Oxygen Treatment Group Research Articles

Study of the Effects of Plasma Pretreatment on the Microstructure of Peanuts

In this study, cold plasma treatments are employed to modify peanuts. This study systematically investigates the effects of various plasma treatment conditions, including power, duration, and gas type, on the microstructure of peanut seed coats and embryos. Observations under a scanning electron microscope (SEM) reveal that as plasma treatment power increases from 100 W to 500 W, the etching level of peanut seed coats significantly intensifies, surface roughness deepens, and concavities become more pronounced. Additionally, micro-pores on the seed coat gradually enlarge and form cracks. Specifically, when the plasma treatment is set at 200 W for 60 s, the oxygen (O2) treatment group shows interconnected cracks on the peanut seed coat surface, with lipid particles exuding and protein particles and polymers decomposing. In contrast, the helium (He) treatment group displays clear cell structures and deep grooves, with no noticeable lipid particles exuding around surface cracks. The argon (Ar) treatment group exhibits a distinct rectangular cell structure with clear boundaries, and although surface cracks form, only a few protein particles escape from the cracks. The embryo surface structure becomes looser after plasma treatment, leading to the disintegration of lipid particles, protein particles, and polymers, affecting the fusion and migration of large and small lipid bodies within the peanut’s internal structure. Increasing treatment duration intensifies the etching phenomenon, resulting in more lipid particles exuding, which indicates a positive correlation between lipid particles exuding and treatment duration. This study sheds light on the mechanisms underlying changes in peanut microstructure due to cold plasma treatment, providing scientific evidence for improving peanut quality, enhancing oil extraction efficiency, and optimizing food processing techniques.

SOLUBLE GUANYLYL CYCLASE ACTIVATION RESCUES HYPEROXIA-INDUCED DYSFUNCTION OF VASCULAR RELAXATION.

Introduction: Perioperative alterations in perfusion lead to ischemia and reperfusion injury, and supplemental oxygen is administered during surgery to limit hypoxic injury but can lead to hyperoxia. We hypothesized that hyperoxia impairs endothelium-dependent and endothelium-independent vasodilation but not the vasodilatory response to heme-independent soluble guanylyl cyclase activation. Methods: We measured the effect of oxygen on vascular reactivity in mouse aortas. Mice were ventilated with 21% (normoxia), 60% (moderate hyperoxia), or 100% (severe hyperoxia) oxygen during 30 minutes of renal ischemia and 30 minutes of reperfusion. After sacrifice, the thoracic aorta was isolated, and segments mounted on a wire myograph. We measured endothelium-dependent and endothelium-independent vasodilation with escalating concentrations of acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, and we measured the response to heme-independent soluble guanylyl cyclase activation with cinaciguat. Vasodilator responses to each agonist were quantified as the maximal theoretical response ( Emax ) and the effective concentration to elicit 50% relaxation (EC 50 ) using a sigmoid model and nonlinear mixed-effects regression. Aortic superoxide was measured with dihydroethidium probe and high-performance liquid chromatography quantification of the specific superoxide product 2-hydroxyethidium. Results: Hyperoxia impaired endothelium-dependent (ACh) and endothelium-independent (SNP) vasodilation compared with normoxia and had no effect on cinaciguat-induced vasodilation. The median ACh Emax was 76.4% (95% confidence interval = 69.6 to 83.3) in the normoxia group, 53.5% (46.7 to 60.3) in the moderate hyperoxia group, and 53.1% (46.3 to 60.0) in the severe hyperoxia group ( P < 0.001, effect across groups), while the ACh EC 50 was not different among groups. The SNP Emax was 133.1% (122.9 to 143.3) in normoxia, 128.3% (118.1 to 138.6) in moderate hyperoxia, and 114.8% (104.6 to 125.0) in severe hyperoxia ( P < 0.001, effect across groups), and the SNP EC 50 was 0.38 log M greater in moderate hyperoxia than in normoxia (95% confidence interval = 0.18 to 0.58, P < 0.001). Cinaciguat Emax and EC 50 were not different among oxygen treatment groups (median range Emax = 78.0% to 79.4% and EC 50 = -18.0 to -18.2 log M across oxygen groups). Aorta 2-hydroxyethidium was 1419 pmol/mg of protein (25th-75th percentile = 1178-1513) in normoxia, 1993 (1831-2473) in moderate hyperoxia, and 2078 (1936-2922) in severe hyperoxia ( P = 0.008, effect across groups). Conclusions: Hyperoxia, compared with normoxia, impaired endothelium-dependent and endothelium-independent vasodilation but not the response to heme-independent soluble guanylyl cyclase activation, and hyperoxia increased vascular superoxide production. Results from this study could have important implications for patients receiving high concentrations of oxygen and at risk for ischemia reperfusion-mediated organ injury.

