Paradoxical herniation associated with hyperbaric oxygen therapy after decompressive craniectomy: A case report

BACKGROUND Whether hyperbaric oxygen therapy(HBOT)can cause paradoxical herniation is still unclear.CASE SUMMARY A 65-year-old patient who was comatose due to brain trauma underwent decompressive craniotomy and gradually regained consciousness after surgery.HBOT was administered 22 d after surgery due to speech impairment.Paradoxical herniation appeared on the second day after treatment,and the patient’s condition worsened after receiving mannitol treatment at the rehabilitation hospital.After timely skull repair,the paradoxical herniation was resolved,and the patient regained consciousness and had a good recovery as observed at the follow-up visit.CONCLUSION Paradoxical herniation is rare and may be caused by HBOT.However,the underlying mechanism is unknown,and the understanding of this phenomenon is insufficient.The use of mannitol may worsen this condition.Timely skull repair can treat paradoxical herniation and prevent serious complications.

Key Genes Involved in the Beneficial Mechanism of Hyperbaric Oxygen for Glioblastoma and Predictive Indicators of Hyperbaric Oxygen Prolonging Survival in Glioblastoma Patients

Objective The prognosis of glioblastoma is poor,and therapy-resistance is largely attributed to intratumor hypoxia.Hyperbaric oxygen(HBO)effectively alleviates hypoxia.However,the sole role of HBO in glioblastoma remains controversial.We previously reported that HBO can promote apoptosis,shorten protrusions,and delay growth of glioblastoma,but the molecular mechanism is unclear.We aimed to test candidate genes in HBO-exposed glioblastoma cells and to analyze their correlation with the survival of glioblastoma patients.Methods Glioblastoma cell lines exposed to repetitive HBO or normobaric air(NBA)were collected for RNA isolation and microarray data analysis.GO analysis,KEGG pathway analysis and survival analysis of the differentially expressed genes(DEGs)were performed.Results HBO not only inhibited hypoxia-inducing genes including CA9,FGF11,PPFIA4,TCAF2 and SLC2A12,but also regulated vascularization by downregulating the expression of COL1A1,COL8A1,COL12A1,RHOJ and FILIP1L,ultimately attenuated hypoxic microenvironment of glioblastoma.HBO attenuated inflammatory microenvironment by reducing the expression of NLRP2,CARD8,MYD88 and CD180.HBO prevented metastasis by downregulating the expression of NTM,CXCL12,CXCL13,CXCR4,CXCR5,CDC42,IGFBP3,IGFBP5,GPC6,MMP19,ADAMTS1,EFEMP1,PTBP3,NF1 and PDCD1.HBO upregulated the expression of BAK1,PPIF,DDIT3,TP53I11 and FAS,whereas downregulated the expression of MDM4 and SIVA1,thus promoting apoptosis.HBO upregulated the expression of CDC25A,MCM2,PCNA,RFC33,DSCC1 and CDC14A,whereas downregulated the expression of ASNS,CDK6,CDKN1B,PTBP3 and MAD2L1,thus inhibiting cell cycle progression.Among these DEGs,17 indicator-genes of HBO prolonging survival were detected.Conclusions HBO is beneficial for glioblastoma.Glioblastoma patients with these predictive indicators may prolong survival with HBO therapy.These potential therapeutic targets especially COL1A1,ADAMTS1 and PTBP3 deserve further validation.

The Effect of Different Hyperbaric Oxygen Treatment Time Windows on Neurological Function and Prognosis in Acute Cerebral Infarction

