1
|
Arieli R. The pulmonary oxygen toxicity index. Respir Physiol Neurobiol 2023; 315:104114. [PMID: 37460079 DOI: 10.1016/j.resp.2023.104114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/03/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
Pulmonary oxygen toxicity (POT) is a major risk in diving while breathing hyperoxic gas and is also considered in clinical hyperbaric oxygen treatment. The POTindex calculated by the power equation K = t2 × PO24.57 with the recovery form Ktr = Ke × e - [- 0.42 + 0.384 × (PO2)ex] × tr which are based on chemical and physiological principles, have a better prediction power than other suggested approaches. Reduction of vital capacity as well as incidence of POT are well predicted by the POTindex. Both the cumulative pulmonary toxic effect and concomitant recovery were suggested to operate at the lower toxic range of PO2 used in saturation diving K = t2 × PO24.57 × e-0.0135 × t, and further experimental support is supplied. The recovery time constant for the full range of PO2 is presented. POTindex is suggested to replace the old method of UPTD for safe diving. Many diving clubs and diving institutes already adopted the POTindex.
Collapse
Affiliation(s)
- R Arieli
- Israel Naval Medical Institute, Haifa, Israel; Eliachar Research Laboratory, Western Galilee Medical Center, Nahariya, Israel.
| |
Collapse
|
2
|
de Jong FJM, Wingelaar TT, van Hulst RA. Pulmonary oxygen toxicity in occupational diving. Occup Med (Lond) 2023; 73:231-232. [PMID: 37364027 PMCID: PMC10292678 DOI: 10.1093/occmed/kqad043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023] Open
Abstract
One of the hazards of occupational diving is pulmonary oxygen toxicity, which can lead to reduced lung diffusion capacity and fibrosis. The current gold standard to determine the ‘safe limits’ for oxygen was developed more than 50 years ago and lacks the accuracy required for occupational specialists. These restrictions may be overcome by new diagnostic methods like exhaled breath analysis, which would allow occupational specialists to accurately monitor pulmonary health in the individual diver, and thus reduce long-term health effects of professional diving.
Collapse
Affiliation(s)
- Feiko J M de Jong
- Department of Anesthesiology, Amsterdam UMC, Location AMC, 1100 DD Amsterdam, The Netherlands
- Royal Netherlands Navy Diving and Submarine Medical Centre, 1780 CA Den Helder, The Netherlands
| | - Thijs T Wingelaar
- Royal Netherlands Navy Diving and Submarine Medical Centre, 1780 CA Den Helder, The Netherlands
- Department of Anesthesiology, Amsterdam UMC, Location AMC, 1100 DD Amsterdam, The Netherlands
| | - Rob A van Hulst
- Department of Anesthesiology, Amsterdam UMC, Location AMC, 1100 DD Amsterdam, The Netherlands
| |
Collapse
|
3
|
Brenna CTA, Khan S, Djaiani G, Au D, Schiavo S, Wahaj M, Janisse R, Katznelson R. Pulmonary function following hyperbaric oxygen therapy: A longitudinal observational study. PLoS One 2023; 18:e0285830. [PMID: 37256885 DOI: 10.1371/journal.pone.0285830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/02/2023] [Indexed: 06/02/2023] Open
Abstract
Hyperbaric oxygen therapy (HBOT) is known to be associated with pulmonary oxygen toxicity. However, the effect of modern HBOT protocols on pulmonary function is not completely understood. The present study evaluates pulmonary function test changes in patients undergoing serial HBOT. We prospectively collected data on patients undergoing HBOT from 2016-2021 at a tertiary referral center (protocol registration NCT05088772). Patients underwent pulmonary function testing with a bedside spirometer/pneumotachometer prior to HBOT and after every 20 treatments. HBOT was performed using 100% oxygen at a pressure of 2.0-2.4 atmospheres absolute (203-243 kPa) for 90 minutes, five times per week. Patients' charts were retrospectively reviewed for demographics, comorbidities, medications, HBOT specifications, treatment complications, and spirometry performance. Primary outcomes were defined as change in percent predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and forced mid-expiratory flow (FEF25-75), after 20, 40, and 60 HBOT sessions. Data was analyzed with descriptive statistics and mixed-model linear regression. A total of 86 patients were enrolled with baseline testing, and the analysis included data for 81 patients after 20 treatments, 52 after 40 treatments, and 12 after 60 treatments. There were no significant differences in pulmonary function tests after 20, 40, or 60 HBOT sessions. Similarly, a subgroup analysis stratifying the cohort based on pre-existing respiratory disease, smoking history, and the applied treatment pressure did not identify any significant changes in pulmonary function tests during HBOT. There were no significant longitudinal changes in FEV1, FVC, or FEF25-75 after serial HBOT sessions in patients regardless of pre-existing respiratory disease. Our results suggest that the theoretical risk of pulmonary oxygen toxicity following HBOT is unsubstantiated with modern treatment protocols, and that pulmonary function is preserved even in patients with pre-existing asthma, chronic obstructive lung disease, and interstitial lung disease.
