Reduction of ferrylmyoglobin in rat diaphragm

1990 ◽  
Vol 259 (6) ◽  
pp. C995-C997 ◽  
Author(s):  
L. Eddy ◽  
A. Arduini ◽  
P. Hochstein
Keyword(s):  
Skeletal Muscle ◽  
Hydrogen Peroxide ◽  
Muscle Damage ◽  
The Other ◽  
Rat Diaphragm ◽  
Rapid Reduction ◽  
Other Hand ◽  
Transmission Spectroscopy

The oxidation of myoglobin was monitored by transmission spectroscopy in isolated, superfused preparations of rat diaphragms. In its deoxygenated form, during anoxia, myoglobin was oxidized by adding hydrogen peroxide (1.0 mM) to its ferryl form (FeIV). On the other hand, peroxide-induced formation of ferrylmyoglobin was not observed when the perfusate contained oxygen. Ferrylmyoglobin was visualized after its derivatization with Na2S to form sulfmyoglobin. Depending on the time of addition, ascorbate (4.0 mM) or ergothioneine (2.0 mM) either prevented the formation of or dissipated ferrylmyoglobin. These agents are known to be reductants of this hypervalent form of myoglobin. In addition to providing the first demonstration of ferrylmyoglobin in skeletal muscle, these observations are consistent with the concept that oxidation of myoglobin to hypervalent states might be an important event in the initiation of muscle damage associated with anoxia and reoxygenation. The rapid reduction of myoglobin would prevent peroxidatic alterations of essential cellular constituents by ferrylmyoglobin.

Decontamination Strategies for Filtering Facepiece Respirators (FFRs) in Healthcare Organizations: A Comprehensive Review

2020 ◽  
Author(s):  
Ashok Kumar Jena ◽  
Jitendra Sharan
Keyword(s):  
Hydrogen Peroxide ◽  
Ethylene Oxide ◽  
Time Use ◽  
Ultraviolet Irradiation ◽  
The Other ◽  
Limited Time ◽  
Healthcare Organizations ◽  
Comprehensive Review ◽  
Dry Heat ◽  
Other Hand

Abstract Filtering facepiece respirators (FFRs) are made for one-time use. A massive shortage of FFRs is widespread during pandemic events and has forced many healthcare organizations to decontaminate them and re-use for a limited time. Many decontamination methods have been proposed for the decontamination of FFRs. This review highlights various aspects of decontamination methods available in the literature. Among various methods available, vaporized hydrogen peroxide, ultraviolet irradiation, and dry heat seem to be the most promising decontaminants for FFRs. On the other hand, microwave, bleach, ethylene oxide, alcohol, hydrogen peroxide liquid, sanitizing wipes, and soap and water are not recommended methods for FFR decontamination.

scholarly journals The Effects of Hydrogen Peroxide on Plant Growth, Mineral Accumulation, as Well as Biological and Chemical Properties of Ficus deltoidea

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 599 ◽  
Author(s):  
Nik Nurnaeimah ◽  
Nashriyah Mat ◽  
Khamsah Suryati Mohd ◽  
Noor Afiza Badaluddin ◽  
Nornasuha Yusoff ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Chemical Properties ◽  
The Other ◽  
Mineral Nutrient ◽  
Flavonoid Content ◽  
Ficus Deltoidea ◽  
Other Hand ◽  
Mineral Accumulation ◽  
And Chemical Properties

