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Cells ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 151
Author(s):  
Alexander Martens ◽  
Nicole de Buhr ◽  
Hiroshi Ishikawa ◽  
Horst Schroten ◽  
Maren von Köckritz-Blickwede

The host–pathogen interaction during meningitis can be investigated with blood-cerebrospinal-fluid-barrier (BCSFB) cell culture models. They are commonly handled under atmospheric oxygen conditions (19–21% O2), although the physiological oxygen conditions are significantly lower in cerebrospinal fluid (CSF) (7–8% O2). We aimed to characterize oxygen levels in a Streptococcus (S.) suis-infected BCSFB model with transmigrating neutrophils. A BCSFB model with human choroid plexus epithelial cells growing on transwell-filters was used. The upper “blood”-compartment was infected and blood-derived neutrophils were added. S. suis and neutrophils transmigrated through the BCSFB into the “CSF”-compartment. Here, oxygen and pH values were determined with the non-invasive SensorDish® reader. Slight orbital shaking improved the luminescence-based measurement technique for detecting free oxygen. In the non-infected BCSFB model, an oxygen value of 7% O2 was determined. However, with S. suis and transmigrating neutrophils, the oxygen value significantly decreased to 2% O2. The pH level decreased slightly in all groups. In conclusion, we characterized oxygen levels in the BCSFB model and demonstrated the oxygen consumption by cells and bacteria. Oxygen values in the non-infected BCSFB model are comparable to in vivo values determined in pigs in the CSF. Infection and transmigrating neutrophils decrease the oxygen value to lower values.


2022 ◽  
Vol 306 ◽  
pp. 118094
Author(s):  
Min Zhang ◽  
Jiun Cai Ong ◽  
Kar Mun Pang ◽  
Xue-Song Bai ◽  
Jens H. Walther

Author(s):  
U. Sravan

Abstract: An IoT based health monitoring system records the patient’s heart beat, body temperature, oxygen levels of blood etc. It can also be used to inform the timing of medication and provides live monitoring of health condition of patient to the doctor available in his chamber. It also sends an SMS alert whenever the health parameter readings go beyond critical values. Keywords: Heart beat, Temperature, Oxygen Levels, Medication timing, SMS alert.


2021 ◽  
Vol 22 (24) ◽  
pp. 13223
Author(s):  
Branden Kusanto ◽  
Andrew Gordon ◽  
Leigh Naylor-Adamson ◽  
Lloyd Atkinson ◽  
Charlie Coupland ◽  
...  

Investigating human platelet function in low-oxygen environments is important in multiple settings, including hypobaric hypoxia (e.g., high altitude), sea level hypoxia-related disease, and thrombus stability. These studies often involve drawing blood from which platelets are isolated and analysed at atmospheric conditions or re-exposed to low oxygen levels in hypoxia chambers before testing. However, it remains unknown how the in vitro handling of the samples itself changes their dissolved oxygen concentration, which might affect platelet function and experimental results. Here, we prepared healthy donor platelet-rich plasma and washed platelet (WP) suspensions and exposed them to 2% oxygen. We found that the use of hypoxia pre-equilibrated tubes, higher platelet concentrations (>2 × 108/mL versus 2 × 107/mL), smaller volumes (600 µL versus 3 mL), and presence of plasma reduced the time for samples to reach 2% oxygen. Notably, oxygen levels decreased below 2% in most suspensions, but also in WP maintained at atmospheric 21% oxygen. Additionally, platelet spreading on fibrinogen was decreased when using hypoxic fibrinogen-coated culture plates regardless of the oxygen percentage (2% or 21%) in which platelet incubation took place. Thus, sample handling and experimental conditions should be carefully monitored in platelet-hypoxia studies as they might compromise results interpretation and comparison across studies.


HardwareX ◽  
2021 ◽  
pp. e00253
Author(s):  
Colin R.N. Marchus ◽  
Jacob A. Knudson ◽  
Alexandra E. Morrison ◽  
Isabell K. Strawn ◽  
Andrew J. Hartman ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nikhil Seshagiri Rao ◽  
Ludwig Lundberg ◽  
Shuai Palmkron ◽  
Sebastian Håkansson ◽  
Björn Bergenståhl ◽  
...  

AbstractOptimisation of cultivation conditions in the industrial production of probiotics is crucial to reach a high-quality product with retained probiotic functionality. Flow cytometry-based descriptors of bacterial morphology may be used as markers to estimate physiological fitness during cultivation, and can be applied for online monitoring to avoid suboptimal growth. In the current study, the effects of temperature, initial pH and oxygen levels on cell growth and cell size distributions of Limosilactobacillus reuteri DSM 17938 were measured using multivariate flow cytometry. A pleomorphic behaviour was evident from the measurements of light scatter and pulse width distributions. A pattern of high growth yielding smaller cells and less heterogeneous populations could be observed. Analysis of pulse width distributions revealed significant morphological heterogeneities within the bacterial cell population under non-optimal growth conditions, and pointed towards low temperature, high initial pH, and high oxygen levels all being triggers for changes in morphology towards cell chain formation. However, cell size did not correlate to survivability after freeze-thaw or freeze-drying stress, indicating that it is not a key determinant for physical stress tolerance. The fact that L. reuteri morphology varies depending on cultivation conditions suggests that it can be used as marker for estimating physiological fitness and responses to its environment.


2021 ◽  
Author(s):  
Federico Pasini ◽  
Manel Garrido‐Baserba ◽  
Travis Sprague ◽  
Pietro Cambiaso ◽  
Diego Rosso

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