The Attenuating Effect of Low-Intensity Pulsed Ultrasound on Hypoxia-Induced Rat Chondrocyte Damage in TMJ Osteoarthritis Based on TMT Labeling Quantitative Proteomic Analysis.

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease with a complex and multifactorial etiology. An increased intrajoint pressure or weakened penetration can exacerbate the hypoxic state of the condylar cartilage microenvironment. Our group previously simulated the hypoxic environment of TMJOA in vitro. Low-intensity pulsed ultrasound (LIPUS) stimulation attenuates chondrocyte matrix degradation via a hypoxia-inducible factor (HIF) pathway-associated mechanism, but the mode of action of LIPUS is currently poorly understood. Moreover, most recent studies investigated the pathological mechanisms of osteoarthritis, but no biomarkers have been established for assessing the therapeutic effect of LIPUS on TMJOA with high specificity, which results in a lack of guidance regarding clinical application. Here, tandem mass tag (TMT)-based quantitative proteomic technology was used to comprehensively screen the molecular targets and pathways affected by the action of LIPUS on chondrocytes under hypoxic conditions. A bioinformatic analysis identified 902 and 131 differentially expressed proteins (DEPs) in the <1% oxygen treatment group compared with the control group and in the <1% oxygen + LIPUS stimulation group compared with the <1% oxygen treatment group, respectively. The DEPs were analyzed by gene ontology (GO), KEGG pathway and protein-protein interaction (PPI) network analyses. By acting on extracellular matrix (ECM)-associated proteins, LIPUS increases energy production and activates the FAK signaling pathway to regulate cell biological behaviors. DEPs of interest were selected to verify the reliability of the proteomic results. In addition, this experiment demonstrated that LIPUS could upregulate chondrogenic factors (such as Sox9, Collagen Ⅱ and Aggrecan) and increase the mucin sulfate content. Moreover, LIPUS reduced the hydrolytic degradation of the ECM by decreasing the MMP3/TIMP1 ratio and vascularization by downregulating VEGF. Interestingly, LIPUS improved the migration ability of chondrocytes. In summary, LIPUS can regulate complex biological processes in chondrocytes under hypoxic conditions and alter the expression of many functional proteins, which results in reductions in hypoxia-induced chondrocyte damage. ECM proteins such as thrombospondin4, thrombospondin1, IL1RL1, and tissue inhibitors of metalloproteinase 1 play a central role and can be used as specific biomarkers determining the efficacy of LIPUS and viable clinical therapeutic targets of TMJOA.

Normobaric oxygen treatment for mild-to-moderate depression: a randomized, double-blind, proof-of-concept trial

Oxygen enriched air may increase oxygen pressure in brain tissue and have biochemical effects even in subjects without lung disease. Consistently, several studies demonstrated that normobaric oxygen treatment has clinical benefits in some neurological conditions. This study examined the efficacy of normobaric oxygen treatment in subjects with depression. In a randomized, double-blind trial, 55 participants aged 18–65 years with mild to moderate depression (had a Hamilton Rating Scale for Depression [HRSD] score of ≥ 8) were recruited to the study from the Southern district in Israel. Participants underwent a psychiatric inclusion assessment at baseline and then were randomly assigned to either normobaric oxygen treatment of 35% fraction of inspired oxygen or 21% fraction of inspired oxygen (room air) through a nasal tube, for 4 weeks, during the night. Evaluations were performed at baseline, 2 and 4 weeks after commencement of study interventions, using the following tools: HRSD; Clinical Global Impression (CGI) questionnaire; World Health Organization-5 questionnaire for the estimation of Quality of Life (WHO-5-QOL); Sense of Coherence (SOC) 13-item questionnaire; and, Sheehan Disability Scale (SDS). A multivariate regression analysis showed that the mean ± standard deviation [SD] changes in the HRSD scores from baseline to week four were − 4.2 ± 0.3 points in the oxygen-treated group and − 0.7 ± 0.6 in the control group, for a between-group difference of 3.5 points (95% confidence interval [CI] − 5.95 to − 1.0; P = 0.007). Similarly, at week four there was a between-group difference of 0.71 points in the CGI score (95% CI − 1.00 to − 0.29; P = 0.001). On the other hand, the analysis revealed that there were no significant differences in WHO-5-QOL, SOC-13 or SDS scores between the groups. This study showed a significant beneficial effect of oxygen treatment on some symptoms of depression.Trial registration: NCT02149563 (29/05/2014).

