Microfluidic Platform for Examination of Effect of Chewing Xylitol Gum on Salivary pH, O2, and CO2

Miniaturization of different measurement processes and a scaled-down approach open the possibility for rapid measurements with the small amounts of samples and reagents into a compact platform with integrated sensors and different measuring components. In this paper, we report a microfluidic approach for measurements of salivary pH, dissolved O2, and CO2 during chewing xylitol gum. The study was done with the samples of 30 healthy volunteers who were chewing a xylitol gum, and the measurements were performed in the microfluidic (MF) chip with integrated commercial PreSens sensors. Xylitol exhibited a significant effect on the pH of saliva in terms of its initial drop, which was the most significant between the 5th and 10th minutes. The effect of xylitol on the amount of oxygen and carbon dioxide in saliva cannot be confirmed. The employed microfluidic platform was shown to be applicable and effective in the analysis of salivary biomarkers relevant to caries development.

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Phase I Safety Assessment of Intrathecal Neostigmine Methylsulfate in Humans

Anesthesiology ◽

10.1097/00000542-199502000-00003 ◽

1995 ◽

Vol 82 (2) ◽

pp. 331-343 ◽

Cited By ~ 180

Author(s):

David D. Hood ◽

James C. Eisenach ◽

Robin Tuttle

Keyword(s):

Carbon Dioxide ◽

Blood Pressure ◽

Heart Rate ◽

Side Effects ◽

Healthy Volunteers ◽

Nausea And Vomiting ◽

Severe Nausea ◽

End Tidal Carbon Dioxide ◽

End Tidal ◽

Ice Water

Background In dogs, sheep, and rats, spinal neostigmine produces analgesia alone and enhances analgesia from alpha 2-adrenergic agonists. This study assesses side effects and analgesia from intrathecal neostigmine in healthy volunteers. Methods After institutional review board approval and informed consent, 28 healthy volunteers were studied. The first 14 volunteers received neostigmine (50-750 micrograms) through a #19.5 spinal needle followed by insertion of a spinal catheter. The remaining 14 volunteers received neostigmine through a #25 or #27 spinal needle without a catheter. Safety measurements included blood pressure, heart rate, oxyhemoglobin saturation, end-tidal carbon dioxide, neurologic evaluation, and computer tests of vigilance and memory. Analgesia in response to ice water immersion was measured. Results Neostigmine (50 micrograms) through the #19.5 needle did not affect any measured variable. Neostigmine (150 micrograms) caused mild nausea, and 500-750 micrograms caused severe nausea and vomiting. Neostigmine (150-750 micrograms) produced subjective leg weakness, decreased deep tendon reflexes, and sedation. The 750-micrograms dose was associated with anxiety, increased blood pressure and heart rate, and decreased end-tidal carbon dioxide. Neostigmine (100-200 micrograms) in saline, injected through a #25 or #27 needle, caused protracted, severe nausea, and vomiting. This did not occur when dextrose was added to neostigmine. Neostigmine by either method of administration reduced visual analog pain scores to immersion of the foot in ice water. Conclusions The incidence and severity of these adverse events from intrathecal neostigmine appears to be affected by dose, method of administration, and baricity of solution. These effects in humans are consistent with studies in animals. Because no unexpected or dangerous side effects occurred, cautious examination of intrathecal neostigmine alone and in combination with other agents for analgesia is warranted.

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Preliminary investigations into the effects of breathing retraining techniques on end-tidal carbon dioxide measures in patients with asthma and healthy volunteers during a single treatment session

Physiotherapy ◽

10.1016/j.physio.2006.07.006 ◽

2007 ◽

Vol 93 (1) ◽

pp. 30-36 ◽

Cited By ~ 1

Author(s):

Anne Bruton ◽

Mary Armstrong ◽

Claire Chadwick ◽

Denise Gibson ◽

Kate Gahr

Keyword(s):

Carbon Dioxide ◽

Healthy Volunteers ◽

Treatment Session ◽

Single Treatment ◽

End Tidal Carbon Dioxide ◽

Breathing Retraining ◽

End Tidal ◽

Single Treatment Session

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P.4.a.019 Carbon dioxide-induced respiratory symptoms and experimental panic in healthy volunteers

European Neuropsychopharmacology ◽

10.1016/s0924-977x(09)70955-1 ◽

2009 ◽

Vol 19 ◽

pp. S596

Author(s):

A. Colasanti ◽

K. Schruers ◽

R. van Diest ◽

G. Esquivel ◽

E. den Boer ◽

...

Keyword(s):

Carbon Dioxide ◽

Healthy Volunteers ◽

Respiratory Symptoms

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Amiloride-sensitive cation channel 2 genotype affects the response to a carbon dioxide panic challenge

Journal of Psychopharmacology ◽

10.1177/0269881116686880 ◽

2017 ◽

Vol 31 (10) ◽

pp. 1294-1301 ◽

Cited By ~ 6

Author(s):

Nicole K Leibold ◽

Daniel LA van den Hove ◽

Wolfgang Viechtbauer ◽

Gunter Kenis ◽

Liesbet Goossens ◽

...

