Microencapsulated bio-markers for assessment of stress conditions in aquatic organisms in vivo

2012 ◽  
Vol 9 (7) ◽  
pp. 542-546 ◽  
Author(s):  
A Sadovoy ◽  
C Teh ◽  
V Korzh ◽  
M Escobar ◽  
I Meglinski
Keyword(s):  
Aquatic Organisms ◽  
Stress Conditions ◽  
Assessment Of Stress

Metallic Elements (Cu, Zn, Ni and Mn) Toxicity Effects Determination on a Fresh Water Fish Cyprinus Carpio (Common Carp) Laboratory Acclimatized

2017 ◽  
Vol 68 (8) ◽  
pp. 1711-1715
Author(s):  
Stefania Gheorghe ◽  
Gabriela Geanina Vasile ◽  
Cristina Gligor ◽  
Irina Eugenia Lucaciu ◽  
Mihai Nita Lazar
Keyword(s):  
Cyprinus Carpio ◽  
Aquatic Organisms ◽  
Control Fish ◽  
Toxicity Tests ◽  
Fresh Water Fish ◽  
Metallic Elements ◽  
Mn Toxicity ◽  
Vitro Effect

Metallic elements copper (Cu), zinc (Zn), nickel (Ni) and manganese (Mn) are some of the most commonly found in water and sediment samples collected from the Danube - Danube Delta. These elements are important as essential micronutrients, being normally present at low concentrations in biological organisms, but in high concentrations they become toxic with immediate and delayed effects. The role of this metals is still controversial, that�s why bioconcentration potential is so important. In this non-clinical study, we tested in vitro effect of heavy metals on carp, Cyprinus carpio, reproducing in vivo presence of Cu, Zn, Ni and Mn in the Romanian�s surface water. The toxicity tests were performed according to OECD 203 by detecting the average (50%) lethal concentration - LC50 on aquatic organisms (freshwater fish) at 96h. The results pointed out that, copper value for LC 50 at 96h was estimated as 3.4 mg/L (concentrations tested in the range of 0.1 - 4.75 mg/L). Zinc value for LC 50 at 96h was estimated as 20.8 mg/L (concentrations tested in the range of 0.028 � 29.6 mg/L). Nickel value for LC 50 at 96h was estimated as 40.1 mg/L (concentrations tested in the range of 0.008 - 84.5 mg/L). For manganese the mortality effects has recorded at LC 50 at 96h at estimated value higher than 53 mg/L (concentrations tested in the range of 0.04 - 53.9 mg/L). The accuracy of the testing metals concentration was insured by the screening of the dilution water, as well as food and control fish, acclimated in laboratory conditions.

Strategies to Protect Hematopoietic Stem Cells from Culture-Induced Stress Conditions

2020 ◽  
Vol 15 ◽  
Author(s):  
Fatima Aerts-Kaya
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Ex Vivo ◽  
Stress Conditions ◽  
Stress Factors ◽  
Hematopoietic Stem ◽  
Induced Stress

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.

Enhanced xenobiotic transporter expression in normal teleost hepatocytes: response to environmental and chemotherapeutic toxins

2001 ◽  
Vol 204 (2) ◽  
pp. 217-227
Author(s):  
J.A. Albertus ◽  
R.O. Laine
Keyword(s):  
Mammalian Cells ◽  
Cellular Localization ◽  
Fundulus Heteroclitus ◽  
Environmental Pollutants ◽  
Human Tumor ◽  
Aquatic Organisms ◽  
In Vivo Studies ◽  
Multixenobiotic Resistance

Many aquatic organisms are resistant to environmental pollutants, probably because their inherent multi-drug-resistant protein extrusion pump (pgp) can be co-opted to handle man-made pollutants. This mechanism of multixenobiotic resistance is similar to the mechanism of multidrug resistance exhibited in chemotherapy-resistant human tumor cells. In the present study, a variety of techniques were used to characterize this toxin defense system in killifish (Fundulus heteroclitus) hepatocytes. The cellular localization and activity of the putative drug efflux system were evaluated. In addition, in vitro and in vivo studies were used to examine the range of expression of this putative drug transporter in the presence of environmental and chemotherapeutic toxins. The broad range of pgp expression generally observed in transformed mammalian cells was found in normal cells of our teleost model. Our findings suggest that the expression of the pgp gene in the killifish could be an excellent indicator of toxin levels or stressors in the environment.

