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Sample records for oxygen therapy hbo

  1. HBO: a possible supplementary therapy for oral potentially malignant disorders.

    PubMed

    Ye, Xiaojing; Zhang, Jing; Lu, Rui; Zhou, Gang

    2014-08-01

    Oral potentially malignant disorders (OPMDs) are chronic inflammatory diseases in which cells suffer hypoxia referring to deprivation of adequate oxygen supply. Hyperbaric oxygen treatment (HBO), which can increase oxygen tension and delivery to oxygen-deficient tissue, is a supplementary therapy to improve or cure disorders involving hypoxia. Although the applications of HBO in wound healings, acute ischemic stroke, radiation-induced soft tissue injury and cancers are extensively reported, there are only few studies on their effect in OPMDs. Not only does HBO furnish oxygen-it also possesses potent anti-inflammatory properties. At the cellular level, HBO can decrease lymphocyte proliferation and promote apoptosis of fibroblasts. At the molecular level, it can decrease expression of HIF, ICAM-1, TNF-α, TGF-β, and IFN-γ, as well as increase vascular VEGF expression and angiogenesis. Thus, we hypothesize that HBO may contribute to treat OPMDs, including oral lichen planus, oral leukoplakia, and oral submucous fibrosis both at the cellular level and the molecular level, and that it would be a safe and inexpensive therapeutic strategy. PMID:24908359

  2. Clinical results in brain injury trials using HBO2 therapy: Another perspective.

    PubMed

    Figueroa, Xavier A; Wright, James K

    2015-01-01

    The current debate surrounding the use of hyperbaric oxygen (HBO2) for neurological indications, specifically mild to moderate chronic traumatic brain injury (mTBI) and post-concussion syndrome (PCS), is mired in confusion due to the use of non-validated controls and an unfamiliarity by many practitioners of HBO2 therapy with the experimental literature. In the past 40 years, the use of an air sham (21% oxygen, 1.14-1.5 atmospheres absolute/atm abs) in clinical and animal studies, instead of observational or crossover controls, has led to false acceptance of the null hypothesis (declaring no effect when one is present), due to the biological activity of these "sham" controls. The recent Department of Defense/Veterans Administration (DoD/VA) sponsored trials, previous published reports on the use of HBO2 therapy on stroke and mTBI and preliminary reports from the HOPPS Army trial, have helped to highlight the biological activity of pressurized air, validate the development of a convincing control for future studies and demonstrate the effectiveness of a hyperbaric intervention for mTBI/ PCS. Approval of HBO2 for neurological indications, especially for mTBI/PCS, should be granted at the federal, state and certifying body levels as a safe and viable treatment for recovery in the post-acute phase. PMID:26403018

  3. Hyperbaric oxygen therapy for radiation myelitis

    SciTech Connect

    Poulton, T.J.; Witcofski, R.L.

    1985-12-01

    Radiation therapy may damage healthy tissues adjacent to tumor. Hyperbaric oxygen therapy (HBO) is useful in treating soft tissue and osteoradionecrosis. In addition, HBO has been recommended to treat radiation-induced myelitis. We used radiation to induce a predictable myelitis in the spinal cords of rats who were randomized into treatment (HBO) and control groups 8 wk after irradiation. Serial neurologic examination showed no benefit or harm as a result of HBO. This small pilot study did not demonstrate any clinically significant benefit of HBO for radiation myelitis in rats.

  4. Sudden hearing loss and vertigo after tooth extraction successfully treated with combined therapy including HBO2: a case report.

    PubMed

    Yilmaz, Huseyin Baki; Erdogan, Raziye Banu Atalay; Paksoy, Mustafa; Sanli, Arif

    2015-01-01

    Sudden sensorineural hearing loss (SSNHL) is a decrease in hearing of at least 30 dB that occurs within three days and which affects at least three consecutive frequencies in either ear or both ears. This case report describes a woman who had sudden hearing loss and vertigo in the right ear after tooth extraction. As the first-line therapy, systemic and intratympanic steroid injections were used this led to a slight improvement; however, the majority of improvement in hearing was not observed until hyperbaric oxygen (HBO2) therapy was instituted on the 20th day of hearing loss. Sudden hearing loss and vertigo after tooth extraction is an otologic emergency and early evaluation and treatment are effective. HBO2, although employed beyond the Undersea and Hyperbaric Medical Society's recommended initial 14 days of symptom onset, very was effective for this particular case.

  5. Oxygen Therapy

    MedlinePlus

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb ... in your home. A different kind of oxygen therapy is called hyperbaric oxygen therapy. It uses oxygen ...

  6. Clinical Effectiveness of Hyperbaric Oxygen Therapy in Complex Wounds

    PubMed Central

    Opasanon, Supaporn; Pongsapich, Warut; Taweepraditpol, Sitthichoke; Suktitipat, Bhoom; Chuangsuwanich, Apirag

    2015-01-01

    Hyperbaric Oxygen (HBO, HBO2) Therapy is a non-invasive therapy. It has been applied as adjuvant treatment in many medical conditions over the past 50 years. Different treatment protocols have been proven effective for specifically indicated conditions. To evaluate the clinical effectiveness of Hyperbaric Oxygen (HBO) Therapy as an adjunctive treatment for patients with complex wounds. In this prospective cohort study, 40 patients with complex wounds were included. All patients received HBO. HBO was delivered with 100% oxygen for 90 min at 2.0–2.4 ATA. Wound sizes were assessed by one wound surgeon before, during, and every 2 weeks for a total of 12 months after HBO. An analysis of demographic data, wound size and wound photography was performed. Over the 22-month period ending October 31, 2013, 40 patients (21 men and 19 women) with a mean age of 59.73 (range, 29–88) with complex wounds were included. All complex wounds studied were at least 6 months old. The mean wound size was 16.72 cm2 in diameter. Thirty-one patients with complex wounds healed after the completion of a series of HBO treatments (77.5%). Two orocutaneous fistulas were completely closed without further surgery. After 5 HBO treatments, the wound size reduced by 29.7% on average (p = 1.24 × 10−6). After 10 HBO treatments, the wound size statistically significantly reduced by an additional 16.9% (p = 0.0002). There were no complications in this study. Wound healing process was accelerated by HBO. Significant wound size reduction was noted after 5 HBO treatments. Because the biggest reduction in wound size occurred within the first 10 HBO treatments, it is important to conduct these first treatments without interruption. HBO is an effective and safe treatment modality for complex wounds. PMID:26442206

  7. [Experience in the treatment of severe forms of sepsis by extracorporeal therapy and hyperbaric oxygenation].

    PubMed

    Zhidkov, K P; Klechikov, V Z; Bogatyr', M N

    1997-01-01

    The results of multiple modality treatment of 81 patients with sepsis complicated by multiple organ failure are assessed. In 40 patients the traditional therapy of sepsis was supplemented with extracorporeal methods (hemoperfusion, autotransfusion of UV-exposed blood, and perfusion of xenospleen slices) and hyperbaric oxygenation (HBO) sessions. In the patients treated traditionally the mortality was 94%, whereas addition of extracorporeal treatment and HBO decreased this value to 40%. Hence, extracorporeal treatment and HBO are recommended for the treatment of sepsis.

  8. Hyperbaric oxygen as an adjunctive therapy in treatment of malignancies, including brain tumours.

    PubMed

    Stępień, Katarzyna; Ostrowski, Robert P; Matyja, Ewa

    2016-09-01

    Hyperbaric oxygen (HBO) therapy is widely used as an adjunctive treatment for various pathological states, predominantly related to hypoxic and/or ischaemic conditions. It also holds promise as an approach to overcoming the problem of oxygen deficiency in the poorly oxygenated regions of the neoplastic tissue. Occurrence of local hypoxia within the central areas of solid tumours is one of the major issues contributing to ineffective medical treatment. However, in anti-cancer therapy, HBO alone gives a limited curative effect and is typically not applied by itself. More often, HBO is used as an adjuvant treatment along with other therapeutic modalities, such as radio- and chemotherapy. This review outlines the existing data regarding the medical use of HBO in cancer treatment, with a particular focus on the use of HBO in the treatment of brain tumours. We conclude that the administration of HBO can provide many clinical benefits in the treatment of tumours, including management of highly malignant gliomas. Applied immediately before irradiation, it is safe and well tolerated by patients, causing rare and limited side effects. The results obtained with a combination of HBO/radiotherapy protocol proved to be especially favourable compared to radiation treatment alone. HBO can also increase the cytostatic effect of certain drugs, which may render standard chemotherapy more effective. The currently available data support the legitimacy of conducting further research on the use of HBO in the treatment of malignancies. PMID:27485098

  9. [Hyperbaric oxygenation therapy, basic concepts].

    PubMed

    García-Covarrubias, L; Cuauhtémoc Sánchez-Rodríguez, E

    2000-01-01

    Hyperbaric oxygen therapy (HBO) is defined as a treatment in which a patient breathes 100% oxygen in a pressurized environment of at least 1.4 absolute atmospheres. The first written reports data from the 15th century, when it was used to treat respiratory diseases. For some time its applications lacked scientific support until the second half of this century when scientific publications were carried out using current methodology. This type of therapy is grounded basically in three gas laws: Henry's Law, Dalton's Law and Boyle's Law. The beneficial effects are: wound healing enhancement; increased neutrophil bactericidal capacity; direct toxic effect against some microorganisms; arteriolar vasoconstriction with subsequent edema reduction and decreased ischemia/reperfusion injury, among others. These are the result of increased environmental pressure and high oxygen tension in body tissues. Currently there are 13 accepted conditions to be treated with HBO and others are still under investigation. Following UHMS-accepted treatment protocols, complications and/or adverse effects are limited. PMID:10721602

  10. [Hyperbaric oxygenation therapy, basic concepts].

    PubMed

    García-Covarrubias, L; Cuauhtémoc Sánchez-Rodríguez, E

    2000-01-01

    Hyperbaric oxygen therapy (HBO) is defined as a treatment in which a patient breathes 100% oxygen in a pressurized environment of at least 1.4 absolute atmospheres. The first written reports data from the 15th century, when it was used to treat respiratory diseases. For some time its applications lacked scientific support until the second half of this century when scientific publications were carried out using current methodology. This type of therapy is grounded basically in three gas laws: Henry's Law, Dalton's Law and Boyle's Law. The beneficial effects are: wound healing enhancement; increased neutrophil bactericidal capacity; direct toxic effect against some microorganisms; arteriolar vasoconstriction with subsequent edema reduction and decreased ischemia/reperfusion injury, among others. These are the result of increased environmental pressure and high oxygen tension in body tissues. Currently there are 13 accepted conditions to be treated with HBO and others are still under investigation. Following UHMS-accepted treatment protocols, complications and/or adverse effects are limited.

  11. Hyperbaric oxygen therapy as additional treatment in deep sternal wound infections – a single center's experience

    PubMed Central

    Bryndza, Magdalena; Chrapusta, Anna; Kobielska, Ewa; Kapelak, Bogusław; Grudzień, Grzegorz

    2016-01-01

    Introduction Deep sternal wound infection (DSWI) is one of the most serious complications after cardiac surgery procedures, observed in 5% of patients. Current standard medical therapy for DSWI includes antibiotics, surgical debridement, resuturing or negative pressure wound therapy (NPWT). Unfortunately, in some cases these methods are insufficient, and additional therapeutic options are needed. Aim To assess the effects and usefulness of additional hyperbaric oxygen therapy (HBO2) in patients with DSWI after cardiac surgery procedures. Material and methods A retrospective analysis of 10 patients after cardiac surgery who developed DSWI in the period 2010–2012 was performed. After 3 months of ineffective conventional therapy including targeted antibiotic, surgical sternal debridement and NPWT, patients were qualified for additional HBO2 therapy. A total of 20 sessions of HBO2 therapy were performed, each 92 minutes long. Results After 4 weeks of HBO2 treatment, 7 patients presented complete wound healing with fibrous scar formation. One patient was qualified for the another cycle of HBO2 therapy with 20 additional sessions, and complete wound healing was observed. In 2 cases, after 5 and 19 sessions, HBO2 was interrupted because of improper qualifications. Conclusions The HBO2 as an additional therapy in DSWI was successful in 80% of cases, and no complications were observed. However, due to the small number of published studies with a small number of patients, randomized, clinical trials are needed to assess the clinical results of HBO2 in DSWI after cardiac surgery procedures. PMID:27785131

  12. The use of hyperbaric oxygen therapy and LED therapy in diabetic foot

    NASA Astrophysics Data System (ADS)

    Marques, Cristiane R. S.; Martin, Airton A.; Lima, Carlos J.; Conrado, Luis A. L.; Silveira, Fabricio L.; Carvalho, Marcos V.

    2004-07-01

    Chronic foot ulcers are common ailments presented in diabetes, which offer severe complications and are often unresponsive to therapy. In this work it was evaluated the effects of adjunctive Hyperbaric Oxygen Therapy (HBO) treatment and LEDtherapy irradiation on ulcer healing (HBO) in addition to conventional treatment. In ulcers of diabetic foot these treatments lead to a reduction in the probability of amputation up to almost four times compared with patients not receiving such co-adjutant treatment. The LEDtherapy irradiation was given concurrently using an energy density of 4J/cm2 for 5 min. During the experiment nine patients with diabetic foot ulcers were submitted for HBO sessions with 2,5 ATM for two hours. The experiment demonstrated the effectiveness of HBO + LEDtherapy treatment by favoring the ulcer healing through an increased fibroblastic response, collagen synthesis and neo-vascularization of the ischaemia, as well as increases in the leukocytic bactericidal activity.

  13. Oxygen Therapy

    MedlinePlus

    ... 85-95% pure oxygen. The concentrator runs on electricity or a battery. A concentrator for home usually ... systems deliver 100% oxygen, and do not require electricity. A small canister can be filled from the ...

  14. Living with Oxygen Therapy

    MedlinePlus

    ... page from the NHLBI on Twitter. Living With Oxygen Therapy Oxygen therapy helps many people function better and be ... chronic obstructive pulmonary disease) Although you may need oxygen therapy continuously or for long periods, it doesn' ...

  15. Risk factors for oxygen toxicity seizures in hyperbaric oxygen therapy: case reports from multiple institutions.

    PubMed

    Seidel, Ruthanna; Carroll, Christopher; Thompson, Debra; Diem, Rena G; Yeboah, Kwabena; Hayes, A J; Hall, Brett; Whelan, Harry T

    2013-01-01

    Oxygen toxicity seizures are a rare but recognized complication of hyperbaric oxygen (HBO2) therapy. Many patients undergoing HBO2 therapy have medical conditions or are taking medications that could contribute to seizures. Previous literature has not extensively reported on these factors in patients experiencing oxygen toxicity seizures. We conducted a chart review at several hyperbaric oxygen centers in the Milwaukee, Wisc., area to explore whether the patients who experienced seizures in the hyperbaric chamber had other medical comorbidities or were on medications which lowered their seizure threshold, thereby contributing to oxygen toxicity seizures. There were a total of seven cases of seizures in five patients. Each patient had risk factors for seizures, including hypercapnia secondary to chronic obstructive pulmonary disease, narcotic withdrawal, alcohol dependence, and antidepressant, tramadol or cephalosporin/ceftriaxone use. We hypothesize that patients who experience oxygen toxicity seizures may have other factors which contribute to the development of these seizures.

  16. Hyperbaric Oxygen Therapy as a Sole Agent Is Not Immunosuppressant in a Highly Immunogenic Mouse Model

    PubMed Central

    Gassas, Adam; Min, Weixian; Evans, A. Wayne; Carter, Susan; Sándor, George K.; Grunebaum, Eyal

    2011-01-01

    Background. Hyperbaric oxygen (HBO) therapy, which is used for many conditions, may also have immunosuppressive effects and could be used for prevention or treatment of graft-versus-host disease (GvHD). If HBO is immunosuppressant, then we hypothesize that HBO therapy will delay the T-cell mediated skin graft rejection. Methods. C57/BL6 black-coated (H2B) mice received skin graft from CBA (H2D) white-coated mice. Mice were treated with either 19 session of 240 kpa oxygen or 29 session of 300 kpa oxygen, for 90 minutes. Mice were housed either 4 per cage or separately, to prevent friction and mechanical factors that may affect graft survival. Skin grafts were assessed daily. Results. There was no difference in length of graft survival between mice that received either regimens of HBO therapy and mice that did not receive HBO therapy. Conclusions. HBO therapy, as a sole agent, did not delay skin graft rejection in a highly immunogenic mouse model. PMID:22046567

  17. Oxygen Therapy

    MedlinePlus

    ... therapy works, it helps to understand how your respiratory system works. This system is a group of organs and tissues that help you breathe. The respiratory system includes the airways and lungs. The airways carry ...

  18. Effects of hyperbaric oxygenation therapy on symptomatic pneumocephalus

    PubMed Central

    Paiva, Wellingson Silva; de Andrade, Almir Ferreira; Figueiredo, Eberval Gadelha; Amorim, Robson Luis; Prudente, Marcelo; Teixeira, Manoel Jacobsen

    2014-01-01

    Background Pneumocephalus (PNC) is defined as a pathological collection of gas within the cranial cavity. The authors studied the effects of hyperbaric oxygenation (HBO2) therapy on a group of patients with PNC, comparing them with a control group to determine the relative impact on pneumocephalus volume, clinical symptoms, and duration of hospitalization. Methods Twenty-four patients with PNC treated at our hospital were consecutively studied. These patients were divided into a treated group (n=13) and a control group (n=11). Thirteen patients (treated group) were treated with HBO2 therapy sessions in a monoplace hyperbaric chamber at 2.5 atmospheres with 100% oxygen concentration. The control group was treated with normobaric oxygenation. Results Clinical improvement was seen in all patients. In the treated group, a decrease of the gas bubble was observed on the computerized tomography scan after each session of HBO2. The treated group also experienced a lower rate of meningitis compared with the control group. The length of hospital stay was significantly higher in the control group compared with the treated group. Conclusions HBO2 therapy in selective cases may lead to clinical and radiological improvement in patients with PNC. PMID:25328392

  19. Mechanisms of action of hyperbaric oxygen therapy.

    PubMed

    Camporesi, Enrico M; Bosco, Gerardo

    2014-01-01

    Therapeutic mechanisms of action for hyperbaric oxygen (HBO2) therapy are based on elevation of both the partial pressure of inspired O2 and of the hydrostatic pressure. This last mechanism contributes to a compression of all gas-filled spaces in the body (Boyle's Law) and is relevant to treat conditions where gas bubbles are present in the body and cause the disease (e.g., intravascular embolism; decompression sickness with intravascular or intra-tissue bubbles). However, the majority of patients treated with HBO2 do not suffer from bubble-induced injuries, but derive clinical improvements from the elevated O2 partial pressures. High O2 partial pressures in various tissues increase the production of reactive O2 species (ROS) and also of reactive nitrogen species (RNS) because of hyperoxia. Most controlled studies have verified that the clinical efficacy from HBO2 derives from modulation of intracellular transduction cascades, leading to synthesis of growth factors and promoting wound healing and ameliorating post-ischemic and post-inflammatory injuries. PMID:24984320

  20. Mechanisms of action of hyperbaric oxygen therapy.

    PubMed

    Camporesi, Enrico M; Bosco, Gerardo

    2014-01-01

    Therapeutic mechanisms of action for hyperbaric oxygen (HBO2) therapy are based on elevation of both the partial pressure of inspired O2 and of the hydrostatic pressure. This last mechanism contributes to a compression of all gas-filled spaces in the body (Boyle's Law) and is relevant to treat conditions where gas bubbles are present in the body and cause the disease (e.g., intravascular embolism; decompression sickness with intravascular or intra-tissue bubbles). However, the majority of patients treated with HBO2 do not suffer from bubble-induced injuries, but derive clinical improvements from the elevated O2 partial pressures. High O2 partial pressures in various tissues increase the production of reactive O2 species (ROS) and also of reactive nitrogen species (RNS) because of hyperoxia. Most controlled studies have verified that the clinical efficacy from HBO2 derives from modulation of intracellular transduction cascades, leading to synthesis of growth factors and promoting wound healing and ameliorating post-ischemic and post-inflammatory injuries.

  1. The role of hyperbaric oxygen therapy in sports medicine.

    PubMed

    Babul, S; Rhodes, E C

    2000-12-01

    During the past decade, we have seen a growing number of individuals participating in sport and recreational activities. All indications show an increase in sport participation at every age level. However, the number of sport and recreational injuries as a result of this increase has also risen. Unfortunately, a primary cost related to injury recovery is the time lost from participating in and resuming normal functional activity. This has compelled health care professionals to seek more efficient and effective therapeutic interventions in treating such injuries. Hyperbaric oxygen (HBO) therapy may serve to provide a means of therapy to facilitate a speedier resumption to pre-injury activity levels as well as improve the short and long term prognosis of the injury. Although a growing interest in sports medicine is becoming evident in the literature, the use of HBO as an intervention in this field has received a great deal of cynicism. To date, numerous professional athletic teams, including hockey (NHL), football (NFL), basketball (NBA) and soccer (MLS), utilise and rely on the use of HBO as adjuvant therapy for numerous sports-related injuries acquired from playing competitive sports. However, to date, very little has been published on the application benefits of hyperbaric therapy and sports injuries. The majority of clinical studies examining the efficacy of HBO in treating soft tissue injuries have been limited in their sample size and study design. Further research needs to be conducted suggesting and validating the significant effects of this treatment modality and further grounding its importance in sports medicine.