Objective:To observe the effects of different hyperbaric oxygen treatment time windows on the prognosis and neurological function of acute cerebral infarction.Method:160 patients with acute cerebral infarction admitted to Xiangyang Central Hospital in Hubei Province were randomly divided into four groups,each with 40 cases,using a random number table method.According to the 2017 guidelines for the treatment of cerebral infarction,the control group received routine treatment for acute cerebral infarction;On the basis of the control group,patients in Group A received hyperbaric oxygen therapy within 48 hours of onset;Group B patients receive hyperbaric oxygen therapy within 3-6 days of onset;Group C patients receive hyperbaric oxygen therapy within 7-12 days of onset.Observe the efficacy,recurrence,and neurological function recovery of four groups of patients after treatment.Result:There was no statistically significant difference in the National Institutes of Health Stroke Scale(NIHSS)and Barthel Index(BI)scores among the four groups before treatment(P>0.05).There were statistically significant differences in NIHSS and BI scores between 14 and 30 days after treatment and before treatment(F=16.352,27.261,11.899,28.326,P<0.05).At 14 and 30 days after treatment,the NIHSS score in Group A decreased compared to the control group,Group B,and Group C,while the BI score increased compared to the control group,Group B,and Group C,with statistical significance(P<0.05).There was no statistically significant difference in NIHSS and BI scores between Group C and the control group after treatment(P>0.05).After 30 days of treatment,the total effective rate of Group A was higher than that of the control group and Group C,and the difference was statistically significant(X2=6.135,P<0.05).The one-year recurrence rate of Group A and Group B is lower than that of Group C and the control group,and the difference is statistically significant(X2=8.331,P<0.05).There was no statistically significant difference in adverse reactions among the four groups(P>0.05).Conclusion:Patients with acute cerebral infarction who receive hyperbaric oxygen therapy within 48 hours can improve neurological function and reduce the recurrence rate.The efficacy of receiving hyperbaric oxygen therapy within 7-12 days of onset is equivalent to that of not receiving hyperbaric oxygen therapy.

Hyperbaric Oxygen Treatment for Long COVID:From Molecular Mechanism to Clinical Practice

Long COVID symptoms typically occur within 3 months of an initial COVID-19 infection,last for more than 2 months,and cannot be explained by other diagnoses.The most common symptoms include fatigue,dyspnea,coughing,and cognitive impairment.The mechanisms of long COVID are not fully understood,but several hypotheses have been put forth.These include coagulation and fibrosis pathway activation,inflammatory and autoimmune manifestations,persistent virus presence,and Epstein-Barr virus reactivation.Hyperbaric oxygen therapy(HBOT)is a therapeutic method in which a person inhales 100%oxygen under pressure greater than that of the atmosphere.HBOT has some therapeutic effects,including improvement of microcirculation,inhibition of cytokine release leading to a reduction in inflammatory responses,inhibition of autoimmune responses,and promotion of neurological repair.Several clinical trials have been carried out using HBOT to treat long COVID.The results suggest that HBOT helps to improve symptom severity,reduce symptom duration,and enhance patients’quality of life.It is believed that HBOT is an effective option for patients with long COVID,which is worth actively promoting.

Hyperbaric oxygen therapy as a complementary treatment for radiation proctitis:Useless or useful?-A literature review

Radiotherapy(RT)is the backbone of multimodality treatment of more than half of cancer cases.Despite new modern RT techniques,late complications may occur such as radiation proctitis(RP).The natural history of RP is unpredictable.Minor symptoms may resolve spontaneously or require conservative treatment.On the other hand,for similar and uncomplicated clinical contexts,symptoms may persist and can even be refractory to the progressive increase in treatment measures.Over the last decades,an enormous therapeutic armamentarium has been considered in RP,including hyperbaric oxygen therapy(HBOT).Currently,the evidence regarding the impact of HBOT on RP and its benefits is conflicting.Additional prospective and randomised studies are necessary to validate HBOT’s effectiveness in the‘real world’clinical practice.This article reviewed the relevant literature on pathophysiology,clinical presentation,different classifications and discuss RP management including a proposal for a therapeutic algorithm with a focus on HBOT.

