scholarly journals Increased biofilm formation ability in Klebsiella pneumoniae after short‐term exposure to a simulated microgravity environment

2016 ◽  
Vol 5 (5) ◽  
pp. 793-801 ◽  
Author(s):  
Haili Wang ◽  
Yanfeng Yan ◽  
Dan Rong ◽  
Jing Wang ◽  
Hongduo Wang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Microgravity Environment ◽  
Short Term ◽  
Short Term Exposure

scholarly journals Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Space Station ◽  
Biological Characteristics ◽  
Microgravity Environment ◽  
Short Term ◽  
Future Space ◽  
Short Term Exposure

Background: Microbes threaten human health in space exploration. Studies have shown that P. mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis. Objective: This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm and its related mechanism. Methods: The strange deformable rods were cultured continuously for 14 days under the microgravity simulated by (HARVs) in a high- aspect ratio vessels. The morphology, growth rate, metabolism and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype. Results: The growth rate, metabolic ability and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability and biofilm forming ability may be caused by the down-regulation of related genes (pstS,sodB and fumC). Conclusion: It provides a certain reference for the prevention and treatment of P. mirabilis infection in the future space station by exploring the effect of simulated microgravity exposure on P. mirabilis.

scholarly journals Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Microgravity Condition ◽  
Biological Characteristics ◽  
Space Environment ◽  
Microgravity Environment ◽  
Constructive Method ◽  
Short Term Exposure

Abstract Background Microbes threaten human health in space exploration. Studies have shown that Proteus mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis. Objective This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm, and its related mechanism. Methods The strange deformable rods were cultured continuously for 14 days under microgravity simulated in high-aspect rotating vessels (HARVs). The morphology, growth rate, metabolism, and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype. Results The growth rate, metabolic ability, and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability, and biofilm forming ability may be caused by the downregulation of related genes (pstS, sodB, and fumC). Conclusion The simulated microgravity condition enables us to explore the potential relationship between bacterial phenotype and molecular biology, thus opening up a suitable and constructive method for medical fields that have not been explored before. It provides a certain strategy for the treatment of P. mirabilis infectious diseases in space environment by exploring the microgravity of P. mirabilis.

Heart Rate and Blood Pressure Response to Short-Term Head-Down Bed Rest: A Nonlinear Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 157-159 ◽  
Author(s):  
R. Balocchi ◽  
A. Di Garbo ◽  
C. Michelassi ◽  
S. Chillemi ◽  
M. Varanini ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Prolonged Exposure ◽  
Orthostatic Intolerance ◽  
Bed Rest ◽  
Microgravity Environment ◽  
Short Term ◽  
Short Term Exposure ◽  
Recurrence Quantification

Abstract:Although it is well-known that prolonged exposure to microgravity environment such as in space travel results in derangements of orthostasis, recent evidence suggests that even short-term exposure may have similar effects and parallels such common examples as prolonged bed rest. Whereas spectral analysis of heart rate and systolic blood pressure have been unable to detect changes, we hypothesized that nonlinear indexes may be better able to uncover such perturbations. Eighteen healthy subjects were exposed to 4-hour head-down tilt, and of these, 4 exhibited fainting. Two nonlinear indexes, mutual information and recurrence quantification were used to analyze the data. Only recurrence quantification was able to detect a “decoupling” of heart rate and systolic blood pressure at rest using discriminant analysis (p < 0.05). These results suggest that orthostatic intolerance may be due to a decoupling of heart rate from systolic blood pressure reflexive activity occurring at rest.

scholarly journals Evaluation of pathogenesis and biofilm formation ability of Yersinia pestis after 40-day exposure to simulated microgravity

2021 ◽  
Author(s):  
Ye Li ◽  
Yulu Chen ◽  
Lei Wang ◽  
Yixuan Li ◽  
Ruifu Yang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Microgravity Condition ◽  
Microgravity Environment ◽  
Crystal Violet Staining ◽  
Rna Seq ◽  
Manned Space ◽  
Manned Space Missions