  2. Severity of Hematuria Effects Resolution in Patients Treated with Hyperbaric Oxygen Therapy for Radiation-Induced Hematuria

    PubMed Central

    Liss, Michael A.; Osann, Kathryn; Cho, Jane; Chua, Walter C.; Dash, Atreya

    2014-01-01

    Introduction We investigated the differences between prostate cancer patients with radiation-induced hematuria treated with hyperbaric oxygen (HBO) therapy that did or did not have a resolution of hematuria. Materials and Methods We performed a retrospective review of prostate cancer patients with radiation-induced hematuria who underwent HBO from April 2000 to March 2010. We performed an analysis of demographic data and severity of hematuria in those who had resolution of or persistent hematuria. Additionally, prostate-specific antigen (PSA) data were also obtained during the study period. Results Overall, 11/22 men had resolution of hematuria after HBO therapy with a median follow-up of 2.2 (0.35–13.6) years. The Radiation Therapy Oncology Group (RTOG) grade of hematuria is predictive of final hematuria outcome (resolution vs. persistent) after HBO (p = 0.026). No significant PSA changes were noted before and after HBO therapy. Conclusions The RTOG hematuria grade is associated with the resolution of hematuria after HBO therapy for radiation-induced hematuria in men treated for prostate cancer. This information may be helpful during shared medical decision-making regarding utility of HBO therapy in the context of severity of hematuria. PMID:23919985

  3. Hyperbaric oxygen therapy in the treatment of diabetic foot ulcers--prudent or problematic: a case report.

    PubMed

    Mutluoglu, Mesut; Uzun, Günalp; Yildiz, Senol

    2010-06-01

    Hyperbaric oxygen (HBO) therapy is increasingly used in the management of problem wounds, notably diabetic foot ulcers. However, concerns about unnecessary, inappropriate, and prolonged use of this adjunctive treatment exist. A case report of a 52-year-old patient with diabetes mellitus, Charcot foot, and a nonhealing plantar ulcer who had received HBO treatments only illustrates these concerns. He presented with normal pedal pulses, adequate transcutaneous partial oxygen pressure levels, no offloading footwear, and a heavily contaminated ulcer (Pseudomonas spp.). Following a course of oral antibiotics, appropriate topical wound care, and offloading instructions, the wound healed within 3 months. Advanced wound therapy modalities are only indicated for use in patients when accepted standards of wound care, including identification and correction of underlying disorders and comorbidities, have failed. To prevent misuse/overuse of HBO therapy, stand-alone HBO centers should include a multidisciplinary wound care team.

  4. Hyperbaric Oxygen Therapy in Branch Retinal Artery Occlusion in a 15-Year-Old Boy with Methylenetetrahydrofolate Reductase Mutation

    PubMed Central

    Kadayifcilar, Sibel; Eldem, Bora

    2015-01-01

    Purpose. To report the efficacy of hyperbaric oxygen (HBO) therapy in a case of branch retinal artery occlusion (BRAO) in a 15-year-old boy. Methods. We report a 15-year-old boy with sudden loss of vision due to BRAO. Examination included laboratory evaluation for systemic risk factors. Follow-up exams included visual acuity, fundus examination, fundus fluorescein angiography, and visual field testing. HBO therapy was employed for treatment. Results. Medical history was positive for isolated glucocorticoid deficiency. Laboratory evaluation disclosed hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) mutation. The visual acuity 0.05 at presentation improved to 0.8 after 20 days of HBO therapy. There was no change on visual fields. Conclusion. In this pediatric case, HBO therapy was useful in the treatment of BRAO. PMID:25722905

  5. Combination of HBO and Memantine in Focal Cerebral Ischemia: Is There a Synergistic Effect?

    PubMed

    Wang, Feng; Liang, Wei; Lei, Chong; Kinden, Renee; Sang, Hanfei; Xie, Yaning; Huang, Yi; Qu, Yan; Xiong, Lize

    2015-12-01

    Hyperbaric oxygen (HBO) therapy and memantine, a non-competitive NMDA antagonist, are both promising treatment strategies for improving stroke prognosis. However, HBO's narrow therapeutic time window (<6 h post-stroke) and the adverse effect of high-dose MEM administration limits the use of these therapeutic interventions. In this study, we investigated whether or not MEM could prolong the narrow therapeutic window of HBO treatment. Transient focal cerebral ischemia was induced in male Sprague-Dawley rats by middle cerebral artery occlusion (MCAO) for 120 min. MCAO produced neurobehavioral deficits, increased infarction volume, increased Evans blue (EB) content and levels of pro-inflammatory factors, as well as depleted glutathione (GSH), and reduced catalase (CAT) and superoxide dismutase (SOD) activity in the ischemic ipsilateral hemisphere. The combination of 5 mg/kg MEM treatment 15 min after the onset of ischemic event and HBO therapy 12 h post-reperfusion significantly restored neurologic scores, EB concentration and IL-10 levels, as well as significantly decreased infarct volume and increased antioxidant activity. These results imply that the combination of MEM and HBO therapy not only prolongs the therapeutic window of HBO treatment, but also lowers the dosage requirement of MEM. The mechanism underlying the neuroprotective effects of the combined treatment may lie in alleviated blood-brain barrier (BBB) permeability, inhibited inflammatory response, and up-regulation of the antioxidant enzyme activity.

  6. Four-week histologic evaluation of grafted calvarial defects with adjunctive hyperbaric oxygen therapy in rats

    PubMed Central

    2016-01-01

    Purpose The aim of this study was to characterize the healing in the grafted calvarial defects of rats after adjunctive hyperbaric oxygen therapy. Methods Twenty-eight male Sprague-Dawley rats (body weight, 250–300 g) were randomly divided into two treatment groups: with hyperbaric oxygen therapy (HBO; n=14) and without HBO (NHBO; n=14). Each group was further subdivided according to the bone substitute applied: biphasic calcium phosphate (BCP; n=7) and surface-modified BCP (mBCP; n=7). The mBCP comprised BCP coated with Escherichia-coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). Two symmetrical circular defects (6-mm diameter) were created in the right and left parietal bones of each animal. One defect was assigned as a control defect and received no bone substitute, while the other defect was filled with either BCP or mBCP. The animals were allowed to heal for 4 weeks, during which those in the HBO group underwent 5 sessions of HBO. At 4 weeks, the animals were sacrificed, and the defects were harvested for histologic and histomorphometric analysis. Results Well-maintained space was found in the grafted groups. Woven bone connected to and away from the defect margin was formed. More angiogenesis was found with HBO and EGCG/BMP-2 (P<0.05). None of the defects achieved complete defect closure. Increased new bone formation with HBO or EGCG/BMP-2 was evident in histologic evaluation, but it did not reach statistical significance in histometric analysis. A synergic effect between HBO and EGCG/BMP-2 was not found. Conclusions Within the limitations of this study, the present findings indicate that adjunctive HBO and EGCG/BMP-2 could be beneficial for new bone formation in rat calvarial defects. PMID:27588214

  7. Successful hyperbaric oxygen therapy for refractory BK virus-associated hemorrhagic cystitis after cord blood transplantation.

    PubMed

    Hosokawa, K; Yamazaki, H; Nakamura, T; Yoroidaka, T; Imi, T; Shima, Y; Ohata, K; Takamatsu, H; Kotani, T; Kondo, Y; Takami, A; Nakao, S

    2014-10-01

    BK virus-associated hemorrhagic cystitis (BKV-HC) is a common and major cause of morbidity in recipients of allogeneic hematopoietic stem cell transplantation. A 32-year-old woman developed severe BKV-HC on day 24 after cord blood transplantation (CBT). Despite supportive therapies - such as hyperhydration, forced diuresis, and urinary catheterization - macroscopic hematuria and bladder irritation persisted for over a month. Hyperbaric oxygen (HBO) therapy at 2.1 atmospheres for 90 min per day was started on day 64 after CBT. Macroscopic hematuria resolved within a week, and microscopic hematuria was no longer detectable within 2 weeks. Hematuria did not recur after 11 sessions of HBO therapy, and no significant side effects were observed during or after treatment. HBO therapy could thus be useful in controlling refractory BKV-HC after CBT.

  8. Hyperbaric oxygen therapy for idiopathic sudden sensorineural hearing loss.

    PubMed

    Murphy-Lavoie, H; Piper, S; Moon, R E; Legros, T

    2012-01-01

    Idiopathic sudden sensorineural hearing loss (ISSHL) is the newest indication approved by the Undersea and Hyperbaric Medical Society's Hyperbaric Oxygen Therapy Committee. Idiopathic sudden sensorineural hearing loss appears to be characterized by hypoxia in the perilymph and therefore the scala tympani and the organ of Corti. A review of the literature reveals more than 100 publications evaluating the use of hyperbaric oxygen (HBO2) for the treatment of ISSHL, including eight randomized controlled trials. The best and most consistent results are obtained when HBO2 is initiated within two weeks of symptom onset and combined with corticosteroid treatment. The average hearing gain is 19.3 dB for moderate hearing loss and 37.7 dB for severe cases. This improvement brings hearing deficits from the moderate/severe range into the slight/no impairment range. This is a significant gain that can markedly improve a patient's quality of life, both clinically and functionally.

  9. Continuous home oxygen therapy.

    PubMed

    Ortega Ruiz, Francisco; Díaz Lobato, Salvador; Galdiz Iturri, Juan Bautista; García Rio, Francisco; Güell Rous, Rosa; Morante Velez, Fátima; Puente Maestu, Luis; Tàrrega Camarasa, Julia

    2014-05-01

    Oxygen therapy is defined as the therapeutic use of oxygen and consists of administering oxygen at higher concentrations than those found in room air, with the aim of treating or preventing hypoxia. This therapeutic intervention has been shown to increase survival in patients with chronic obstructive pulmonary disease (COPD) and respiratory failure. Although this concept has been extended by analogy to chronic respiratory failure caused by respiratory and non-respiratory diseases, continuous oxygen therapy has not been shown to be effective in other disorders. Oxygen therapy has not been shown to improve survival in patients with COPD and moderate hypoxaemia, nor is there consensus regarding its use during nocturnal desaturations in COPD or desaturations caused by effort. The choice of the oxygen source must be made on the basis of criteria such as technical issues, patient comfort and adaptability and cost. Flow must be adjusted to achieve appropriate transcutaneous oxyhaemoglobin saturation correction.

  10. De novo cataract development following a standard course of hyperbaric oxygen therapy.

    PubMed

    Gesell, L B; Trott, A

    2007-01-01

    A 49 y/o female under went 48 hyperbaric oxygen (HBO2) treatments at 2.5 ATA (atmospheres absolute) (253 kPa) for 90 minutes for chronic refractory osteomyelitis of the sacrum and recurrent failure of a sacral myocutaneous flap. Prior to HBO2 therapy, formal ophthalmic exams revealed myopia but no evidence of cataract formation. Eight weeks following the completion of HBO2 therapy, on repeat ophthalmic exam, the patient was discovered to have worsening myopia. Changes of the crystalline lens, consistent with nuclear cataract development, were identified in each eye. Other common causes of cataract formation including diabetes, corticosteroid use, and excessive exposure to ultraviolet light, were excluded. While transient visual changes are known to occur during HBO2 therapy, cataract formation has only rarely been reported and only after prolonged courses of treatment (150 or more treatments). This case identifies the need to further investigate the ocular effects of HBO2 therapy, especially with regard to cataract development and progression.

  11. Hyperbaric oxygen therapy and cancer--a review.

    PubMed

    Moen, Ingrid; Stuhr, Linda E B

    2012-12-01

    Hypoxia is a critical hallmark of solid tumors and involves enhanced cell survival, angiogenesis, glycolytic metabolism, and metastasis. Hyperbaric oxygen (HBO) treatment has for centuries been used to improve or cure disorders involving hypoxia and ischemia, by enhancing the amount of dissolved oxygen in the plasma and thereby increasing O(2) delivery to the tissue. Studies on HBO and cancer have up to recently focused on whether enhanced oxygen acts as a cancer promoter or not. As oxygen is believed to be required for all the major processes of wound healing, one feared that the effects of HBO would be applicable to cancer tissue as well and promote cancer growth. Furthermore, one also feared that exposing patients who had been treated for cancer, to HBO, would lead to recurrence. Nevertheless, two systematic reviews on HBO and cancer have concluded that the use of HBO in patients with malignancies is considered safe. To supplement the previous reviews, we have summarized the work performed on HBO and cancer in the period 2004-2012. Based on the present as well as previous reviews, there is no evidence indicating that HBO neither acts as a stimulator of tumor growth nor as an enhancer of recurrence. On the other hand, there is evidence that implies that HBO might have tumor-inhibitory effects in certain cancer subtypes, and we thus strongly believe that we need to expand our knowledge on the effect and the mechanisms behind tumor oxygenation.

  12. Audit of oxygen therapy.

    PubMed

    Gravil, J H; O'Neill, V J; Stevenson, R D

    1997-06-01

    We audited the use of oxygen in our hospital. Over three days we found 119 patients using oxygen, 21 wearing their mask incorrectly or not at all. The commonest indication was chronic obstructive pulmonary disease. Forty patients had no record of arterial gas analysis. Of those who had, 29 did not require oxygen and the average time from last arterial gas analysis was 5.7 days and only eight patients were being monitored with an oximeter. Taking into account the risk of exacerbating carbon dioxide retention and the problems that arise when discharging a patient who has been receiving oxygen therapy for the duration of their admission, we fee oxygen therapy should only be administered with the knowledge of the arterial gases and with frequent reassessment during therapy.

  13. Practical procedures: oxygen therapy.

    PubMed

    Olive, Sandra

    Knowing when to start patients on oxygen therapy can save lives, but ongoing assessment and evaluation must be carried out to ensure the treatment is safe and effective. This article outlines when oxygen therapy should be used and the procedures to follow. It also describes the delivery methods applicable to different patient groups, along with the appropriate target saturation ranges, and details relevant nurse competencies.

  14. Acute oxygen therapy.

    PubMed

    Akbar, Fazal; Campbell, Ian Allen

    2004-05-01

    Oxygen therapy is a central part of our clinical practice and is widely used in many pulmonary and non-pulmonary conditions worldwide but it is sometimes used unnecessarily and can be harmful. Optimum use is not only important for patient care but is also sound fiscally because of the expense of oxygen and the cost of devices utilised. This article is aimed both at reviewing available research and guidelines for the use of oxygen and providing knowledge of different administering and monitoring devices and equipment. Various hospital based audits have shown oxygen as being poorly prescribed and inappropriately administered and it is important for everyone involved in patient care to understand the basics of oxygen therapy before optimum practice can be implemented and followed. PMID:15225466

  15. How Does Oxygen Therapy Work?

    MedlinePlus

    ... this page from the NHLBI on Twitter. How Does Oxygen Therapy Work? Oxygen therapy provides you with ... pass through your nose or mouth like it does with the other delivery systems. A humidifier adds ...

  16. [Utility of hyperbaric oxygenation in radiotherapy for malignant brain tumors--a literature review].

    PubMed

    Beppu, Takaaki; Tanaka, Katsuyuki; Kohshi, Kiyotaka

    2009-06-01

    Over the past 50 years, hyperbaric oxygenation (HBO) therapy has been used in a wide variety of medical conditions; this theraphy causes an increase in oxygen tension in blood and tissues. In the treatment of malignant gliomas, HBO therapy is used for the radiosensitization of cells in combination with radiotherapy (RT). Further, HBO therapy is applied for the treatment and prevention of radiation-induced brain necrosis that is the most serious complication observed after radiosurgery. We reviewed the literature to evaluate the manner in which HBO therapy contributes to clinical fields in cases of RT administration for malignant brain tumors.

  17. Morphological study of rat skin flaps treated with subcutaneous dimethyl sulfoxide combined with hyperbaric oxygen therapy.

    PubMed

    Almeida, K G; Oliveira, R J; Dourado, D M; Filho, E A; Fernandes, W S; Souza, A S; Araújo, F H S

    2015-01-01

    This study investigated the effects of hyperbaric oxygen therapy (HBOT) and dimethyl sulfoxide (DMSO) in tissue necrosis, genotoxicity, and cell apoptosis. Random skin flaps were made in 50 male Wistar rats, randomly divided into the following groups. Control group (CT), wherein a rectangular skin section (2 x 8 cm) was dissected from the dorsal muscle layer, preserving the cranial vessels, lifted, and refixed to the bed; distilled water (DW) group, in which DW was injected into the distal half of the skin flap; DMSO group, wherein 5% DMSO was injected; HBOT group, comprising animals treated only with HBOT; and HBOT + DMSO group, comprising animals treated with 100% oxygen at 2.5 atmospheres absolute for 1 h, 2 h after the experiment, daily for 10 consecutive days. A skinflap specimen investigated by microscopy. The percentage of necrosis was not significantly different between groups. The cell viability index was significantly different between groups (P < 0.001): 87.40% (CT), 86.20% (DW), 84.60% (DMSO), 86.60% (DMSO + HBO), and 91% (HBO) (P < 0.001), as was the cell apoptosis index of 12.60 (CT), 12.00 (DW), 15.40 (DMSO), 9.00 (HBO), and 12.00 (DMSO + HBO) (P < 0.001). The genotoxicity test revealed the percentage of cells with DNA damage to be 22.80 (CT), 22.60 (DW), 26.00 (DMSO), 8.80 (DMSO + HBO), and 7.20 (HBO) (P < 0.001). Although the necrotic area was not different between groups, there was a significant reduction in the cellular DNA damage and apoptosis index in the HBOT group. PMID:26782463

  18. Morphological study of rat skin flaps treated with subcutaneous dimethyl sulfoxide combined with hyperbaric oxygen therapy.

    PubMed

    Almeida, K G; Oliveira, R J; Dourado, D M; Filho, E A; Fernandes, W S; Souza, A S; Araújo, F H S

    2015-12-28

    This study investigated the effects of hyperbaric oxygen therapy (HBOT) and dimethyl sulfoxide (DMSO) in tissue necrosis, genotoxicity, and cell apoptosis. Random skin flaps were made in 50 male Wistar rats, randomly divided into the following groups. Control group (CT), wherein a rectangular skin section (2 x 8 cm) was dissected from the dorsal muscle layer, preserving the cranial vessels, lifted, and refixed to the bed; distilled water (DW) group, in which DW was injected into the distal half of the skin flap; DMSO group, wherein 5% DMSO was injected; HBOT group, comprising animals treated only with HBOT; and HBOT + DMSO group, comprising animals treated with 100% oxygen at 2.5 atmospheres absolute for 1 h, 2 h after the experiment, daily for 10 consecutive days. A skinflap specimen investigated by microscopy. The percentage of necrosis was not significantly different between groups. The cell viability index was significantly different between groups (P < 0.001): 87.40% (CT), 86.20% (DW), 84.60% (DMSO), 86.60% (DMSO + HBO), and 91% (HBO) (P < 0.001), as was the cell apoptosis index of 12.60 (CT), 12.00 (DW), 15.40 (DMSO), 9.00 (HBO), and 12.00 (DMSO + HBO) (P < 0.001). The genotoxicity test revealed the percentage of cells with DNA damage to be 22.80 (CT), 22.60 (DW), 26.00 (DMSO), 8.80 (DMSO + HBO), and 7.20 (HBO) (P < 0.001). Although the necrotic area was not different between groups, there was a significant reduction in the cellular DNA damage and apoptosis index in the HBOT group.

  19. Effect of hyperbaric oxygen on the growth and development of medicinal maggots.

    PubMed

    Sherman, Ronald A; Khavari, Borna; Werner, Darryl

    2013-01-01

    Some wound care therapists use both maggot debridement therapy (MDT) and hyperbaric oxygen (HBO2) therapy to treat non-healing wounds. Some practitioners have reported success using both MDT and HBO2 therapy concurrently; others have not. To begin evaluating the utility of using MDT and HBO2 therapy concurrently, we assessed the effects of hyperbaric oxygen (HBO2) on maggot growth and development, as a surrogate for debridement capacity. Replicate sets of medical-grade blowfly larvae were placed on liver-agar wound models and exposed to HBO2 at 2.0 atmospheres absolute (atm abs) for 90 minutes on 0 (control), 1, 2 or 3 sequential days. The effects of HBO2 exposure were quantified by measuring the maggots' subsequent growth and development. Exposure to HBO2 was most lethal to young larvae (second instars), but not to older larvae (third instars). There was no dose-relationship between the number of HBO2 treatments and rate of larval survival. Our findings suggest that maggot therapy and HBO2 therapy may be administered concurrently, as long as the larvae are not too immature (that is, as long as they are beyond the second instar) by the time they take their first dive. A clinical trial evaluating the clinical benefits of concurrent HBO2 therapy and MDT is warranted.

  20. Hyperbaric oxygen therapy after Bothrops lanceolatus snake bites in Martinique: a brief report.

    PubMed

    Hochedez, P; Thomas, L; Mehdaoui, H

    2010-01-01

    Every year 10 to 20 cases of snake bites are reported on the Caribbean island of Martinique. The only snake involved, Bothrops lanceolatus, is endemic on the island, and its bite may lead to systemic multifocal thrombotic complications in the'absence of the monospecific antivenom. Between January 1988 and January 2009, more than 250 snake bites have been reported, and five patients were treated with hyperbaric oxygen (HBO2) therapy for local complications. The patients were male, bitten on the leg or the hand, and presented with severe complications such as necrotizing soft tissue infections, compartment syndrome or abscesses despite prompt wound care and administration of antivenomous serum. Outcomes were favorable for these five patients, except for one who was left with a functional defect of the hand. Although snake bites are not part of the currently recommended indications for HBO2 therapy, local complications, namely compartment syndrome, necrotizing soft tissue infections and enhancement of healing in selected problem wounds, are approved uses of HBO2 therapy as defined by the Hyperbaric Oxygen Therapy Committee and would benefit from prospective studies. PMID:21226390

  1. Functional MRI during Hyperbaric Oxygen: Effects of Oxygen on Neurovascular Coupling and BOLD fMRI signals

    PubMed Central

    Cardenas, Damon P.; Muir, Eric R.; Huang, Shiliang; Boley, Angela; Lodge, Daniel; Duong, Timothy Q.