Collapse
Affiliation(s)
- Connor T A Brenna
- Department of Anesthesiology & Pain Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Shawn Khan
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - George Djaiani
- Hyperbaric Medicine Unit, Toronto General Hospital, Toronto, Ontario, Canada
| | - Darren Au
- Department of Anesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada
| | - Simone Schiavo
- Department of Anesthesiology & Pain Medicine, University of Toronto, Toronto, Ontario, Canada
- Hyperbaric Medicine Unit, Toronto General Hospital, Toronto, Ontario, Canada
- Department of Anesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada
| | - Mustafa Wahaj
- Hyperbaric Medicine Unit, Toronto General Hospital, Toronto, Ontario, Canada
| | - Ray Janisse
- Hyperbaric Medicine Unit, Toronto General Hospital, Toronto, Ontario, Canada
| | - Rita Katznelson
- Department of Anesthesiology & Pain Medicine, University of Toronto, Toronto, Ontario, Canada
- Hyperbaric Medicine Unit, Toronto General Hospital, Toronto, Ontario, Canada
- Department of Anesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada
| |
Collapse
|
4
|
Luo Y, Li J, Ding Q, Wang H, Liu C, Wu J. Functionalized Hydrogel-Based Wearable Gas and Humidity Sensors. NANO-MICRO LETTERS 2023; 15:136. [PMID: 37225851 PMCID: PMC10209388 DOI: 10.1007/s40820-023-01109-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/13/2023] [Indexed: 05/26/2023]
Abstract
Breathing is an inherent human activity; however, the composition of the air we inhale and gas exhale remains unknown to us. To address this, wearable vapor sensors can help people monitor air composition in real time to avoid underlying risks, and for the early detection and treatment of diseases for home healthcare. Hydrogels with three-dimensional polymer networks and large amounts of water molecules are naturally flexible and stretchable. Functionalized hydrogels are intrinsically conductive, self-healing, self-adhesive, biocompatible, and room-temperature sensitive. Compared with traditional rigid vapor sensors, hydrogel-based gas and humidity sensors can directly fit human skin or clothing, and are more suitable for real-time monitoring of personal health and safety. In this review, current studies on hydrogel-based vapor sensors are investigated. The required properties and optimization methods of wearable hydrogel-based sensors are introduced. Subsequently, existing reports on the response mechanisms of hydrogel-based gas and humidity sensors are summarized. Related works on hydrogel-based vapor sensors for their application in personal health and safety monitoring are presented. Moreover, the potential of hydrogels in the field of vapor sensing is elucidated. Finally, the current research status, challenges, and future trends of hydrogel gas/humidity sensing are discussed.
Collapse
Affiliation(s)
- Yibing Luo
- State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Jianye Li
- State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Qiongling Ding
- State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Hao Wang
- State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Chuan Liu
- State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Jin Wu
- State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
| |
Collapse
|
5
|
Analysis of Volatile Organic Compounds in Exhaled Breath Following a COMEX-30 Treatment Table. Metabolites 2023; 13:metabo13030316. [PMID: 36984755 PMCID: PMC10056109 DOI: 10.3390/metabo13030316] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/17/2023] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
The COMEX-30 hyperbaric treatment table is used to manage decompression sickness in divers but may result in pulmonary oxygen toxicity (POT). Volatile organic compounds (VOCs) in exhaled breath are early markers of hyperoxic stress that may be linked to POT. The present study assessed whether VOCs following COMEX-30 treatment are early markers of hyperoxic stress and/or POT in ten healthy, nonsmoking volunteers. Because more oxygen is inhaled during COMEX-30 treatment than with other treatment tables, this study hypothesized that VOCs exhaled following COMEX-30 treatment are indicators of POT. Breath samples were collected before and 0.5, 2, and 4 h after COMEX-30 treatment. All subjects were followed-up for signs of POT or other symptoms. Nine compounds were identified, with four (nonanal, decanal, ethyl acetate, and tridecane) increasing 33–500% in intensity from before to after COMEX-30 treatment. Seven subjects reported pulmonary symptoms, five reported out-of-proportion tiredness and transient ear fullness, and four had signs of mild dehydration. All VOCs identified following COMEX-30 treatment have been associated with inflammatory responses or pulmonary diseases, such as asthma or lung cancer. Because most subjects reported transient pulmonary symptoms reflecting early-stage POT, the identified VOCs are likely markers of POT, not just hyperbaric hyperoxic exposure.
