Hyperbaric Oxygen Intervention Research Articles

Analysis of the efficacy of hyperbaric oxygen therapy for disorders of consciousness: A retrospective cohort study.

To analyze the efficacy and associated factors affecting the prognosis in patients with disturbance of consciousness after hyperbaric oxygen (HBO) treatment. A retrospective study was carried out on patients with disorders of consciousness (DOC) receiving HBO treatment from January to January 2022 in the Second Department of Rehabilitation Medicine of the Second Hospital of Hebei Medical University, China. HBO therapy improved the Glasgow Coma Scale (GCS) and Chinese Nanjing Persistent Vegetative State Scale (CNPVSS), as well as the clinical efficacy in patients with DOC. The comparison of GCS and CNPVSS scores in patients with DOC before and after HBO treatment was all statistically significant, with 325 patients (67.1%) showing effective results and 159 patients (32.9%) having unchanged outcomes. Univariate analysis indicated that there were statistically significant differences in age, HBO intervention time, HBO treatment times, pre-treatment GCS score, and etiology and underlying diseases between the good and poor prognoses groups. Multivariate regression analysis showed that HBO intervention time ≤7 days, HBO treatment ＞ times, high GCS score before HBO treatment, and brain trauma were independent influencing factors in achieving a good prognosis for patients with DOC. Low pre-treatment GCS scores were an independent risk factor for a poor prognosis in patients with brain trauma while being male, late HBO intervention time, fewer HBO treatment times, and low pre-treatment GCS scores were independent risk factors for a poor prognosis in patients with DOC after a stroke. Being ≥50 years of age, late HBO intervention time, and low pre-treatment GCS scores were independent risk factors for a poor prognosis in patients with DOC after hypoxic-ischaemic encephalopathy. HBO therapy can improve the GCS, CNPVSS scores and clinical efficacy in patients with DOC, and the timing of HBO intervention ≤7 days, times of HBO treatment, high pre-treatment GCS score, and brain trauma were the independent influencing factors of good prognosis in patients with DOC.

Hyperbaric intervention ameliorates the negative effects of long-term high-altitude exposure on cognitive control capacity.

Hypoxia due to reduced partial pressure of oxygen from high-altitude exposure affects the cognitive function of high-altitude migrants. Executive function is an important component of human cognitive function, characterized by high oxygen consumption during activity, and its level can be measured using cognitive control capacity (CCC). In addition, there is evidence for the potential value of hyperbaric oxygen (HBO) interventions in improving cognitive decline on the plateau. Therefore, the objective of this study was to investigate the effect of long-term high-altitude exposure on CCC in high-altitude newcomers and whether hyperbaric oxygen intervention has an ameliorative effect. This study measured the magnitude of participants' CCC using a Backward Masking Majority Function Task (MFT-M). Study 1 was a controlled study of different altitude conditions, with 64 participants in the high-altitude newcomer group and 64 participants in the low-altitude resident group, each completing the MFT-M task once. Study 2 was a controlled HBO intervention study in which newcomers who had lived at a high altitude for 2years were randomly divided into the HBO group (n = 28) and control group (n = 28). 15 times hyperbaric oxygen interventions were performed in the HBO group. Subjects in both groups completed the MFT-M task once before and once after the intervention. Study 1 showed that CCC was significantly higher in the low-altitude resident group than in the high-altitude newcomer group (p = 0.031). Study 2 showed that the CCC in the HBO group was significantly higher after 15 hyperbaric interventions than before (p = 0.005), while there was no significant difference in the control group (p = 0.972). The HBO group had significantly higher correct task rates than the control group after the intervention (p = 0.001). This study confirms that long-term high-altitude exposure leads to impairment of CCC in high-altitude newcomers and that hyperbaric oxygen intervention is effective in improving CCC.

Effect of Hyperbaric Oxygen Intervention on Oxidative Stress and Expression of Nerve Growth Factor in Patients with Craniocerebral Injury

Effect of Hyperbaric Oxygen Intervention on Oxidative Stress and Expression of Nerve Growth Factor in Patients with Craniocerebral Injury

Effects of Hyperbaric Oxygen Intervention on the Degenerated Intervertebral Disc: From Molecular Mechanisms to Animal Models.