    2015-01-01

    Hyperbaric oxygen (HBO) therapy is used to treat a number of ailments. Improved understanding of how HBO affects neuronal activity, cerebral blood flow (CBF) and blood-oxygenation-level dependent (BOLD) changes could shed light on the role of oxygen in neurovascular coupling and help guide HBO treatments. The goal of this study was to test two hypotheses: i) activation-induced CBF fMRI response is not dependent on hemoglobin deoxygenation, and ii) activation-induced BOLD fMRI is markedly attenuated under HBO. CBF and BOLD fMRI of forepaw stimulation in anesthetized rats under HBO at 3 atmospheres absolute (ATA) was compared with normobaric air. Robust BOLD and CBF fMRI were detected under HBO. Inflow effects and spin-density changes did not contribute significantly to the BOLD fMRI signal under HBO. Analysis of the T2*-weighted signal at normobaric air and 1, 2 and 3ATA oxygen in the tissue and the superior sagittal sinus showed a strong dependence on increasing inhaled [O2]. Spontaneous electrophysiological activity and evoked local-field potentials were reduced under HBO. The differences between normobaric air and HBO in basal and evoked electrical activity could not fully account for the strong BOLD responses under HBO. We concluded that activation-induced CBF regulation in the brain does not operate through an oxygen-sensing mechanism and that stimulus-evoked BOLD responses and the venous T2*-weighted signals still have room to increase under 3ATA HBO. To our knowledge, this is the first fMRI study under HBO, providing insights into the effects of HBO on neural activity, neurovascular coupling, tissue oxygenation, and the BOLD signal. PMID:26143203

  2. Functional MRI during hyperbaric oxygen: Effects of oxygen on neurovascular coupling and BOLD fMRI signals.

    PubMed

    Cardenas, Damon P; Muir, Eric R; Huang, Shiliang; Boley, Angela; Lodge, Daniel; Duong, Timothy Q

    2015-10-01

    Hyperbaric oxygen (HBO) therapy is used to treat a number of ailments. Improved understanding of how HBO affects neuronal activity, cerebral blood flow (CBF) and blood-oxygenation-level dependent (BOLD) changes could shed light on the role of oxygen in neurovascular coupling and help guide HBO treatments. The goal of this study was to test two hypotheses: i) activation-induced CBF fMRI response is not dependent on hemoglobin deoxygenation, and ii) activation-induced BOLD fMRI is markedly attenuated under HBO. CBF and BOLD fMRI of forepaw stimulation in anesthetized rats under HBO at 3 atmospheres absolute (ATA) were compared with normobaric air. Robust BOLD and CBF fMRI were detected under HBO. Inflow effects and spin-density changes did not contribute significantly to the BOLD fMRI signal under HBO. Analysis of the T2(⁎)-weighted signal at normobaric air and 1, 2 and 3ATA oxygen in the tissue and the superior sagittal sinus showed a strong dependence on increasing inhaled [O2]. Spontaneous electrophysiological activity and evoked local-field potentials were reduced under HBO. The differences between normobaric air and HBO in basal and evoked electrical activity could not fully account for the strong BOLD responses under HBO. We concluded that activation-induced CBF regulation in the brain does not operate through an oxygen-sensing mechanism and that stimulus-evoked BOLD responses and the venous T2(⁎)-weighted signals still have room to increase under 3ATA HBO. To our knowledge, this is the first fMRI study under HBO, providing insights into the effects of HBO on neural activity, neurovascular coupling, tissue oxygenation, and the BOLD signal.

  3. Home Oxygen Therapy

    MedlinePlus

    ... important advantage of liquid oxygen is you can transfer some of the liquid oxygen into a smaller, ... from gas stoves, candles, lighted fireplaces, or other heat sources. Don't use any flammable products like ...

  4. Hyperbaric oxygen therapy for carbon monoxide poisoning.

    PubMed

    Weaver, Lindell K

    2014-01-01

    Despite established exposure limits and safety standards, and the availability of carbon monoxide (CO) alarms, each year 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO, or from longer exposures to lower levels. Common symptoms include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status. Some patients may have chest pain, shortness of breath and myocardial ischemia, and may require mechanical ventilation and treatment of shock. Individuals poisoned by CO often go on to develop neurological problems, including cognitive sequelae, anxiety and depression, persistent headaches, dizziness, sleep problems, motor weakness, vestibular and balance problems, gaze abnormalities, peripheral neuropathies, hearing loss, tinnitus and Parkinsonian-like syndrome. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO2) hastens COHb elimination and favorably modulates inflammatory processes instigated by CO poisoning, an effect not observed with breathing normobaric oxygen. Hyperbaric oxygen improves mitochondrial function, inhibits lipid peroxidation transiently, impairs leukocyte adhesion to injured microvasculature, and reduces brain inflammation caused by the CO-induced adduct formation of myelin basic protein. Based upon three supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO2 should be considered for all cases of acute symptomatic CO poisoning. Hyperbaric oxygen is indicated for CO poisoning complicated by cyanide poisoning, often concomitantly with smoke inhalation.

  5. Effect of combined therapy with ephedrine and hyperbaric oxygen on neonatal hypoxic-ischemic brain injury.

    PubMed

    Chen, Siyuan; Xiao, Nong; Zhang, Xiaoping

    2009-11-13

    Perinatal hypoxic-ischemic (HI) is a major cause of brain injury in the newborn, and there is a lack of effective therapies to reduce injury-related disorders. The aim of the present study was to evaluate the effect of a combination of ephedrine and hyperbaric oxygen (HBO) on neonatal hypoxic-ischemic brain injury. 7-day-old Sprague-Dawley rat pups were randomly divided into sham operation, HI, ephedrine, HBO, and combined group. The ephedrine group was intraperitoneally injected with ephedrine, HBO group was treated for 2h at 2.5 absolute atmosphere (ATA) per day, the combined group received both ephedrine and HBO treatments, the sham operation and HI groups were intraperitoneally injected with normal saline. Rat brains at 7 days after HI, were collected to determine histopathological damage and the expression levels of Caspase-3 and Nogo-A. Four weeks after insult, animals were challenged with Morris water maze test. The expressions of Caspase-3 and Nogo-A were reduced in treating groups compared to those in HI group (P<0.01). Compared with the single treatment groups, the expression levels of Caspase-3 and Nogo-A were significantly reduced in the combined group (P<0.01). Compared with the single treatment groups, the average time of escape latency was significantly shorter (P<0.01) and the number of platform location crossing was more (P<0.05) in combined group. These findings indicate that the combination of ephedrine and HBO can enhance the neuroprotective effect in the neonatal rat HI model partially mediated by inhibiting Caspase-3 and Nogo-A pathways.

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

    PubMed Central

    Comert, Bilgin; Isik, Ahmet Turan; Aydin, Sezai; Bozoglu, Ergun; Unal, Bulent; Deveci, Salih; Mas, Nuket; Cinar, Esref; Mas, Mehmet Refik

    2007-01-01

    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, GroupI). 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 II received saline, Group III 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 II (974 ± 110, 384 ± 40, 851 ± 56, and 1664 ± 234 U/L, respectively, P < 0.05, for all). Combining the two treatment options revealed 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 III, IV and V compared to Group II (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. PMID:18069760

  7. Treatment of laryngeal radionecrosis with hyperbaric oxygen therapy: a case report.

    PubMed

    Hsu, Ying-Che; Lee, Ka-Wo; Ho, Kuen-Yao; Tsai, Kun-Bow; Kuo, Wen-Rei; Wang, Ling-Feng; Chiang, Feng-Yu

    2005-02-01

    An 81-year-old male with early-stage laryngeal carcinoma had been treated with 60 Gy curative radiotherapy. He complained of a sore throat, foul odor in the mouth, progressive dyspnea, and fever 2 months after the completion of radiotherapy. Direct laryngoscopy revealed narrowing of the glottis with diffuse ulcerative necrotic tissue. Biopsies at multiple sites and pathology revealed intense coagulation necrosis with complete denudation of covering epithelium without any malignancy. Since laryngeal radionecrosis was suspected, the patient received hyperbaric oxygen (HBO) therapy 40 times for 1 hour of 100% O2 at 2 atm absolute pressure. His clinical symptoms gradually improved and repeated endolaryngeal biopsies were undertaken near the end of HBO therapy and again 6 months later. The patient's larynx healed completely with diffuse fibrosis and no malignant cells were found on pathology. Radionecrosis must be differentiated from cancer recurrence following curative radiotherapy for early laryngeal cancer. HBO therapy could be a useful treatment adjunct for laryngeal radionecrosis. PMID:15825695

  8. Oxygen therapy - infants

    MedlinePlus

    ... help breathing than they can get from an oxygen hood or nasal cannula, but do not need a machine to completely ... is not warm enough. Most (but not all) nasal cannulas use cool, dry oxygen. At higher flow rates, this can irritate the ...

  9. Hyperbaric oxygen therapy

    MedlinePlus

    ... units may be available in outpatient centers. The air pressure inside a hyperbaric oxygen chamber is about two and a half times higher than the normal pressure in the ... Air or gas embolism Bone infections ( osteomyelitis ) that have ...

  10. Oxygen therapy in preterm infants.

    PubMed

    Cherian, S; Morris, I; Evans, J; Kotecha, S

    2014-06-01

    Despite being the most widely used and vital therapy in neonatology, optimal strategies for the use of oxygen in preterm infants remain controversial. Achieving the balance between attaining adequate tissue oxygenation and avoiding oxygen toxicity is challenging. There remains a paucity of clear evidence based guidance for clinicians on safe oxygen saturation targets. What does seem apparent is that these targets vary over time in the life of a preterm infant. This article summarises the evidence behind current practice of oxygen monitoring and administration from the first few minutes after birth, through to the acute neonatal and later convalescent periods. Finally, we review the use of home oxygen for preterm infants with bronchopulmonary dysplasia including administration and weaning from domically home oxygen.

  11. A prospective, randomized, controlled study of hyperbaric oxygen therapy: effects on healing and oxidative stress of ulcer tissue in patients with a diabetic foot ulcer.

    PubMed

    Ma, Le; Li, Pingsong; Shi, Zehong; Hou, Tuanjie; Chen, Xiao; Du, Jin

    2013-03-01

    Although hyperbaric oxygen (HBO) therapy has been reported to help heal chronic foot ulcers in patients with diabetes mellitus (DM), production of HBO-related oxidative stress is a concern. To assess the therapeutic effect and oxidative stress of HBO, a 2-week, prospective, randomized, controlled clinical study was conducted from January 1, 2010 to January1, 2012 among 36 consecutively admitted patients with diabetic foot ulcers (DFU). Average patient age was 60.08 ± 5.97 years and average DM duration was 16.4 ± 11.3 years; 86.1% had type 2 DM, and 47.2% had Wagner grade-III foot ulcers. Patients randomized to the control group (n = 18) received standard care including offloading, wound debridement, and glucose control. HBO treatment group patients (n = 18) received standard care and twice-daily HBO sessions for 90 minutes at 2.5 atmospheres absolute (ATA) 5 days a week for 2 weeks. Transcutaneous oxygen pressure (TcPo2) at the edge of the ulcer and wound size were measured at baseline and after 7 and 14 days of treatment. Ulcer tissues were harvested on days 7 and 14 to determine oxidative stress by measuring malondialdehyde (MDA) and antioxidant enzyme (superoxide dismutase [SOD], catalase [CAT], and glutathione peroxidase [GPx]) levels. Compared to baseline, TcPo2 in the HBO group increased on day 7 (477.8 ± 118.2 mm Hg versus 37.06 ± 5.23 mm Hg, P <0.01) and day 14 (501.1 ± 137.7 mm Hg versus 35.61 ± 4.85 mm Hg, P <0.01). Ulcer size reduction in the HBO group was greater than that of the control group (42.4% ± 20.0% versus 18.1% ± 6.5%, P <0.05). MDA levels, SOD, and CAT were all significantly higher in the HBO than in the control group on day 14 (P<0.05). The results of this study suggest HBO treatment for 2 weeks initiates a healing response in chronic DFUs, but the observed oxidative stress in local ulcer tissue may offset this effect long-term. Until needed additional research has been conducted, prolonged and/or inappropriate HBO treatment should

  12. Case report: successful use of hyperbaric oxygen therapy for a complete scalp degloving injury.

    PubMed

    Khandelwal, S; Wall, J; Kaide, C; Katz, G

    2008-01-01

    We report a case of a complete scalp degloving injury in a 43-year-old previously healthy, tobacco-using female whose hair was caught in a tractor power take-off causing an instantaneous total scalping injury. Microsurgical replantation was started 4 hours after injury with the surgical procedure lasting 4 hours. Only the superficial temporal arteries were reanastomosed with no venous anastomosis possible. Hyperbaric oxygen (HBO2) treatment at 2.5 atmospheres absolute (ATA) for 90 minutes was administered immediately after surgery due to duskiness of the flap. Further HBO2 treatments were administered twice daily for seven days and then once daily for 30 days. Additionally, leech therapy was used for the first ten postoperative days. The patient's right auricle and most of the left auricle were completely lost. Despite the tenuous vascular inflow and initially absent venous drainage, at 3 month follow-up there was reepithelialization of her scalp except for an area of granulation tissue in the occipitoparietal area. At one year follow-up the area of granulation tissue was reduced, but there was no detectable hair growth or nerve function. We propose that HBO2 may facilitate tissue survival in scalp degloving injuries in the face of incomplete surgical revascularization. PMID:19175199

  13. Hyperbaric oxygen in the treatment of osteoradionecrosis: a review of its use and efficacy

    SciTech Connect

    Fattore, L.; Strauss, R.A.

    1987-03-01

    Hyperbaric oxygen (HBO) therapy is an established technology that is proving to be effective in the treatment of osteoradionecrosis. However, the studies that have shown this treatment modality to be effective have not established the optimum pressures, times of exposure, and frequency and number of treatment necessary for healing. In addition, most of the studies used HBO as an adjunctive treatment in the management of refractory osteoradionecrosis. The efficacy of HBO as a primary treatment modality has not as yet been established. Strictly controlled clinical trials are necessary for identification of patients who are likely to respond to HBO without aggressive surgery, to delineate a timetable for treatment of patients with HBO, and to coordinate surgery with HBO to resolve osteoradionecrosis when a significant amount of bone loss is involved.

  14. Hyperbaric oxygen treatment reduces neutrophil-endothelial adhesion in chronic wound conditions through S-nitrosation.

    PubMed

    Kendall, Alexandra C; Whatmore, Jacqueline L; Winyard, Paul G; Smerdon, Gary R; Eggleton, Paul

    2013-01-01

    Hyperbaric oxygen (HBO) therapy is an effective treatment for diabetic chronic wounds. HBO reduces inflammation and accelerates wound healing, by mechanisms that remain unclear. Here we examined a mechanism by which HBO may reduce neutrophil recruitment, through changes in endothelial and neutrophil adhesion molecule expression and function. Human umbilical vein endothelial cells and neutrophils were exposed to selected chronic wound conditions, comprising hypoxia in the presence of lipopolysaccharide and tumor necrosis factor-alpha, and then treated with HBO. We observed neutrophil adhesion to endothelial cells following treatment with chronic wound conditions, which was reversed by HBO treatment. This was partly explained by reduced expression of endothelial intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 by HBO. No changes in neutrophil adhesion molecule expression (CD18, CD11b, CD62L, CD31) were observed following HBO treatment. However, HBO decreased hydrogen peroxide generation by neutrophils, and induced nitrous oxide-related protein modifications. The transnitrosating agent S-nitroso-L-cysteine ethyl ester (600 μM) also reduced neutrophil adhesion to human umbilical vein endothelial cell monolayers, and the iNOS inhibitor 1400 W (10 μM) and HgCl2, which promotes the decomposition of S-nitrosothiols (1 mM), reversed the effect of HBO, suggesting that S-nitrosation may inhibit neutrophil-endothelial cell adhesion. This study indicates that HBO could reduce inflammation in wounds through reduced neutrophil recruitment, mediated by S-nitrosation. PMID:24134224

  15. Hyperbaric oxygen therapy as salvage treatment for sudden sensorineural hearing loss: a prospective controlled study.

    PubMed

    Pezzoli, M; Magnano, M; Maffi, L; Pezzoli, L; Marcato, P; Orione, M; Cupi, D; Bongioannini, G

    2015-07-01

    The most commonly used treatment for sensorineural sudden hearing loss (SSHL) in clinical practice is the administration of steroids; however, a favorable result is not always obtained. We studied 58 patients who failed to recover after primary treatment with IV steroids, 44 of these met our inclusion criteria (mean age 50.7, 27 males, range 30-74). We treated 23 patients (mean age 47.3, 16 males, age range 22-74) with hyperbaric oxygen therapy (HBO) (2.5 ATA for 60 min for 15 treatments), while 21 (mean age 54.5, 11 males, age range 22-71) patients refused to be treated and served as a non-randomized control group. Patients treated with HBO had a mean improvement of 15.6 dB (SD ± 15.3), with 1 of them completely healed, 5 with a good recovery, 10 with a fair recovery and 7 unchanged. Patients who were not treated had a spontaneous mean improvement of 5.0 dB (SD ± 11.4) with 3 patients with a good recovery, 1 patient with a fair recovery and 17 patients unchanged. Mean improvement was significantly better in patients treated with HBO compared to controls (p = 0.0133). Patients with worst hearing had the greater degree of improvement whether or not they were treated in the first 10 days after the onset of the hearing loss or between 11 and 30 days. In conclusion, hyperbaric oxygen therapy can lead to significant improvement of pure tone hearing thresholds in patients with SSHL who failed primary corticosteroid treatment and are within 4 weeks of the onset of deafness.

  16. Exposure to Hyperbaric Oxygen Intensified Vancomycin-Induced Nephrotoxicity in Rats

    PubMed Central

    Sandbank, Judith; Kozer, Eran; Dagan, Zahi; Goldman, Michael; Bahat, Hilla; Stav, Kobi; Zisman, Amnon; Klin, Baruch; Abu-Kishk, Ibrahim

    2016-01-01

    It has been suggested that oxidative stress is a potential mechanism for vancomycin-induced nephrotoxicity and hyperbaric oxygen therapy (HBO) has been shown to be effective in treating renal toxicity that has been pharmacologically induced in animal models. The aim of this study was to investigate the effect of HBO therapy on vancomycin-induced nephrotoxicity in rats. The study group comprised 36 Sprague Dawley male rats. We treated 30 with 500 mg/kg of intraperitoneal vancomycin once a day for 7 days. Half of these rats received a daily 1-hour treatment with HBO at 2 Atmospheres (ATM) on the same 7 days and formed the HBO+ group. The other 15 subjects received no HBO treatment (HBO- group). The remaining six rats served as the control group, three received HBO treatments alone and no treatment was administered to the other three rats. Laboratory results were obtained on day 8 and the intervention and control groups were compared. Rats in the HBO+ group gained less weight than the HBO- group (11.6 grams vs 22.6 grams; P = 0,008) and had significantly higher serum blood urea nitrogen (99.6 vs 52.6 mg/dL; P<0.001), serum creatinine (0.42 vs 0.16 mg/dL; P = 0.001) and magnesium (3.6 vs 3.1mg/dL; P = 0.014). The vancomycin blood levels were also higher in the HBO+ group (27.8 vs 6.7 μg/mL; P = 0.078). There were no pathological kidney changes in the control group. All the kidneys from the treated groups (vancomycin +HBO and vancomycin HBO-) showed moderate to severe histopathological changes with no statistical significance between them. This study demonstrated that exposure to hyperbaric oxygen intensified vancomycin-induced nephrotoxicity in rats. PMID:27092557

  17. Exposure to Hyperbaric Oxygen Intensified Vancomycin-Induced Nephrotoxicity in Rats.

    PubMed

    Sabler, Itay M; Berkovitch, Matitiahu; Sandbank, Judith; Kozer, Eran; Dagan, Zahi; Goldman, Michael; Bahat, Hilla; Stav, Kobi; Zisman, Amnon; Klin, Baruch; Abu-Kishk, Ibrahim

    2016-01-01

    It has been suggested that oxidative stress is a potential mechanism for vancomycin-induced nephrotoxicity and hyperbaric oxygen therapy (HBO) has been shown to be effective in treating renal toxicity that has been pharmacologically induced in animal models. The aim of this study was to investigate the effect of HBO therapy on vancomycin-induced nephrotoxicity in rats. The study group comprised 36 Sprague Dawley male rats. We treated 30 with 500 mg/kg of intraperitoneal vancomycin once a day for 7 days. Half of these rats received a daily 1-hour treatment with HBO at 2 Atmospheres (ATM) on the same 7 days and formed the HBO+ group. The other 15 subjects received no HBO treatment (HBO- group). The remaining six rats served as the control group, three received HBO treatments alone and no treatment was administered to the other three rats. Laboratory results were obtained on day 8 and the intervention and control groups were compared. Rats in the HBO+ group gained less weight than the HBO- group (11.6 grams vs 22.6 grams; P = 0,008) and had significantly higher serum blood urea nitrogen (99.6 vs 52.6 mg/dL; P<0.001), serum creatinine (0.42 vs 0.16 mg/dL; P = 0.001) and magnesium (3.6 vs 3.1 mg/dL; P = 0.014). The vancomycin blood levels were also higher in the HBO+ group (27.8 vs 6.7 μg/mL; P = 0.078). There were no pathological kidney changes in the control group. All the kidneys from the treated groups (vancomycin +HBO and vancomycin HBO-) showed moderate to severe histopathological changes with no statistical significance between them. This study demonstrated that exposure to hyperbaric oxygen intensified vancomycin-induced nephrotoxicity in rats.

  18. A Multidisciplinary Approach with Hyperbaric Oxygen Therapy Improve Outcome in Snake Bite Injuries

    PubMed Central

    Korambayil, Pradeoth Mukundan; Ambookan, Prashanth Varkey; Abraham, Siju Varghese; Ambalakat, Ajay

    2015-01-01

    Aim: Snakebite injuries are common in tropical India among those who are involved in outdoor activities. These injuries results in cellulitis, gangrene at the bite area, bleeding manifestations, compartment syndrome, regional lymphadenopathy, septicemia, hypotension, and disseminated intravascular coagulation (DIC) resulting in significant morbidity and mortality. The purpose of this study is to share our experience of multidisciplinary approach in the management of snakebite injuries of the extremities with various treatment modalities including hyperbaric oxygen (HBO) therapy, surgical debridement, and soft tissue reconstruction to provide an effective treatment for snake bite injuries. Methods: The study was conducted in the Department of Plastic Surgery, during the period October 2012–December 2014, wherein all the patients who were admitted with snakebite injuries were enrolled and the patients treated in plastic surgery department were included into the study. Out of total 766 patients, there were 323 patients treated with anti snake venom (ASV) and 29 died among the treated patients; 205 patients belonged to pediatric age group. Results: Out of 112 patients referred to Department of Plastic Surgery, 50 cases presented with cellulitis, 24 patients with compartment syndrome, and 38 patients were referred for the management of soft tissue cover over the extremities. Among 112 patients, 77 involved the lower extremity and 35 the upper extremity. Conclusion: Multidisciplinary approach including hyperbaric oxygen (HBO) therapy improves outcome in the management of snakebite injuries of the extremities. PMID:26862269

  19. Effect of prophylactic hyperbaric oxygen treatment for radiation-induced brain injury after stereotactic radiosurgery of brain metastases

    SciTech Connect

    Ohguri, Takayuki . E-mail: ogurieye@med.uoeh-u.ac.jp; Imada, Hajime; Kohshi, Kiyotaka; Kakeda, Shingo; Ohnari, Norihiro; Morioka, Tomoaki; Nakano, Keita; Konda, Nobuhide; Korogi, Yukunori

    2007-01-01

    Purpose: The purpose of the present study was to evaluate the prophylactic effect of hyperbaric oxygen (HBO) therapy for radiation-induced brain injury in patients with brain metastasis treated with stereotactic radiosurgery (SRS). Methods and Materials: The data of 78 patients presenting with 101 brain metastases treated with SRS between October 1994 and September 2003 were retrospectively analyzed. A total of 32 patients with 47 brain metastases were treated with prophylactic HBO (HBO group), which included all 21 patients who underwent subsequent or prior radiotherapy and 11 patients with common predictors of longer survival, such as inactive extracranial tumors and younger age. The other 46 patients with 54 brain metastases did not undergo HBO (non-HBO group). Radiation-induced brain injuries were divided into two categories, white matter injury (WMI) and radiation necrosis (RN), on the basis of imaging findings. Results: Radiation-induced brain injury occurred in 5 lesions (11%) in the HBO group (2 WMIs and 3 RNs) and in 11 (20%) in the non-HBO group (9 WMIs and 2 RNs). The WMI was less frequent for the HBO group than for the non-HBO group (p = 0.05), although multivariate analysis by logistic regression showed that WMI was not significantly correlated with HBO (p = 0.07). The 1-year actuarial probability of WMI was significantly better for the HBO group (2%) than for the non-HBO group (36%) (p < 0.05). Conclusions: The present study showed a potential value of prophylactic HBO for Radiation-induced WMIs, which justifies further evaluation to confirm its definite benefit.