The use of high-flow nasal oxygen vs. standard oxygen therapy in hematological malignancy patients with acute respiratory failure in hematology wards

Background/aimHigh flow nasal cannula (HFNC) was mostly used in intensive care units (ICUs) with few studies in other departments. We hypothesized that HFNC applied at wards is beneficial for acute respiratory failure in hematological malignancy patients.Materials and methodsThe study is a single center, randomized controlled study. Inclusion criteria were hypoxemic respiratory failure and hematological malignancy. Patients were randomized to either venturi mask/nasal cannula oxygen treatment or HFNC.ResultsOne hundred patients were included in the study. Median age was 58.5 (18–86) years and APACHE II score was 17 (5–29). HFNC group was 51 patients and the oxygen treatment group 49 patients. P/F ratios were similar between the groups throughout the study period. Endotracheal intubation was required in 10 (20.0%) patients in oxygen group and 17 (33.0%) patients in HFNC group (p = 0.14). A total of 17 (35.0%) patients in oxygen group and 17 (33.0%) patients in HFNC group received noninvasive mechanical ventilation (p = 0.97). Median VAS comfort scores at the 2nd and 24th hours were not different between groups. The 28-day mortality rate was 36.7% (18 deaths) in the standard group and 45.0% (23 deaths) in the HFNC group (p = 0.39).ConclusionHFNC applied in wards is not superior to standard oxygen treatment for acute respiratory failure in hematological malignancy patients.

The Clinical Effects of Hyperbaric Oxygen in the Treatment of Sudden Deafness

Objective: To observe the clinical effect of hyperbaric oxygen in the treatment of sudden deafness. Methods: Ninety-six patients with sudden deafness diagnosed by the otolaryngology department were divided into 2 groups which comprised of 48 patients in the conventional treatment group and the other 48 patients in the hyperbaric oxygen treatment group. Both groups were treated with methylcobalamin, vitamin B1, and ginkgo biloba extract. The patients in the hyperbaric oxygen treatment group were given hyperbaric oxygen therapy of 2.0 ATA once a day. Each course of treatment lasted 10 days and after two courses of treatment, the clinical efficacies of the two groups were compared. Results: After two courses of treatment, the effect of treatment in the hyperbaric oxygen treatment group was significantly better than that of the conventional treatment group. Conclusion: Hyperbaric oxygen therapy can effectively improve the hearing level of patients with sudden deafness and the overall effective rate of treatment.

The Effects of Ultra-early Hyperbaric Oxygen Intervention in the Treatment of Diffuse Axonal Injury

Objective: To investigate the efficacy and mechanism of ultra-early hyperbaric oxygen intervention in the treatment of diffuse axonal injury (DAI). Methods: Eighty-six patients with diffuse axonal injury were selected and then divided into an ultra-early hyperbaric oxygen treatment group and a conventional treatment group with 43 patients in each group. The Glasgow Coma Scale (GCS) on the 10th day (10d), 20th day (20d), and 30th day (30d) after treatment and the Glasgow Outcome Score (GOS) 6 months later were observed and compared between both the groups. Results: The average score of the GCS at 10d, 20d, and 30d as well as the GOS 6 months later in the ultra-early hyperbaric oxygen treatment group were higher than those in the conventional treatment group (P &lt; 0.05). Conclusion: Hyperbaric oxygen therapy is one of the unique and effective methods in clinical treatment especially for the treatment of DAI patients and it is worthy of promotion.

Oxygen Therapy in Headache Disorders: A Systematic Review.