Hyperbaric oxygen therapy improves cognitive functioning after brain injury

Hyperbaric oxygen therapy has been widely applied and recognized in the treatment of brain injury; however, the correlation between the protective effect of hyperbaric oxygen therapy and changes of metabolites in the brain remains unclear. To investigate the effect and potential mechanism of hy- perbaric oxygen therapy on cognitive functioning in rats, we established traumatic brain injury models using Feeney＇s free falling method. We treated rat models with hyperbaric oxygen therapy at 0.2 MPa for 60 minutes per day. The Morris water maze test for spatial navigation showed that the average escape latency was significantly prolonged and cognitive function decreased in rats with brain injury. After treatment with hyperbaric oxygen therapy for 1 and 2 weeks, the rats＇ spatial learning and memory abilities were improved. Hydrogen proton magnetic resonance spectroscopy analysis showed that the N-acetylaspartate/creatine ratio in the hippocampal CA3 region was sig- nificantly increased at 1 week, and the N-acetylaspartate/choline ratio was significantly increased at 2 weeks after hyperbaric oxygen therapy. Nissl staining and immunohistochemical staining showed that the number of nerve cells and Nissl bodies in the hippocampal CA3 region was significantly increased, and glial fibrillary acidic protein positive cells were decreased after a 2-week hyperbaric oxygen therapy treatment. Our findings indicate that hyperbaric oxygen therapy significantly im- proves cognitive functioning in rats with traumatic brain injury, and the potential mechanism is me- diated by metabolic changes and nerve cell restoration in the hippocampal CA3 region.

Hyperbaric oxygen treatment promotes neural stem cell proliferation in the subventricular zone of neonatal rats with hypoxic-ischemic brain damage

Hyperbaric oxygen therapy for the treatment of neonatal hypoxic-ischemic brain damage has been used clinically for many years, but its effectiveness remains controversial. In addition, the mechanism of this potential neuroprotective effect remains unclear. This study aimed to investigate the influence of hyperbaric oxygen on the proliferation of neural stem cells in the subventricular zone of neonatal Sprague-Dawley rats （7 days old） subjected to hypoxic-ischemic brain damage. Six hours after modeling, rats were treated with hyperbaric oxygen once daily for 7 days. Immunohistochemistry revealed that the number of 5-bromo-2＇-deoxyuridine positive and nestin positive cells in the subventricular zone of neonatal rats increased at day 3 after hypoxic-ischemic brain damage and peaked at day 5. After hyperbaric oxygen treatment, the number of 5-bromo-2＇- deoxyuddine positive and nestin positive cells began to increase at day 1, and was significantly higher than that in normal rats and model rats until day 21. Hematoxylin-eosin staining showed that hyperbaric oxygen treatment could attenuate pathological changes to brain tissue in neonatal rats, and reduce the number of degenerating and necrotic nerve cells. Our experimental findings indicate that hyperbaric oxygen treatment enhances the proliferation of neural stem cells in the subventricular zone of neonatal rats with hypoxic-ischemic brain damage, and has therapeutic potential for promoting neurological recovery following brain injury.

Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury:not by immediately improving cerebral oxygen saturation and oxygen partial pressure

Although hyperbaric oxygen （HBO） therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury （TBI）, the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation （rSO2） and oxygen partial pressure （PaO2）. To test this idea, we compared two groups： a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO2 were measured. The controls were also examined for rSO2 and PaO2, but received no treatment, rSO2 levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO2 levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

Effect of mesenchymal stem cells transplantation combining with hyperbaric oxygen therapy on rehabilitation of rat spinal cord injury

Objective:To investigate the effect of BMSCs transplantation plus hyperbaric oxygen(HBO)on repair of rat SCI.Methods:Seventy five male rats were divided randomly into five groups:sham,vehicle.BMSCs transplantation group,combination group,15 rats in each group.Every week after the SCI onset,all animals were evaluated for behavior outcome by Basso-BeattleBresnahan(BBB) score and inclined plane test.Axon recovery was examined with focal spinal cord tissue by electron microscope at 6 weeks after the SCI onset.HE staining and BrdU staining were performed to examine the BMSCs and lesion post injury.Somatosensory evoked potential(SEP) testing was performed to detect the recovery of neural conduction.Results from the behavior tests from combination group were significant higher than rats which received only transplantation or HBO treatment.Results from histopathology showed favorable recovery from combination group than other treatment groups.The number of BrdU+ in combination group were measureable more than transplantation group(P<0.05).The greatest decrease in TNF-α,IL-1β,IL-6.IFN-α determined by Elisa assay in combination group were evident too.Conclusions:BMSCs transplantation can promote the functional recovery of rat hind limbs after SCI,and its combination with HBO has a synergistic effect.