  20. A Prolonged NO-Dependent, Opioid-Mediated Antinociceptive Effect of Hyperbaric Oxygen in Mice

    PubMed Central

    Zelinski, Lisa M.; Ohgami, Yusuke; Chung, Eunhee; Shirachi, Donald Y.; Quock, Raymond M.

    2009-01-01

    Hyperbaric oxygen (HBO2) therapy is reported to cause pain relief in several conditions of chronic pain. A single 60-min session of HBO2 treatment produced a prolonged antinociceptive effect in mice that persisted for 90 min after cessation of treatment. The HBO2-induced antinociception was significantly attenuated by pretreatment prior to HBO2 exposure with the opioid antagonist naltrexone, the non-specific nitric oxide synthase (NOS)-inhibitor NG-nitro-L-arginine methyl ester (L-NAME) and the selective neuronal NOS-inhibitor S-methyl-L-thiocitrulline (SMTC) but not the selective endothelial NOS-inhibitor N5-(1-iminoethyl)-L-ornithine (L-NIO). The antinociception was also significantly reduced by central pretreatment with a rabbit antiserum against dynorphin1-13 but not by rabbit antisera against either β-endorphin or methionine-enkephalin. The prolonged antinociceptive effect at 90 min after HBO2-induced treatment was also significantly attenuated by naltrexone but not L-NAME administered 60 min following HBO2 treatment but prior to nociceptive testing. These findings indicate that the antinociception that persists for 90 min after HBO2 exposure is mediated by nitric oxide (NO) and opioid mechanisms but that the NO involvement is critical during the HBO2 treatment and not at the time of nociceptive testing. These results are consistent with the concept that HBO2 may induce an NO-dependent release of opioid peptide to cause a long-acting antinociceptive effect. PMID:18976963

  1. Hyperbaric oxygen therapy stimulates colonic stem cells and induces mucosal healing in patients with refractory ulcerative colitis: a prospective case series

    PubMed Central

    Bekheit, Mohamed; Baddour, Nahed; Katri, Khaled; Taher, Yousry; El Tobgy, Khaled; Mousa, Essam

    2016-01-01

    Background Hyperbaric oxygen (HBO) is used as part of treatment in a variety of clinical conditions. Its use in the treatment of ulcerative colitis has been reported in few clinical reports. Objective We report the effect of HBO on refractory ulcerative colitis exploring one potential mechanism of action. Design A review of records of patients with refractory ulcerative colitis who received HBO was conducted. Clinical and histopathological scoring was utilised to evaluate the response to HBO therapy (HBOT). Results All patients manifested clinical improvement by the 40th cycle of HBOT. The median number of stool frequency dropped from seven motions/day (range=3–20) to 1/day (range=0.5–3), which was significant (z=−4.6, p<0.001). None of the patients manifested persistent blood passage after HBOT (z=−3.2, p=0.002). The severity index significantly improved after HBOT (z=−4.97, p<0.001). Histologically, a significant reduction of the scores of activity was recorded accompanied by a significant increase in the proliferating cell nuclear antigen labelling index of the CD44 cells of the colonic mucosa (p=0.001). Conclusions HBOT is effective in the setting of refractory ulcerative colitis. The described protocol is necessary for successful treatment. HBOT stimulates colonic stem cells to promote healing. PMID:27195128

  2. Differences in Cognitive Function of Rats with Traumatic Brain Injuries Following Hyperbaric Oxygen Therapy.

    PubMed

    Zhang, Xiaonian; Wang, Xiaoyan; Sun, Xinting; Sun, Xiaojing; Zhang, Yue; Zhang, Hao

    2016-01-01

    BACKGROUND Hyperbaric oxygen (HBO) is a historical therapeutic option in the treatment of various types of brain damage. At present, clinical treatment of hypoxic-ischemic injury is giving priority to cognitive training. The effects of HBO on cognitive dysfunction were observed in a controlled cortical impact (CCI) rat model. MATERIAL AND METHODS Seventy male SD rats were randomly divided into control (n=10) and intervention (n=60) groups. All rats underwent baseline water maze testing 1 day before modeling, and were retested 8 weeks after modeling. The percentage of residence time during escape latency in the target quadrant and the total time were recorded. Data were analyzed by SPSS 16.0 software. P<0.05 was considered statistically significant. RESULTS After 8 weeks, no statistical difference (P>0.05) existed in spatial learning ability in the 3-day and 5-day groups when compared with baseline. The other groups were statistically different by auto-comparison (P<0.05). No statistical difference (P>0.05) in spatial memory existed in the 5-day and 1-week groups when compared with baseline, while a significant difference was noted in the other groups by self-comparison (P<0.05). No statistical difference (P>0.05) was noted in the level of expression of growth-associated protein-43 (GAP-43) and synaptophysin (Syn) in the 1-day group compared with the control group. The remaining groups and the control group were statistically different (P<0.05), while the level of expression of GAP-43 and Syn in the 5-day, 1-week, and 2-week groups was significantly different compared with that in the control group (P<0.01). CONCLUSIONS If HBO therapy was provided 5-7 days after craniocerebral trauma, there was apparent improvement in cognitive function and neuroplasticity. PMID:27450528

  3. Differences in Cognitive Function of Rats with Traumatic Brain Injuries Following Hyperbaric Oxygen Therapy

    PubMed Central

    Zhang, Xiaonian; Wang, Xiaoyan; Sun, Xinting; Sun, Xiaojing; Zhang, Yue; Zhang, Hao

    2016-01-01

    Background Hyperbaric oxygen (HBO) is a historical therapeutic option in the treatment of various types of brain damage. At present, clinical treatment of hypoxic-ischemic injury is giving priority to cognitive training. The effects of HBO on cognitive dysfunction were observed in a controlled cortical impact (CCI) rat model. Material/Methods Seventy male SD rats were randomly divided into control (n=10) and intervention (n=60) groups. All rats underwent baseline water maze testing 1 day before modeling, and were retested 8 weeks after modeling. The percentage of residence time during escape latency in the target quadrant and the total time were recorded. Data were analyzed by SPSS 16.0 software. P<0.05 was considered statistically significant. Results After 8 weeks, no statistical difference (P>0.05) existed in spatial learning ability in the 3-day and 5-day groups when compared with baseline. The other groups were statistically different by auto-comparison (P<0.05). No statistical difference (P>0.05) in spatial memory existed in the 5-day and 1-week groups when compared with baseline, while a significant difference was noted in the other groups by self-comparison (P<0.05). No statistical difference (P>0.05) was noted in the level of expression of growth-associated protein-43 (GAP-43) and synaptophysin (Syn) in the 1-day group compared with the control group. The remaining groups and the control group were statistically different (P<0.05), while the level of expression of GAP-43 and Syn in the 5-day, 1-week, and 2-week groups was significantly different compared with that in the control group (P<0.01). Conclusions If HBO therapy was provided 5–7 days after craniocerebral trauma, there was apparent improvement in cognitive function and neuroplasticity. PMID:27450528

  4. Comparison of two different steroid treatments with hyperbaric oxygen for idiopathic sudden sensorineural hearing loss.

    PubMed

    Sevil, Ergun; Bercin, Sami; Muderris, Togay; Gul, Fatih; Kiris, Muzaffer

    2016-09-01

    The purpose of the study was to assess the efficacy of the association of intratympanic (IT) steroid and hyperbaric oxygen (HBO) therapy in patients presenting with idiopathic sudden sensorineural hearing loss (ISSNHL), and to compare this protocol with another consisting of intravenous (IV) steroid administration and HBO therapy. A total of 80 patients diagnosed with ISSNHL were included in this prospective trial. Patients were divided into three categories: a mild-to-moderate ISSNHL group with a pure-tone average (PTA) ≤60 decibels (dB), a severe ISSNHL group with a PTA of 60-80 dB, and a profound ISSNHL group with a PTA ≥81 dB. The first protocol consisted of 20 sessions of HBO therapy together with IV methylprednisolone 1 mg/kg body weight and a 10 mg taper every 3 days for 10 days. The second protocol consisted of HBO therapy for 20 sessions, together with an IT injection of dexamethasone at a dose of 4 mg/mL, 0.5-0.7 mL once a day for 7 consecutive days, performed 3 h before the HBO therapy. In the mild-to-moderate ISSNHL patients, the mean hearing gain and successful treatment rate was 19 (0-27) dB and 78.9 %, respectively in the IT + HBO treatment group, and 18 (3-44) dB and 70.5 % in the IV + HBO therapy group. In the severe ISSNHL patients, the mean hearing gain and successful treatment rate was 33 (1-54) dB and 81.8 %, respectively in the IT + HBO treatment group and 33.5 (7-57) dB and 58.2 % in the IV + HBO group. In the profound ISSNHL patients, the mean hearing gain and successful treatment rate was 36 (4-69) dB and 40 %, respectively in the IT + HBO therapy group, and 39.5 (0-92) dB and 72.7 % in the IV + HBO treatment group. The results demonstrated that patients with severe hearing loss success rate was superior in the group submitted to IT + HBO treatment, conversely IV + HBO therapy may be benefit for patients with profound hearing loss. Nevertheless, these clinical results were not statistically significant.

  5. History of Oxygen Therapy and Retrolental Fibroplasia.

    ERIC Educational Resources Information Center

    James, L. Stanley, Ed.; Lanman, Jonathan T., Ed.

    1976-01-01

    Presented is a historical report on the use of oxygen therapy with premature infants and the development of retrolental fibroplasia (RLF), a condition leading to detachment of the retina and arrest of growth of the eye. Covered are the following topics: the early history of oxygen use for premature infants (such as for prevention of cyanotic…

  6. What Are the Risks of Oxygen Therapy?

    MedlinePlus

    ... spray or have a humidifier added to your oxygen equipment. If you have an uncomfortable nasal cannula or face mask, your home equipment provider can help you find a device that fits better. Your provider also can recommend ... from transtracheal oxygen therapy can be more serious. With this type ...

  7. Long-term oxygen therapy: battling breathlessness.

    PubMed

    Wick, Jeannette Y

    2012-12-01

    Approximately 1 million of the 1.4 million Americans (71%) receiving long-term oxygen therapy (LTOT) are Medicare beneficiaries, confirming that LTOT is most often prescribed for individuals 65 years of age or older. Although several conditions create a need for supplemental oxygen, the majority of patients have chronic obstructive pulmonary disease (COPD). People with healthy lungs can extract the oxygen from air, while those with damaged lungs need higher oxygen concentrations. They can supplement their oxygen using one of three options: high-pressure oxygen tanks, liquid oxygen, or oxygen concentrators. The multicenter Nocturnal Oxygen Therapy Trial and the smaller Medical Research Council study identified LTOT as an intervention that improved survival in patients with COPD or chronic respiratory failure, approximately doubling survival at 19 months in patients who were adherent to oxygen. Despite its advantages, LTOT is plagued with problems: compliance with clinical guidelines, patient adherence, and cost. Fires associated with smoking in the vicinity of supplemental oxygen are the leading cause of residential fire deaths in the United States.

  8. MRI Findings of Otic and Sinus Barotrauma in Patients with Carbon Monoxide Poisoning during Hyperbaric Oxygen Therapy

    PubMed Central

    Wang, Ping; Zhang, Xiao-Ming; Zhai, Zhao-Hua; Li, Pei-Ling

    2013-01-01

    Background and Purpose To study the MRI findings of otic and sinus barotrauma in patients with carbon monoxide(CO) poisoning during hyperbaric oxygen (HBO) therapy and examine the discrepancies of otic and sinus abnormalities on MRI between barotrauma and acute otitis media with effusion. Materials and Methods Eighty patients with CO-poisoning diagnosed with otic and sinus barotrauma after HBO therapy were recruited. Brain MRI was performed to predict delayed encephalopathy. Over the same period, 88 patients with acute otitis media with effusion on MRI served as control. The abnormalities of the middle ear and paranasal sinuses on MRI were noted and were compared between groups. Nine patients with barotrauma were followed up by MRI. Results In the barotrauma group, 92.5% of patients had bilateral middle ear abnormalities on MRI, and 60% of patients had both middle ear cavity and mastoid cavity abnormalities on MRI in both ears. Both rates were higher than those in the control group (p = 0.000). In the two groups, most abnormalities on MRI were observed in the mastoid cavity. The rate of sinus abnormalities of barotrauma was 66.3%, which was higher than the 50% in the control group (p = 0.033). In the nine patients with barotrauma followed up by MRI, the otic barotrauma and sinus abnormalities had worsened in 2 patients and 5 patients, respectively. Conclusion MRI is able to depict the abnormalities of otic and sinus barotrauma in patients with CO-poisoning during HBO therapy and to differentiate these from acute otitis media with effusion. PMID:23776523

  9. Oxygen therapy multicentric study--a nationwide audit to oxygen therapy procedures in internal medicine wards.

    PubMed

    Neves, J T; Lobão, M J

    2012-01-01

    Oxygen therapy is a common and important treatment in Internal Medicine wards, however, several studies report that it isn't provided accordingly with the best of care. The goal of this work is to evaluate oxygen therapy procedures in Portuguese Internal Medicine wards, comparing them to the standards established by the British Thoracic Society (BTS) in its consensus statement "BTS guideline for emergency oxygen use in adult patients". Between September 3rd and 23rd 2010, each one of the 24 enrolled hospitals audited the oxygen therapy procedures for one randomly chosen day. All Internal Medicine inpatients under oxygen therapy or with oxygen prescription were included. Data was collected regarding oxygen prescription, administration and monitoring. Of the 1549 inpatients, 773 met inclusion criteria. There was an oxygen prescription in 93,4%. Most prescriptions were by a fixed dose (82,4%), but only 11,6% of those stated all the required parameters. Absence of oxygen therapy duration and monitoring were the most frequent errors. Oxygen was administered to only 77,0% of the patients with fixed dose prescriptions. FiO(2) or flow rate and the delivery device were the same as prescribed in 70,9 and 89,2% of the patients, respectively. Out of the 127 patients with oxygen therapy prescriptions by target SatO(2) range, 82,7% were on the prescribed SatO(2) objective range. Several errors were found in oxygen therapy procedures, particularly regarding fixed dose prescriptions, jeopardizing the patients. Although recommended by BTS, oxygen therapy prescriptions by target SatO(2) range are still a minority.

  10. Oxygen Therapy in Chronic Obstructive Pulmonary Disease

    PubMed Central

    Kim, Victor; Benditt, Joshua O.; Wise, Robert A.; Sharafkhaneh, Amir

    2008-01-01

    Since the introduction of oxygen as a therapeutic agent 70 years ago, much has been learned regarding the detrimental effects of hypoxemia and the beneficial impact of oxygen therapy. It is projected that there are close to 800,000 patients receiving long-term oxygen therapy (LTOT) in the United States, at a cost of approximately $1.8 billion annually. The large numbers of patients receiving supplemental oxygen as treatment and the high costs incurred in providing oxygen therapy necessitate the practitioner to know the indications for LTOT as well its effects on survival, pulmonary hemodynamics, sleep, and exercise capacity. It is now recognized that the basis for LTOT prescription for all patients is founded on data that are over 25 years old and that only involve a very select cohort of patients. It is clear that further studies are required to assess the effects of oxygen on patients with chronic obstructive pulmonary disease with only mild hypoxemia, not only survival but also on neurocognitive function, quality of life, exercise physiology, and sleep quality. In addition, although proven to be safe when prescribed long term to individuals with lung disease, there are some concerns about worsening carbon dioxide retention and increased oxidant injury. The goals of this article are to briefly describe the indications for chronic oxygen administration, the physiologic effects of treatment, and potential toxicities, as well as its effect on morbidity and mortality. PMID:18453364

  11. Should hyperbaric oxygen be used to treat the pregnant patient for acute carbon monoxide poisoning

    SciTech Connect

    Van Hoesen, K.B.; Camporesi, E.M.; Moon, R.E.; Hage, M.L.; Piantadosi, C.A. )

    1989-02-17

    Carbon monoxide (CO) is the leading cause of death due to poisoning. Although uncommon, CO poisoning does occur during pregnancy and can result in fetal mortality and neurological malformations in fetuses who survive to term. Uncertainty arises regarding the use of hyperbaric oxygen (HBO) as a treatment for the pregnant patient because of possible adverse effects on the fetus that could be induced by oxygen at high partial pressures. While the dangers of hyperoxia to the fetus have been demonstrated in animal models, careful review of animal studies and human clinical experience indicates that the short duration of hyperoxic exposure attained during HBO therapy for CO poisoning can be tolerated by the fetus in all stages of pregnancy and reduces the risk of death or deformity to the mother and fetus. A case is presented of acute CO poisoning during pregnancy that was successfully treated with HBO. Recommendations are suggested for the use of HBO during pregnancy.

  12. Oxygen therapy: time to move on?

    PubMed

    Kelly, Carol

    2014-12-01

    This analysis examines the roots of clinical practice regarding oxygen therapy and finds that some aspects have changed very little over the past 200 years. Oxygen is commonly prescribed and administered as a therapy across all healthcare settings, particularly for the treatment and management of respiratory conditions, both acute and chronic. Yet despite its widespread use and recent advances in understanding and guidance, poor practice and controversies regarding its use persist. This historical analysis highlights origins in practice that may suggest where the roots of these fallacies lie, highlighting potential ambiguities and myths that have permeated clinical and social contexts. It can be considered that based on clinical presumptions and speculation the prolific and injudicious use of oxygen was encouraged and the legacy for today's practice seeded. The conjectures proposed here may enable modern day erroneous beliefs to be confronted and clinical practice to move on.

  13. Hyperbaric oxygen therapy for laryngeal radionecrosis

    SciTech Connect

    Ferguson, B.J.; Hudson, W.R.; Farmer, J.C. Jr.

    1987-01-01

    Radionecrosis of the larynx is a debilitating disease associated with pain, dysphagia, respiratory obstruction, and, in some cases, the need for laryngectomy. Persistent poor wound healing can lead to death. A series of eight patients with advanced (grades III and IV, Chandler classification) radionecrosis of the larynx treated with adjunctive hyperbaric oxygen therapy is presented. Signs and symptoms of radionecrosis were dramatically ameliorated in seven of eight patients, while one patient, despite subjective improvement, eventually required laryngectomy. There were no deaths. These results are compared to previous series on radionecrosis of the larynx in which hyperbaric oxygen was not used. This series indicates that hyperbaric oxygen therapy is a useful and effective adjunctive treatment modality in the management of laryngeal radionecrosis.

  14. Therapeutic effect of hyperbaric oxygenation in acute acoustic trauma.

    PubMed

    Vavrina, J; Müller, W

    1995-01-01

    Retrospectively 78 patients with uni- or bilateral acute acoustic trauma (AAT) were evaluated to assess the therapeutic effect of hyperbaric oxygenation (HBO). All subjects received saline or dextran (Rheomacodrex) infusions with Ginkgo extracts (Tebonin) and prednisone. Thirty six patients underwent additional hyperbaric oxygenation at a pressure of 2 atmospheres absolute for 60 minutes once daily. Both treatment groups were comparable as far as age, gender, initial hearing loss and prednisone dose are concerned. The delay of therapy onset was 15 hours in both groups and treatment was started within 72 hours in all cases. Control audiometry was performed after 6.5 days, when the HBO group had had 5 exposures to hyperbaric oxygenation. The average hearing gain in the group without HBO was 74.3 dB and in the group treated additionally with HBO 121.3 dB (P < 0.004). It is concluded, that hyperbaric oxygenation significantly improves hearing recovery after AAT. Therefore acute acoustic trauma with significant hearing threshold depression remains an otological emergency. Minimal therapy involving waiting for spontaneous recovery, which is mostly incomplete leaving a residual C5 or C6 and handicapping tinnitus, is not the treatment of choice. Randomized prospective clinical trials with a larger patient series are needed and further experimental studies are required to understand the physiological mechanisms of HBO responsible for the clinical success in AAT.

  15. Effect of hyperbaric oxygenation on mitochondrial function of neuronal cells in the cortex of neonatal rats after hypoxic-ischemic brain damage

    PubMed Central

    Yang, L.; Hei, M.Y.; Dai, J.J.; Hu, N.; Xiang, X.Y.

    2016-01-01

    The timing and mechanisms of protection by hyperbaric oxygenation (HBO) in hypoxic-ischemic brain damage (HIBD) have only been partially elucidated. We monitored the effect of HBO on the mitochondrial function of neuronal cells in the cerebral cortex of neonatal rats after HIBD. Neonatal Sprague-Dawley rats (total of 360 of both genders) were randomly divided into normal control, HIBD, and HIBD+HBO groups. The HBO treatment began immediately after hypoxia-ischemia (HI) and continued once a day for 7 consecutive days. Animals were euthanized 0, 2, 4, 6, and 12 h post-HI to monitor the changes in mitochondrial membrane potential (ΔΨm) occurring soon after a single dose of HBO treatment, as well as 2, 3, 4, 5, 6, and 7 days post-HI to study ΔΨm changes after a series of HBO treatments. Fluctuations in ΔΨm were observed in the ipsilateral cortex in both HIBD and HIBD+HBO groups. Within 2 to 12 h after HI insult, the ΔΨm of the HIBD and HIBD+HBO groups recovered to some extent. A secondary drop in ΔΨm was observed in both groups during the 1-4 days post-HI period, but was more severe in the HIBD+HBO group. There was a secondary recovery of ΔΨm observed in the HIBD+HBO group, but not in the HIBD group, during the 5-7 days period after HI insult. HBO therapy may not lead to improvement of neural cell mitochondrial function in the cerebral cortex in the early stage post-HI, but may improve it in the sub-acute stage post-HI. PMID:27119428

  16. Expression of T helper cell-associated inflammatory mediator mRNAs in cells of bronchoalveolar lavage fluid samples and oxygen concentration in arterial blood samples from healthy horses exposed to hyperbaric oxygen.