Abstract Background: With the increase of manned space missions and the rise of space microbiology, the research of microbes grown under microgravity environment attracts more attentions. The research scope in space microbiology has been extended beyond pathogens directly related to spaceflight Y. pestis, the causative agent of plague, is also of interest to researchers. Results: After Y. pestis strain 201 cultivated for 40 consecutive passages in either simulated microgravity and normal gravity (NG) conditions, the cultures were used to observe the main phenotypic features of Y. pestis. By using crystal violet staining assays, increased biofilm amount was detected in Y. pestis grown under SMG condition. Besides that, the damage degrees of Hela cell caused by SMG-grown Y. pestis were found diminished in relative to those NG condition. Consistent with this observation, death course was delayed in mice infected with SMG-grown Y. pestis, suggesting that microgravity condition could contribute the attenuated virulence. RNA-seq-based transcriptomics analysis showed a total of 219 genes were differentially regulated, of which 92 upregulated and 127 downregulated. We found dozens of virulence-associated genes were downregulated, which partially explained the reduced virulence of Y. pestis under SMG condition. Our study demonstrated that long-term exposure to simulated microgravity influence the pathogenesis and biofilm formation ability of Y. pestis in a different way, which provides a novel avenue to study the mechanism of physiology and virulence in this pathogen.Conclusions: Microgravity enhanced the ability of biofilm formation of Y. pestis. The virulence and cytotoxicity of Y. pestis were reduced under the microgravity environment. The expressions of many virulence-associated genes of Y. pestis were differentially regulated in response to the stimulated microgravity.

scholarly journals Decreased Biofilm Formation Ability of a Multidrug-Resistant Pseudomonas aeruginosa Strain After Exposure to a Simulated Microgravity Environment

2021 ◽  
Vol 13 (10) ◽  
Author(s):  
Bin Zhang ◽  
Po Bai ◽  
Dapeng Wang ◽  
Junfeng Wang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Treatment Strategies ◽  
Underlying Mechanism ◽  
Multidrug Resistant ◽  
Microgravity Environment ◽  
Factors Affecting ◽  
Swimming Motility ◽  
Type Iv

Background: The refractory infection induced by multidrug-resistant (MDR) Pseudomonas aeruginosa has become one of the most urgent problems in hospitals. The biofilms formed by P. aeruginosa increase its resistance to antibiotics. A simulated microgravity (SMG) environment provides a platform to understand the factors affecting biofilm formation in bacteria. Objectives: This study aimed to investigate the SMG effects on MDR P. aeruginosa biofilm formation and explore the relevant mechanisms. Methods: In this study, a clinostat was used to simulate a microgravity (MG) environment. The motility and biofilm formation ability of MDR P. aeruginosa were observed using the swimming test and the crystal violet staining method, respectively. The underlying mechanism of phenotypic changes was further investigated by comparative transcriptomic analysis. Results: Multidrug-resistant P. aeruginosa grown under the SMG condition exhibited decreased swimming motility and biofilm formation ability compared to those under the normal gravity (NG) condition. Further analysis revealed that the decreased swimming motility and biofilm formation ability could be attributed to the downregulated expression of genes responsible for flagellar synthesis (flhB, fliQ, and fliR) and type IV pili biogenesis (pilDEXY1Y2VW). Conclusions: This is the first study to perform experiments on MDR P. aeruginosa under the SMG condition. It will be beneficial to understand the mechanism of MDR P. aeruginosa biofilm formation and develop new treatment strategies for infectious diseases induced by MDR P. aeruginosa in the future.

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

Short-term exposure and long-term consequences of neonatal exposure to Δ9-tetrahydrocannabinol (THC) and ibuprofen in mice

2016 ◽  
Vol 307 ◽  
pp. 137-144 ◽  
Author(s):  
Gaëtan Philippot ◽  
Fred Nyberg ◽  
Torsten Gordh ◽  
Anders Fredriksson ◽  
Henrik Viberg
Keyword(s):  
Neonatal Exposure ◽  
Short Term ◽  
Short Term Exposure ◽  
Long Term Consequences
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