Collapse
|
6
|
Imbert JP, Massimelli JY, Kulkarni A, Matity L, Bryson P, Bryson P. A review of accelerated decompression from heliox saturation in commercial diving emergencies. Diving Hyperb Med 2022; 52. [PMID: 36525682 PMCID: PMC9767825 DOI: 10.28920/dhm52.4.245-259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 08/18/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Saturation diving is a specialised method of intervention in offshore commercial diving. Emergencies may require the crew to be evacuated from the diving support vessel. Because saturation divers generally need several days to reach surface, the emergency evacuation of divers is based on dedicated hyperbaric rescue systems. There are still potential situations for which these systems cannot be used or deployed, and where an emergency decompression provides an alternative solution. METHODS Our objective was to describe historical cases and assess the benefit of emergency decompressions, with the collection of data from the authors' direct experience and networks, providing witness or first-hand information. RESULTS We documented three cases of emergency decompression following bell evacuations, and six cases of accelerated decompression performed in the chamber or hyperbaric rescue chamber. Review of these cases showed: 1) the complicated nature of such emergencies that make decisions difficult; 2) the variety of solutions implemented; and 3) the surprisingly safe and successful outcomes of several operations. Analysis of the accelerated decompression occurrences allowed derivation of the options used; upward initial excursion, increased chamber partial pressure of oxygen associated to increased ascent rates, and inert gas switching. We identified four published procedures for accelerated decompression. CONCLUSIONS Despite modern hyperbaric rescue systems, accelerated decompression remains an essential tool in case of emergency. The diving industry needs clear guidance on what can be achieved, depending on the saturation depth and the level of emergency.
Collapse
Affiliation(s)
| | | | | | | | - Philip Bryson
- Dr Philip Bryson, International SOS, Forest Grove House, Foresterhill Road, Aberdeen, AB25 2ZP, UK
| | | | | | | | | | | |
Collapse
|
7
|
Tauchunfälle. Notf Rett Med 2022. [DOI: 10.1007/s10049-021-00965-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
8
|
GONG WY, XU B, LIU L, LI ST. Effects of different doses of dezocine on central nervous system in mice. FOOD SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1590/fst.73021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Wen-yi GONG
- Shanghai General Hospital of Nanjing Medical University, China; Wusong Hospital, China
| | | | | | - Shi-tong LI
- Shanghai General Hospital of Nanjing Medical University, China
| |
Collapse
|
9
|
Dugrenot E, Balestra C, Gouin E, L'Her E, Guerrero F. Physiological effects of mixed-gas deep sea dives using a closed-circuit rebreather: a field pilot study. Eur J Appl Physiol 2021; 121:3323-3331. [PMID: 34435274 DOI: 10.1007/s00421-021-04798-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 08/19/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE Deep diving using mixed gas with closed-circuit rebreathers (CCRs) is increasingly common. However, data regarding the effects of these dives are still scarce. This preliminary field study aimed at evaluating the acute effects of deep (90-120 msw) mixed-gas CCR bounce dives on lung function in relation with other physiological parameters. METHODS Seven divers performed a total of sixteen open-sea CCR dives breathing gas mixture of helium, nitrogen and oxygen (trimix) within four days at 2 depths (90 and 120 msw). Spirometric parameters, SpO2, body mass, hematocrit, short term heart rate variability (HRV) and critical flicker fusion frequency (CFFF) were measured at rest 60 min before the dive and 120 min after surfacing. RESULTS The median [1st-3rd quartile] of the forced vital capacity was lower (84% [76-93] vs 91% [74-107] of predicted values; p = 0.029), whereas FEV1/FVC was higher (98% [95-99] vs 95% [89-99]; p = 0.019) after than before the dives. The other spirometry values and SpO2 were unchanged. Body mass decreased from 73.5 kg (72.0-89.6) before the dives to 70.0 kg (69.2-85.8) after surfacing (p = 0.001), with no change of hematocrit or CFFT. HRV was increased as indicated by the higher SDNN, RMSSD and pNN50 after than before dives. CONCLUSION The present observation represents the first original data regarding the effects of deep repeated CCR dives. The body mass loss and decrease of FVC after bounce dives at depth of about 100 msw may possibly impose an important physiological stress for the divers.