    PubMed

    Looijen, Maty G P; New, Dallas J; Fischer, Carrie D; Dardari, Rkia; Irwin, Karyn M; Berezowski, Christopher J; Bond, Stephanie L; Léguillette, Renaud

    2016-10-01

    OBJECTIVE To evaluate the mRNA expression of T helper (Th)1, Th2, and Th17 cell-associated inflammatory mediators in cells of bronchoalveolar lavage fluid samples collected from healthy horses exposed to hyperbaric oxygen (HBO) and to monitor blood oxygen concentration during and following HBO therapy. ANIMALS 8 healthy horses. PROCEDURES In a randomized controlled crossover design study, each horse was exposed (beginning day 1) to 100% oxygen at a maximum of 3 atmospheres absolute (304 kPa) daily for 10 days or ambient air at atmospheric pressure in the HBO chamber for an equivalent amount of time (control). Bronchoalveolar lavage fluid samples were collected on days 0 and 10. After validation of candidate reference genes, relative mRNA expressions of various innate inflammatory, Th1 cell-derived, Th2 cell-derived (including eotaxin-2), Th17 cell-derived, and regulatory cytokines were measured by quantitative PCR assays. For 3 horses, arterial blood samples were collected for blood gas analysis during a separate HBO session. RESULTS The optimal combination of reference genes was glyceraldehyde-3-phosphate dehydrogenase, hypoxanthine ribosyltransferase, and ribosomal protein L32. Compared with day 0 findings, expression of eotaxin-2 mRNA was significantly lower (0.12-fold reduction) and the percentage of neutrophils in bronchoalveolar lavage fluid samples was significantly lower on day 10 when horses received HBO therapy. Values of Pao2 rapidly increased (> 800 mm Hg) but immediately decreased to pretreatment values when HBO sessions ended. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that HBO therapy does not increase mRNA expression of inflammatory cytokines, but reduces eotaxin-2 mRNA transcription. The Pao2 increase was transient with no cumulative effects of HBO. PMID:27668587

  17. Hyperbaric Oxygen Reduces Production of Reactive Oxygen Species in Neutrophils from Polytraumatized Patients Yielding in the Inhibition of p38 MAP Kinase and Downstream Pathways.

    PubMed

    Grimberg-Peters, Deborah; Büren, Carina; Windolf, Joachim; Wahlers, Thorsten; Paunel-Görgülü, Adnana

    2016-01-01

    Trauma represents the leading cause of death among young people in western countries. Among the beneficial role of neutrophils in host defence, excessive priming and activation of neutrophils after major trauma lead to an overwhelming inflammatory response and secondary host tissue injury due to the release of toxic metabolites and enzymes. Hyperbaric oxygen (HBO) therapy has been proposed to possess antiinflammatory effects and might represent an appropriate therapeutic option to lower inflammation in a broad range of patients. Here, we studied the effects of HBO on the activity of neutrophils isolated from severely injured patients (days 1-2 after trauma), in fact on the production of reactive oxygen species (ROS) and release of neutrophil extracellular traps (NETs). We found exposure to HBO therapy to significantly diminish phorbol-12-myristate-13-acetate (PMA)-induced ROS production in neutrophils isolated from patients and healthy volunteers. At the same time, marked decrease in NETs release was found in control cells and a less pronounced reduction in patient neutrophils. Impaired ability to produce ROS following exposure to HBO was demonstrated to be linked to a strong downregulation of the activity of p38 MAPK. Only slight suppression of ERK activity could be found. In addition, HBO did not influence neutrophil chemotaxis or apoptosis, respectively. Collectively, this study shows for the first time that HBO therapy suppresses ROS production in inflammatory human neutrophils, and thus might impair ROS-dependent pathways, e.g. kinases activation and NETs release. Thus, HBO might represent a feasible therapy for patients suffering from systemic inflammation, including those with multiple trauma. PMID:27529549

  18. Hyperbaric Oxygen Reduces Production of Reactive Oxygen Species in Neutrophils from Polytraumatized Patients Yielding in the Inhibition of p38 MAP Kinase and Downstream Pathways

    PubMed Central

    Windolf, Joachim; Wahlers, Thorsten

    2016-01-01

    Trauma represents the leading cause of death among young people in western countries. Among the beneficial role of neutrophils in host defence, excessive priming and activation of neutrophils after major trauma lead to an overwhelming inflammatory response and secondary host tissue injury due to the release of toxic metabolites and enzymes. Hyperbaric oxygen (HBO) therapy has been proposed to possess antiinflammatory effects and might represent an appropriate therapeutic option to lower inflammation in a broad range of patients. Here, we studied the effects of HBO on the activity of neutrophils isolated from severely injured patients (days 1–2 after trauma), in fact on the production of reactive oxygen species (ROS) and release of neutrophil extracellular traps (NETs). We found exposure to HBO therapy to significantly diminish phorbol-12-myristate-13-acetate (PMA)-induced ROS production in neutrophils isolated from patients and healthy volunteers. At the same time, marked decrease in NETs release was found in control cells and a less pronounced reduction in patient neutrophils. Impaired ability to produce ROS following exposure to HBO was demonstrated to be linked to a strong downregulation of the activity of p38 MAPK. Only slight suppression of ERK activity could be found. In addition, HBO did not influence neutrophil chemotaxis or apoptosis, respectively. Collectively, this study shows for the first time that HBO therapy suppresses ROS production in inflammatory human neutrophils, and thus might impair ROS-dependent pathways, e.g. kinases activation and NETs release. Thus, HBO might represent a feasible therapy for patients suffering from systemic inflammation, including those with multiple trauma. PMID:27529549

  19. Clinical research on postoperative efficacy and related factors of early simulation hyperbaric oxygen therapy for severe craniocerebral injury.

    PubMed

    Xu, Lanjuan; Li, Baolin; Yang, Caifu; Li, Chengjian; Peng, Yueli

    2016-01-01

    In order to discuss the clinical efficacy of simulation hyperbaric oxygen therapy (HBOT) for severe craniocerebral injury and analyze the related factors of it, 108 patients who transferred to our department during December 2010 - December 2014 for ventilator treatment after operation of severe craniocerebral injury were taken as the subjects of the study. These patients were divided into conventional treatment group and simulation hyperbaric oxygen therapy group to contrast the curative effects. At the meantime, GOS score and length of stay in intensive care unit (ICU) of two groups 6 months after treatment, as well as changes in the indexes of the HBO group during treatment were performed statistical analysis. Then factors affecting prognosis of simulation HBOT were performed regression analysis and principal component analysis. The results showed that when compared to the control group, differences in cases with four GOS score and one GOS score in the treatment group were significant (p<0.05). Jugular venous oxygen saturation (SjvO2), jugular bulb oxygen partial pressure (PjO2), arterial partial pressure of oxygen (PaO2) and arterial oxygen saturation (SaO2) of the simulation HBO group before the first time treatment on the first day and after the first time treatment on the third day were significantly increased, with statistical significance (p<0.05); serum lactic acid (Lac) and blood glucose (Glu) decreased significantly (p<0.05). Prior to and during the first treatment on the first day, jugular bulb pressure (Pj) and central venous pressure (CVP) had no significant difference (p>0.05). Regression analysis indicated that factors affecting prognosis included cerebral contusion, coronary heart disease, hydrocephalus and tracheotomy. Principal component analysis found the factors were hydrocephalus, coronary heart disease, tracheotomy, cerebral contusion, cerebral infarction and glasgow coma scale (GCS) before treatment. Therefore, stimulation HBOT can

  20. Efficiency of hyperbaric oxygen therapy in experimental acute acoustic trauma from firearms.

    PubMed

    Kuokkanen, J; Aarnisalo, A A; Ylikoski, J

    2000-01-01

    In acute acoustic trauma (AAT), excessive noise exposure causes rupture of cell membranes and decreased cochlear blood flow. This leads to decreased oxygen tension in inner ear fluids and reduction of a variety of different oxygen-dependent cellular activities. Hyperbaric oxygen treatment (HBO) may help the cells suffering from hypoxia to survive. We exposed male Wistar rats to 60 impulses of 162-dB SPL from a 7.62-mm assault rifle equipped with a blank adaptor. After the exposure, 15 animals were given HBO treatment for 90 min daily for 10 consecutive days at 0.25 MPa. After a survival time of 4 weeks, auditory brainstem responses were measured and the left cochleae processed for light microscopy. The impulse noise caused permanent damage to the cochlea of all animals, with the most severe lesions in the lower middle coil, where a significantly smaller number of hair cells was missing in the HBO-treated group. The morphological damage was also reflected in function, as measured by auditory brainstem responses, which showed the greatest threshold shifts at 6.0, 8.0 and 10.0 kHz. PMID:10909001

  1. Reactive oxygen species in redox cancer therapy.

    PubMed

    Tong, Lingying; Chuang, Chia-Chen; Wu, Shiyong; Zuo, Li

    2015-10-10

    The role of reactive oxygen species (ROS) in cancer cells has been intensively studied for the past two decades. Cancer cells mostly have higher basal ROS levels than their normal counterparts. The induction of ROS has been shown to be associated with cancer development, metastasis, progression, and survival. Various therapeutic approaches targeting intracellular ROS levels have yielded mixed results. As widely accepted dietary supplements, antioxidants demonstrate both ROS scavenging ability and anti-cancer characteristics. However, antioxidants may not always be safe to use since excessive intake of antioxidants could lead to serious health concerns. In this review, we have evaluated the production and scavenging systems of ROS in cells, as well as the beneficial and harmful roles of ROS in cancer cells. We also examine the effect of antioxidants in cancer treatment, the effect of combined treatment of antioxidants with traditional cancer therapies, and the side effects of excessive antioxidant intake.

  2. Hyperbaric oxygen in chronic traumatic brain injury: oxygen, pressure, and gene therapy.

    PubMed

    Harch, Paul G

    2015-01-01

    Hyperbaric oxygen therapy is a treatment for wounds in any location and of any duration that has been misunderstood for 353 years. Since 2008 it has been applied to the persistent post-concussion syndrome of mild traumatic brain injury by civilian and later military researchers with apparent conflicting results. The civilian studies are positive and the military-funded studies are a mixture of misinterpreted positive data, indeterminate data, and negative data. This has confused the medical, academic, and lay communities. The source of the confusion is a fundamental misunderstanding of the definition, principles, and mechanisms of action of hyperbaric oxygen therapy. This article argues that the traditional definition of hyperbaric oxygen therapy is arbitrary. The article establishes a scientific definition of hyperbaric oxygen therapy as a wound-healing therapy of combined increased atmospheric pressure and pressure of oxygen over ambient atmospheric pressure and pressure of oxygen whose main mechanisms of action are gene-mediated. Hyperbaric oxygen therapy exerts its wound-healing effects by expression and suppression of thousands of genes. The dominant gene actions are upregulation of trophic and anti-inflammatory genes and down-regulation of pro-inflammatory and apoptotic genes. The combination of genes affected depends on the different combinations of total pressure and pressure of oxygen. Understanding that hyperbaric oxygen therapy is a pressure and oxygen dose-dependent gene therapy allows for reconciliation of the conflicting TBI study results as outcomes of different doses of pressure and oxygen. PMID:26171141

  3. Hyperbaric oxygen in chronic traumatic brain injury: oxygen, pressure, and gene therapy.

    PubMed

    Harch, Paul G

    2015-01-01

    Hyperbaric oxygen therapy is a treatment for wounds in any location and of any duration that has been misunderstood for 353 years. Since 2008 it has been applied to the persistent post-concussion syndrome of mild traumatic brain injury by civilian and later military researchers with apparent conflicting results. The civilian studies are positive and the military-funded studies are a mixture of misinterpreted positive data, indeterminate data, and negative data. This has confused the medical, academic, and lay communities. The source of the confusion is a fundamental misunderstanding of the definition, principles, and mechanisms of action of hyperbaric oxygen therapy. This article argues that the traditional definition of hyperbaric oxygen therapy is arbitrary. The article establishes a scientific definition of hyperbaric oxygen therapy as a wound-healing therapy of combined increased atmospheric pressure and pressure of oxygen over ambient atmospheric pressure and pressure of oxygen whose main mechanisms of action are gene-mediated. Hyperbaric oxygen therapy exerts its wound-healing effects by expression and suppression of thousands of genes. The dominant gene actions are upregulation of trophic and anti-inflammatory genes and down-regulation of pro-inflammatory and apoptotic genes. The combination of genes affected depends on the different combinations of total pressure and pressure of oxygen. Understanding that hyperbaric oxygen therapy is a pressure and oxygen dose-dependent gene therapy allows for reconciliation of the conflicting TBI study results as outcomes of different doses of pressure and oxygen.

  4. Options for home oxygen therapy equipment: storage and metering of oxygen in the home.

    PubMed

    McCoy, Robert W

    2013-01-01

    Home oxygen therapy equipment options have increased over the past several decades, in response to innovations in technology, economic pressure from third-party payers, and patient demands. The delivery of oxygen in the home has evolved from packaged gas systems containing 99% United States Pharmacopeia oxygen provided by continuous-flow delivery to intermittent-flow delivery, with oxygen concentrators delivering < 99% oxygen purity. The majority of published papers indicating the value of long-term oxygen therapy have been based on continuous-flow delivery of 99% United States Pharmacopeia oxygen. The lack of research on new home oxygen therapy devices requires more clinical involvement from physician and respiratory therapist to evaluate the performance of oxygen devices used in the home to ensure the patient is provided adequate oxygenation at all activity levels. New standards of care are required to address the need to have consistent titration of long-term oxygen therapy to meet the patient's home needs at all activity levels. Consistent labeling of metering devices on home oxygen equipment will need to be developed by professional medical societies to be implemented by standards organizations that direct industrial manufacturers. Home oxygen therapy will need professionally trained respiratory therapists reimbursed for skills and service to ensure that patients receive optimal benefits from home oxygen equipment to improve patient outcomes and prevent complications and associated costs.

  5. Outcome measures for palliative oxygen therapy: relevance and practical utility.

    PubMed

    Antoniu, Sabina; Mihaltan, Florin

    2014-06-01

    Dyspnea is a common symptom in many advanced malignant and non-malignant diseases and often is refractory to the usual therapies. In such circumstances palliative care approaches are necessary and among them palliative care oxygen therapy can be applied although currently its effectiveness is rather uncertain. Palliative oxygen therapy can be given on either continuous basis or on demand. Often the continuous palliative oxygen therapy is seen as long-term oxygen therapy although their aims are rather different. Palliative oxygen therapy was evaluated in populations with mixed underlying diseases, with outcome measures not only the most appropriate for the setting and therefore these limitations might have influenced the overall perceived therapeutic benefit. Therefore an evaluation of this method in subsets defined based on the etiology and pathogenic mechanisms and with appropriate outcome measures would help to better define the criteria for its indication and would increase its acceptability.

  6. [Hyperbaric oxygen therapy as adjuvant in stump surgical wound healing].

    PubMed

    Pani, Ugo

    2015-01-01

    Oxygen is an essential gas. Oxygen is also a biological medicine. Hyperbaric oxygen therapy is a treatment which is based on the respiration of pure oxygen in a particular pressurised environment (hyperbaric chamber). The pressure allows the diffusion of oxygen into the blood at a concentration which is ten/fifteen/twenty times the normal level. The increase in oxygen in bodily liquids stimulates the synthesis of a gas, nitric oxide (NO), which has a powerful anti-inflammatory effect and promotes the formation of new blood vessels (also through the employment of stem cells) thus accelerating the healing of wounds. Hyperbaric oxygen therapy reactivates metabolic processes which have stopped and is able to help the recovery and obvious improvement of patients suffering from several serious illnesses. Hyperbaric oxygen therapy is a medicine, and as such requires careful dosage, monitoring of its results, and prevention of possible side effects.

  7. Hyperbaric oxygen can induce neuroplasticity and improve cognitive functions of patients suffering from anoxic brain damage

    PubMed Central

    Hadanny, A.; Golan, H.; Fishlev, G.; Bechor, Y.; Volkov, O.; Suzin, G.; Ben-Jacob, E.; Efrati, S.

    2015-01-01

    Abstract Purpose: Cognitive impairment may occur in 42–50% of cardiac arrest survivors. Hyperbaric oxygen therapy (HBO2) has recently been shown to have neurotherapeutic effects in patients suffering from chronic cognitive impairments (CCI) consequent to stroke and mild traumatic brain injury. The objective of this study was to assess the neurotherapeutic effect of HBO2 in patients suffering from CCI due to cardiac arrest. Methods: Retrospective analysis of patients with CCI caused by cardiac arrest, treated with 60 daily sessions of HBO2. Evaluation included objective computerized cognitive tests (NeuroTrax), Activity of Daily Living (ADL) and Quality of life questionnaires. The results of these tests were compared with changes in brain activity as assessed by single photon emission computed tomography (SPECT) brain imaging. Results: The study included 11 cases of CCI patients. Patients were treated with HBO2, 0.5–7.5 years (mean 2.6 ± 0.6 years) after the cardiac arrest. HBO2 was found to induce modest, but statistically significant improvement in memory, attention and executive function (mean scores) of 12% , 20% and 24% respectively. The clinical improvements were found to be well correlated with increased brain activity in relevant brain areas as assessed by computerized analysis of the SPECT imaging. Conclusions: Although further research is needed, the results demonstrate the beneficial effects of HBO2 on CCI in patients after cardiac arrest, even months to years after the acute event. PMID:26409406

  8. Hyperbaric oxygen therapy improves cognitive functioning after brain injury.

    PubMed

    Liu, Su; Shen, Guangyu; Deng, Shukun; Wang, Xiubin; Wu, Qinfeng; Guo, Aisong

    2013-12-15

    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 hyperbaric 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 significantly 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 improves cognitive functioning in rats with traumatic brain injury, and the potential mechanism is mediated by metabolic changes and nerve cell restoration in the hippocampal CA3 region.

  9. E-cigarette use in patients receiving home oxygen therapy.

    PubMed

    Lacasse, Yves; Légaré, Martin; Maltais, François

    2015-01-01

    Current smokers who are prescribed home oxygen may not benefit from the therapy. In addition to being an obvious fire hazard, there is some evidence that the physiological mechanisms by which home oxygen is believed to operate are inhibited by smoking. Although their effectiveness is yet to be demonstrated, electronic cigarettes (e-cigarettes) are often regarded as an aid to smoking cessation. However, several burn accidents in e-cigarette smokers receiving home oxygen therapy have also been reported, leading Health Canada to release a warning of fire risk to oxygen therapy patients from e-cigarettes. It is the authors' position that patients receiving oxygen should definitely not use e-cigarettes. The authors provide suggestions for addressing the delicate issue of home oxygen therapy in current cigarette and⁄or e-cigarette smokers. PMID:25848719

  10. Hyperbaric oxygen therapy. Promoting healing in difficult cases

    SciTech Connect

    Cohn, G.H.

    1986-02-01

    Inhalation of pressurized 100% oxygen is a helpful adjunctive treatment for certain patients, because the increased oxygen carried by the blood to the tissue enhances new growth of microcirculation and, thus, healing. Patients with tissue breakdown after radiation therapy, refractory osteomyelitis, gas gangrene, soft-tissue infection with necrosis from mixed aerobic and anaerobic organisms, crush injuries resulting in acute ischemia, and compromised skin grafts or non-healing wounds are likely to benefit from hyperbaric oxygen therapy.

  11. Hyperbaric oxygen and hyperbaric air treatment result in comparable neuronal death reduction and improved behavioral outcome after transient forebrain ischemia in the gerbil.

    PubMed

    Malek, Michal; Duszczyk, Malgorzata; Zyszkowski, Marcin; Ziembowicz, Apolonia; Salinska, Elzbieta

    2013-01-01

    Anoxic brain injury resulting from cardiac arrest is responsible for approximately two-thirds of deaths. Recent evidence suggests that increased oxygen delivered to the brain after cardiac arrest may be an important factor in preventing neuronal damage, resulting in an interest in hyperbaric oxygen (HBO) therapy. Interestingly, increased oxygen supply may be also reached by application of normobaric oxygen (NBO) or hyperbaric air (HBA). However, previous research also showed that the beneficial effect of hyperbaric treatment may not directly result from increased oxygen supply, leading to the conclusion that the mechanism of hyperbaric prevention of brain damage is not well understood. The aim of our study was to compare the effects of HBO, HBA and NBO treatment on gerbil brain condition after transient forebrain ischemia, serving as a model of cardiac arrest. Thereby, we investigated the effects of repetitive HBO, HBA and NBO treatment on hippocampal CA1 neuronal survival, brain temperature and gerbils behavior (the nest building), depending on the time of initiation of the therapy (1, 3 and 6 h after ischemia). HBO and HBA applied 1, 3 and 6 h after ischemia significantly increased neuronal survival and behavioral performance and abolished the ischemia-evoked brain temperature increase. NBO treatment was most effective when applied 1 h after ischemia; later application had a weak or no protective effect. The results show that HBO and HBA applied between 1 and 6 h after ischemia prevent ischemia-evoked neuronal damage, which may be due to the inhibition of brain temperature increase, as a result of the applied rise in ambient pressure, and just not due to the oxygen per se. This perspective is supported by the finding that NBO treatment was less effective than HBO or HBA therapy. The results presented in this paper may pave the way for future experimental studies dealing with pressure and temperature regulation.