MicroRNA (miRNA) 107 expression is downregulated but Wnt3a protein and β-catenin are upregulated in degenerated intervertebral disc (IVD). We investigated mir-107/Wnt3a-β-catenin signaling in vitro and in vivo following hyperbaric oxygen (HBO) intervention. Our results showed 96 miRNAs were upregulated and 66 downregulated in degenerated nucleus pulposus cells (NPCs) following HBO treatment. The 3' untranslated region (UTR) of the Wnt3a mRNA contained the "seed-matched-sequence" for miR-107. MiR-107 was upregulated and a marked suppression of Wnt3a was observed simultaneously in degenerated NPCs following HBO intervention. Knockdown of miR-107 upregulated Wnt3a expression in hyperoxic cells. HBO downregulated the protein expression of Wnt3a, phosphorylated LRP6, and cyclin D1. There was decreased TOP flash activity following HBO intervention, whereas the FOP flash activity was not affected. HBO decreased the nuclear translocation of β-catenin and decreased the secretion of MMP-3 and -9 in degenerated NPCs. Moreover, rabbit serum KS levels and the stained area for Wnt3a and β-catenin in repaired cartilage tended to be lower in the HBO group. We observed that HBO inhibits Wnt3a/β-catenin signaling-related pathways by upregulating miR-107 expression in degenerated NPCs. HBO may play a protective role against IVD degeneration and could be used as a future therapeutic treatment.

Real-world evidence of hyperbaric oxygen therapy on cardiovascular outcomes in patients with chronic osteomyelitis

BackgroundThe effectiveness of hyperbaric oxygen (HBO) therapy for chronic osteomyelitis remains inconclusive. In particular, recent studies have shown that chronic osteomyelitis is a crucial risk factor for cardiovascular diseases. However, the preventive effect of HBO on cardiovascular events has not been reported in patients with chronic osteomyelitis. MethodsWe conducted a population-based cohort study to evaluate the impact of HBO on patients with chronic osteomyelitis. Overall, 5312 patients with chronic osteomyelitis were selected from the Taiwan National Health Insurance Database to evaluate the impact of HBO in patients with chronic osteomyelitis. Propensity-score (PS) matching and inverse probability weighting (IPTW) were employed to balance covariates between the HBO and non-HBO groups. The primary outcome was all-cause mortality. The secondary outcomes were myocardial infarction (MI) and stroke hospitalisation. Furthermore, we evaluated the appropriate timing for HBO intervention by the restricted cubic spline (RCS) functions. ResultsAfter 1:4 PS-matching, the HBO group (n = 265) was associated with lower 1-year mortality (hazard ratio [HR], 0.49; 95 % confidence interval [CI], 0.25–0.95) than the non-HBO group (n = 994); this was consistent with the IPTW weighting results (HR, 0.25; 95 % CI, 0.20–0.33). The risk of stroke was lower in the HBO group (HR, 0.46; 95 % CI, 0.34–0.63) than that in the non-HBO group. However, HBO therapy failed to reduce the risk of MI. Using the RCS model, patients with intervals within 90 days (HR, 1.38; 95 % CI, 1.04–1.84) presented a significant risk of 1-year mortality. After 90 days, as the length of interval increased, the risk gradually decreased and became insignificant. ConclusionThe present study revealed that adjunctive HBO could benefit the 1-year mortality and stroke hospitalisation in patients with chronic osteomyelitis. HBO was recommended to be initiated within 90 days of chronic osteomyelitis hospitalisation.

EFEITOS DA INTERVENÇÃO DE OXIGÊNIO MICRO-HIPERBÁRICO DE 4 SEMANAS NA FUNÇÃO DO SISTEMA OXIDANTE-ANTIOXIDANTE

ABSTRACT Introduction Hyperbaric oxygen intervention has an important effect on the function of the body’s oxidation-antioxidant system. Objective To verify the effects of a 4-week micro-hyperbaric oxygen intervention on oxidation-antioxidation system function in skeleton athletes. Methods The experimental group underwent a 1.3 ATA HBO intervention for 4 weeks and the control group underwent natural recovery. The levels of MDA, PC, SOD, CAT, GSH-PX, T-AOC, BU, CK, T, and C of the two groups were measured at Week 0, Week 2, and Week 4. Results The MDA, PC, and CK of the Exp group were significantly lower than Con group (P < 0.05) in Week 4. The SOD, CAT, and T-AOC of the Exp group were significantly higher in Week 4 than in Week 0 (P < 0.05) and significantly higher than the Con group values (P < 0.05). Conclusions A four-week 1.3 ATA HBO intervention decreased the level of oxidative stress, increased the activity of antioxidant enzymes, and reduced the degree of exercise fatigue in skeleton athletes. Level of Evidence II; Therapeutic studies - Investigating treatment results.