Hyperbaric Oxygen Treatment Improves Hearing Level via Attenuating TLR4/NF-κB Mediated Inflammation in Sudden Sensorineural Hearing Loss Patients

Objective Hyperbaric oxygen treatment(HBOT)has demonstrated efficacy in improving hearing levels of patients with idiopathic sudden sensorineural hearing loss(ISSHL);however,the underlying mechanisms are not well understood.HBOT alleviates the inflammatory response,which is mediated by Toll-like receptor(TLR)4 and nuclear factor(NF)-κB.In this study we investigated whether HBOT attenuates inflammation in ISHHL patients via alteration of TLR4 and NF-κB expression.Methods ISHHL patients(n=120)and healthy control subjects(n=20)were enrolled in this study.Patients were randomly divided into medicine group treated with medicine only(n=60)and HBO group receiving both HBOT and medicine(n=60).Audiometric testing was performed pre-and posttreatment.TLR4,NF-кB,and TNF-αexpression in peripheral blood of ISSHL patients and healthy control subjects was assessed by ELISA before and after treatment.Results TLR4,NF-κB,and TNF-αlevels were upregulated in ISSHL patients relative to healthy control subjects;the levels were decreased following treatment and were lower in the HBO group than that in the medicine group post-treatment(P<0.05 and P<0.01).Conclusion HBOT alleviates hearing loss in ISSHL patients by suppressing the inflammatory response induced by TLR4 and NF-κB signaling.

Changes of plasma C-reactive protein in patients with craniocerebral injury before and after hyperbaric oxygenation: A randomly controlled study

Changes of plasma C-reactive protein in patients with craniocerebral injury before and after hyperbaric oxygenation： A randomly controlled study BACKGROUND： Plasma inflammatory factor, such as C-reactive protein, whose content is regarded as a sensitively pathological marked protein and quantitative indexes of central nervous system injury, has been paid more and more attention in clinic. OBJECTIVE： To observe the effects and clinical significance of C-reactive protein in patients with craniocerebral injury after hyperbaric oxygenation. DESIGN： Randomized controlled study. SETTING： Departments of Neurosurgery, Laboratory and Hyperbaric Oxygen, the Second Affiliated Hospital, Medical College of Shantou University. PARTICIPANTS： A total of 60 patients with craniocerebral injury were selected from Department of Neurosurgery, the Second Affiliated Hospital, Medical College of Shantou University from October 2006 to April 2007. There were 37 males and 23 females and the mean age was 26 years. All subjects were certainly diagnosed as history of craniocerebral injury. Patients hospitalized at 24 hours after injury, Glasgow Coma Score ranged from 3 to 12 points, and all patients were certainly diagnosed with CT or MR scanning. Patients and their relatives provided confirmed consent. All the subjects were randomly divided into hyperbaric oxygenation group and control group with 30 in each group. METHODS： Patients in the control group were treated with routinely neurosurgical therapy after hospitalization; however, based the same basic treatment in the control group, patients in the hyperbaric oxygenation group received hyperbaric oxygenation by using iced-wheel four-door 2-cabin air-compression chamber （made in Yantai） from 24 hours to 10 days after operation or injury. After entering the cabin, patients who had a clear consciousness breathed the oxygen by using face mask; contrarily, patients directly breathed the oxygen. Therapeutic project： Expression was increased for about 15–20 minutes, maintained for about 70–80 minutes, and decreased for 20 minutes. Otherwise, pressure was maintained from 0.2 to 0.25 MPa. Hyperbaric oxygenation took an hour for once a day and 10 times were regarded as a course. Venous blood was collected before treatment and on the next day of the first course end. Content of C-reactive protein in plasma was measured with immune turbidimetry in hyperbaric oxygenation group; in addition, content of C-reactive protein in plasma was directly measured with the same method at the corresponding time in the control group. If the content was less or equal to 8 mg/L, it was regarded as normal value. Effects of the two groups were evaluated based on Glasgow Coma Score before and after treatment. MAIN OUTCOME MEASURES： Content of plasma C-reactive protein and Glasgow Coma Score in the two groups before and after treatment. RESULTS： All 60 patients were involved in the final analysis. ① Content of plasma C-reactive protein： The two contents were obviously higher than normal value after craniocerebral injury. There was no significant difference in the two groups before treatment （P 〉 0.05）, but both contents were decreased after treatment, and there was significant difference between HBOT group and control group after treatment （t =4.756, P 〈 0.01）. In addition, there was significant difference in hyperbaric oxygen therapy group before and after treatment （t =5.236, P 〈 0.01）. ② Glasgow Coma Score： There was no significant difference in the two groups before treatment （P 〉 0.05）, but scores were increased in both groups after treatment （t =9.92, 2.51, P 〈 0.01, 0.05）; on the other hand, therefore, there was significant difference between the two groupsafter treatment （t =9.21, P 〈 0.01）. CONCLUSION： Hyperbaric oxygenation can remarkably decrease content of plasma C-reactive protein in patients with craniocerebral injury at the phase of stress.