scholarly journals Slug deficiency enhances self-renewal of hematopoietic stem cells during hematopoietic regeneration

Blood ◽  
2010 ◽  
Vol 115 (9) ◽  
pp. 1709-1717 ◽  
Author(s):  
Yan Sun ◽  
Lijian Shao ◽  
Hao Bai ◽  
Zack Z. Wang ◽  
Wen-Shu Wu
Keyword(s):  
Hematopoietic Cells ◽  
Stress Conditions ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Steady State Condition ◽  
Therapeutic Benefits ◽  
Evolutionarily Conserved ◽  
Novel Strategy

Abstract Both extrinsic and intrinsic mechanisms tightly govern hematopoietic stem cell (HSC) decisions of self-renewal and differentiation. However, transcription factors that can selectively regulate HSC self-renewal division after stress remain to be identified. Slug is an evolutionarily conserved zinc-finger transcription factor that is highly expressed in primitive hematopoietic cells and is critical for the radioprotection of these key cells. We studied the effect of Slug in the regulation of HSCs in Slug-deficient mice under normal and stress conditions using serial functional assays. Here, we show that Slug deficiency does not disturb hematopoiesis or alter HSC homeostasis and differentiation in bone marrow but increases the numbers of primitive hematopoietic cells in the extramedullary spleen site. Deletion of Slug enhances HSC repopulating potential but not its homing and differentiation ability. Furthermore, Slug deficiency increases HSC proliferation and repopulating potential in vivo after myelosuppression and accelerates HSC expansion during in vitro culture. Therefore, we propose that Slug is essential for controlling the transition of HSCs from relative quiescence under steady-state condition to rapid proliferation under stress conditions. Our data suggest that inhibition of Slug in HSCs may present a novel strategy for accelerating hematopoietic recovery, thus providing therapeutic benefits for patients after clinical myelosuppressive treatment.

scholarly journals RNA atlas of human bacterial pathogens uncovers stress dynamics linked to infection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kemal Avican ◽  
Jehad Aldahdooh ◽  
Matteo Togninalli ◽  
A. K. M. Firoj Mahmud ◽  
Jing Tang ◽  
...  
Keyword(s):  
Stress Responses ◽  
Large Scale ◽  
Bacterial Pathogens ◽  
Stress Conditions ◽  
Altered Expression ◽  
Online Resource ◽  
Species Specific ◽  
In Vitro Stress

AbstractBacterial processes necessary for adaption to stressful host environments are potential targets for new antimicrobials. Here, we report large-scale transcriptomic analyses of 32 human bacterial pathogens grown under 11 stress conditions mimicking human host environments. The potential relevance of the in vitro stress conditions and responses is supported by comparisons with available in vivo transcriptomes of clinically important pathogens. Calculation of a probability score enables comparative cross-microbial analyses of the stress responses, revealing common and unique regulatory responses to different stresses, as well as overlapping processes participating in different stress responses. We identify conserved and species-specific ‘universal stress responders’, that is, genes showing altered expression in multiple stress conditions. Non-coding RNAs are involved in a substantial proportion of the responses. The data are collected in a freely available, interactive online resource (PATHOgenex).

scholarly journals Comparative Analysis of Mycobacterial Truncated Hemoglobin Promoters and thegroEL2Promoter in Free-Living and Intracellular Mycobacteria

2012 ◽  
Vol 78 (18) ◽  
pp. 6499-6506 ◽  
Author(s):  
Sunil V. Joseph ◽  
G. K. Madhavilatha ◽  
R. Ajay Kumar ◽  
Sathish Mundayoor
Keyword(s):  
Fluorescent Protein ◽  
Expression Profiles ◽  
Stress Conditions ◽  
Pcr Analysis ◽  
Truncated Hemoglobin ◽  
Oxygen Intermediates ◽  
Free Living ◽  
Content Type ◽  
Time Points