Mechanism of Hyperbaric Oxygen Combined with Astaxanthin Mediating Keap1/Nrf2/HO-1 Pathway to Improve Exercise Fatigue in Mice.

Objective This work aimed to explore the application and optimization of the electrophysiological monitoring system to real-time monitor the exercise-induced fatigue (EIF) animals and investigate the intervention mechanism of hyperbaric oxygen (HBO) combined with natural astaxanthin (NAX) on EIF. Methods First, a system was constructed for acquisition, processing, and feature extraction of electrocardiograph (ECG) signal and surface electromyography (EMG) signal for EIF monitoring. The mice were randomly divided into a control group (CG), EIF group (EG), HBO treatment (HBO) group, and HBO combined with NAX treatment (HBO + NAX) group. The effect of the constructed system on classification recognition of EIF was analyzed. The levels of serum antioxidative stress indicators of mice in each group were detected, including malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), glutathione-peroxidation (GSH-Px), and total antioxidant capacity (T-AOC). In addition, the mRNA and protein levels of Keap1/Nrf2/HO-1 pathway related genes in liver tissue were detected. Results The results showed that the normalized least mean squares algorithm effectively removed the motion artifact interference of ECG signal and can clearly display the signal peak, and high-pass filtering and power frequency filtering effectively removed the motion and baseline drift interference of surface EMG signal. The recognition sensitivity, specificity, and accuracy of the EIF recognition model based on the long- and short-term memory network were 90.0%, 93.3%, and 92.5%, respectively. Compared with the CG, the characteristics of ECG signal and surface EMG signal of the mice in the EIF group changed greatly (P < 0.05); the serum MDA level was increased obviously; the CAT, SOD, GSH, GSH-Px, and T-AOC levels were observably reduced (P < 0.05); the expressions of Keap1 and HO-1 in the liver were reduced remarkably, while the expression of Nrf2 was increased notably (P < 0.05). Compared with the EIF group, the characteristics of ECG signal and surface EMG signal of the mice in the HBO and HBO + NAX groups were obviously improved (P < 0.05); the serum MDA level was significantly reduced; the CAT, SOD, GSH, GSH-Px, and T-AOC levels were greatly increased (P < 0.05); the expressions of Keap1 and HO-1 in the liver were greatly increased, while the expression of Nrf2 was decreased sharply (P < 0.05). Conclusion Therefore, the feature extraction and classification system of ECG signal combined with surface EMG signal could realize real-time monitoring of EIF status. HBO intervention could improve the body's ability to resist oxidative stress through the Keap1/Nrf2/HO-1 pathway and then improve the EIF state. In addition, the improvement effect of HBO + NAX was more obvious.

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.

Effects of repetitive hyperbaric oxygen therapy on neuroprotection in middle cerebral artery occlusion rats

Hyperbaric oxygen (HBO) has been suggested as a possible therapy for brain injury. However, the effects of HBO after transient brain ischemia are inconsistent and the underlying mechanisms are not fully known. The present study aimed to investigate the effects of repetitive HBO intervention in a transient middle cerebral artery occlusion (MCAO) animal model. Seventy-two Sprague-Dawley rats received MCAO and were randomly assigned to normal air control or HBO intervention groups. Each group was divided into 3 subgroups according to the intervention time period (7, 14, and 21 days). HBO was started 24 h post-MCAO for 1 h/day at 3.0 ATA with no-air breaks. After the final intervention, half of the rats in each subgroup were sacrificed and the right motor cortex was removed to examine levels of Akt phosphorylation and glutathione (GSH), as well as glutathione peroxidase (GPx) and reductase (GR) activity. The other half of the rats were used to examine infarct volume. At 24 h post-MCAO and the end of the final intervention, rats underwent tests to examine motor performance. We noted that 14- and 21-day HBO interventions significantly reduced infarct volume and increased Akt phosphorylation and GSH levels and GPx and GR activity. Motor performance was also significantly improved after 14- and 21-day interventions. No significant differences were observed between the controls and 7-day intervention groups. Repetitive HBO intervention starting 24 h post-MCAO and applied for at least 14 days, provided neuroprotective effects through modulating the cell survival pathway and antioxidative defense system.