Hydrogen peroxide (H2O2) is defined as a reactive oxygen species (ROS), able to cause damage to a variety of cellular structures. On the other hand, recent work has demonstrated that H2O2 can also act as a potent signaling molecule that mediates various physiological and biochemical processes in plants. This study was carried out to investigate the effects of H2O2 on the growth, mineral nutrient accumulation, as well as the biologic and chemical properties of Ficus deltoidea var. deltoidea. F. deltoidea plants were spray-treated with 0- (control), 8-, 16-, 30- and 60-mM H2O2 under field conditions. Plant height, leaf area, chlorophyll content, net photosynthetic rate, stomatal conductance and quantum yield of the F. deltoidea plants significantly increased after treatment with 16 and 30-mM H2O2. The results indicate that 60-mM H2O2 increased the accumulation of arsenic, iron and sodium content in the leaves of F. deltoidea. On the other hand, 8-mM H2O2 significantly enhanced the accumulation of arsenic, iron, calcium and potassium content in the syconium of F. deltoidea plants. In addition, H2O2 treatment did not produce any significant effects on antimony and magnesium accumulation in the leaves or the syconium of F. deltoidea plants. The results show that the F. deltoidea plant has strong antidiabetic properties and its α-glucosidase activity increased in treated plants compared to standard acarbose. Hydrogen peroxide, particularly in concentrations of 16 and 30 mM, increased the antioxidant activity, total phenolic and flavonoid content and the vitexin and isovitexin content. There was a positive correlation between antioxidant activity with total phenol and total flavonoid content in H2O2-treated plants. The quantitative analysis by HPTLC indicates that the amount of vitexin and isovitexin increased with the higher concentrations of H2O2. From this study, it can be concluded that spraying 16 and 30-mM H2O2 once a week enhances growth, mineral accumulation and stimulates bioactive compounds of the F. deltoidea plants.

scholarly journals STUDIES ON OXIDATION AND REDUCTION BY PNEUMOCOCCUS

1924 ◽  
Vol 39 (5) ◽  
pp. 745-755 ◽  
Author(s):  
Oswald T. Avery ◽  
James M. Neill
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Oxygen ◽  
Hemolytic Activity ◽  
Active Agent ◽  
Organic Peroxide ◽  
Cell Extract ◽  
The Other ◽  
Cell Extracts ◽  
Other Hand ◽  
The Stability

In the present work on oxidation and reduction by sterile extracts of pneumococcus, the preparations employed contain among other constituents, a hemolytic substance the properties of which have been described by Cole (1, 2) in his studies on pneumococcus hemotoxin. Pneumococcus extracts prepared by the methods described are actively hemolytic, 0.005 cc. of extract causing complete lysis of 2.5 cc. of a 1 per cent suspension of red cells from rabbit blood. This hemolytic property of pneumococcus extracts is destroyed by 10 minutes exposure to 55°C. When pneumotoxin-containing extracts are protected from the action of molecular oxygen, their hemolytic activity remains unimpaired for considerable periods of time. In the presence of air, on the other hand, the stability of the hemolytic substance depends upon whether the particular type of extract contains a "complete" or "incomplete" oxidation-reduction system. Sterile broth extracts of unwashed pneumococci are reactive with molecular oxygen, and as a result of this union peroxide is formed whenever these extracts are exposed to air. The hemolytic activity of "complete" extracts of this type is rapidly decreased and finally destroyed in the presence of molecular oxygen. On the other hand, the "incomplete" type of extract prepared by saline extraction of washed pneumococci may be exposed to air with little or no loss of hemolytic power. This "incomplete" washed cell extract, unless reactivated, does not undergo autoxidation in the presence of air; under these circumstances peroxide is not formed and the hemolytic activity of this type of extract is not impaired by exposure to air. The stability of the hemolytic agent in the "incomplete" type of extract is evidence that this substance is itself not reactive with or affected by molecular oxygen, even in the presence of the cell enzymes. The destruction of the same hemolytic substance in extracts capable of undergoing autoxidation may be ascribed to the action of some peroxide formed by the union of molecular oxygen with easily oxidized or autoxidizable substances of the extract. It is now known that a peroxide, having the reactions of hydrogen peroxide, accumulates in sterile pneumococcus extracts during oxidation. It has been shown in the present study that the addition of preformed hydrogen peroxide destroys the hemolytic activity of pneumococcus extracts, although higher concentrations were required than were detected in oxidized extracts themselves. These facts and the known action of superoxides in analogous types of reaction make it seem not unlikely that the active agent in the destruction of pneumotoxin in oxidized cell extracts may be a peroxide; either hydrogen peroxide or some higher organic peroxide formed during autoxidation of the extract.

