Keyword(s):  
Water Deficit ◽  
Cytosine Methylation ◽  
Methylation Pattern ◽  
Root Tips ◽  
Pea Root ◽  
Response To Water

Toxic Gases

2019 ◽  
Author(s):  
Stephanie T Weiss ◽  
Kathryn W Weibrecht
Keyword(s):  
Carbon Monoxide ◽  
Hydrogen Sulfide ◽  
Hyperbaric Oxygen ◽  
Hydrogen Cyanide ◽  
Correct Diagnosis ◽  
Normobaric Oxygen ◽  
Levels Of Care ◽  
Cyanide Antidote ◽  
Gas Poisoning ◽  
Toxic Gas

This review looks at the potential causes, diagnoses, and possible treatments for three asphyxiant gases: carbon monoxide, hydrogen cyanide, and hydrogen sulfide, Exposure to these gases can lead to central nervous system depression, unconsciousness, and death due to tissue hypoxia. These gases are among the most common causes of fatalities related to toxic gas poisoning, with carbon monoxide responsible for 36% and hydrogen sulfide 7.7%. It is necessary to remove victims affected by poisoning immediately from the source of the toxic gas, administer oxygen, and assess their stability. As symptoms of these gases can differ widely, ranging from broad and unspecific to highly morbid, and may require different levels of care, the correct diagnosis should also rely on inferences from the patient history and the context of the admission, including evidence of fire and chemical reactions. Normobaric oxygen and hyperbaric oxygen are the two main treatments for carbon monoxide, although studies have been inconclusive in regards to the effectiveness of hyperbaric oxygen. The Cyanokit (containing hydroxocobalamin) is considered to be more effective for hydrogen cyanide when compared with the Cyanide Antidote Kit due to the former’s low toxicity and high effectiveness. Hydrogen sulfide is often used as a suicide agent, the mortality of which is close to 100%. Figures show the mechanisms by which the asphyxiant gases carry out their negative effects on the human body. Tables show the half-life of carboxyhemoglobin with oxygen therapy and a comparison between the Cyanide Antidote Kit and the Cyanokit. This review contains 3 figures, 13 tables, and 44 references.  Keywords: Inhalation, poisoning, carbon monoxide, cyanide, methemoglobin, carboxyhemoglobin, hydrogen sulfide, smoke

scholarly journals Oxidation Treatment of Dilute Hydrogen Cyanide. On the Formation of Carbon Monoxide and Carbon Dioxide.

1993 ◽  
Vol 19 (3) ◽  
pp. 540-543
Author(s):  
Makoto Akiyoshi ◽  
Satoru Hisaki ◽  
Takashi Fukuda ◽  
Eiji Obata ◽  
Koji Ando
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Hydrogen Cyanide ◽  
Oxidation Treatment
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