Longitudinal study of hyperbaric oxygen intervention on balance and affective symptoms in military service members with persistent post-concussive symptoms.

Dizziness and imbalance are common after mild traumatic brain injury (mTBI). Hyperbaric oxygen (HBO2) has been proposed for persistent post-concussive symptoms after mTBI, but its effect on vestibular function is unknown. To describe balance function in military service-members before and after intervention, and to explore the influence of post-traumatic stress disorder (PTSD), anxiety, and depression on vestibular outcomes. Seventy-one participants with mTBI and seventy-five healthy adults without brain injury were enrolled (NCT01611194 and NCT01925963). mTBI participants were randomized to 40 HBO2 sessions or 40 sham chamber sessions over 12 weeks. Normative controls received no intervention. Balance and neuropsychological function were measured at baseline, 13 weeks, and 6 months. The mTBI cohort performed worse than healthy controls on balance and gait measures and reported more affective symptoms. Some within-group improvements were noted at 13 weeks and 6 months. Significant between-intervention differences on balance measures were minimal but effects on postural control generally favored HBO2. Those with affective symptoms, particularly PTSD, had the most improvement in postural control and otolith function following 13 weeks of HBO2. HBO2 may influence balance function after mTBI, particularly in those with affective symptoms.

Outcome and prognostic factors of patients treated in the intensive care unit for carbon monoxide poisoning

Carbon monoxide (CO), a colorless and odorless gas, is one of the common causes of poisoning-related deaths worldwide. CO poisoning can result in hypoxic brain damage and death, but intensive care can improve the likely outcome for critically ill patients. However, there is a paucity of clinical data regarding the prognostic factors and association between organ dysfunction and clinical outcome of patients treated for CO poisoning in the intensive care unit (ICU). We performed a retrospective study of patients admitted to a university affiliated hospital ICU between July 2001 and December 2010 following CO poisoning. Outcomes were survival to ICU discharge and to hospital discharge. Seven hundred and eighty-seven patients were admitted to the university hospital following CO poisoning, of which 140 (17.8%) were admitted to the hospital ICU. The overall mortality rate of the patients admitted to the ICU was 14.3% (20/140). Univariate analysis indicated that non-surviving patients with CO poisoning were more likely to have initial blood carboxyhemoglobin (COHb) level>30%, shock, acute respiratory failure, Acute Physiology and Chronic Health Evaluation II (APACHE II) score≥25, Glasgow coma scale (GCS) score of 3, acute renal failure, dysfunction or failure of more than 3 organs, low blood pH, low HCO3- level, high potassium level, and high glucose level. They were also more likely to have not received hyperbaric oxygen (HBO) intervention. Multivariate logistical regression analysis indicated that the mortality rate of patients treated in the ICU for CO poisoning was higher if their initial APACHE II score was ≥25, GCS was 3, and more than 3 organs were dysfunctional. Moreover, HBO intervention in ICU significantly decreased patients' risk of mortality due to CO poisoning. In conclusion, we observed that APACHE II score >25, GCS 3, and dysfunction of more than 3 organ systems on admission to emergency department was associated with a significant mortality risk in patients treated in the ICU for CO poisoning. Moreover, HBO therapy could reduce the risk of mortality in patients with CO poisoning in ICU.

Randomized controlled trial of hyperbaric oxygen therapy in adhesive postoperative small bowel obstruction.