Collapse
Affiliation(s)
- Emmanuel Dugrenot
- TEK diving SAS, F-29200, Brest, France
- Univ Brest, ORPHY, IBSAM, 6 avenue Le Gorgeu, F-29200, Brest, France
| | - Costantino Balestra
- Environmental and Occupational Physiology Laboratory, (ISEK), Haute Ecole Bruxelles-Brabant (HE2B), 1160, Brussels, Belgium
| | | | - Erwan L'Her
- Médecine Intensive et Réanimation, CHRU de Brest, Brest, NA, France
| | - François Guerrero
- Univ Brest, ORPHY, IBSAM, 6 avenue Le Gorgeu, F-29200, Brest, France.
| |
Collapse
|
10
|
Kot J, Winklewski PJ. Commentary on using critical flicker fusion frequency to measure gas narcosis. Diving Hyperb Med 2021; 51:227-228. [PMID: 34157742 DOI: 10.28920/dhm51.2.227-228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 02/26/2021] [Indexed: 11/05/2022]
Affiliation(s)
- Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, Poland.,Address for correspondence: Jacek Kot, National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, Poland,
| | | |
Collapse
|
11
|
Arieli R, Aviner B. Acclimatization and Deacclimatization to Oxygen: Determining Exposure Limits to Avoid CNS O 2 Toxicity in Active Diving. Front Physiol 2020; 11:1105. [PMID: 33013472 PMCID: PMC7498636 DOI: 10.3389/fphys.2020.01105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 08/10/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ran Arieli
- The Israel Naval Medical Institute, Israel Defense Forces Medical Corps, Haifa, Israel.,Eliachar Research Laboratory, Western Galilee Medical Center, Nahariya, Israel
| | - Ben Aviner
- The Israel Naval Medical Institute, Israel Defense Forces Medical Corps, Haifa, Israel
| |
Collapse
|
12
|
Aviner B, Arieli R, Yalov A. Power Equation for Predicting the Risk of Central Nervous System Oxygen Toxicity at Rest. Front Physiol 2020; 11:1007. [PMID: 33013440 PMCID: PMC7461992 DOI: 10.3389/fphys.2020.01007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/24/2020] [Indexed: 11/13/2022] Open
Abstract
Patients undergoing hyperbaric oxygen therapy and divers engaged in underwater activity are at risk of central nervous system oxygen toxicity. An algorithm for predicting CNS oxygen toxicity in active underwater diving has been published previously, but not for humans at rest. Using a procedure similar to that employed for the derivation of our active diving algorithm, we collected data for exposures at rest, in which subjects breathed hyperbaric oxygen while immersed in thermoneutral water at 33°C (n = 219) or in dry conditions (n = 507). The maximal likelihood method was employed to solve for the parameters of the power equation. For immersion, the CNS oxygen toxicity index is KI = t2 × PO210.93, where the calculated risk from the Standard Normal distribution is ZI = [ln(KI0.5) – 8.99)]/0.81. For dry exposures this is KD = t2 × PO212.99, with risk ZD = [ln(KD0.5) – 11.34)]/0.65. We propose a method for interpolating the parameters at metabolic rates between 1 and 4.4 MET. The risk of CNS oxygen toxicity at rest was found to be greater during immersion than in dry conditions. We discuss the prediction properties of the new algorithm in the clinical hyperbaric environment, and suggest it may be adopted for use in planning procedures for hyperbaric oxygen therapy and for rest periods during saturation diving.