Improvement in the SiO2/4H-SiC Interfacial Region by Thermal Treatments with Hydrogen Peroxide

2012 ◽  
Vol 717-720 ◽  
pp. 753-756
Author(s):  
Eduardo Pitthan ◽  
Silma A. Corrêa ◽  
Rodrigo Palmieri ◽  
Gabriel Vieira Soares ◽  
Henri I. Boudinov ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
The Other ◽  
Significant Alteration ◽  
Interfacial Region ◽  
Thermal Treatments ◽  
Other Hand

The effect of sequential thermal treatments with growth/removal steps of SiO2 films intercalated with hydrogen peroxide treatments on the SiO2/4H-SiC interfacial region thickness were investigated on both Si and C faces. In the Si face case, samples that were submitted to more H2O2 treatments presented thinner interfacial region thicknesses. In the C face case, on the other hand, no significant alteration in this region was observed.

CORTISOLWIRKUNGEN AUF DEN PROTEINUND ENERGIESTOFFWECHSEL IN DER PERIPHERIE

1968 ◽  
Vol 59 (2) ◽  
pp. 193-202
Author(s):  
H. Kröner ◽  
W. Staib
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Energy Consumption ◽  
Connective Tissue ◽  
Oxidative Metabolism ◽  
The Other ◽  
Other Hand ◽  
Inhibition Of Protein Synthesis ◽  
Short Time ◽  
Rna And Dna

ABSTRACT By measuring protein, RNA and DNA in skeletal muscle and spleen we were unable to demonstrate an enhanced catabolism due to cortisol. On the other hand we could demonstrate a reduced anabolism by diminished incorporation of 14C labelled leucin in protein of muscle, spleen and skin. Simultaneously an increase of ATP and an equivalent decrease of ADP were found in connective tissue, which were regarded as a consequence of reduced energy consumption. In skeletal muscle a decrease of energy consumption due to cortisol was only indirect demonstrable by reduced glycolysis when oxidative metabolism was eliminated for a short time. It seems obvious, that inhibition of protein synthesis causes the diminished energy consumption.

Capillary Diffusion Distances - Their Importance for Cardiac and Skeletal Muscle Performance

Physiology ◽  
1988 ◽  
Vol 3 (4) ◽  
pp. 134-138 ◽  
Author(s):  
O Hudlicka ◽  
S Egginton ◽  
MD Brown
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Delivery ◽  
The Other ◽  
Muscle Performance ◽  
Important Indicator ◽  
Capillary Supply ◽  
Other Hand ◽  
Potential Oxygen ◽  
Skeletal Muscle Performance

Intercapillary distances are considered an important indicator of oxygen delivery to tissue. In this article, various indices of capillary supply to cardiac and skeletal muscle are related to the performance of the same organ. It becomes apparent that there are several situations in which maximal muscle performance is not improved, although intercapillary distances are shortened, implying greater potential oxygen delivery. On the other hand, there are also cases where performance is improved without any change in capillary supply.

THE UPTAKE OF 17β-OESTRADIOL IN BREAST TISSUE OF FEMALE RATS

1968 ◽  
Vol 58 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Sten Sander
Keyword(s):  
Skeletal Muscle ◽  
Direct Effect ◽  
Breast Tissue ◽  
The Other ◽  
Female Rats ◽  
Competitive Effect ◽  
Simultaneous Injection ◽  
Other Hand ◽  
Uptake Pattern ◽  
Wet Weight

ABSTRACT The uptake of radioactivity in breast tissue after the injection of tritiated oestradiol in rats has been studied. The breast tissue accumulates more radioactivity per unit wet weight than skeletal muscle and fat, for at least 4 hours. The uptake of radioactivity does not, however, reach the high levels observed in the uterus. On the other hand, the uptake pattern found in the breast tissue corresponds to previous findings in other oestrogen responsive organs. The uptake of radioactivity by breast tissue in castrated rats is higher than in control animals with their ovaries intact. It is also found that simultaneous injection of non-radioactive oestradiol reduces the uptake of radioactivity. These findings may be explained as a competitive effect between non-labelled and labelled oestradiol. The accumulation of oestradiol observed may be consistent with the idea of a direct effect on breast tissue.

scholarly journals Immunohistochemical localization of two proteinases in skeletal muscle.