Hyperbaric oxygen (HBO) therapy is a controversial treatment for adhesive postoperative small bowel obstruction (ASBO), with only a few retrospective studies reported. The aim of this study was to assess the clinical impact of HBO therapy in the treatment of ASBO. Patients with ASBO were randomly assigned to no-HBO (standard arm) or HBO (intervention arm). Patients of the intervention arm were treated once daily at a pressure of 2.0atm absolute and received 100% oxygen. The primary endpoint was the success rate of medical treatment. This study was registered at the UMIN Clinical Trial Registry as UMIN000010399. The no-HBO group included 40 patients, and the HBO group included 33 patients. Patient characteristics, time to oral intake, and length of hospital stay were similar between the two groups. No significant differences were noted between the no-HBO and HBO groups in the need for long intestinal tube decompression (20.0 versus 18.2%, respectively, p = 1.000) and the need for operative intervention (10.0 versus 18.2%, respectively, p = 0.332). The overall success rate of medical treatment was 72.5% in the no-HBO group and 78.8% in the HBO group (p = 0.594). In this randomized controlled trial, HBO for ASBO has no additional effect in medical treatment.

Increased Efficacy of Antivenom Combined with Hyperbaric Oxygen on Deinagkistrodon acutus Envenomation in Adult Rats.

Background:Snakebites are a neglected threat to global human health with a high morbidity rate. The present study explored the efficacy of antivenom with hyperbaric oxygen (HBO) intervention on snakebites, which could provide the experimental basis for clinical adjuvant therapy.Methods:Male Sprague–Dawley rats (n = 96) were randomized into four groups: the poison model was established by injecting Deinagkistrodon acutus (D. acutus) venom (0.8 LD50) via the caudal vein; the antivenom group was injected immediately with specific antivenom via the caudal vein after successful establishment of the envenomation model; and the antivenom + HBO group was exposed to HBO environment for 1 h once at predetermined periods of 0 h, 4 h, 12 h, and 23 h after antivenin administration. Each HBO time point had six rats; the control group was left untreated. The rats in the experimental group were euthanized at the corresponding time points after HBO therapy, and brain tissue and blood were harvested immediately. Hematoxylin and eosin (H&E) staining was used to investigate the pathological changes in the rat brain. Immunohistochemistry (IHC), real-time polymerase chain reaction (PCR), and Western blotting were used to detect the expression of Nestin mRNA and protein in the subventricular zone (SVZ) of the brain. The levels of coagulation function (prothrombin time, activated partial thromboplastin time [APTT], and fibrinogen) and oxidation/antioxidation index (malondialdehyde [MDA] and superoxide dismutase [SOD]) were analyzed. Data were analyzed using one-way analysis of variance.Results:The brain tissue from rats in the poison model was observed for pathological changes using H&E staining. Tissues showed edema, decreased cell number, and disordered arrangement in the SVZ in the snake venom group. The antivenom − HBO intervention significantly alleviated these observations and was more prominent in the antivenom + HBO group. The serum levels of SOD and MDA in the snake venom group were increased and the antivenom − HBO intervention further increased the SOD levels but significantly decreased the MDA levels; however, this was enhanced within 1 h after HBO administration (MDA: F = 5.540, P = 0.008, SOD: F = 7.361, P = 0.000). Activated partial thromboplastin time (APTT) was significantly abnormal after venom administration but improved after antivenom and was even more significant in the antivenom + HBO group 5 h after envenomation (F = 25.430, P = 0.000). Only a few nestin-positive cells were observed in the envenomation model. The expression levels were significant in the antivenom and antivenom + HBO groups within 1 and 5 h after envenomation and were more significant in the antivenom + HBO group as determined by IHC, real-time PCR, and Western blotting (P < 0.05). D. acutus envenomation has neurotoxic effects in the brain of rats.Conclusions:Antivenin and HBO, respectively, induced a neuroprotective effect after D. acutus envenomation by attenuating brain edema, upregulating nestin expression in SVZ, and improving coagulopathy and oxidative stress. The intervention efficacy of antivenom with HBO was maximum within 5 h after envenomation and was more efficacious than antivenom alone.

