A PDMS-Based Interdigitated Platform for Trophoblast Invasion Study Under Oxygen Stress Conditions

2021 ◽  
Author(s):  
Hyeran Cho ◽  
Ahmed Fuwad ◽  
Gun Ko ◽  
Gi Jin Kim ◽  
Tae-Joon Jeon ◽  
...  
Keyword(s):  
Stress Conditions ◽  
Trophoblast Invasion ◽  
Oxygen Stress

Alterations in the formation of lipopolysaccharide and membrane vesicles on the surface of Pseudomonas aeruginosa PAO1 under oxygen stress conditions

Microbiology ◽  
2003 ◽  
Vol 149 (10) ◽  
pp. 2789-2795 ◽  
Author(s):  
W. Sabra ◽  
H. Lünsdorf ◽  
A.-P. Zeng
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Vesicles ◽  
Electron Microscopic Examination ◽  
Surface Characteristics ◽  
Opportunistic Pathogen ◽  
Stress Conditions ◽  
Electron Microscopic ◽  
Oxygen Stress ◽  
Relative Expression ◽  
Hydrophilic Surfaces

It has been postulated that phenotypic variation in the relative expression of two chemically distinct types of lipopolysaccharide (LPS), a serotype-specific LPS (B-band) and a common antigen LPS (A-band) in Pseudomonas aeruginosa is an important mechanism enabling this opportunistic pathogen to alter its surface characteristics to mediate adhesion and to survive under extreme conditions. To further investigate this, the relative expression levels of the two distinct types of LPS in P. aeruginosa PAO1 were investigated with cells grown in a chemostat at different dissolved oxygen tensions (pO2). The A-band LPS was constitutively expressed as pO2 was increased from nearly zero to 350 % of air saturation. In contrast, the B-band LPS showed a remarkable increase with increased pO2. Almost no B-band LPS was found in cells grown at a pO2 of less than 3 % of air saturation. Electron microscopic examination of cells revealed increased formation of membrane vesicles (MVs) on the surface of P. aeruginosa PAO1 under oxygen stress conditions. The toxicity of the supernatant of P. aeruginosa cultures to the growth of a hybridoma cell line significantly increased in samples taken from oxygen-stressed steady-state cultures. Furthermore, studies of adhesion in a continuous-flow biofilm culture revealed an increased adhesiveness for hydrophilic surfaces in P. aeruginosa PAO1 grown at a higher pO2. The oxygen-dependent alterations of cell-surface components and properties observed in this work provide a possible explanation for the emergence of P. aeruginosa lacking the B-band LPS in chronically infected cystic fibrosis patients. The results are also useful for understanding the processes involved in the formation of MVs in P. aeruginosa.

The over-expression of phasin and regulator genes promoting the synthesis of polyhydroxybutyrate in Cupriavidus necator H16 under non-stress conditions

2021 ◽  
Author(s):  
Ruohao Tang ◽  
Xiaowei Peng ◽  
Caihong Weng ◽  
Yejun Han
Keyword(s):  
Bacterial Growth ◽  
Stress Condition ◽  
Stress Conditions ◽  
Comparative Transcriptome ◽  
Low Oxygen ◽  
Oxygen Stress ◽  
Percentage Content ◽  
Over Expression ◽  
Phb Production ◽  
Regulator Genes

Cupriavidus necator H16 is an ideal strain for polyhydroxybutyrate (PHB) production from CO 2 . Low-oxygen-stress can induce PHB synthesis in C. necator H16 while reducing bacterial growth under chemoautotrophic culture. The optimum growth and PHB synthesis of C. necator H16 cannot be achieved simultaneously, which restricts PHB production. The present study was initiated to address the issue through comparative transcriptome and gene function analysis. Firstly, the comparative transcriptome of C. necator H16 chemoautotrophically cultured under low-oxygen-stress and non-stress conditions was studied. Three types of transcription different genes were discovered: PHB enzymatic synthesis, PHB granulation, and regulators. Under low-oxygen-stress condition, acetoacetyl-CoA reductase gene phaB2 , PHB synthase gene phaC2 , phasins genes phaP1 and phaP2 , regulators genes uspA and rpoN were up-regulated 3.0, 2.5, 1.8, 2.7, 3.5, 1.6 folds, respectively. Secondly, the functions of up-regulated genes and their applications in PHB synthesis were further studied. It was found that the over-expression of phaP1 , phaP2 , uspA , and rpoN can induce PHB synthesis under non-stress condition, while phaB2 and phaC2 have no significant effect. Under the optimum condition, PHB percentage content in C. necator H16 was respectively increased by 37.2%, 28.4%, 15.8%, and 41.0% with the over-expression of phaP1 , phaP2 , uspA , and rpoN , and the corresponding PHB production increased by 49.8%, 42.9%, 47.0%, and 77.5% under non-stress chemoautotrophic conditions. Similar promotion by phaP1 , phaP2 , uspA , and rpoN was observed in heterotrophically cultured C. necator H16. The PHB percentage content and PHB production were respectively increased by 54.4% and 103.1% with the over-expression of rpoN under non-stress heterotrophic conditions. Importance Microbial fixation of CO 2 is an effective way to reduce greenhouse gases. Some microbes such as C. necator H16 usually accumulate PHB when they grow under stress. Low-oxygen-stress can induce PHB synthesis when C. necator H16 is autotrophically cultured with CO 2 , H 2 , and O 2 , while under stress, growth is restricted and total PHB yield is reduced. Achieving the optimal bacterial growth and PHB synthesis at the same time is an ideal condition for transforming CO 2 into PHB by C. necator H16. The present study was initiated to clarify the molecular basis of low-oxygen-stress promoting PHB accumulation and to realize the optimal PHB production by C. necator H16. Genes up-regulated under non-stress conditions were identified through comparative transcriptome analysis and over-expression of phasin and regulator genes were demonstrated to promote PHB synthesis in C. necator H16.