Collapse
Affiliation(s)
- Ben Aviner
- The Israel Naval Medical Institute, Israel Defense Forces Medical Corps, Haifa, Israel
| | - Ran Arieli
- The Israel Naval Medical Institute, Israel Defense Forces Medical Corps, Haifa, Israel.,Eliachar Research Laboratory, Western Galilee Medical Center, Nahariya, Israel
| | | |
Collapse
|
13
|
Arieli R. Effect of an air break on the occurrence of seizures in hyperbaric oxygen therapy may be predicted by the power equation for hyperoxia at rest. Diving Hyperb Med 2020; 50:75-76. [PMID: 32187622 DOI: 10.28920/dhm50.1.75-76] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 11/29/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Ran Arieli
- The Israel Naval Medical Institute, Israel Defence Forces Medical Corps, Haifa, Israel; Eliachar Research Laboratory, Western Galilee Medical Centre, Nahariya, Israel.,Corresponding author: Dr Ran Arieli, 12 Klil-Hakhoresh, Rakefet, D.N. Misgav 2017500, Israel.
| |
Collapse
|
14
|
Hyperoxia Alters Ultrastructure and Induces Apoptosis in Leukemia Cell Lines. Biomolecules 2020; 10:biom10020282. [PMID: 32059539 PMCID: PMC7072400 DOI: 10.3390/biom10020282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/29/2020] [Accepted: 02/11/2020] [Indexed: 12/11/2022] Open
Abstract
Oxygenation conditions are crucial for growth and tumor progression. Recent data suggests a decrease in cancer cell proliferation occurring after exposure to normobaric hyperoxia. Those changes are associated with fractal dimension. The purpose of this research was to study the impact of hyperoxia on apoptosis and morphology of leukemia cell lines. Two hematopoietic lymphoid cancer cell lines (a T-lymphoblastoid line, JURKAT and a B lymphoid line, CCRF-SB) were tested under conditions of normobaric hyperoxia (FiO2 > 60%, ± 18h) and compared to a standard group (FiO2 = 21%). We tested for apoptosis using a caspase-3 assay. Cell morphology was evaluated by cytospin, microphotography after coloration, and analysis by a fractal dimension calculation software. Our results showed that exposure of cell cultures to transient normobaric hyperoxia induced apoptosis (elevated caspase-3) as well as significant and precocious modifications in cell complexity, as highlighted by increased fractal dimensions in both cell lines. These features are associated with changes in structure (pycnotic nucleus and apoptosis) recorded by microscopic analysis. Such morphological alterations could be due to several molecular mechanisms and rearrangements in the cancer cell, leading to cell cycle inhibition and apoptosis as shown by caspase-3 activity. T cells seem less resistant to hyperoxia than B cells.
Collapse
|
15
|
Arieli R. Pulmonary oxygen toxicity in saturation dives with PO 2 close to the lower end of the toxic range - A quantitative approach. Respir Physiol Neurobiol 2019; 268:103243. [PMID: 31158523 DOI: 10.1016/j.resp.2019.05.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 05/29/2019] [Indexed: 12/18/2022]
Abstract
Pulmonary oxygen toxicity (POT) has been extensively described at partial pressures of oxygen (PO2) ≥ 1 bar, but much less so at lower PO2. We proposed the POT index [K = t2 × (PO2)4.57] as a means of evaluating the severity of POT, expressed either as reduced lung function or the incidence of POT in a group of divers. In the exponential recovery process (e - [- 0.42 + 0.384 × (PO2)ex] × tr), the time constant increases linearly from 0.0024 to 0.54 h-1 for a PO2 of 1.1 to 2.5 bar. A linear relationship was demonstrated between the incidence of POT and the POT index, given by the equation: POT incidence % = 1.85 + 0.171 × K. In saturation diving, PO2 is kept close to the lower end of the toxic limits for POT, which is approximately 0.5 bar. We suggested that at this low range of PO2, the two processes of cumulative toxicity and recovery operate simultaneously. For one example of saturation diving, we show that a recovery time constant of 0.0135 h-1 yields the measured incidence of POT. We therefore propose the formula K = t2 × PO24.57 × e-0.0135 × t for calculation of the POT index in further analyses of POT in saturation diving.
Collapse
Affiliation(s)
- Ran Arieli
- Israel Naval Medical Institute, Israel Defence Forces Medical Corps, Haifa, Israel; Eliachar Research Laboratory, Western Galilee Medical Center, Nahariya, Israel.
| |
Collapse
|