Hyperbaric Oxygen Intervention Modulates Early Brain Injury after Experimental Subarachnoid Hemorrhage in Rats: Possible Involvement of TLR4/NF-κ B-Mediated Signaling Pathway

Background/Aims: Previous studies have proved that the activation of TLR4/NF-κ B signaling pathway is involved in inflammatory processes in early brain injury (EBI) after subarachnoid hemorrhage (SAH). Hyperbaric oxygen (HBO) intervention has successfully been used to treat several animal models of tissue injury via its anti-inflammation property. This study was undertaken to investigate the influence of HBO administration on the TLR4/NF-κ B signaling pathway in rats at the early stage of SAH. Methods: Male Sprague-Dawley rats (n = 150) were randomly divided into 5 groups: the sham, the sham + 2.8 atmospheres absolute (ATA) HBO group, the SAH group, the SAH + 2.0ATA HBO group, the SAH + 2.8ATA HBO group. Each group (n = 30) was randomly subdivided into three subgroups that were examined at the following time points: 24 h, 48 h and 72 h post-injury. HBO (100% O2, 2.0ATA or 2.8ATA for 90mins) was initiated 12 h after injury. Neurological deficit, brain edema and blood-brain barrier (BBB) permeability were assessed to evaluate the development of EBI. The expressions of TLR4, NF-κ B and pro-inflammatory cytokines in the cortical were determined by real time polymerase chain reaction (RT-PCR), western blot, immunohistochemistry, or enzyme-linked immunosorbent assay (ELISA). Results: Our study showed that treatment with HBO significantly decreased the expressions of TLR4, NF-κ B and the downstream inflammatory agents, such as TNF-α, IL-6, IL-1β and ICAM-1, and also improved brain edema, blood-brain barrier permeability and neurologic function. Conclusions: These findings indicate that HBO treatment may result in abatement of the development of EBI after SAH, possibly through suppression of TLR4/NF-κ B signaling pathway.

Hyperbaric Oxygen Alleviates Experimental (Spinal Cord) Injury by Downregulating HMGB1/NF-κB Expression

We presented an insight into the effect of hyperbaric oxygen (HBO) on spinal cord injury (SCI), aiming to uncover the dynamics of high-mobility group protein B1 (HMGB1) and nuclear factor κB (NF-κB) after HBO intervention in rats with acute SCI. Prognosis of SCI is directly linked with the control of secondary injury, in which the inflammatory response plays a leading role. HBO therapy can reduce this secondary damage to the spinal cord. We used an animal model to characterize the therapeutic effect of HBO on SCI. A growing number of studies have confirmed that HBO has gradually become an indispensable element after SCI in reducing neurological disorders, and improving the physical function and quality of life of patients. The role of HBO in the process of HMGB1/NF-κB-related secondary inflammatory responses in SCI has yet to be characterized. Rats were randomly categorized into sham, sham + HBO, SCI, and SCI + HBO groups. The expression levels of HMGB1 and NF-κB were measured at days 1, 3, 7, and 14 after SCI. After SCI, significant increases in mRNA and protein expression were observed for both HMGB1 and NF-κB (P< 0.01) compared with sham group. HMGB1 mRNA and protein expression levels were decreased after HBO intervention. The decreases were significant at days 7 and 14 (P< 0.05) post-HBO. In the SCI + HBO group, the significant decreases in NF-κB mRNA and protein expression levels were also observed at days 3, 7, and 14 (P< 0.05). After HBO intervention, a significant increase was seen in the Basso, Beattie, and Bresnahan score at days 7 and 14 (P< 0.05). HBO intervention may reduce the secondary damage of SCI caused by inflammatory responses via downregulating the expression of HMGB1/NF-κB, and promoting the repair of neurological function. N/A.

Hyperbaric oxygen intervention on expression of hypoxia-inducible factor-1α and vascular endothelial growth factor in spinal cord injury models in rats