scholarly journals Glial cell line-derived neurotrophic factor as a new approach for functional neural networks reorganization in oxygen stress conditions

2016 ◽  
Vol 10 ◽  
Author(s):  
Vedunova Maria ◽  
Mishchenko Tatiana ◽  
Shishkina Tatiana ◽  
Mitroshina Elena ◽  
Shirokova Olesya ◽  
...  
Keyword(s):  
Neural Networks ◽  
Cell Line ◽  
Glial Cell ◽  
Neurotrophic Factor ◽  
Stress Conditions ◽  
Oxygen Stress ◽  
New Approach

Self-Injurious Behavior vs. Nonsuicidal Self-Injury

Crisis ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Christopher M. Bloom ◽  
Shareen Holly ◽  
Adam M. P. Miller
Keyword(s):  
Positive Reinforcement ◽  
Empirical Investigation ◽  
High Stress ◽  
Animal Research ◽  
Stress Conditions ◽  
Human Populations ◽  
Pharmacological Interventions ◽  
Self Injury ◽  
Cns Stimulant ◽  
Nonsuicidal Self Injury

Background: Historically, the field of self-injury has distinguished between the behaviors exhibited among individuals with a developmental disability (self-injurious behaviors; SIB) and those present within a normative population (nonsuicidal self-injury; NSSI),which typically result as a response to perceived stress. More recently, however, conclusions about NSSI have been drawn from lines of animal research aimed at examining the neurobiological mechanisms of SIB. Despite some functional similarity between SIB and NSSI, no empirical investigation has provided precedent for the application of SIB-targeted animal research as justification for pharmacological interventions in populations demonstrating NSSI. Aims: The present study examined this question directly, by simulating an animal model of SIB in rodents injected with pemoline and systematically manipulating stress conditions in order to monitor rates of self-injury. Methods: Sham controls and experimental animals injected with pemoline (200 mg/kg) were assigned to either a low stress (discriminated positive reinforcement) or high stress (discriminated avoidance) group and compared on the dependent measures of self-inflicted injury prevalence and severity. Results: The manipulation of stress conditions did not impact the rate of self-injury demonstrated by the rats. The results do not support a model of stress-induced SIB in rodents. Conclusions: Current findings provide evidence for caution in the development of pharmacotherapies of NSSI in human populations based on CNS stimulant models. Theoretical implications are discussed with respect to antecedent factors such as preinjury arousal level and environmental stress.

Light and oxygen stress in Spirulina platensis (cyanobacteria) grown outdoors in tubular reactors

1996 ◽  
Vol 97 (1) ◽  
pp. 175-179 ◽  
Author(s):  
Avigad Vonshak ◽  
Giuseppe Torzillo ◽  
Paola Accolla ◽  
Luisa Tomaselli
Keyword(s):  
Spirulina Platensis ◽  
Oxygen Stress ◽  
Tubular Reactors

Flavonoid profiling by LC-MS IN 14 – 3-3ν knockout mutants of Arabidopsis thaliana during drought stress conditions

Planta Medica ◽  
2014 ◽  
Vol 80 (10) ◽  
Author(s):  
F Nabbie ◽  
O Shperdheja ◽  
J Millot ◽  
J Lindberg ◽  
B Peethambaran
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Stress Conditions ◽  
Knockout Mutants

STRESS PADA LANSIA MENJADI FAKTOR PENYEBAB DAN AKIBAT TERJADINYA PENYAKIT

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Nur Hidaayah
Keyword(s):  
Drinking Water ◽  
Free Radicals ◽  
The Elderly ◽  
The State ◽  
Young Age ◽  
Fresh Fruit ◽  
Stress Conditions ◽  
Harmful Substances ◽  
Available Resources

Stress conditions in the elderly means an imbalance condition of biological, psychological, and social are closely related to the response to the threats and dangers faced by the elderly. Pressure or interference that is not fun is usually created when the elderly see a mismatch between the state and the 3 systems available resources. Maintenance actions that need to be done there are 2 types, namely : prevention of exposure to a stressor (precipitation factor) and serious treatment of the imbalance condition/ illness (precipitation factor). Prevention includes: sports, hobbies, friendship, avoid eating foods high in free radicals and harmful substances, sex and setting arrangements adequate rest. Habits of the above if done at a young age to avoid exposure to stress in the elderly. Treatment of the imbalance condition / illness, include : drinking water, meditation, eating fresh fruit, and adequate rest.

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