  12. Otological complications associated with hyperbaric oxygen therapy.

    PubMed

    Yamamoto, Yoko; Noguchi, Yoshihiro; Enomoto, Mitsuhiro; Yagishita, Kazuyoshi; Kitamura, Ken

    2016-09-01

    The objective of the present study was to clarify the features of otological complications for hyperbaric oxygen therapy (HBOT) and the risk factors for these complications. We enrolled 1115 patients (776 males and 339 females; age 5-89 years) who underwent HBOT. All otological symptoms experienced during HBOT sessions were evaluated, and risk factors were analysed using multivariate logistic regression analysis. Otoscopic findings and interventions for otological complications were assessed in 58 symptomatic patients who visited the Otolaryngology Department. Otological symptoms were experienced by 165 (14.8 %) of the 1115 patients. The multivariate logistic regression analysis identified ages of >60 years and female sex as independent risk factors, whereas patients with sports injuries were at lower risk than those with other primary diseases, except for severe infectious disease. Eighty-two patients (49.7 %) suffered from symptoms at the first HBOT session. The most prevalent symptoms were otalgia (157/165), followed by ear fullness (13/165), hearing loss (12/165) and tinnitus (3/165). One patient experienced vertigo and deterioration of the bone-conduction pure-tone thresholds, suggesting inner ear barotrauma. In 116 ears of the 58 symptomatic patients, abnormal otoscopic findings were recognized in 58 ears (50.0 %). Twenty-seven of the 58 ears required myringotomy or tube insertion, and HBOT was stopped in eight ears in four patients. Of the remaining 58 ears with normal otoscopic findings, 51 received no treatment. Physicians should be aware of both middle and inner ear barotrauma as potential complications of HBOT. PMID:26650550

  13. Effects of topical oxygen therapy on ischemic wound healing.

    PubMed

    Rao, Congqiang; Xiao, Liling; Liu, Hongwei; Li, Shenghong; Lu, Jinqiang; Li, Jiangxuan; Gu, Shixing

    2016-01-01

    [Purpose] This study evaluated the effects of topical oxygen therapy on the hind limb wounds of rats under ischemic conditions. [Subjects and Methods] Twelve injured rats were treated with topical oxygen on skin wounds located on the hind limb and compared with twelve injured control rats. Indexes including gross morphology of the wound, wound healing time, wound healing rate, and histological and immunohistochemical staining of sections of wound tissue were examined at different time points after intervention. [Results] The wound healing time was shorter in the topical oxygen therapy group than the control group. The wound healing rate and granulation tissue formation in the topical oxygen therapy group showed significant improvement on days 3, 7, and 14. Through van Gieson staining, the accumulation of collagen fiber in the topical oxygen therapy group was found to have improved when compared with the control group on day 7. Through semiquantitative immunohistochemical staining, many more new vessels were found in the topical oxygen therapy group compared with the model control group on day 7. [Conclusion] The results of the experiment showed that topical oxygen therapy improved ischemic wound healing.

  14. Ozone Therapy for Tumor Oxygenation: a Pilot Study

    PubMed Central

    2004-01-01

    Tumor hypoxia is an adverse factor for chemotherapy and radiotherapy. Ozone therapy is a non-conventional form of medicine that has been used successfully in the treatment of ischemic disorders. This prospective study was designed to assess the effect of ozone therapy on tumor oxygenation. Eighteen subjects were recruited for the study. Systemic ozone therapy was administered by autohemotransfusion on three alternate days over one week. Tumor oxygenation levels were measured using polarographic needle probes before and after the first and the third ozone therapy session. Overall, no statistically significant change was observed in the tumor oxygenation in the 18 patients. However, a significant decrease was observed in hypoxic values ≤10 and ≤5 mmHg of pO2. When individually assessed, a significant and inverse non-linear correlation was observed between increase in oxygenation and the initial tumor pO2 values at each measuring time-point, thus indicating that the more poorly-oxygenated tumors benefited most (rho = −0.725; P = 0.001). Additionally, the effect of ozone therapy was found to be lower in patients with higher hemoglobin concentrations (rho = −0.531; P < 0.034). Despite being administered over a very short period, ozone therapy improved oxygenation in the most hypoxic tumors. Ozone therapy as adjuvant in chemo-radiotherapy warrants further research. PMID:15257330

  15. [Oxygen therapy in acute and chronic conditions: Indications, oxygen systems, assessement and follow-up].

    PubMed

    Luna Paredes, M C; Asensio de la Cruz, Oscar; Cortell Aznar, Isidoro; Martínez Carrasco, M C; Barrio Gómez de Agüero, M I; Pérez Ruiz, E; Pérez Frías, J

    2009-08-01

    Oxygen therapy has become a major tool for infants with acute and chronic respiratory failure. Appropriate goals when prescribing supplemental oxygen are reduction and prevention of hypoxemia, prevention and treatment of pulmonary hypertension and decrease in respiratory and cardiac overload. This is commonplace in the acute setting and is also becoming widespread in chronic pathologies. However, there is a lack of consensus on many fundamental issues, such as appropriate indications, desirable targets and outcome measures amongst centres, reflecting a variety of clinical practices. The Techniques Group of the Spanish Society of Pediatric Pneumology undertook to design recommendations for a rational approach to oxygen therapy, reviewing the existing literature in order to establish its indications, benefits and potential risks as well as its cost-effectivenes. General aspects of oxygen treatment are reviewed including physiological mechanisms, indications, delivery systems and assessment methods. Management of patients on home oxygen therapy is also addressed with discussion of benefits and potential risks of supplemental oxygen use.

  16. The role of hyperbaric oxygen therapy in crush injuries.

    PubMed

    Dougherty, Judith E

    2013-01-01

    Hyperbaric oxygen therapy has been approved for primary or adjunctive care in 14 indications. A hyperbaric environment exists when a patient's whole body is physically exposed to 100% oxygen and pressure that is greater than one atmosphere absolute. Hyperbaric oxygen therapy works through the ideal gas laws and is effective as an adjunctive therapy in the treatment of crush injuries. Oxygen is considered a drug and can have contraindications and adverse effects. Hyperbaric therapy works through several different mechanisms in the crush injury. Effects of hyperoxygenation, reduction of edema, infection control enhancement, blood vessel and collagen formation, and reduction of free radicals and reperfusion injury help in healing in patient with crush injuries. PMID:23736669

  17. Hyperbaric Oxygen Treatment Induces a Two-Phase Antinociceptive Response of Unusually Long Duration in Mice

    PubMed Central

    Chung, Eunhee; Zelinski, Lisa M.; Ohgami, Yusuke; Shirachi, Donald Y.; Quock, Raymond M.

    2009-01-01

    Hyperbaric oxygen (HBO2) therapy is approved by the FDA for limited clinical indications but is reported to produce pain relief in several chronic pain conditions. However, there have been no studies to explain this apparent analgesic effect of HBO2. Research conducted in our laboratory demonstrates that four daily 60-min HBO2 treatments at 3.5 ATA induced an unparalleled antinociceptive response that consists of 1) an early phase that lasted at least six hours after the HBO2 treatment before dissipating; and 2) a late phase that emerged about 18 hours after the early phase and lasted for up to three weeks. The early phase was sensitive to antagonism by acutely intracerebroventricular (i.c.v.)-administered opioid antagonist naltrexone and the nitric oxide synthase (NOS)-inhibitor L-NAME. The late phase was inhibited by treatment with i.c.v. naltrexone or L-NAME during the four HBO2 treatments but was not antagonized by either naltrexone or L-NAME following acute pretreatment two weeks after HBO2 treatment. These experimental results implicate a novel mechanism that is activated by HBO2, resulting in an antinociceptive response of unusually long duration that is of potential interest in the clinical management of pain. Perspective Hyperbaric oxygen treatment of mice can induce a two-phase antinociceptive response of unusually long duration. Nitric oxide and opioid receptors appear to initiate or mediate both phases of the antinociceptive response. Further elucidation of the underlying mechanism may potentially identify molecular targets that cause long-lasting activation of endogenous analgesic systems. PMID:20418186

  18. Oxygen Therapy Little Help for Those with Milder COPD

    MedlinePlus

    ... after tripping over their oxygen equipment, and five patients reported fires or burns. There's also the cost. In recent years, Medicare has paid more than $2 billion annually toward oxygen therapy, according to ... Accountability Office. But patients still have to foot 20 percent of the ...

  19. Effect of hyperbaric oxygen conditions on the ordering of interfacial water.

    PubMed

    Ypma, Rolf E; Pollack, Gerald H

    2015-01-01

    Hyperbaric oxygen (HBO2) conditions are applied clinically to treat diverse conditions. There is a lack of a unifying consensus as to how HBO2 acts effectively against a broad range of medical conditions, and numerous differing biological explanations have been offered. The possibility of a mechanism dependent on the extensive ordering of interfacial water has not yet been investigated. We examined the hypothesis that zones of ordered water, dubbed "exclusion zones" or "EZ," are expanded under hyperbaric oxygen conditions. Specifically, we tested whether there are significant quantitative differences in EZ size at steady state under high-pressure and/or high-oxygen conditions, compared to normal atmospheric conditions. Oxygen concentration and mechanical pressure were examined separately and in combination. Statistically significant increases in EZ size were seen at elevated air pressures and at high oxygen concentrations. These experimental results suggest the possibility of an ordered water-mediated mechanism of action for hyperbaric oxygen therapy.

  20. Effectiveness of hyperbaric oxygen for experimental treatment of schistosomiasis mansoni using praziquantel-free and encapsulated into liposomes: assay in adult worms and oviposition.

    PubMed

    Frezza, Tarsila Ferraz; de Souza, Ana Luiza Ribeiro; Prado, César Corat Ribeiro; de Oliveira, Claudineide Nascimento Fernandes; Gremião, Maria Palmira Daflon; Giorgio, Selma; Dolder, Mary Anne Heidi; Joazeiro, Paulo Pinto; Allegretti, Silmara Marques

    2015-10-01

    The treatment of schistosomiasis depends on a single drug: praziquantel (PZQ). However, this treatment presents limitations such as low and/or erratic bioavailability that can contribute to cases of tolerance. Improvements to the available drug are urgently needed and studies with a controlled system of drug release, like liposomes, have been gaining prominence. The present study evaluated the activity and synergy between liposomal-praziquantel (lip.PZQ) and hyperbaric oxygen therapy (HBO). Mice received doses of 60 or 100mg/kg PZQ or lip.PZQ, 50 days post-infection, and after the treatment, were exposed to HBO (3 atmosphere absolute - ATA) for 1h. The viability of adult worms and oviposition were analyzed, by necropsy and Kato-Katz examination performed after 15 days of treatment. A concentration of 100mg/kg of lip.PZQ+HBO was more effective (48.0% reduction of worms, 83.3% reduction of eggs/gram of feces) and 100% of the mice had altered of oograms (indicating interruption of oviposition) compared to other treatments and to the Control group (infected and untreated). It is known that PZQ requires participation of the host immune system to complete its antischistosomal activity and that HBO is able to stimulate the immune system. The drug became more available in the body when incorporated into liposomes and, used with HBO, the HBO worked as an adjuvant. This explains the decreases of oviposition and worms recovered form hepatic portal system.

  1. Deep Frostbite Treated With Hyperbaric Oxygen and Thrombolytic Therapies.

    PubMed

    Higdon, Brian; Youngman, Laura; Regehr, Michelle; Chiou, Andy

    2015-08-01

    The authors present a case of deep frostbite treated with both hyperbaric oxygen and thrombolytic therapies. Both of these therapies are experimental and have not yet achieved widespread clinical use. The patient described in this paper sustained frostbite after becoming intoxicated and falling unconscious in a snowy field. He was treated acutely for hypothermia and came into the authors' care for wound management. Of his 6 digits with extensive, deep frostbite, 1 digit eventually required partial amputation, and another had protracted osteomyelitis treated with intravenous antibiotics. The authors present a case history in the context of current research and provide a listing of previous case reports of hyperbaric oxygen therapy for frostbite.

  2. [Effects of portable liquid oxygen therapy on walking].

    PubMed

    Arnedillo Muñoz, A; León Jiménez, A; Fernández Berni, J J; Córdoba Doña, J A; Rosano Romero, A

    1999-02-01

    The effect on walking of portable liquid oxygen therapy (PLOT), which involves carrying a tank, remains unclear. Our aim was to evaluate the repercussion of PLOT on performance in the 6 minute walking test. We enrolled 30 patients receiving home oxygen therapy in a randomized crossover study, collecting data on arterial blood gases at baseline, spirometry, and performance on the 6 minute walking test at baseline and at later sessions with PLOT and with compressed air simulating oxygen. During the tests we measured peak heart rate, distance walked and time that oxygen saturation remained over 89%. For compressed air, no improvement over baseline values was observed for any of the parameters measured. During the PLOT tests, however, patients walked farther than at baseline and arterial oxygen saturation rose to the prescribed flow rate. Dyspnea was not significantly affected.

  3. Representations of Education in HBO's "The Wire", Season 4

    ERIC Educational Resources Information Center

    Trier, James

    2010-01-01

    "The Wire" is a crime drama that aired for five seasons on the Home Box Office (HBO) cable channel from 2002-2008. The entire series is set in Baltimore, Maryland, and as Kinder (2008) points out, "Each season "The Wire" shifts focus to a different segment of society: the drug wars, the docks, city politics, education, and the media" (p. 52). In…

  4. Heavily boron-doped Si layers grown below 700 C by molecular beam epitaxy using a HBO2 source

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Fathauer, R. W.; Grunthaner, P. J.

    1989-01-01

    Boron doping in Si layers grown by molecular beam epitaxy (MBE) at 500-700 C using an HBO2 source has been studied. The maximum boron concentration without detectable oxygen incorporation for a given substrate temperature and Si growth rate has been determined using secondary-ion mass spectrometry analysis. Boron present in the Si MBE layers grown at 550-700 C was found to be electrically active, independent of the amount of oxygen incorporation. By reducing the Si growth rate, highly boron-doped layers have been grown at 600 C without detectable oxygen incorporation.

  5. Acute oxygen therapy: a review of prescribing and delivery practices

    PubMed Central

    Cousins, Joyce L; Wark, Peter AB; McDonald, Vanessa M

    2016-01-01

    Oxygen is a commonly used drug in the clinical setting and like other drugs its use must be considered carefully. This is particularly true for those patients who are at risk of type II respiratory failure in whom the risk of hypercapnia is well established. In recent times, several international bodies have advocated for the prescription of oxygen therapy in an attempt to reduce this risk in vulnerable patient groups. Despite this guidance, published data have demonstrated that there has been poor uptake of these recommendations. Multiple interventions have been tested to improve concordance, and while some of these interventions show promise, the sustainability of these interventions are less convincing. In this review, we summarize data that have been published on the prevalence of oxygen prescription and the accurate and appropriate administration of this drug therapy. We also identify strategies that have shown promise in facilitating changes to oxygen prescription and delivery practice. There is a clear need to investigate the barriers, facilitators, and attitudes of clinicians in relation to the prescription of oxygen therapy in acute care. Interventions based on these findings then need to be designed and tested to facilitate the application of evidence-based guidelines to support sustained changes in practice, and ultimately improve patient care. PMID:27307722

  6. Acute oxygen therapy: a review of prescribing and delivery practices.

    PubMed

    Cousins, Joyce L; Wark, Peter A B; McDonald, Vanessa M

    2016-01-01

    Oxygen is a commonly used drug in the clinical setting and like other drugs its use must be considered carefully. This is particularly true for those patients who are at risk of type II respiratory failure in whom the risk of hypercapnia is well established. In recent times, several international bodies have advocated for the prescription of oxygen therapy in an attempt to reduce this risk in vulnerable patient groups. Despite this guidance, published data have demonstrated that there has been poor uptake of these recommendations. Multiple interventions have been tested to improve concordance, and while some of these interventions show promise, the sustainability of these interventions are less convincing. In this review, we summarize data that have been published on the prevalence of oxygen prescription and the accurate and appropriate administration of this drug therapy. We also identify strategies that have shown promise in facilitating changes to oxygen prescription and delivery practice. There is a clear need to investigate the barriers, facilitators, and attitudes of clinicians in relation to the prescription of oxygen therapy in acute care. Interventions based on these findings then need to be designed and tested to facilitate the application of evidence-based guidelines to support sustained changes in practice, and ultimately improve patient care.

  7. Acute oxygen therapy: a review of prescribing and delivery practices.

    PubMed

    Cousins, Joyce L; Wark, Peter A B; McDonald, Vanessa M

    2016-01-01

    Oxygen is a commonly used drug in the clinical setting and like other drugs its use must be considered carefully. This is particularly true for those patients who are at risk of type II respiratory failure in whom the risk of hypercapnia is well established. In recent times, several international bodies have advocated for the prescription of oxygen therapy in an attempt to reduce this risk in vulnerable patient groups. Despite this guidance, published data have demonstrated that there has been poor uptake of these recommendations. Multiple interventions have been tested to improve concordance, and while some of these interventions show promise, the sustainability of these interventions are less convincing. In this review, we summarize data that have been published on the prevalence of oxygen prescription and the accurate and appropriate administration of this drug therapy. We also identify strategies that have shown promise in facilitating changes to oxygen prescription and delivery practice. There is a clear need to investigate the barriers, facilitators, and attitudes of clinicians in relation to the prescription of oxygen therapy in acute care. Interventions based on these findings then need to be designed and tested to facilitate the application of evidence-based guidelines to support sustained changes in practice, and ultimately improve patient care. PMID:27307722

  8. Hyperbaric oxygen therapy improves local microenvironment after spinal cord injury.

    PubMed

    Wang, Yang; Zhang, Shuquan; Luo, Min; Li, Yajun

    2014-12-15

    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.

  9. Measurement of intracellular oxygen concentration during photodynamic therapy in vitro.

    PubMed

    Weston, Mark A; Patterson, Michael S

    2014-01-01

    A technique is introduced that monitors the depletion of intracellular ground state oxygen concentration ([(3)O(2)]) during photodynamic therapy of Mat-LyLu cell monolayers and cell suspensions. The photosensitizer Pd(II) meso-tetra(4-carboxyphenyl)porphine (PdT790) is used to manipulate and indicate intracellular [(3)O(2)] in both of the in vitro models. The Stern-Volmer relationship for PdT790 phosphorescence was characterized in suspensions by flowing nitrogen over the suspension while short pulses of 405 nm light were used to excite the sensitizer. The bleaching of sensitizer and the oxygen consumption rate were also measured during continuous exposure of the cell suspension to the 405 nm laser. Photodynamic therapy (PDT) was conducted in both cell suspensions and in cell monolayers under different treatment conditions while the phosphorescence signal was acquired. The intracellular [(3)O(2)] during PDT was calculated by using the measured Stern-Volmer relationship and correcting for sensitizer photobleaching. In addition, the amount of oxygen that was consumed during the treatments was calculated. It was found that even at large oxygen consumption rates, cells remain well oxygenated during PDT of cell suspensions. For monolayer treatments, it was found that intracellular [(3)O(2)] is rapidly depleted over the course of PDT.

  10. The twists and turns of neonatal oxygen therapy.

    PubMed

    Stenson, Benjamin J; Orme, Judith A

    2012-12-01

    Although supplemental oxygen is one of the commonest treatments in neonatal medicine, the evidence base for deciding which newborns need it, and what is the appropriate dose remains weak. Clinical research in this area is difficult because it requires clinicians to depart from established practice and, in the case of oxygen therapy, the stakes seem far higher to them than for other investigational treatments. Consequently, beyond the knowledge that extreme hyperoxia and hypoxia are harmful, the middle ground remains uncertain for both preterm and term infants.

  11. [Home oxygen therapy and noninvasive ventilation for stable COPD].

    PubMed

    Tachikawa, Ryo; Chin, Kazuo

    2016-05-01

    Chronic obstructive pulmonary disease (COPD) is the most common underlying disease of home oxygen therapy (HOT) and long-term noninvasive ventilation (NIV) in Japan. Although both have been increasingly used for stable COPD in clinical practice, there are numerous questions to be resolved with regard to the indication of these therapies. Here we briefly reviewed current indication and available evidence of HOT and long-term NIV for stable COPD. We also outline research agenda that should be investigated in future studies. PMID:27254949

  12. Acute carbon monoxide poisoning: Emergency management and hyperbaric oxygen therapy

    SciTech Connect

    Severance, H.W.; Kolb, J.C.; Carlton, F.B.; Jorden, R.C.

    1989-10-01

    An ice storm in February 1989 resulted in numerous incidences of carbon monoxide poisoning in central Mississippi secondary to exposure to open fires in unventilated living spaces. Sixteen cases were treated during this period at the University of Mississippi Medical Center and 6 received Hyperbaric Oxygen therapy. These 6 cases and the mechanisms of CO poisoning are discussed and recommendations for emergency management are reviewed.10 references.

  13. Oxygen carrying microbubbles for enhanced sonodynamic therapy of hypoxic tumours.

    PubMed

    McEwan, Conor; Owen, Joshua; Stride, Eleanor; Fowley, Colin; Nesbitt, Heather; Cochrane, David; Coussios, Constantin C; Borden, M; Nomikou, Nikolitsa; McHale, Anthony P; Callan, John F

    2015-04-10

    Tumour hypoxia represents a major challenge in the effective treatment of solid cancerous tumours using conventional approaches. As oxygen is a key substrate for Photo-/Sono-dynamic Therapy (PDT/SDT), hypoxia is also problematic for the treatment of solid tumours using these techniques. The ability to deliver oxygen to the vicinity of the tumour increases its local partial pressure improving the possibility of ROS generation in PDT/SDT. In this manuscript, we investigate the use of oxygen-loaded, lipid-stabilised microbubbles (MBs), decorated with a Rose Bengal sensitiser, for SDT-based treatment of a pancreatic cancer model (BxPc-3) in vitro and in vivo. We directly compare the effectiveness of the oxygen-loaded MBs with sulphur hexafluoride (SF6)-loaded MBs and reveal a significant improvement in therapeutic efficacy. The combination of oxygen-carrying, ultrasound-responsive MBs, with an ultrasound-responsive therapeutic sensitiser, offers the possibility of delivering and activating the MB-sensitiser conjugate at the tumour site in a non-invasive manner, providing enhanced sonodynamic activation at that site.

  14. Histone acetyltransferase Hbo1 destabilizes estrogen receptor α by ubiquitination and modulates proliferation of breast cancers.

    PubMed

    Iizuka, Masayoshi; Susa, Takao; Takahashi, Yoshihisa; Tamamori-Adachi, Mimi; Kajitani, Takashi; Okinaga, Hiroko; Fukusato, Toshio; Okazaki, Tomoki

    2013-12-01

    The estrogen receptor (ER) is a key molecule for growth of breast cancers. It has been a successful target for treatment of breast cancers. Elucidation of the ER expression mechanism is of importance for designing therapeutics for ER-positive breast cancers. However, the detailed mechanism of ER stability is still unclear. Here, we report that histone acetyltransferase Hbo1 promotes destabilization of estrogen receptor α (ERα) in breast cancers through lysine 48-linked ubiquitination. The acetyltransferase activity of Hbo1 is linked to its activity for ERα ubiquitination. Depletion of Hbo1 and anti-estrogen treatment displayed a potent growth suppression of breast cancer cell line. Hbo1 modulated transcription by ERα. Mutually exclusive expression of Hbo1 and ERα was observed in roughly half of the human breast tumors examined in the present study. Modulation of ER stability by Hbo1 in breast cancers may provide a novel therapeutic possibility.

  15. Balancing the Risks and Benefits of Oxygen Therapy in Critically III Adults

    PubMed Central

    Mutlu, Gökhan M.