1983 ◽  
Vol 31 (6) ◽  
pp. 827-830 ◽  
Author(s):  
W T Stauber ◽  
V Fritz ◽  
B Dahlmann ◽  
H Reinauer
Keyword(s):  
Skeletal Muscle ◽  
Mast Cells ◽  
Soleus Muscle ◽  
Extensor Digitorum Longus ◽  
Muscle Fibers ◽  
Immunohistochemical Localization ◽  
Extensor Digitorum ◽  
The Other ◽  
Other Hand

Immunohistochemical localizations of cytosolic and myofibrillar proteinases revealed a different myofiber locale for each enzyme in the rat. Although the cytosolic proteinase was most pronounced in mast cells within soleus and extensor digitorum longus (EDL) muscles, certain fibers of the EDL were also positive. The myofibrillar proteinase, on the other hand, appeared to be present in interstitial spaces between muscle fibers in the EDL but conversely present in some fibers of the soleus muscle.

Detoxification of Citrinin and Ochratoxin A by Hydrogen Peroxide

1994 ◽  
Vol 77 (3) ◽  
pp. 631-637 ◽  
Author(s):  
Sophie G Fouler ◽  
Alka B Trivedi ◽  
Naofumi Kitabatake
Keyword(s):  
Hydrogen Peroxide ◽  
Ochratoxin A ◽  
Hela Cells ◽  
Room Temperature ◽  
The Other ◽  
Toxic Compound ◽  
Other Hand ◽  
Alkaline Conditions

Abstract The effects of hydrogen peroxide on citrinin and ochratoxin A toxicity were examined using HeLa cells. The citrinin was completely detoxified by prior incubation with 0.05% hydrogen peroxide for 30 min at room temperature, and the toxic compound(s) that resulted from heating citrinin at 100°C were also detoxified upon reheating it with hydrogen peroxide. On the other hand, ochratoxin A was not detoxified by hydrogen peroxide at room temperature, but its toxicity was reduced by heating ochratoxin A with hydrogen peroxide under alkaline conditions.

scholarly journals A comparison of overshoot modelling with observations of polar mesospheric summer echoes at radar frequencies of 56 and 224 MHz

2015 ◽  
Vol 33 (6) ◽  
pp. 737-747 ◽  
Author(s):  
O. Havnes ◽  
H. Pinedo ◽  
C. La Hoz ◽  
A. Senior ◽  
T. W. Hartquist ◽  
...  
Keyword(s):  
No Reduction ◽  
The Other ◽  
Rapid Reduction ◽  
Electron Heating ◽  
Vhf Radar ◽  
Radar Observations ◽  
Other Hand ◽  
Initial Reduction ◽  
Summer Echoes ◽  
Identical Behaviour

Abstract. We have compared radar observations of polar mesospheric summer echoes (PMSEs) modulated by artificial electron heating, at frequencies of 224 MHz (EISCAT VHF) and 56 MHz (MORRO). We have concentrated on 1 day of observation, lasting ~ 3.8 h. The MORRO radar, with its much wider beam, observes one or more PMSE layers all the time while the VHF radar observes PMSEs in 69% of the time. Statistically there is a clear difference between how the MORRO and the VHF radar backscatter reacts to the heater cycling (48 s heater on and 168 s heater off). While MORRO often reacts by having its backscatter level increased when the heater is switched on, as predicted by Scales and Chen (2008), the VHF radar nearly always sees the "normal" VHF overshoot behaviour with an initial rapid reduction of backscatter. However, in some heater cycles we do see a substantial recovery of the VHF backscatter after its initial reduction to levels several times above that just before the heater was switched on. For the MORRO radar a recovery during the heater-on phase is much more common. The reaction when the heater was switched off was a clear overshoot for nearly all VHF cases but less so for MORRO. A comparison of individual curves for the backscatter values as a function of time shows, at least for this particular day, that in high layers above ~ 85 km height, both radars see a reduction of the backscatter as the heater is switched on, with little recovery during the heater-on time. These variations are well described by present models. On the other hand, the backscatter in low layers at 81–82 km can be quite different, with modest or no reduction in backscatter as the heater is switched on, followed by a strong recovery for both radars to levels several times above that of the undisturbed PMSEs. This simultaneous, nearly identical behaviour at the two very different radar frequencies is not well described by present modelling.

Sign in / Sign up

Export Citation Format

Share Document