Background: The global active prevalence of migraines is approximately 14.7%. Oxygen therapy may reduce the use of non-steroidal anti-inflammatory drugs (NSAIDs) which often have various negative side effects. The purpose of this systematic review is to analyze the literature on the efficacy of high flow oxygen for the management of headache disorders, compared to placebo treatment. Methods: Studies were identified by PubMed, Web of Science and Scopus database from 1980 to the 30 October 2020. The search included the following terms: “oxygen therapy” and “headache” and “migraine”. Studies were included if high flow oxygen was used in the treatment of headache disorders. All selected studies were qualitatively analyzed. Results: Our literature search identified 71 studies, of which 65 were discarded and 6 were included in the meta-analysis. The random effect model did not show a pooled significant resolution of headache disorders (OR 2.08 (95% CI 0.92–4.70), p < 0.0001) in the oxygen therapy group compared to the placebo group. Conclusion: In our systematic review of six studies, there were no significant differences between high flow oxygen and placebo treatment groups.

Role of dissolved oxygen on behavioural and stress response of golden mahseer, Tor putitora

Aim: The study assessed the effect of different concentration of dissolved oxygen in Tor putitora, commonly known as Golden mahseer on physiological activities of juveniles regarding their growth performance, behavioural response and stress. Methodology: Twenty-seven acclimatized fingerlings of Tor putitora were selected for the experiment, in which nine were exposed to each group of dissolved oxygen treatment (Natural, 6.76 mg l-1, low 4.81mg l-1 and high, 10.20 mg ml-1) in aquaria (60×30×30) cm. The body weight (g), cortisol concentration (ng g-1) and behaviour profile was assessed using the Ethovision XT-13 software (Noldus, Info Tech, Wageningen, The Netherlands). Results: The average value of body weight (g), cortisol concentration (ng g-1) and all behavioural profiles of Tor putitora showed a significant difference at P&lt;0.05. The average concentration of cortisol was lower in high oxygen dissolved exposed juveniles as compared to other oxygen treatment groups. Interpretation: High oxygen content in water bodies reduces the stress level and stereotyped behavioural responses of fishes. These novel data, on cognitive swimming pattern in Tor putitora, is quite important for enhancement of production and maintaining the fish health issues. Key words: Behavioural profiling, Cortisol, Dissolved oxygen, Stress, Tor putitora

Oxygenation before Endoscopic Sedation Reduces the Hypoxic Event during Endoscopy in Elderly Patients: A Randomized Controlled Trial.

Background: Sedation endoscopy increases patient and examiner satisfaction but involves complications. The most serious complication is hypoxia, the risk factors for which are old age, obesity, and American Society of Anesthesiologists physical status of 3 or greater. However, clear evidence of oxygenation during sedation endoscopy for elderly people is lacking in US, European, and Korean guidelines. Method: This study was conducted for 1 year starting in August 2018 to evaluate whether pre-oxygenation use 1 min before sedation endoscopy could reduce the incidence of hypoxia in patients older than 65 years of age. A total of 70 patients were divided into the non-oxygenated group (n = 35; control group) and oxygen-treated group (n = 35; experimental group) during endoscopy. Result: The incidence of hypoxia was 28 (80%) in the control group versus 0 (0%) in the pre-oxygenated group. Factors related to hypoxia in the non-oxygenated group were a relatively high dose of midazolam and concomitant injection with narcotic analgesics such as pethidine. Conclusion: The incidence of hypoxia during sedation endoscopy is high in patients over 65 years, but oxygenation during endoscopic sedation in elderly people can significantly reduce the incidence of intraprocedural hypoxic events.

Hypoventilation following oxygen administration associated with alfaxalone–dexmedetomidine–midazolam anesthesia in New Zealand White rabbits