Background Hyperbaric oxygen (HBO) intervention is a main therapeutic method and the curative effect has been certified for spinal cord injury (SCI), but the mechanisms of the neuroprotective effect of HBO on SCI remain elusive. This study aimed to observe the change in expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) after SCI at different time points and to investigate the neuroprotective mechanism of HBO on SCI in rats. Methods A total of 160 adult Sprague-Dawley rats, weighing between 250 and 300 g, were randomly assigned to four experimental groups (n=40 per group). SCI group: SCI was created with a special NYU impactor of Allen's by a 25 gram-centimeter impacting energy on T10 of the spinal cord. SCI+HBO group: HBO therapy after SCI model was established. Sham operation (SH) group: only laminectomy of T10 and no impact on the spinal cord was done. SH+HBO group: HBO therapy after sham operation. The hindlimb functional recovery was evaluated using Basso, Beattie, and Bresnahan (BBB) score and the expressions of HIF-1α and VEGF were observed with fluorescent quantitation PCR and Western blotting method of six rats picked randomly from each group at different time points of 1, 3, 7, and 14 days after operation. Results Rats in the SCI group and SCI+HBO group were paralyzed completely after operation with BBB 0-1 score. Rats in the SH group and SH+HBO group could walk after sham operation with BBB 20-21 score. The BBB score of rats in the SCI+HBO group (4.67±1.97 and 10.83±2.23) was higher than that in the SCI group (1.83±0.75 and 6.67±2.16) at 7 and 14 days time points obviously (P &lt;0.05). The expressions of HIF-1α and VEGF in the SCI group and SCI+HBO group were higher than in the SH group and SH+HBO group at any time point obviously (P &lt;0.05), while the SCI+HBO group presented the least expression of HIF-1α mRNA and protein (3.82±0.41 and 0.59±0.06; 2.26±0.41 and 0.37±0.05; 1.58±0.26 and 0.29±0.05) than that in the SCI group (6.36±0.58 and 0.76±0.07; 3.55±0.47 and 0.51±0.07; 2.27±0.39 and 0.40±0.06) respectively at 3, 7, and 14 days time points (P &lt;0.05) with significant difference and more expression of VEGF mRNA and protein (5.83±0.77 and 0.72±0.06; 4.59±0.51 and 0.63±0.06) than that in the SCI group (3.06±0.30 and 0.48±0.07; 2.25±0.24 and 0.39±0.09) respectively at 7 and 14 days time points (P &lt;0.05) with significant difference. Conclusions HBO could improve the hind limb functional recovery after SCI in rats. The elevation and duration of the expression of VEGF and the reduction of expression of HIF-1α by HBO intervention may be inversely related in the repair of damaged spinal cord and neuroprotective effect.

Effects of hyperbaric oxygen on the expression of caveolin-2 in brain tissues and the blood brain barrier after focal cerebral ischemia and reperfusion

Objective To investigate the effects of hyperbaric oxygen (HBO) on the expression of caveolin2 and matrix-metalloproteinase-9 (MMP-9) in brain tissues and the blood brain barrier (BBB) after cerebral ischemia and reperfusion (I/R) in rats. Methods Three hundred and seventy male Wistar rats were randomly assigned into sham,ischemia-reperfusion,HBO,and I/R + HBO groups. After creating cerebral I/R models,oxygen at 0.25 MPa was administered 5 times,and 2％ Evans blue (EB) was injected into the tail veins 1 h before the rats were sacrificed.The permeability of the BBB,the expression of caveolin-2 and MMP-9,and EB content were determined by Western blotting,immunohistochemistry,and spectrophotometery,respectively. Results In the I/R group,the EB content increased steadily to a peak at 4 hours.EB content in the IR + HBO group was significantly lower than in the I/R group.Caveolin-2 and MMP-9 were significantly augmented by I/R injury at the 24th,48th and 72nd hours.Compared to the I/R group,HBO intervention decreased their expression levels. Conclusion HBO intervention can reverse the increase of caveolin-2 and MMP-9 caused by I/R injury,which suggests a mechanism for protective effects of HBO on the permeability of the BBB in I/R injury. Key words: Hyperbaric oxygen ; Ischemia-reperfusion ; Blood brain barrier; Caveolin-2 ; Matrix-met-alloproteinase-9

Changes of CD11,CD54 in patients with acute cerebral infarction after hyperbaric oxygen intervention and their influence on patients" prognosis