    2013-01-01

    Oxygen therapy is an integral part of the treatment of critically ill patients. Maintenance of adequate oxygen delivery to vital organs often requires the administration of supplemental oxygen, sometimes at high concentrations. Although oxygen therapy is lifesaving, it may be associated with deleterious effects when administered for prolonged periods at high concentrations. Here, we review the recent advances in our understanding of the molecular responses to hypoxia and high levels of oxygen and review the current guidelines for oxygen therapy in critically ill patients. PMID:23546490

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

    PubMed Central

    Zhou, Hai-xiao; Liu, Zhi-gang; Liu, Xiao-jiao; Chen, Qian-xue

    2016-01-01

    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. PMID:26981097

  17. Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis

    SciTech Connect

    Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W.; Komarnicky, Lydia T.

    2012-11-01

    Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for radiation-induced HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam radiation delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for radiation-induced HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.

  18. Approaching Oxygen-Guided Intensity-Modulated Radiation Therapy.

    PubMed

    Epel, Boris; Redler, Gage; Pelizzari, Charles; Tormyshev, Victor M; Halpern, Howard J

    2016-01-01

    The outcome of cancer radiation treatment is strongly correlated with tumor oxygenation. The aim of this study is to use oxygen tension distributions in tumors obtained using Electron Paramagnetic Resonance (EPR) imaging to devise better tumor radiation treatment. The proposed radiation plan is delivered in two steps. In the first step, a uniform 50% tumor control dose (TCD50) is delivered to the whole tumor. For the second step an additional dose boost is delivered to radioresistant, hypoxic tumor regions. FSa fibrosarcomas grown in the gastrocnemius of the legs of C3H mice were used. Oxygen tension images were obtained using a 250 MHz pulse imager and injectable partially deuterated trityl OX63 (OX71) spin probe. Radiation was delivered with a novel animal intensity modulated radiation therapy (IMRT) XRAD225Cx microCT/radiation therapy delivery system. In a simplified scheme for boost dose delivery, the boost area is approximated by a sphere, whose radius and position are determined using an EPR O2 image. The sphere that irradiates the largest fraction of hypoxic voxels in the tumor was chosen using an algorithm based on Receiver Operator Characteristic (ROC) analysis. We used the fraction of irradiated hypoxic volume as the true positive determinant and the fraction of irradiated normoxic volume as the false positive determinant in the terms of that analysis. The most efficient treatment is the one that demonstrates the shortest distance from the ROC curve to the upper left corner of the ROC plot. The boost dose corresponds to the difference between TCD90 and TCD50 values. For the control experiment an identical radiation dose to the normoxic tumor area is delivered.

  19. Effect of hyperbaric oxygenation on brain hemodynamics, hemoglobin oxygenation and mitochondrial NADH.

    PubMed

    Meirovithz, Elhanan; Sonn, Judith; Mayevsky, Avraham

    2007-06-01

    To determine the HbO(2) oxygenation level at the microcirculation, we used the hyperbaric chamber. The effects of hyperbaric oxygenation (HBO) were tested on vitality parameters in the brain at various pressures. Microcirculatory hemoglobin oxygen saturation (HbO(2)), cerebral blood flow (CBF) and mitochondrial NADH redox state were assessed in the brain of awake restrained rats using a fiber optic probe. The hypothesis was that HBO may lead to maximal level in microcirculatory HbO(2) due to the amount of the dissolved O(2) to provide the O(2) consumed by the brain, and therefore no O(2) will be dissociated from the HbO(2). Awake rats were exposed progressively to 15 min normobaric hyperoxia, 100% O(2) (NH) and to 90 min hyperbaric hyperoxia (HH) from 1.75 to 6.0 absolute atmospheres (ATA). NH and HH gradually decreased the blood volume measured by tissue reflectance and NADH but increased HbO(2) in relation to pO(2) in the chamber up to a nearly maximum effect at 2.5 ATA. Two possible approximations were found to describe the relationship between NADH and HbO(2): linear or logarithmic. These findings show that the increase in brain microcirculatory HbO(2) is due to an increase in O(2) supply by dissolved O(2), reaching a maximum at 2.5 ATA. NADH is oxidized (decreased signal) in parallel to the HbO(2) increase, showing maximal tissue oxygenation and cellular mitochondrial NADH oxidation at 2.5 ATA. In conclusion, in the normoxic brain, the level of microcirculatory HbO(2) is about 50% as compared to the maximal level recorded at 2.5 ATA and the minimal level measured during anoxia.

  20. Hyperbaric oxygen therapy and the possibility of ocular complications or contraindications.

    PubMed

    McMonnies, Charles W

    2015-03-01

    Hyperbaric oxygen therapy increases oxygen pressure and the concentration of reactive oxygen species in blood and tissues. Increased oxygen pressure may be beneficial in some diseases, such as in the treatment of diabetic leg ulcers and diabetic retinopathy; however, due to their cytotoxic properties, an excess of reactive oxygen species in tissues and/or deficiencies in antioxidant activity, may contribute to complications of hyperbaric oxygen therapy, such as cataract. This review examines the possibility that increased tissue concentrations of reactive oxygen species may also exacerbate other ocular diseases. For example, reactive oxygen species and deficiencies in antioxidant activities contribute to the pathogenetic processes in keratoconus. Such impact may be exacerbated by exposure to additional reactive oxygen species during hyperbaric oxygen therapy. The senescent eye may be particularly prone to oxidative damage as exemplified by conditions such as macular degeneration and cataract. Because of its high consumption of oxygen, the retina is particularly susceptible to oxidative stress, which plays a major role in retinopathy. For example, under normal conditions age-related macular degeneration involves oxidative stress and death of the retinal pigment epithelial cells. Hyperbaric oxygen therapy may exacerbate these processes. In addition to cataract, age-related macular degeneration and keratoconus, there may be other ocular diseases for which exposure to hyperbaric oxygen therapy-related oxidative stress may be significantly adverse. In all such cases, careful pre-examination and evaluation of the potential risk and benefit from this form of therapy appears to be warranted. Unless it could interfere with the benefits of hyperbaric oxygen therapy, antioxidant dietary supplementation may be indicated in conjunction with any hyperbaric oxygen therapy, when there are co-existing diseases for which oxidative stress could have significantly adverse side effects

  1. Protective effects of hyperbaric oxygen and iloprost on ischemia/reperfusion-induced lung injury in a rabbit model

    PubMed Central

    2012-01-01

    Background The role of multiorgan damage in the mortality caused by ischemic limb injury is still not clarified. The objective of this study was to examine the potential protective effects of hyperbaric oxygen (HBO) and iloprost (IL) therapy on lung damage induced by limb ischemia/reperfusion injury in a rabbit model, using both biochemical and histopathological aspects. Methods Forty New Zealand white rabbits were randomly allocated into one of five study groups: HBO group (single session of HBO treatment); IL group (25 ng/kg/min infusion of IL); HBO + IL group (both HBO and IL); Control group (0.9% saline only); and a sham group. Acute hind limb ischemia-reperfusion was established by clamping the abdominal aorta for 1 h. HBO treatment and IL infusion were administrated during 60 min of ischemia and 60 min of reperfusion period. Blood pH, partial pressure of oxygen, partial pressure of carbon dioxide and levels of bicarbonate, sodium, potassium, creatine kinase, lactate dehydrogenase, and tumor necrosis factor alpha were determined at the end of the reperfusion period. Malondialdehyde was measured in the plasma and lung as an indicator of free radicals. After sacrifice, left lungs were removed and histopathological examination determined the degree of lung injury. Results In the control group, blood partial pressure of oxygen and bicarbonate levels were significantly lower and creatine kinase, lactate dehydrogenase, malondialdehyde and tumor necrosis factor-α levels were significantly higher than those of the HBO group, IL group, HBO + IL group and sham group. Similarly, the malondialdehyde levels in the lung tissue and plasma levels were significantly lower in the treatment groups compared with the control group. The extent of lung injury according to the histological findings was significantly higher in the control group. Conclusions These results suggest that both HBO and IL therapies and their combination might be effectively used in the

  2. Effects of hyperbaric oxygenation on oxidative stress in acute transient focal cerebral ischemic rats.

    PubMed

    Wang, Ray-Yau; Chang, Heng-Chih; Chen, Chun-Hao; Tsai, Yi-Wei; Yang, Yea-Ru

    2012-01-01

    The aim of this study was to investigate the effects of hyperbaric oxygenation (HBO) after brain ischemia. Middle cerebral artery occlusion (MCAO) procedure was used to induce the brain ischemia. Rats were assigned to control or HBO group after brain ischemia. In order to examine the role of glutathione after HBO treatment, another group of brain ischemic rats were included to receive the glutathione synthesis inhibitor and HBO treatment. HBO was administered at a pressure of 3 atmospheres absolute for 1 h with 100% oxygen, starting at 3 h post brain ischemia in HBO groups. Animals in control group were placed in their home cage and exposed to normobaric room air. The infarct volume (IV), activation of astrocyte, and level of total glutathione and lipid peroxidation (LP) were assessed 24 h post-reperfusion. Significant reduction in IV was noted in HBO group when compared with control group. The activation of astrocyte was significantly increased in the right cerebral cortex and right striatum in the HBO group when compared with those of the control group. The glutathione level was higher with lower LP level in right cortex and right striatum after HBO as compared with those of the control. However, such effects of HBO treatment were markedly reduced by glutathione synthesis inhibitor administration. These results show that inhibiting glutathione synthesis dramatically reduces the effectiveness of HBO in acute transient focal cerebral ischemia.

  3. Neuroprotective effect of hyperbaric oxygen therapy on anterior ischemic optic neuropathy.

    PubMed

    Avraham-Lubin, Bat-Chen R; Dratviman-Storobinsky, Olga; El, Shimrit Dadon-Bar; Hasanreisoglu, Murat; Goldenberg-Cohen, Nitza

    2011-01-01

    The study investigated the therapeutic effect of hyperbaric oxygen (HBO) on anterior ischemic optic neuropathy in a rodent model (rAION). rAION was laser-induced in one eye of 63 mice. The fellow (uninjured) eye served as an internal control. Thirty-three mice underwent two 90-min sessions of 100% oxygen (2 atm) treatment immediately following injury and one session daily thereafter for up to 14 days. The remaining mice were untreated. Retinas were harvested at different time points, and mRNA levels of various genes were analyzed by real-time polymerase chain reaction and histologic study. Untreated mice: day 1 post-rAION - SOD-1 (oxidative-stress-related) decreased to 82% of control (uninjured eye) levels (P < 0.05), Caspase-3 (proapoptotic) decreased to 89%, Bcl-xL mildly increased (117%; all NS); day 3 - HO-1 and endothelial nitric oxide synthase (eNOS; ischaemia-related) decreased to 74%, and Bcl-2-associated X protein, Caspase-3, and B-cell lymphoma 2 (Bcl-2; apoptotic) increased by 170, 120, and 111%, respectively (all NS); day21 - HO-1 increased to 222% (NS) and eNOS decreased to 48% (P < 0.05). Treated mice: day 1 - SOD-1 and Caspase-3 remained unchanged, Bcl-2 and Bcl-xL mildly increased (112 and 126% respectively); day 3 - HO-1 and eNOS increased, apoptosis-related gene decreased; day 21 - SOD-1 decreased whereas eNOS increased (P < 0.05), and HO-1 increased to a lesser degree than without treatment. None of the oxygen-treated animals had retinal ganglion cell loss or a decrease in Thy-1 expression. In conclusion, HBO treatment after rAION induction influences the expression of apoptosis-related genes as well as oxidative-stress-induced and ischaemia-related genes and may exert a neuroprotective effect. PMID:21577253

  4. Histone Acetyl Transferase (HAT) HBO1 and JADE1 in Epithelial Cell Regeneration

    PubMed Central

    Havasi, Andrea; Haegele, Joseph A.; Gall, Jonathan M.; Blackmon, Sherry; Ichimura, Takaharu; Bonegio, Ramon G.; Panchenko, Maria V.

    2014-01-01

    HBO1 acetylates lysine residues of histones and is involved in DNA replication and gene transcription. Two isoforms of JADE1, JADE1S and JADE1L, bind HBO1 and promote acetylation of histones in chromatin context. We characterized the role of JADE1-HBO1 complexes in vitro and in vivo during epithelial cell replication. Down-regulation of JADE1 by siRNA diminished the rate of DNA synthesis in cultured cells, decreased endogenous HBO1 protein expression, and prevented chromatin recruitment of replication factor Mcm7, demonstrating that JADE1 is required for cell proliferation. We used a murine model of acute kidney injury to examine expression of HBO1-JADE1S/L in injured and regenerating epithelial tissue. In control kidneys, JADE1S, JADE1L, and HBO1 were expressed in nuclei of proximal and distal tubular epithelial cells. Ischemia and reperfusion injury resulted in an initial decrease in JADE1S, JADE1L, and HBO1 protein levels, which returned to baseline during renal recovery. HBO1 and JADE1S recovered as cell proliferation reached its maximum, whereas JADE1L recovered after bulk proliferation had ceased. The temporal expression of JADE1S correlated with the acetylation of histone H4 on lysines 5 and 12, but not with acetylation of histone H3 on lysine 14, demonstrating that the JADE1S-HBO1 complex specifically marks H4 during epithelial cell proliferation. These data implicate JADE1-HBO1 complex in acute kidney injury and suggest distinct roles for JADE1 isoforms during epithelial cell recovery. PMID:23159946

  5. Hyperbaric oxygen therapy promotes neurogenesis: where do we stand?

    PubMed Central

    2011-01-01

    Neurogenesis in adults, initiated by injury to the central nervous system (CNS) presents an autologous repair mechanism. It has been suggested that hyperbaric oxygen therapy (HBOT) enhances neurogenesis which accordingly may improve functional outcome after CNS injury. In this present article we aim to review experimental as well as clinical studies on the subject of HBOT and neurogenesis. We demonstrate hypothetical mechanism of HBOT on cellular transcription factors including hypoxia-inducible factors (HIFs) and cAMP response element binding (CREB). We furthermore reveal the discrepancy between experimental findings and clinical trials in regards of HBOT. Further translational preclinical studies followed by improved clinical trials are needed to elucidate potential benefits of HBOT. PMID:22146131

  6. Burning HOT: revisiting guidelines associated with home oxygen therapy.

    PubMed

    Litt, Elizabeth J; Ziesche, Rolf; Happak, Wolfgang; Lumenta, David Benjamin

    2012-01-01

    Burn injuries secondary to home oxygen therapy (HOT) have become increasingly common in recent years, yet several guidelines for HOT and chronic obstructive pulmonary disease (COPD) neglect to stress the dangers of open flames. This retrospective review of burn injury admissions secondary to HOT to our burn centre from 2007 to 2012 aimed to establish the extent of this problem and to discuss the current literature and a selection of national guidelines. Out of six patients (five female, one male) with a median age of 72 (range 58-79), four were related to smoking, and two due to lighting candles. The mean total body surface area (TBSA) affected was 17% (range 2-60%). Five patients sustained facial burns, two suffered from inhalation injury (33.3%), and five required surgery (83.3%). Mean total length of stay was 20 days (range 8 to 33), and one patient died. Although mentioned in the majority, some guidelines fail to address the issue of smoking in light of the associated risk for injury, which in turn might have future implications in litigation related to iatrogenic injuries. Improved HOT guidelines will empower physicians to discourage smoking, and fully consider the risks versus benefits of home oxygen before prescription. With a view on impeding a rising trend of burns secondary to HOT, we suggest revision to national guidelines, where appropriate. PMID:23272298

  7. Burning HOT: revisiting guidelines associated with home oxygen therapy

    PubMed Central

    Litt, Elizabeth J; Ziesche, Rolf; Happak, Wolfgang; Lumenta, David Benjamin

    2012-01-01

    Burn injuries secondary to home oxygen therapy (HOT) have become increasingly common in recent years, yet several guidelines for HOT and chronic obstructive pulmonary disease (COPD) neglect to stress the dangers of open flames. This retrospective review of burn injury admissions secondary to HOT to our burn centre from 2007 to 2012 aimed to establish the extent of this problem and to discuss the current literature and a selection of national guidelines. Out of six patients (five female, one male) with a median age of 72 (range 58-79), four were related to smoking, and two due to lighting candles. The mean total body surface area (TBSA) affected was 17% (range 2-60%). Five patients sustained facial burns, two suffered from inhalation injury (33.3%), and five required surgery (83.3%). Mean total length of stay was 20 days (range 8 to 33), and one patient died. Although mentioned in the majority, some guidelines fail to address the issue of smoking in light of the associated risk for injury, which in turn might have future implications in litigation related to iatrogenic injuries. Improved HOT guidelines will empower physicians to discourage smoking, and fully consider the risks versus benefits of home oxygen before prescription. With a view on impeding a rising trend of burns secondary to HOT, we suggest revision to national guidelines, where appropriate. PMID:23272298

  8. Modulation of the Tumor Vasculature and Oxygenation to Improve Therapy

    PubMed Central

    Siemann, Dietmar W.; Horsman, Michael R.

    2015-01-01

    The tumor microenvironment is increasingly recognized as a major factor influencing the success of therapeutic treatments and has become a key focus for cancer research. The progressive growth of a tumor results in an inability of normal tissue blood vessels to oxygenate and provide sufficient nutritional support to tumor cells. As a consequence the expanding neoplastic cell population initiates its own vascular network which is both structurally and functionally abnormal. This aberrant vasculature impacts all aspects of the tumor microenvironment including the cells, extracellular matrix, and extracellular molecules which together are essential for the initiation, progression and spread of tumor cells. The physical conditions that arise are imposing and manifold, and include elevated interstitial pressure, localized extracellular acidity, and regions of oxygen and nutrient deprivation. No less important are the functional consequences experienced by the tumor cells residing in such environments: adaptation to hypoxia, cell quiescence, modulation of transporters and critical signaling molecules, immune escape, and enhanced metastatic potential. Together these factors lead to therapeutic barriers that create a significant hindrance to the control of cancers by conventional anticancer therapies. However, the aberrant nature of the tumor microenvironments also offers unique therapeutic opportunities. Particularly interventions that seek to improve tumor physiology and alleviate tumor hypoxia will selectively impair the neoplastic cell populations residing in these environments. Ultimately, by combining such therapeutic strategies with conventional anticancer treatments it may be possible to bring cancer growth, invasion, and metastasis to a halt. PMID:26073310

  9. The effects of combined hyperbaric oxygen therapy on patients with post-stroke depression.

    PubMed

    Yan, Dong; Shan, Jin; Ze, Yu; Xiao-Yan, Zeng; Xiao-Hua, Hu

    2015-05-01

    [Purpose] To observe the effect of combined hyperbaric oxygen therapy on patients with post-stroke depression. [Subjects] Ninety patients with post-stroke depression were randomly divided into 3 groups: fluoxetine treatment group (n = 30), hyperbaric oxygen therapy group (n = 30), and hyperbaric oxygen combined treatment group (n = 30). [Methods] Fluoxetine treatment group received anti-depression drugs (fluoxetine, 20 mg/day), hyperbaric oxygen therapy group received hyperbaric oxygen (once a day, 5 days/week), hyperbaric oxygen combined treatment group received fluoxetine and hyperbaric oxygen treatments as described above. All patients received routine rehabilitation therapy. Hamilton Depression Scale (HAMD), and Scandinavian Stroke Scale (SSS) scores were evaluated before and at the end of 4th week. The total effective rate of depression release between the 3 groups was also compared at the end of study. [Results] The end scores of HAMD and SSS in the 3 groups were significantly lower than those before treatment. The total effective rate of combined hyperbaric oxygen therapy group after treatment was higher than the other two groups. [Conclusions] Combined hyperbaric oxygen therapy plays an important role in the treatment of patients with post-stroke depression. The total effective rate of combined hyperbaric oxygen therapy was higher than other routine anti post-stroke depression treatments.

  10. Role of Jade-1 in the histone acetyltransferase (HAT) HBO1 complex.

    PubMed

    Foy, Rebecca L; Song, Ihn Young; Chitalia, Vipul C; Cohen, Herbert T; Saksouk, Nehme; Cayrou, Christelle; Vaziri, Cyrus; Côté, Jacques; Panchenko, Maria V

    2008-10-24

    Regulation of global chromatin acetylation is important for chromatin remodeling. A small family of Jade proteins includes Jade-1L, Jade-2, and Jade-3, each bearing two mid-molecule tandem plant homology domain (PHD) zinc fingers. We previously demonstrated that the short isoform of Jade-1L protein, Jade-1, is associated with endogenous histone acetyltransferase (HAT) activity. It has been found that Jade-1L/2/3 proteins co-purify with a novel HAT complex, consisting of HBO1, ING4/5, and Eaf6. We investigated a role for Jade-1/1L in the HBO1 complex. When overexpressed individually, neither Jade-1/1L nor HBO1 affected histone acetylation. However, co-expression of Jade-1/1L and HBO1 increased acetylation of the bulk of endogenous histone H4 in epithelial cells in a synergistic manner, suggesting that Jade1/1L positively regulates HBO1 HAT activity. Conversely, small interfering RNA-mediated depletion of endogenous Jade resulted in reduced levels of H4 acetylation. Moreover, HBO1-mediated H4 acetylation activity was enhanced severalfold by the presence of Jade-1/1L in vitro. The removal of PHD fingers affected neither binding nor mutual Jade-1-HBO1 stabilization but completely abrogated the synergistic Jade-1/1L- and HBO1-mediated histone H4 acetylation in live cells and in vitro with reconstituted oligonucleosome substrates. Therefore, PHDs are necessary for Jade-1/1L-induced acetylation of nucleosomal histones by HBO1. In contrast to Jade-1/1L, the PHD zinc finger protein ING4/5 failed to synergize with HBO1 to promote histone acetylation. The physical interaction of ING4/5 with HBO1 occurred in the presence of Jade-1L or Jade-3 but not with the Jade-1 short isoform. In summary, this study demonstrates that Jade-1/1L are crucial co-factors for HBO1-mediated histone H4 acetylation.

  11. Long term consequences of oxygen therapy in the neonatal period

    PubMed Central

    Jobe, Alan H.; Kallapur, Suhas G.