ObjectiveTo investigate the relationship between oxygen administration and ventilation in rabbits administered intramuscular alfaxalone–dexmedetomidine–midazolam. Study designProspective, randomized, blinded study. AnimalsA total of 25 New Zealand White rabbits, weighing 3.1–5.9 kg and aged 1 year. MethodsRabbits were anesthetized with intramuscular alfaxalone (4 mg kg–1), dexmedetomidine (0.1 mg kg–1) and midazolam (0.2 mg kg–1) and randomized to wait 5 (n = 8) or 10 (n = 8) minutes between drug injection and oxygen (100%) administration (facemask, 1 L minute–1). A control group (n = 9) was administered medical air 10 minutes after drug injection. Immediately before (PREoxy/air5/10) and 2 minutes after oxygen or medical air (POSToxy/air5/10), respiratory rate (fR), pH, PaCO2, PaO2, bicarbonate and base excess were recorded by an investigator blinded to treatment allocation. Data [median (range)] were analyzed with Wilcoxon, Mann–Whitney U and Kruskal–Wallis tests and p < 0.05 considered significant. ResultsHypoxemia (PaO2 < 88 mmHg, 11.7 kPa) was observed at all PRE times: PREoxy5 [71 (61–81) mmHg, 9.5 (8.1–10.8) kPa], PREoxy10 [58 (36–80) mmHg, 7.7 (4.8–10.7) kPa] and PREair10 [48 (32–64) mmHg, 6.4 (4.3–8.5) kPa]. Hypoxemia persisted when breathing air: POSTair10 [49 (33–66) mmHg, 6.5 (4.4–8.8) kPa]. Oxygen administration corrected hypoxemia but was associated with decreased fR (>70%; p = 0.016, both groups) and hypercapnia (p = 0.016, both groups). Two rabbits (one per oxygen treatment group) were apneic (no thoracic movements for 2.0–2.5 minutes) following oxygen administration. fR was unchanged when breathing air (p = 0.5). PaCO2 was higher when breathing oxygen than air (p < 0.001). Conclusions and clinical relevanceEarly oxygen administration resolved anesthesia-induced hypoxemia; however, fR decreased and PaCO2 increased indicating that hypoxemic respiratory drive is an important contributor to ventilation using the studied drug combination.

Effects of hyperbaric oxygen therapy on uncomplicated incisional and open wound healing in dogs.

To determine the safety of a hyperbaric oxygen therapy (HBOT) protocol and its influence on the healing of uncomplicated open and incisional wounds in dogs. Prospective, controlled experimental study. Adult dogs (n = 10). Two 2 × 2-cm open wounds and two 3-cm-long full-thickness dermal incisions were created on the dorsum of each dog. Dogs in the hyperbaric oxygen treatment group (HBO) received HBOT once daily (1.7 atmospheres absolute [ATA], 30 minutes on day 1; 2.0 ATA, 40 minutes on days 2-7) for 7 consecutive days, and dogs in the control group (CON) received standardized wound care. Dogs were monitored during HBOT for adverse side effects. Total wound area, percentage epithelialization, and percentage contraction were compared for the open wounds. Subjective wound scores were compared for the open and incisional wounds. Biopsies of both wound types were taken and used to determine histopathology scores. Bacterial cultures were completed on open wounds. No difference was detected between HBO and CON uncomplicated open and incisional wounds at any time for contraction, epithelialization, subjective wound scores, histopathology scores, or bacterial loads. All HBO dogs tolerated hyperbaric oxygen treatments with no adverse effects. The HBOT protocol tested here was safe but did not enhance the healing of uncomplicated acute wounds and incisions of dogs. These results do not provide evidence to support the use of HBOT to manage uncomplicated wounds in dogs.

Effect of sub-anesthesia dose of isoflurane in 60% oxygen on acute lung injury in aged rats with sepsis

Objective To investigate the effect of sub-anesthesia dose of isoflurane in 60% oxygen on acute lung injury in aged rats with sepsis. Methods Ninety male Sprague-Dawley rats, aged 12-14 months, weighing 500-800 g, were divided into 3 groups (n=30 each) using a random number table: sham operation group (Sham group), sepsis group (S group), and sepsis plus isoflurane plus oxygen treatment group (S+ I+ O group). Sepsis was induced by cecal ligation and puncture in S and S+ I+ O groups.In group S+ I+ O, 0.7% isoflurane in 60% oxygen was inhaled for 1 h starting from 1 and 6 h after operation.Eighteen rats were selected in each group and observed for 7 days after operation, and the survival rate was recorded.Six rats were selected in each group at 24 h after operation, and bronchoalveolar lavage fluid (BALF) was collected to determine the protein concentrations (by BCA protein assay), blood samples were collected from the femoral artery for blood gas analysis, PaO2 was recorded, and the oxygenation index was calculated.Six rats in each group were sacrificed at 24 h after operation, the left lung specimens were obtained and stained with hematoxylin and eosin for examination of pathological changes, the right lung specimens were obtained for determination of wet to dry weight ratio (W/D ratio), and blood samples were collected from the right atrium for measurement of the concentrations of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), high-mobility group box 1 protein (HMGB1) and IL-10 in serum (by enzyme-linked immunosorbent assay). Results Compared with group Sham, the survival rate was significantly decreased, and the concentrations of IL-1β, IL-6, TNF-α, HMGB1 and IL-10 in serum were increased in S and S+ I+ O groups, and W/D ratio and protein concentrations in BALF were significantly increased, and the oxygenation index was decreased in group S (P<0.05). Compared with group S, the survival rate was significantly increased, W/D ratio and protein concentrations in BALF were decreased, the oxygenation index was increased, the concentrations of IL-1β, IL-6, TNF-α and HMGB1 in serum were decreased, and the concentration of serum IL-10 was increased (P<0.05), and the pathological changes were significantly attenuated in group S+ I+ O. Conclusion Sub-anesthesia dose of isoflurane in 60% oxygen can reduce acute lung injury in aged rats with sepsis, and the mechanism may be ralated to inhibiting systemic inflammatory responses. Key words: Isoflurane; Oxygen; Sepsis; Respiratory distress syndrome, adult; Aged