Keyword(s):

Carbon Dioxide ◽

Healthy Volunteers ◽

Emotional Response ◽

Treatment Options ◽

Genetic Research ◽

Current Treatment ◽

Cation Channel ◽

Differential Sensitivity ◽

Future Research ◽

Genotype Effect

Until recently, genetic research into panic disorder (PD) has had only limited success. Inspired by rodent research, demonstrating that the acid-sensing ion channel 1a (ASIC1a) is critically involved in the behavioral fear response to carbon dioxide (CO2) exposure, variants in the human homologue gene amiloride-sensitive cation channel 2 (ACCN2) were shown to be associated with PD. However, the relationship between changes in brain pH and ACCN2, as done in rodents by CO2 exposure, has not been investigated yet in humans. Here, we examined this link between the ACCN2 gene and the response to CO2 exposure in two studies: in healthy volunteers as well as PD patients and using both behavioral and physiological outcome measures. More specifically, 107 healthy volunteers and 183 PD patients underwent a 35% CO2 inhalation. Negative affect was assessed using visual analogue scales and the panic symptom list (PSL), and, in healthy volunteers, cardiovascular measurements. The single nucleotide polymorphism rs10875995 was significantly associated with a higher emotional response in PD patients and with an increase in systolic as well as diastolic blood pressure in healthy subjects. In all measurements, subjects homozygous for the T-allele showed a heightened reactivity to CO2. Furthermore, a trend towards an rs685012 genotype effect on the emotional response was found in PD patients. We provide the first evidence that genetic variants in the ACCN2 are associated with differential sensitivity to CO2 in PD patients as well as healthy volunteers, further supporting ACCN2 as a promising candidate for future research to improve current treatment options.

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Effect of Artificial Carbon Dioxide-Rich Water Immersion on Peripheral Blood Flow in Healthy Volunteers: Preliminary Study about Artificial Carbon Dioxide-Rich Water

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2021.6591 ◽

2021 ◽

Vol 9 (A) ◽

pp. 527-531

Author(s):

Andi Rizky Arbaim Hasyar ◽

Haerani Rasyid ◽

Irfan Idris ◽

Irawan Yusuf

Keyword(s):

Carbon Dioxide ◽

Blood Flow ◽

Healthy Volunteers ◽

Peripheral Blood ◽

Water Immersion ◽

Treatment Options ◽

Peripheral Blood Flow ◽

Mixed Solution ◽

Doppler Flowmetry ◽

Improvement Effect

BACKGROUND: Peripheral blood circulation disorder is one of the global health problems. Balneotherapy that uses CO2 springs may be one of the complementary treatment options. The device to produce artificial CO2-rich water is needed to achieve an improvement effect, at least almost like the improvement effect of natural balneotherapy. AIM: This study aims to investigate the effect of artificial CO2-rich water immersion on peripheral blood flow using Bicarbonated JesC CREA BC-2000. METHODS AND MATERIALS: Thirty-nine healthy volunteers participated in this study. Each subject immersed both of their legs in a mixed solution from water and CO2 at temperature 38°C. This solution was mixed using a device, namely, “Bicarbonated JesC CREA BC-2000”. Peripheral blood flow was measured for 5 min before immersion (in this study, we denoted it as the mean basal blood flow), 10 min during immersion, and 5 min after immersion using pocket JMS laser Doppler flowmetry MBF-IIA. Repeated analysis of variance was used for statistical analysis. RESULTS: There is the difference in peripheral blood flow among before, during, and after immersing the legs into artificial CO2-rich water using Bicarbonated JesC CREA BC-2000 (p < 0.001). CONCLUSION: Bicarbonated JesC CREA BC-2000 may be used as the device to produce an artificial CO2-rich water bath that may affect peripheral blood flow in healthy volunteers.

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Ventilatory parameters measured during a physiological study of simulated powered air-purifying respirator failure in healthy volunteers

Anaesthesia and Intensive Care ◽

10.1177/0310057x20978982 ◽

2021 ◽

pp. 0310057X2097898

Author(s):

Lachlan F Miles ◽

Timothy Makar ◽

Chad W Oughton ◽

Philip J Peyton

Keyword(s):

Carbon Dioxide ◽

Partial Pressure ◽

Healthy Volunteers ◽

Minute Ventilation ◽

Peripheral Oxygen Saturation ◽

Thermal Discomfort ◽

Fraction Of Inspired Oxygen ◽

Mechanical Devices ◽

End Tidal ◽

High Level

Powered air-purifying respirators (PAPR) are a high level of respiratory personal protective equipment. Like all mechanical devices, they are vulnerable to failure. The precise physiological consequences of failure in live subjects have not previously been reported. We conducted an observational safety study simulating PAPR failure in a group of nine healthy volunteers, wearing loose-fitting hoods, who were observed for a period of ten minutes, or until they requested the experiment be aborted, with continuous monitoring of gas exchange. Relative to baseline, participants demonstrated median reductions in peripheral oxygen saturation of 3.5% (95% confidence interval (CI) –4% to –2%; P = 0.0039) and fraction of inspired oxygen of 0.045 (95% CI –0.05 to –0.04; P = 0.0039), and median increases in inspired partial pressure of carbon dioxide of 27 mmHg (95% CI 23.5–32 mmHg; P = 0.0039), end-tidal partial pressure of carbon dioxide of 11 mmHg (95% CI 7–16 mmHg; P = 0.0039) and minute ventilation of 30 l/min (95% CI 19.4–35.9 l/min; P = 0.0039). Median collateral entrainment of room air into the hood was 17.6 l/min (interquartile range 12.3–27.0 l/min). All subjects reported thermal discomfort, with two (22.2%) requesting early termination of the experiment. Whilst the degree of rebreathing in this experiment was not sufficient to cause dangerous physiological derangement, the degree of reported thermal discomfort combined with the consequences of entrainment of possibly contaminated air into the hood, pose a risk to wearers in the event of failure.

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