scholarly journals The effect of short-term kaempferol exposure on reactive oxygen levels and integrity of human (HL-60) leukaemic cells

2005 ◽  
Vol 1740 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Charles S. Bestwick ◽  
Lesley Milne ◽  
Lynn Pirie ◽  
Susan J. Duthie
Keyword(s):  
Reactive Oxygen ◽  
Short Term ◽  
Oxygen Levels ◽  
Leukaemic Cells

scholarly journals Mycobacterium tuberculosis Lsr2 Is a Global Transcriptional Regulator Required for Adaptation to Changing Oxygen Levels and Virulence

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
I. L. Bartek ◽  
L. K. Woolhiser ◽  
A. D. Baughn ◽  
R. J. Basaraba ◽  
W. R. Jacobs ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mouse Model ◽  
Oxygen Tension ◽  
Reactive Oxygen ◽  
Transcriptional Regulator ◽  
Oxygen Availability ◽  
World Population ◽  
Lung Pathology ◽  
Content Type ◽  
Oxygen Levels

ABSTRACTTo survive a dynamic host environment,Mycobacterium tuberculosismust endure a series of challenges, from reactive oxygen and nitrogen stress to drastic shifts in oxygen availability. The mycobacterial Lsr2 protein has been implicated in reactive oxygen defense via direct protection of DNA. To examine the role of Lsr2 in pathogenesis and physiology ofM. tuberculosis, we generated a strain deleted forlsr2. Analysis of theM. tuberculosisΔlsr2strain demonstrated that Lsr2 is not required for DNA protection, as this strain was equally susceptible as the wild type to DNA-damaging agents. Thelsr2mutant did display severe growth defects under normoxic and hyperoxic conditions, but it was not required for growth under low-oxygen conditions. However, it was also required for adaptation to anaerobiosis. The defect in anaerobic adaptation led to a marked decrease in viability during anaerobiosis, as well as a lag in recovery from it. Gene expression profiling of the Δlsr2mutant under aerobic and anaerobic conditions in conjunction with published DNA binding-site data indicates that Lsr2 is a global transcriptional regulator controlling adaptation to changing oxygen levels. The Δlsr2strain was capable of establishing an early infection in the BALB/c mouse model; however, it was severely defective in persisting in the lungs and caused no discernible lung pathology. These findings demonstrateM. tuberculosisLsr2 is a global transcriptional regulator required for control of genes involved in adaptation to extremes in oxygen availability and is required for persistent infection.IMPORTANCEM. tuberculosiscauses nearly two million deaths per year and infects nearly one-third of the world population. The success of this aerobic pathogen is due in part to its ability to successfully adapt to constantly changing oxygen availability throughout the infectious cycle, from the high oxygen tension during aerosol transmission to anaerobiosis within necrotic lesions. An understanding of howM. tuberculosiscopes with these changes in oxygen tension is critical for its eventual eradication. Using a mutation inlsr2, we demonstrate that the Lsr2 protein present in all mycobacteria is a global transcriptional regulator in control of genes required for adaptation to changes in oxygen levels.M. tuberculosislackinglsr2was unable to adapt to both high and very low levels of oxygen and was defective in long-term anaerobic survival. Lsr2 was also required for disease pathology and for chronic infection in a mouse model of TB.

scholarly journals To the Editor: Is the Serum Level of Reactive Oxygen Metabolites Appropriate for Evaluating Short-Term Surgical Stress of Patients Undergoing Colectomy?

2015 ◽  
Vol 100 (4) ◽  
pp. 770-772
Author(s):  
Fumihko Fujita ◽  
Yasuhiro Torashima ◽  
Mitsuhisa Takatsuki ◽  
Tamotsu Kuroki ◽  
Susumu Eguchi
Keyword(s):  
Colon Cancer ◽  
Laparoscopic Surgery ◽  
Free Radical ◽  
Pain Control ◽  
Surgical Stress ◽  
Reactive Oxygen ◽  
Reactive Oxygen Metabolites ◽  
Short Term ◽  
Anesthesia Group ◽  
Oxygen Metabolites

To demonstrate whether reactive oxygen and free radical measuring are appropriate to evaluate short-term surgical stress after laparoscopic colectomy. The subjects consisted of 22 cases (laparoscopic surgery, 16; and laparotomy, 6) that underwent surgery for colon cancer. The reactive oxygen metabolites (ROM) value in the blood were measured perioperatively. The average ROM values immediately prior to surgery, immediately following surgery, and 1 day following surgery were 360.1, 316.0, and 346.7 U.CARR, respectively, meaning that ROM declined immediately following surgery compared with immediately prior to surgery (P < 0.05), while a tendency was observed for these values to increase again 1 day following surgery. In the comparison of pain control 1 day following surgery, a significantly lower value was indicated in the epidural anesthesia group (n = 12) compared with the fentanyl intravenous injection group (n = 10). Moreover, no significant change was observed in the surgical stress level in a comparison of patient background items such as age, sex, and so forth, laparoscopic surgery, and laparotomy. The low-invasiveness of laparoscopic surgery was not indicated in the ROM value 1 day following surgery, probably because pain control offsets the level of surgical stress using this method.