Evaluation of Hyperbaric Oxygen Treatment in Acute Traumatic Spinal Cord Injury in Rats Using Diffusion Tensor Imaging.

This study aimed to evaluate the therapeutic effect of hyperbaric oxygen (HBO) on acute spinal cord injury (SCI) by measuring the in vivo diffusion tensor imaging (DTI) parameters apparent diffusion coefficient (ADC) and fractional anisotropy (FA) and observing diffusion tensor tractography (DTT) of fiber bundle morphology. The rats were randomly divided into sham-operated (SH), SCI, and SCI and hyperbaric oxygen treatment (SCI + HBO) groups (n = 6 in each group). The Basso-Bettie-Bresnahan (BBB) score was used to evaluate motor function recovery, and DTI was performed on days 3, 7, 14, and 21 after surgery. BBB scores and FA values decreased significantly after SCI, while the two values significantly improved in the SCI + HBO group compared with the SCI group on days 7, 14, and 21. ADC increased significantly on days 14 and 21 postoperatively in the SCI group compared with the SH group but did not significantly differ between the SCI and SCI + HBO groups at any time point. BBB scores had the same variation trend with ADC values and FA values in all three groups. In the SH group, DTT showed a well-organized spinal cord, but the spinal cord showed interruptions at sites of injury after SCI. In conclusion, HBO promotes the recovery of neuronal function after SCI. Parameters of DTI, especially FA, can quantitatively evaluate the efficacy of HBO treatment in SCI, while DTT enables the visualization of the fiber tracking of spinal cord tracts.

Effects of hyperbaric oxygen on hippocampal neuronal apoptosis in rats with acute carbon monoxide poisoning.

Acute carbon monoxide (CO) poisoning causes serious health problems such as neuropsychological sequelae. This study aimed to investigate neuronal apoptosis and the effects of hyperbaric oxygen (HBO₂) on different regions of the rat hippocampus after CO poisoning. 90 mature male Sprague Dawley rats were randomly divided into three groups: the normal control group (NC group), the acute carbon monoxide-poisoned group (CO group) and the hyperbaric oxygen treatment group (HBO₂ group). CO exposure included 0, 1, 3, 7, 14 and 21 treatment days, one exposure on the first day, and sacrifice on each of the following days. HBO₂ exposure included treatment for 0, 1, 3, 7, 14 and 21 days, daily treatment after CO exposure, and sacrifice after the last HBO₂ treatment on each of those days. Hematoxylin-eosin staining, immunohistochemical staining, immunofluorescence staining, and western blot analysis were performed to detect apoptosis in brain tissue samples. MMP-9 and caspase-3 were prominently increased by CO exposure and inhibited by HBO₂ in the CA3 region in the hippocampus at one, three and seven days (immunohistochemical staining [IHC]: P ⟨ 0.05). Neu N and the ratio of Bcl-2/ BAX were prominently decreased by CO exposure and rescued by HBO₂ in the CA3 region after seven days of treatment (IHC: P ⟨ 0.05). These findings indicated that neuronal apoptosis in the rat hippocampus could be induced by acute CO exposure, especially in the CA3 region. HBO₂ could effectively inhibit neuronal apoptosis, especially in the CA3 region after seven days of treatment. The application of HBO₂ to inhibit MMP-9 and apoptosis may contribute to brain recovery after acute CO poisoning.