Hyperbaric oxygen therapy improves local microenvironment after spinal cord injury

Clinical studies have shown that hyperbaric oxygen therapy improves motor function in patients with spinal cord injury. In the present study, we explored the mechanisms associated with the recovery of neurological function after hyperbaric oxygen therapy in a rat model of spinal cord injury. We established an acute spinal cord injury model using a modification of the free-falling object method, and treated the animals with oxygen at 0.2 MPa for 45 minutes, 4 hours after injury. The treatment was administered four times per day, for 3 days. Compared with model rats that did not receive the treatment, rats exposed to hyperbaric oxygen had fewer apoptotic cells in spinal cord tissue, lower expression levels of aquaporin 4/9 mRNA and protein, and more NF-200 positive nerve fibers. Furthermore, they had smaller spinal cord cavities, rapid recovery of somatosensory and motor evoked potentials, and notably better recovery of hindlimb motor function than model rats. Our findings indicate that hyperbaric oxygen therapy reduces apoptosis, downregulates aquaporin 4/9 mRNA and protein expression in injured spinal cord tissue, improves the local microenvironment for nerve regeneration, and protects and repairs the spinal cord after injury.

Early hyperbaric oxygen therapy inhibits aquaporin 4 and adrenocorticotropic hormone expression in the pituitary gland of rabbits with blast-induced craniocerebral injury

In the present study, rabbits were treated with hyperbaric oxygen for 1 hour after detonator-blastinduced craniocerebral injury. Immunohistochemistry showed significantly reduced aquaporin 4 expression and adrenocorticotropic hormone expression in the pituitary gland of rabbits with craniocerebral injury. Aquaporin 4 expression was positively correlated with adrenocorticotropic hormone expression. These findings indicate that early hyperbaric oxygen therapy may suppress adrenocorticotropic hormone secretion by inhibiting aquaporin 4 expression.