scholarly journals The 2011 marine heat wave off southwest Australia

2012 ◽  
Vol 9 (2) ◽  
pp. 1691-1703 ◽  
Author(s):  
T. H. Rose ◽  
D. A. Smale ◽  
G. Botting
Keyword(s):  
Dissolved Oxygen ◽  
Heat Wave ◽  
Extreme Events ◽  
Algal Blooms ◽  
Multiple Use ◽  
Short Term ◽  
Oxygen Levels ◽  
Australian Coastline ◽  
Western Australian ◽  
Marine Heat Wave

Abstract. Over 2000 km of Western Australian coastline experienced a significant marine heat wave in February and March 2011. Seawater temperature anomalies of +2–4 °C were recorded at a number of locations and satellite-derived SSTs were the highest on record. Here, we present seawater temperatures from southwestern Australia and describe, in detail, the marine climatology of Cockburn Sound; a large, multiple-use coastal embayment. We compared temperature and dissolved oxygen levels in 2011 with data from routine monitoring conducted from 2002–2010. A significant warming event, 2–4 °C in magnitude, persisted for >8 weeks, and seawater temperatures at 10 to 20 m depth were significantly higher than those recorded in the previous 9 yr. Dissolved oxygen levels were depressed at most monitoring sites, being ~2 mg l−1 lower than usual in early March 2011. Ecological responses to short-term extreme events are poorly understood, but evidence from elsewhere along the Western Australian coastline suggests that the heat wave was associated with high rates of coral bleaching, fish, invertebrate and macroalgae mortalities, and algal blooms. However, more ecological information from Cockburn Sound and other multiple-use embayments is urgently needed. The 2011 heat wave provided insights into conditions that may become more prevalent in Cockburn Sound, and elsewhere, if the intensity and frequency of short-term extreme events increases as predicted.

scholarly journals In Vitro Study of the Toxicity Mechanisms of Nanoscale Zero-Valent Iron (nZVI) and Released Iron Ions Using Earthworm Cells

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2189
Author(s):  
Jaroslav Semerad ◽  
Natividad Isabel Navarro Pacheco ◽  
Alena Grasserova ◽  
Petra Prochazkova ◽  
Martin Pivokonsky ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Zero Valent Iron ◽  
Oxygen Species ◽  
Iron Ions ◽  
Short Term ◽  
Nanoscale Zero Valent Iron ◽  
Toxicity Mechanisms

During the last two decades, nanomaterials based on nanoscale zero-valent iron (nZVI) have ranked among the most utilized remediation technologies for soil and groundwater cleanup. The high reduction capacity of elemental iron (Fe0) allows for the rapid and cost-efficient degradation or transformation of many organic and inorganic pollutants. Although worldwide real and pilot applications show promising results, the effects of nZVI on exposed living organisms are still not well explored. The majority of the recent studies examined toxicity to microbes and to a lesser extent to other organisms that could also be exposed to nZVI via nanoremediation applications. In this work, a novel approach using amoebocytes, the immune effector cells of the earthworm Eisenia andrei, was applied to study the toxicity mechanisms of nZVI. The toxicity of the dissolved iron released during exposure was studied to evaluate the effect of nZVI aging with regard to toxicity and to assess the true environmental risks. The impact of nZVI and associated iron ions was studied in vitro on the subcellular level using different toxicological approaches, such as short-term immunological responses and oxidative stress. The results revealed an increase in reactive oxygen species production following nZVI exposure, as well as a dose-dependent increase in lipid peroxidation. Programmed cell death (apoptosis) and necrosis were detected upon exposure to ferric and ferrous ions, although no lethal effects were observed at environmentally relevant nZVI concentrations. The decreased phagocytic activity further confirmed sublethal adverse effects, even after short-term exposure to ferric and ferrous iron. Detection of sublethal effects, including changes in oxidative stress-related markers such as reactive oxygen species and malondialdehyde production revealed that nZVI had minimal impacts on exposed earthworm cells. In comparison to other works, this study provides more details regarding the effects of the individual iron forms associated with nZVI aging and the cell toxicity effects on the specific earthworms’ immune cells that represent a suitable model for nanomaterial testing.

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