ABSTRACTThe success ofMycobacterium tuberculosisdepends on its ability to withstand and survive the hazardous environment inside the macrophages that are created by reactive oxygen intermediates, reactive nitrogen intermediates, severe hypoxia, low pH, and high CO2levels. Therefore, an effective detoxification system is required for the pathogen to persistin vivo. The genome ofM. tuberculosiscontains a new family of hemoproteins named truncated hemoglobin O (trHbO) and truncated hemoglobin N (trHbN), encoded by theglbOandglbNgenes, respectively, important in the survival ofM. tuberculosisin macrophages. Mycobacterial heat shock proteins are known to undergo rapid upregulation under stress conditions. The expression profiles of the promoters of these genes were studied by constructing transcriptional fusions with green fluorescent protein and monitoring the promoter activity in both free-living and intracellular milieus at different time points. WhereasglbNshowed an early response to the oxidative and nitrosative stresses tested,glbOgave a lasting response to lower concentrations of both stresses. At all time points and under all stress conditions tested,groEL2showed higher expression than both trHb promoters and expression of both promoters showed an increase while inside the macrophages. Real-time PCR analysis of trHb andgroEL2mRNAs showed an initial upregulation at 24 h postinfection. The presence of theglbOprotein imparted an increased survival toM. smegmatisin THP-1 differentiated macrophages compared to that imparted by theglbNandhsp65proteins. The comparative upregulation shown by both trHb promoters while grown inside macrophages indicates the importance of these promoters for the survival ofM. tuberculosisin the hostile environment of the host.

scholarly journals Corticosterone Levels in the Brain Show a Distinct Ultradian Rhythm but a Delayed Response to Forced Swim Stress

Endocrinology ◽  
2008 ◽  
Vol 149 (7) ◽  
pp. 3244-3253 ◽  
Author(s):  
Susanne K. Droste ◽  
Lotte de Groote ◽  
Helen C. Atkinson ◽  
Stafford L. Lightman ◽  
Johannes M. H. M. Reul ◽  
...  
Keyword(s):  
Pulse Frequency ◽  
Plasma Corticosterone ◽  
Stress Conditions ◽  
Male Rats ◽  
Ultradian Rhythm ◽  
Delayed Response ◽  
Corticosterone Concentration ◽  
Rapid Sampling ◽  
The Brain

Circulating corticosterone levels show an ultradian rhythm resulting from the pulsatile release of glucocorticoid hormone by the adrenal cortex. Because the pattern of hormone availability to corticosteroid receptors is of functional significance, it is important to determine whether there is also a pulsatile pattern of corticosterone concentration within target tissues such as the brain. Furthermore, it is unclear whether measurements of plasma corticosterone levels accurately reflect corticosterone levels in the brain. Given that the hippocampus is a principal site of glucocorticoid action, we investigated in male rats hippocampal extracellular corticosterone concentrations under baseline and stress conditions using rapid-sampling in vivo microdialysis. We found that hippocampal extracellular corticosterone concentrations show a distinct circadian and ultradian rhythm. The PULSAR algorithm revealed that the pulse frequency of hippocampal corticosterone is 1.03 ± 0.07 pulses/h between 0900 and 1500 h and is significantly higher between 1500 and 2100 h (1.31 ± 0.05). The hippocampal corticosterone response to stress is stressor dependent but resumes a normal ultradian pattern rapidly after the termination of the stress response. Similar observations were made in the caudate putamen. Importantly, simultaneous measurements of plasma and hippocampal glucocorticoid levels showed that under stress conditions corticosterone in the brain peaks 20 min later than in plasma but clears concurrently, resulting in a smaller exposure of the brain to stress-induced hormone than would be predicted by plasma hormone concentrations. These data are the first to demonstrate that the ultradian rhythm of corticosterone is maintained over the blood-brain barrier and that tissue responses cannot be reliably predicted from the measurement of plasma corticosterone levels.

Sign in / Sign up

Export Citation Format

Share Document