Quantitative Proteomics Reveals the Mechanism of Oxygen Treatment on Lenses of Alzheimer’s Disease Model Mice

Alzheimer's disease (AD) is a neurodegenerative disease with well-characterized pathological features. Yet the underlying mechanisms have not been resolved and an effective therapeutic approach is lacking. Cerebral hypoxia is considered a risk factor of AD. We tested whether oxygen supplementation can relieve AD symptoms and how it affects the expression levels of proteins in the lens. Triple transgenic AD model (3xTg-AD) mice were divided into oxygen treated (OT) and control (Ctrl) groups. Their cognitive performances were tested in a Morris water maze (MWM) paradigm. Then, their eye lens tissues were subjected to quantitative proteomics analysis by the iTRAQ (isobaric tags for relative and absolute quantification) method. The up- and downregulated proteins were classified according to a Gene Ontology (GO) database in PANTHER. Behavioral and proteomic data were compared between the groups. Mice in the OT group had better learning and memorizing performance compared with the Ctrl group in MWM test. Lenses from the OT group had 205 differentially regulated proteins, relative to lenses from the Ctrl group, including proteins that are involved in the clearance of amyloid β-protein. The results of this study indicate that oxygen treatment can improve cognitive function in AD model mice and alters protein expression in a manner consistent with improved redox regulation.

Hyperbaric oxygen promotes malignant glioma cell growth and inhibits cell apoptosis.

Glioblastoma multiforme (GBM) is the most frequently diagnosed intracranial malignant tumor in adults. Clinical studies have indicated that hyperbaric oxygen may improve the prognosis and reduce complications in glioma patients; however, the specific mechanism by which this occurs remains unknown. The present study investigated the direct effects of hyperbaric oxygen stimulation on glioma by constructing an intracranial transplanted glioma model in congenic C57BL/6J mice. Bioluminescent imaging (BLI) was used to assess the growth of intracranial transplanted GL261-Luc glioma cells in vivo, while flow cytometric and immunohistochemical assays were used to detect and compare the expression of the biomarkers, Ki-67, CD34 and TUNEL, reflecting the cell cycle, apoptosis and angiogenesis. BLI demonstrated that hyperbaric oxygen promoted the growth of intracranially transplanted GL261-Luc glioma cells in vivo. Flow cytometric analysis indicated that hyperbaric oxygen promoted GL261-Luc glioma cell proliferation and also prevented cell cycle arrest. In addition, hyperbaric oxygen inhibited the apoptosis of the transplanted glioma cells. Immunohistochemical analysis also indicated that hyperbaric oxygen increased positive staining for Ki-67 and CD34, while reducing staining for TUNEL (a marker of apoptosis). The microvessel density was significantly increased in the hyperbaric oxygen treatment group compared with the control group. In conclusion, hyperbaric oxygen treatment promoted the growth of transplanted malignant glioma cells in vivo and also inhibited the apoptosis of these cells.

Effects of hyperbaric oxygen therapy on NACHT domain-leucine-rich-repeat- and pyrin domain-containing protein 3 inflammasome expression in rats following spinal cord injury.

The clinical application of hyperbaric oxygen therapy (HBOT) in spinal cord injury (SCI) has been reported, however the mechanism underlying its therapeutic effects remains to be elucidated. In the present study, SCI was modeled in male Sprague‑Dawley rats. A total of 120rats were randomly divided into four groups: Sham‑operated group (SH); sham‑operated and hyperbaric oxygen group (SH+HBO); spinal cord injury group (SCI) and spinal cord injury and hyperbaric oxygen treatment group (SCI+HBO). The rats in each group were randomly divided into five smaller groups (12h, 1, 3,7and 14days after surgery). The mRNA and protein expression levels of NACHT domain‑, leucine‑rich‑repeat‑ and pyrin domain‑containing protein3 (NALP3) inflammasome, including NALP3, adaptor molecule apoptosis‑associated speck‑like protein (ASC) and caspase‑1 were determined at several time points following injury. The results of the present study demonstrated that HBOT compromised the mRNA and protein expression levels of NALP3, ASC and caspase‑1 in the SCI model rats and HBOT mitigated SCI‑induced interleukin1β release in the injured spinal cord tissue. It was concluded that HBOT is an effective approach, which can prevent against spinal cord injury, likely by inactivating NALP3 inflammasome.