Objective To observe the changes of CD11 a, CD11c and CD54 and its' influence on prognosis after the intervention of hyperbaric oxygen(HBO) in patients with acute cerebral infarction (ACI).Methods Sixty-four ACI patients were divided into control group( C group) and HBO therapy group( HBOT group).C group (33 cases) received routine treatment only, HBOT group ( 31 cases) received routine treatment and hyperbaric oxygen therapy.CD 11 a, CD11 c and CD54 were measured in both groups at ≤72h, the 7th d, 10th d, 12th d, 20th d after ACI, and neural functional damage scores(NDS) were evaluated at the same time.CD11a, CDllc and CD54 were also measured in normal control group (25 cases).Results Plasma levels of CD11a, CD11c and CD54 rose significantly both in HBOT group and C group and peaked at≤72 h after ACI, there was no significant difference between two groups (P > 0.05), then declined at the 7th d.Levels of CD11 a, and CD11c maintained at the peak for 7 d in H BOT group and for 10 d in C group.CD54 peak remained for 10 d in HBOT group, and for 12 d in C group.A correlation analysis and linear regression analysis showed that the NDS levels at 20th d (short-term curative effect), 6 months and 12 months (long-term outcome) could be explained by 97.3 % , 96.7% and 96.6% , respectively by the admission levels of CD11 a and/or CD11 c and/or CD54 and other related factors.Conclusion After hyperbaric oxygen therapy peak level duration of CD11a, CD11c and CD54 could be shortened.Hyperbaric oxygen could influence intercellular adhesion molecule changing process, reduce leukocytes adhesion, decrease expressions of CD11a CD11c and CD54, and protect ACI patients.Before treatment, expression of CD11a, CD11c and CD54 may predict the severity, short or long-term outcome and prognosis of ACI patients. Key words: CD11; CD54; Hyperbaric oxygen therapy; Acute cerebral infarction; Neural functional recovery

Effects of hyperbaric oxygen on the acute lung injury induced by oleic acid in rats

To explore the effect of hyperbaric oxygen (HBO) on acute lung injury (ALI) induced by oleic acid (OA) in rats. Eighty healthy Sprague-Dawley (SD) rats were randomly divided into four groups. In OA group (n=30), ALI was produced by injection of OA 0.15 ml/kg through tail vein. Ten rats were randomly selected and sacrificed after injection of OA at the time of 4 hours, 3 days, and 7 days, respectively. In OA plus HBO group (n=20), rats received HBO intervention in a special box with oxygen of 2.5 atm (1 atm=101.325 kPa) for 90 minutes. Ten rats were randomly respectively sacrificed at 3 days and 7 days. In simple HBO group, 20 rats were sacrificed at 3 days and 7 days of HBO intervention, respectively. Other 10 rats were assigned as control group. Blood, lung specimens were collected after sacrifice. Serum contents of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and IL-6 were measured. Gross changes and pathological findings of the left lung were recorded. The wet to the dry weigh (W/D) of the right lung was determined. Partial pressure of oxygen in arterial blood (PaO2, mm Hg, 1 mm Hg=0.133 kPa) fell from 107.70+/-5.37 to 57.40+/-2.63 in OA group. Congestion, bleeding and edema could be seen grossly. They could also be found under microscope with disappearance of normal structure, and accumulation of fluid in interstitium with inflammatory cell infiltration and hyaline membrane formation were also found. Lung W/D ratio was increased as compared with the control group (6.94+/-0.44 vs. 4.59+/-0.44, P<0.05). A marked increase was found in serum TNF-alpha, IL-1 beta, IL-6 levels [TNF-alpha (microg/L): 18.52+/-1.20 vs. 5.27+/-0.61, IL-1 beta (microg/L): 13.73+/-1.37 vs. 6.13+/-1.51, IL-6 (microg/L): 14.51+/-1.21 vs. 11.14+/-0.89]. After HBO therapy for 3 days and 7 days, PaO2 (mm Hg, 3 days: 79.20+/-1.68 vs. 59.00+/-2.70, 7 days: 94.30+/-3.77 vs. 74.00+/-3.85) and lung W/D (3 day: 7.43+/-0.73 vs. 9.82+/-0.99, 7 days : 6.75+/-1.14 vs. 8.77+/-1.60) of HBO group were ameliorated to varying degrees compared with OA model group (P<0.05 or P<0.01). HBO therapy for 3 days could lower levels of IL-1 beta (microg/L) in the serum (6.46+/-1.99 vs. 9.09+/-1.09, P<0.05). It is suggested that HBO treatment for ALI in rats had effects of improving arterial blood gases and the lung water transport, and inhibiting inflammatory mediators production.