The Effect of Mild-Pressure Hyperbaric Therapy (Oasis O₂) on Fatigue and Oxidative Stress

Mild-pressure hyperbaric therapy (mHBT) has become increasingly popular among elite athletes and most recently among the general public yet there is very little scientific underpinnings on its therapeutic use. In this study, fifteen healthy volunteers (8 men, 7 women, mean age 29.7 ± 8.1 years) were exposed to 1.3 atmospheres absolute (ATA) for 40 minutes in a mild hyperbaric chamber called “Oasis O2” to determine the effect of ambient air at 1.3 ATA on oxidative stress, antioxidant potential, fatigue, and blood chemistry. Reactive oxygen metabolites (ROMs), an index of oxidative stress, significantly reduced by 11% (p = 0.006), while biological antioxidant potential (BAP), an index of antioxidant capacity, did not show a significant change (p = 0.749). WBC count significantly reduced by 10.4% (p = 0.005) whereas WBC differential did not show a marked change. The mean visual analog scale (VAS) score for fatigue significantly decreased from 5.0 to 2.1 (p < 0.001). Our findings suggest that mild-pressure hyperbaric therapy reduces oxidative stress as indicated by a significant decrease in serum ROM, and also helps improve fatigue as seen by a significant decrease in VAS fatigue scores.

Seam Tracking Technology for Hyperbaric Underwater Welding

Automatic weld seam tracking technology to be used in hyperbaric underwater damaged pipeline repair welding is much more important, because of poor bevel preparation and severe working condition. A weld seam tracking system based on digital signal processing（DSP） passive light weld image processing technology has been established. A convenient charge coupled device（CCD） camera system was used in the high pressure environment with the help of an aperture and focus altering mechanism to guarantee overall image visibility in the scope of pressure below 0.7 MPa. The system can be used in the hyperbaric environment to pick up the real welding image of both the welding arc and the welding pool. The newly developed DSP technology was adopted to achieve the goal of system real time characteristics. An effective weld groove edge recognition technique including narrow interesting window opening, middle value wave filtering, Sobel operator weld edge detecting and edge searching in a defined narrow area was proposed to remove the guide error and system accuracy was ensured. The results of tracking simulation and real tracking application with arc striking have proved the validity and the accuracy of the mentioned system and the image processing method.

Combination of allopurinol and hyperbaric oxygen therapy:A new treatment in experimental acute necrotizing pancreatitis?

AIM： To investigate the individual and combined effects of allopurinol and hyperbaric oxygen （HBO） therapy on biochemical and histopathological changes, oxidative stress, and bacterial translocation （BT） in the experimental rat acute pancreatitis （AP）. METHODS： Eighty-five Sprague-Dawley rats were included in the study. Fifteen of the eighty-five rats were used as controls （sham, Group I ）. AP was induced via intraductal taurocholate infusion in the remaining seventy rats. Rats that survived to induction of acute necrotizing pancreatitis were randomized into four groups. Group H received saline, Group m allopurinol, Group IV allopurinol plus HBO and Group v HBO alone. Serum amylase levels, oxidative stress parameters, BT and histopathologic scores were determined. RESULTS： Serum amylase levels were lower in Groups Ⅲ, Ⅳ and v compared to Group H （974 ± 110, 384 ± 40, 851 ＋ 56, and 1664 Ⅳ 234 U/L, respectively, P 〈 0.05, for all）. Combining the two treatment optionsrevealed significantly lower median [25-75 percentiles] histopathological scores when compared to individual administrations （13 [12.5-15] in allopurinol group, 9.5 [7-11.75] in HBO group, and 6 [4.5-7.5] in combined group, P 〈 0.01）. Oxidative stress markers were significantly better in all treatment groups compared to the controls. Bacterial translocation into the pancreas and mesenteric lymph nodes was lower in Groups m, iV and v compared to Group H （54%, 23%, 50% vs 100% for translocation to pancreas, and 62%, 46%, 58% vs 100% for translocation to mesenteric lymph nodes, respectively, P 〈 0.05 for all）. CONCLUSION： The present study confirms the benefit of HBO and allopurinol treatment when administered separately in experimental rat AP. Combination of these treatment options appears to prevent progression of pancreatic injury parameters more effectively.