Effect of concurrent oxygen therapy on accuracy of forecasting imminent postoperative desaturation

Episodic postoperative desaturation occurs predominantly from respiratory depression or airway obstruction. Monitor display of desaturation is typically delayed by over 30 s after these dynamic inciting events, due to perfusion delays, signal capture and averaging. Prediction of imminent critical desaturation could aid development of dynamic high-fidelity response systems that reduce or prevent the inciting event from occurring. Oxygen therapy is known to influence the depth and duration of desaturation epochs, thereby potentially influencing the accuracy of forecasting of desaturation. In this study, postoperative pulse oximetry data were retrospectively modeled using autoregressive methods to create prediction models for [Formula: see text] and imminent critical desaturation in the postoperative period. The accuracy of these models in predicting near future [Formula: see text] values was tested using root mean square error. The model accuracy for prediction of critical desaturation ([Formula: see text] [Formula: see text]) was evaluated using meta-analytical methods (sensitivity, specificity, likelihood ratios, diagnostic odds ratios and area under summary receiver operating characteristic curves). Between-study heterogeneity was used as a measure of reliability of the model across different patients and evaluated using the tau-squared statistic. Model performance was evaluated in [Formula: see text] patients who received postoperative oxygen supplementation and [Formula: see text] patients who did not receive oxygen. Our results show that model accuracy was high with root mean square errors between 0.2 and 2.8%. Prediction accuracy as defined by area under the curve for critical desaturation events was observed to be greater in patients receiving oxygen in the 60-s horizon ([Formula: see text] vs. [Formula: see text]). This was likely related to the higher frequency of events in this group (median [IQR] [Formula: see text] [Formula: see text]) than patients who were not treated with oxygen ([Formula: see text] [Formula: see text]; [Formula: see text]). Model reliability was reflected by the homogeneity of the prediction models which were homogenous across both prediction horizons and oxygen treatment groups. In conclusion, we report the use of autoregressive models to predict [Formula: see text] and forecast imminent critical desaturation events in the postoperative period with high degree of accuracy. These models reliably predict critical desaturation in patients receiving supplemental oxygen therapy. While high-fidelity prophylactic interventions that could modify these inciting events are in development, our current study offers proof of concept that the afferent limb of such a system can be modeled with a high degree of accuracy.

Effect of VEGF and CX43 on the promotion of neurological recovery by hyperbaric oxygen treatment in spinal cord–injured rats

Background contextSpinal cord injury (SCI) is a serious health issue that may result in high health care costs, with additional social and psychological burdens. Hyperbaric oxygen (HBO) treatment has been found to be beneficial for neurological recovery; however, the underlying mechanisms are yet to be characterized. PurposeThe aim of this study was to investigate the mechanisms of HBO treatment in SCI by measuring the expression levels of vascular endothelial growth factor (VEGF) and Connexin43 (CX43) in the injured spinal cord tissue. Study design/settingAn experiment animal study of rats undergoing SCI and HBO treatment. MethodsThe spinal cord injury model was established in rats, which were randomly divided into the following four groups: (1) the sham-operated group (SH), (2) the sham-operated and hyperbaric oxygen treatment group (SH+HBO), (3) the spinal cord injury group (SCI), and (4) the spinal cord injury and hyperbaric oxygen treatment group (SCI+HBO). For groups of SH+HBO and SCI+HBO, the animals received 1 hour of HBO at 2.0 ATA in 100% O2 twice per day for 3 days and then daily for the following days consecutively after surgery. After operation, neurological assessments were performed, the spinal cord tissue samples were harvested for histopathological evaluation, Western blot and real-time polymerase chain reaction analysis. ResultsThe Basso-Bettie-Bresnahan scores were significantly improved in the SCI+HBO group compared with the SCI group on the postoperative 7th and 14th days. The histology scores were significantly decreased by HBO treatment compared with that in the SCI group on the postoperative 3rd, 7th, and 14th days. Western blot analysis and real-time polymerase chain reaction revealed that the expression level of vascular endothelial growth factor (VEGF) in the SCI+HBO group was significantly increased compared with the SCI group. The protein expression level of CX43 and its mRNA level in the SCI+HBO group were significantly decreased on the postoperative 3rd and 7th days, whereas its expression was significantly increased by HBO treatment on the postoperative 14th day compared with the SCI group. ConclusionsHBO treatment improved neurological recovery when applied after SCI. The expression level changes of VEGF and CX43 may contribute to the further understanding on the molecular mechanisms of HBO treatment on SCI.