Hyperbaric oxygen therapy combined with Schwann cell transplantation promotes spinal cord injury recovery

Schwann cell transplantation and hyperbaric oxygen therapy each promote recovery from spinal cord injury, but it remains unclear whether their combination improves therapeutic results more than monotherapy. To investigate this, we used Schwann cell transplantation via the tail vein, hyperbaric oxygen therapy, or their combination, in rat models of spinal cord contusion injury. The combined treatment was more effective in improving hindlimb motor function than either treatment alone; injured spinal tissue showed a greater number of neurite-like structures in the injured spinal tissue, somatosensory and motor evoked potential latencies were notably shorter, and their amplitudes greater, after combination therapy than after monotherapy. These findings indicate that Schwann cell transplantation combined with hyperbaric oxygen therapy is more effective than either treatment alone in promoting the recovery of spinal cord in rats after injury.

Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

Transplantation of umbilical cord-derived mesenchymal stem cells（UC-MSCs） for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen（HBO） treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid（2.5–3.0 atm impact force）. The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions.

Hyperbaric oxygen preconditioning improves postoperative cognitive dysfunction by reducing oxidant stress and inflammation

Postoperative cognitive dysfunction is a crucial public health issue that has been increasingly studied in efforts to reduce symptoms or prevent its occurrence. However, effective advances remain lacking. Hyperbaric oxygen preconditioning has proved to protect vital organs, such as the heart, liver, and brain. Recently, it has been introduced and widely studied in the prevention of postoperative cognitive dysfunction, with promising results. However, the neuroprotective mechanisms underlying this phenomenon remain controversial. This review summarizes and highlights the definition and application of hyperbaric oxygen preconditioning, the perniciousness and pathogenetic mechanism underlying postoperative cognitive dysfunction, and the effects that hyperbaric oxygen preconditioning has on postoperative cognitive dysfunction. Finally, we conclude that hyperbaric oxygen preconditioning is an effective and feasible method to prevent, alleviate, and improve postoperative cognitive dysfunction, and that its mechanism of action is very complex, involving the stimulation of endogenous antioxidant and anti-inflammation defense systems.

Effects of hyperbaric oxygen on intestinal mucosa apoptosis caused by ischemia-reperfusion injury in rats

BACKGROUND:Hyperbaric oxygen(HBO)is an effective adjuvant therapy for ischemiareperfusion(I/R)injury of the brain,small intestine and testis in addition to crushing injury.Studies have shown that HBO increases the activity of villi of the ileum 30 minutes after I/R injury.The present study aimed to observe the effect of HBO on apoptosis of epithelial cells in the small intestine during different periods of I/R and to elucidate the potential mechanisms.METHODS:Rats were subjected to 60-minute ischemia by clamping the superior mesenteric artery and 60-minute reperfusion by removal of clamping.The rats were randomly divided into four groups:I/R group,HBO precondition or HBO treatment before ischemia(HBO-P),HBO treatment during ischemia period(HBO-I),and HBO treatment during reperfusion(HBO-R).After 60-minute reperfusion,samples of the small intestine were prepared to measure the level of ATP by using the colorimetric method and immunochemical expression of caspase-3.The levels of TNF-αin intestinal tissue were measured using the enzyme-linked immunosorbent assay method(Elisa).RESULTS:TNF-αlevels were significantly lower in the HBO-I group than in the HBO-P(P<0.05),HBO-R and I/R groups;there was no significant difference between the HBO-R and I/R groups(P>0.05).The expression of caspas-3 was significantly lower in the HBO-I group than in the HBO-P group(P<0.05);it was also significantly lower in the HBO-P group than in the I/R and HBO-R groups(P<0.05).ATP level was significantly lower in the HBO-I group than in the HBO-P group(P<0.05),and also it was significantly lower in the HBO-P group than in the I/R and HBO-R groups(P<0.05).CONCLUSIONS:There is an association between HBO,small intestinal I/R injury,and mucosa apoptosis.HBO maintains ATP and aerobic metabolism,inhibites TNF-αproduction,and thus prevents intestinal mucosa from apoptosis.Best results can be obtained when HBO is administered to patients in the period of ischemia,and no side effects are produced when HBO is given during the Period of Reperfusion.