    2010-01-01

    Summary Preterm and term infants are frequently exposed to high concentrations of oxygen for prolonged periods. In experimental models, high and prolonged oxygen exposures cause delayed alveolar septation and a bronchopulmonary dysplasia phenotype. Often, however, the oxygen exposure is tolerated in that the infants recover without severe lung or systemic injury. Multiple exposures change oxygen sensitivity in adult and newborn animals. Examples are antenatal corticosteroids, inflammatory mediators or preconditioning with oxygen, which will increase tolerance to oxygen injury. Intrauterine growth restriction or postnatal nutritional deficits will increase oxygen injury. Different infants probably have quite variable sensitivities to oxygen injury, but there are no biomarkers available to predict the risk of oxygen injury. PMID:20452844

  12. Reactive Oxygen Species and Targeted Therapy for Pancreatic Cancer.

    PubMed

    Zhang, Lun; Li, Jiahui; Zong, Liang; Chen, Xin; Chen, Ke; Jiang, Zhengdong; Nan, Ligang; Li, Xuqi; Li, Wei; Shan, Tao; Ma, Qingyong; Ma, Zhenhua

    2016-01-01

    Pancreatic cancer is the fourth leading cause of cancer-related death in the United States. Reactive oxygen species (ROS) are generally increased in pancreatic cancer cells compared with normal cells. ROS plays a vital role in various cellular biological activities including proliferation, growth, apoptosis, and invasion. Besides, ROS participates in tumor microenvironment orchestration. The role of ROS is a doubled-edged sword in pancreatic cancer. The dual roles of ROS depend on the concentration. ROS facilitates carcinogenesis and cancer progression with mild-to-moderate elevated levels, while excessive ROS damages cancer cells dramatically and leads to cell death. Based on the recent knowledge, either promoting ROS generation to increase the concentration of ROS with extremely high levels or enhancing ROS scavenging ability to decrease ROS levels may benefit the treatment of pancreatic cancer. However, when faced with oxidative stress, the antioxidant programs of cancer cells have been activated to help cancer cells to survive in the adverse condition. Furthermore, ROS signaling and antioxidant programs play the vital roles in the progression of pancreatic cancer and in the response to cancer treatment. Eventually, it may be the novel target for various strategies and drugs to modulate ROS levels in pancreatic cancer therapy.

  13. Antioxidant Response of Chronic Wounds to Hyperbaric Oxygen Therapy

    PubMed Central

    Sureda, Antoni; Batle, Juan M.; Martorell, Miquel; Capó, Xavier; Tejada, Silvia; Tur, Josep A.; Pons, Antoni

    2016-01-01

    We analyzed the effects of the clinical hyperbaric oxygen therapy (HBOT) on the plasma antioxidant response and levels of endothelin-1, Interleukine-6 (IL-6) and vascular endothelial growth factor (VEGF) in patients with chronic wounds (20.2±10.0 months without healing). They received 20 HBOT sessions (five sessions/week), and blood samples were obtained at sessions 1, 5 and 20 before and 2 hours after the HBOT. An additional blood sample was collected 1 month after wound recovery. Serum creatine kinase activity decreased progressively in accordance with the wound healing. Plasma catalase activity significantly increased after the first and fifth sessions of HBOT. Plasma myeloperoxidase activity reported significantly lower values after sessions. Plasma VEGF and IL-6 increased after sessions. Endothelin-1 levels were progressively decreasing during the HBOT, being significant at the session 20. Plasma malondialdehyde concentration was significantly reduced at the last session. Both creatine kinase activity and malondialdehyde levels were maintained lower 1 month after wound recovery respect to initial values. In conclusion, HBOT enhanced the plasma antioxidant defenses and may contribute to activate the healing resolution, angiogenesis and vascular tone regulation by increasing the VEGF and IL-6 release and the endothelin-1 decrease, which may be significant factors in stimulating wound healing. PMID:27654305

  14. The use of medical orders in acute care oxygen therapy.

    PubMed

    Wong, Ming; Elliott, Malcolm

    The life of every living organism is sustained by the presence of oxygen and the acute deprivation of oxygen will, therefore, result in hypoxia and ultimately death. Although oxygen is normally present in the air, higher concentrations are required to treat many disease processes. Oxygen is therefore considered to be a drug requiring a medical prescription and is subject to any law that covers its use and prescription. Administration is typically authorized by a physician following legal written instructions to a qualified nurse. This standard procedure helps prevent incidence of misuse or oxygen deprivation which could worsen the patients hypoxia and ultimate outcome. Delaying the administration of oxygen until a written medical prescription is obtained could also have the same effect. Clearly, defined protocols should exist to allow for the legal administration of oxygen by nurses without a physicians order because any delay in administering oxygen to patients can very well lead to their death. PMID:19377391

  15. High-flow oxygen therapy and other inhaled therapies in intensive care units.

    PubMed

    Levy, Sean D; Alladina, Jehan W; Hibbert, Kathryn A; Harris, R Scott; Bajwa, Ednan K; Hess, Dean R

    2016-04-30

    In this Series paper, we review the current evidence for the use of high-flow oxygen therapy, inhaled gases, and aerosols in the care of critically ill patients. The available evidence supports the use of high-flow nasal cannulae for selected patients with acute hypoxaemic respiratory failure. Heliox might prevent intubation or improve gas flow in mechanically ventilated patients with severe asthma. Additionally, it might improve the delivery of aerosolised bronchodilators in obstructive lung disease in general. Inhaled nitric oxide might improve outcomes in a subset of patients with postoperative pulmonary hypertension who had cardiac surgery; however, it has not been shown to provide long-term benefit in patients with acute respiratory distress syndrome (ARDS). Inhaled prostacyclins, similar to inhaled nitric oxide, are not recommended for routine use in patients with ARDS, but can be used to improve oxygenation in patients who are not adequately stabilised with traditional therapies. Aerosolised bronchodilators are useful in mechanically ventilated patients with asthma and chronic obstructive pulmonary disease, but are not recommended for those with ARDS. Use of aerosolised antibiotics for ventilator-associated pneumonia and ventilator-associated tracheobronchitis shows promise, but the delivered dose can be highly variable if proper attention is not paid to the delivery method.

  16. High-flow oxygen therapy and other inhaled therapies in intensive care units.

    PubMed

    Levy, Sean D; Alladina, Jehan W; Hibbert, Kathryn A; Harris, R Scott; Bajwa, Ednan K; Hess, Dean R

    2016-04-30

    In this Series paper, we review the current evidence for the use of high-flow oxygen therapy, inhaled gases, and aerosols in the care of critically ill patients. The available evidence supports the use of high-flow nasal cannulae for selected patients with acute hypoxaemic respiratory failure. Heliox might prevent intubation or improve gas flow in mechanically ventilated patients with severe asthma. Additionally, it might improve the delivery of aerosolised bronchodilators in obstructive lung disease in general. Inhaled nitric oxide might improve outcomes in a subset of patients with postoperative pulmonary hypertension who had cardiac surgery; however, it has not been shown to provide long-term benefit in patients with acute respiratory distress syndrome (ARDS). Inhaled prostacyclins, similar to inhaled nitric oxide, are not recommended for routine use in patients with ARDS, but can be used to improve oxygenation in patients who are not adequately stabilised with traditional therapies. Aerosolised bronchodilators are useful in mechanically ventilated patients with asthma and chronic obstructive pulmonary disease, but are not recommended for those with ARDS. Use of aerosolised antibiotics for ventilator-associated pneumonia and ventilator-associated tracheobronchitis shows promise, but the delivered dose can be highly variable if proper attention is not paid to the delivery method. PMID:27203510

  17. Effects of radiotherapy after hyperbaric oxygenation on malignant gliomas

    PubMed Central

    Kohshi, K; Kinoshita, Y; Imada, H; Kunugita, N; Abe, H; Terashima, H; Tokui, N; Uemura, S

    1999-01-01

    The purpose of this non-randomized trial was to evaluate the efficacy of radiotherapy combined with hyperbaric oxygen (HBO) in patients with malignant glioma. Between 1987 and 1997, 29 patients in whom computerized tomography (CT) or magnetic resonance imaging (MRI) scans showed post-operative residual tumours were locally irradiated with nitrosourea-based chemotherapy. Treatments were consecutively combined with HBO at two institutions since 1991 and 1993. Fifteen patients were irradiated daily after HBO, and the periods of time from decompression to irradiation were within 15 and 30 min in 11 and four patients respectively. Fourteen other patients were treated without HBO. Tumour responses were assessed by CT or MRI scans and survival times were compared between the treated groups. In the HBO group, 11 of 15 patients (73%) showed ≥ 50% tumour regression. All responders were irradiated within 15 min after decompression. In the non-HBO group, four of 14 patients (29%) showed tumour regression. The median survivals in patients with and without HBO were 24 and 12 months, respectively, and were significantly different (P < 0.05). No serious side-effects were observed in the HBO patients. In conclusion, irradiation after HBO seems to be a useful form of treatment for malignant gliomas, but irradiation should be administered immediately after decompression. © 1999 Cancer Research Campaign PMID:10390002

  18. Hyperbaric oxygen therapy in sudden sensorineural hearing loss following spinal anesthesia: case reports.

    PubMed

    Carneiro, Sandra N; Guerreiro, Ditza V; Cunha, Anita M; Camacho, Óscar F; Aguiar, Isabel C

    2016-01-01

    The management of sudden sensorineural hearing loss following spinal anesthesia is currently an open problem. Several strategies have been used with variable results and, to the best of our knowledge, there are no prior accounts in the literature on the use of hyperbaric oxygen therapy in the treatment of this complication. We report two cases of acute onset of unilateral hearing loss after spinal anesthesia, with significantly improved results after hyperbaric oxygen therapy. A hypothesis on the possible mechanism behind this complication is discussed. A relation is established between hyperbaric oxygen therapy and this hypothetical mechanism, in order to explain successful results in the reported cases.

  19. Glutamate metabolism of astrocytes during hyperbaric oxygen exposure and its effects on central nervous system oxygen toxicity.

    PubMed

    Chen, Yu-Liang; Li, Dan; Wang, Zhong-Zhuang; Xu, Wei-Gang; Li, Run-Ping; Zhang, Jun-Dong

    2016-01-20

    Hyperbaric oxygen (HBO) has been used widely in many underwater missions and clinical work. However, exposure to extremely high oxygen pressure may cause central nervous system oxygen toxicity (CNS-OT). The regulation of astrocyte glutamate metabolism is closely related to epilepsy. This study aimed to observe the effects of HBO exposure on glutamate metabolism in astrocytes and confirm the role of glutamate metabolism in CNS-OT. Anesthetized rats were exposed to 5 atmosphere absolute HBO for 80 min and microdialysis samples of brain interstitial fluid were continuously collected. Extracellular glutamate and glutamine concentrations were also detected. Freely moving rats were exposed to HBO of the same pressure for 20 min and glutamine synthetase (GS) activity in brain tissues was measured. Finally, we observed the effects of different doses of drugs related to glutamate metabolism on the latency of CNS-OT. Results showed that HBO exposure significantly increased glutamate content, whereas glutamine content was significantly reduced. Moreover, HBO exposure significantly reduced GS activity. Glutamate transporter-1 (GLT-1) selective antagonist ceftriaxone prolonged CNS-OT latency, whereas GLT-1 selective inhibitor dihydrokainate shortened CNS-OT latency. In summary, HBO exposure improved glutamate concentration and reduced glutamine concentration by inhibition of GS activity. GLT-1 activation also participated in the prevention of HBO-induced CNS-OT. Our research will provide a potential new target to terminate or attenuate CNS-OT. PMID:26619231

  20. Glutamate metabolism of astrocytes during hyperbaric oxygen exposure and its effects on central nervous system oxygen toxicity.

    PubMed

    Chen, Yu-Liang; Li, Dan; Wang, Zhong-Zhuang; Xu, Wei-Gang; Li, Run-Ping; Zhang, Jun-Dong

    2016-01-20

    Hyperbaric oxygen (HBO) has been used widely in many underwater missions and clinical work. However, exposure to extremely high oxygen pressure may cause central nervous system oxygen toxicity (CNS-OT). The regulation of astrocyte glutamate metabolism is closely related to epilepsy. This study aimed to observe the effects of HBO exposure on glutamate metabolism in astrocytes and confirm the role of glutamate metabolism in CNS-OT. Anesthetized rats were exposed to 5 atmosphere absolute HBO for 80 min and microdialysis samples of brain interstitial fluid were continuously collected. Extracellular glutamate and glutamine concentrations were also detected. Freely moving rats were exposed to HBO of the same pressure for 20 min and glutamine synthetase (GS) activity in brain tissues was measured. Finally, we observed the effects of different doses of drugs related to glutamate metabolism on the latency of CNS-OT. Results showed that HBO exposure significantly increased glutamate content, whereas glutamine content was significantly reduced. Moreover, HBO exposure significantly reduced GS activity. Glutamate transporter-1 (GLT-1) selective antagonist ceftriaxone prolonged CNS-OT latency, whereas GLT-1 selective inhibitor dihydrokainate shortened CNS-OT latency. In summary, HBO exposure improved glutamate concentration and reduced glutamine concentration by inhibition of GS activity. GLT-1 activation also participated in the prevention of HBO-induced CNS-OT. Our research will provide a potential new target to terminate or attenuate CNS-OT.

  1. UV Damage-Induced Phosphorylation of HBO1 Triggers CRL4DDB2-Mediated Degradation To Regulate Cell Proliferation.

    PubMed

    Matsunuma, Ryoichi; Niida, Hiroyuki; Ohhata, Tatsuya; Kitagawa, Kyoko; Sakai, Satoshi; Uchida, Chiharu; Shiotani, Bunsyo; Matsumoto, Masaki; Nakayama, Keiichi I; Ogura, Hiroyuki; Shiiya, Norihiko; Kitagawa, Masatoshi

    2015-11-16

    Histone acetyltransferase binding to ORC-1 (HBO1) is a critically important histone acetyltransferase for forming the prereplicative complex (pre-RC) at the replication origin. Pre-RC formation is completed by loading of the MCM2-7 heterohexameric complex, which functions as a helicase in DNA replication. HBO1 recruited to the replication origin by CDT1 acetylates histone H4 to relax the chromatin conformation and facilitates loading of the MCM complex onto replication origins. However, the acetylation status and mechanism of regulation of histone H3 at replication origins remain elusive. HBO1 positively regulates cell proliferation under normal cell growth conditions. Whether HBO1 regulates proliferation in response to DNA damage is poorly understood. In this study, we demonstrated that HBO1 was degraded after DNA damage to suppress cell proliferation. Ser50 and Ser53 of HBO1 were phosphorylated in an ATM/ATR DNA damage sensor-dependent manner after UV treatment. ATM/ATR-dependently phosphorylated HBO1 preferentially interacted with DDB2 and was ubiquitylated by CRL4(DDB2). Replacement of endogenous HBO1 in Ser50/53Ala mutants maintained acetylation of histone H3K14 and impaired cell cycle regulation in response to UV irradiation. Our findings demonstrate that HBO1 is one of the targets in the DNA damage checkpoint. These results show that ubiquitin-dependent control of the HBO1 protein contributes to cell survival during UV irradiation.

  2. UV Damage-Induced Phosphorylation of HBO1 Triggers CRL4DDB2-Mediated Degradation To Regulate Cell Proliferation

    PubMed Central

    Matsunuma, Ryoichi; Ohhata, Tatsuya; Kitagawa, Kyoko; Sakai, Satoshi; Uchida, Chiharu; Shiotani, Bunsyo; Matsumoto, Masaki; Nakayama, Keiichi I.; Ogura, Hiroyuki; Shiiya, Norihiko; Kitagawa, Masatoshi

    2015-01-01

    Histone acetyltransferase binding to ORC-1 (HBO1) is a critically important histone acetyltransferase for forming the prereplicative complex (pre-RC) at the replication origin. Pre-RC formation is completed by loading of the MCM2-7 heterohexameric complex, which functions as a helicase in DNA replication. HBO1 recruited to the replication origin by CDT1 acetylates histone H4 to relax the chromatin conformation and facilitates loading of the MCM complex onto replication origins. However, the acetylation status and mechanism of regulation of histone H3 at replication origins remain elusive. HBO1 positively regulates cell proliferation under normal cell growth conditions. Whether HBO1 regulates proliferation in response to DNA damage is poorly understood. In this study, we demonstrated that HBO1 was degraded after DNA damage to suppress cell proliferation. Ser50 and Ser53 of HBO1 were phosphorylated in an ATM/ATR DNA damage sensor-dependent manner after UV treatment. ATM/ATR-dependently phosphorylated HBO1 preferentially interacted with DDB2 and was ubiquitylated by CRL4DDB2. Replacement of endogenous HBO1 in Ser50/53Ala mutants maintained acetylation of histone H3K14 and impaired cell cycle regulation in response to UV irradiation. Our findings demonstrate that HBO1 is one of the targets in the DNA damage checkpoint. These results show that ubiquitin-dependent control of the HBO1 protein contributes to cell survival during UV irradiation. PMID:26572825

  3. Update on middle ear barotrauma after hyperbaric oxygen therapy-insights on pathophysiology.

    PubMed

    Lima, Marco Antônio Rios; Farage, Luciano; Cury, Maria Cristina Lancia; Bahamad, Fayez

    2014-04-01

    Introduction Middle ear barotrauma is the most common side effect of hyperbaric oxygen therapy. Knowledge and understanding of its pathophysiology are crucial for an accurate diagnosis and proper decision making about treatment and prevention. Objective Describe up-to-date information on pathophysiology of middle ear barotrauma after hyperbaric oxygen therapy considering the physiology of pressure variation of the middle ear. Data Synthesis Middle ear barotrauma occurs especially during the compression phase of hyperbaric oxygen therapy. The hyperoxic environment in hyperbaric oxygen therapy leads to ventilatory dysfunction of the eustachian tube, especially in monoplace chambers, where the patients are pressurized with 100% O2, favoring middle ear barotrauma. Conclusion The eustachian tube, the tympanic cavity, and mastoid work together in a neural controlled feedback system in which various mechanisms concur for middle ear pressure regulation.

  4. Detection techniques for singlet oxygen production during photodynamic therapy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Li, Buhong

    2016-03-01

    Singlet oxygen is widely considered to be the major cytotoxic reactive oxygen species (ROS) generated during photodynamic therapy (PDT). This talk summarizes recent advances and future perspectives in detection techniques for singlet oxygen production, and the advantages and limitations of each technique will be presented. In addition, our custom developed novel configuration of a near-infrared sensitive camera and adaptive optics for in vivo fast imaging of singlet oxygen luminescence around 1270 nm will be highlighted. For clinical PDT application, the challenges for direct measrement of singlet oxygen luminescence will be discussed.

  5. [Protective effects of hyperbaric oxygen treatment on kidney cells of type 2 diabetic rats].

    PubMed

    Nie, Wen-Jie; Cao, Xiu-Qin; Shao, Gui-Qiang

    2014-04-25

    The major objective was to explore the effect of early hyperbaric oxygen (HBO) therapy on the tissue structure, apoptosis, and metalloproteinases of kidney cells in Goto-Kakizaki (GK) rats with type 2 diabetes mellitus. GK rats (n = 24) were divided randomly and evenly into model, metformin hydrochloride (MH), and hyperbaric oxygen (HBO) groups, while healthy Wistar rats (n = 8) were used as normal control group. The healthy rats in the normal control group and the GK rats in the model group were both intragastrically administered with purified water (5 mL/kg) once per day. Meanwhile, the rats in the MH group received intragastric administration of MH (250 mg/kg) once daily, while the rats in the HBO group inhaled pure oxygen under a constant pressure (0.15 MPa) for 30 min. After 3 weeks of treatment, the body weight of each rat was measured, and the blood samples were collected from tails. Subsequently, the kidneys of all rats were excised for weighing mass and further examination. For each renal sample, the sections were firstly embedded with paraffin and sliced to prepare histopathologic sections stained using HE, PAS and Masson, respectively, for subsequent observation with optical microscopy. Later, the apoptosis of kidney cells was examined using the TUNEL method by computing the apoptotic index. Furthermore, the histopathologic sections were also examined using the immunohistochemistry approach with Caspase-3, MMP-2, and TIMP-2 antibodies, respectively. At the same time, the plasma concentration of TGF-β1 of the rats in each group was detected using ELISA method. These resultant data showed that the pathological changes of the HBO group were less than those of the model group with respect to increased glomerular volume density of mesangial cells, broadening mesangial matrix and thickening basement membrane as well as swelling renal tubular epithelial cells. The index of cell apoptosis and Caspase-3 expression in the HBO group showed no significant

  6. Clinical evidence on high flow oxygen therapy and active humidification in adults.

    PubMed

    Gotera, C; Díaz Lobato, S; Pinto, T; Winck, J C

    2013-01-01

    Recently there has been growing interest in an alternative to conventional oxygen therapy: the heated, humidified high flow nasal cannula oxygen therapy (HFNC). A number of physiological effects have been described with HFNC: pharyngeal dead space washout, reduction of nasopharyngeal resistance, a positive expiratory pressure effect, an alveolar recruitment, greater humidification, more comfort and better tolerance by the patient, better control of FiO2 and mucociliary clearance. There is limited experience of HFNC in adults. There are no established guidelines or decision-making pathways to guide use of the HFNC therapy for adults. In this article we review the existing evidence of HFNC oxygen therapy in adult patients, its advantages, limitations and the current literature on clinical applications. Further research is required to determine the long-term effect of this therapy and identify the adult patient population to whom it is most beneficial.

  7. Effect of hyperbaric oxygen therapy combined with autologous platelet concentrate applied in rabbit fibula fraction healing

    PubMed Central

    Neves, Paulo César Fagundes; de Campos Vieira Abib, Simone; Neves, Rogério Fagundes; Pircchio, Oronzo; Saad, Karen Ruggeri; Saad, Paulo Fernandes; Simões, Ricardo Santos; Moreira, Marcia Bento; de Souza Laurino, Cristiano Frota

    2013-01-01

    OBJECTIVES: The purpose is to study the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing the fibula bone of rabbits after induced fractures. METHODS: A total of 128 male New Zealand albino rabbits, between 6–8 months old, were subjected to a total osteotomy of the proximal portion of the right fibula. After surgery, the animals were divided into four groups (n = 32 each): control group, in which animals were subjected to osteotomy; autologous platelet concentrate group, in which animals were subjected to osteotomy and autologous platelet concentrate applied at the fracture site; hyperbaric oxygen group, in which animals were subjected to osteotomy and 9 consecutive daily hyperbaric oxygen therapy sessions; and autologous platelet concentrate and hyperbaric oxygen group, in which animals were subjected to osteotomy, autologous platelet concentrate applied at the fracture site, and 9 consecutive daily hyperbaric oxygen therapy sessions. Each group was divided into 4 subgroups according to a pre-determined euthanasia time points: 2, 4, 6, and 8 weeks postoperative. After euthanasia at a specific time point, the fibula containing the osseous callus was prepared histologically and stained with hematoxylin and eosin or picrosirius red. RESULTS: Autologous platelet concentrates and hyperbaric oxygen therapy, applied together or separately, increased the rate of bone healing compared with the control group. CONCLUSION: Hyperbaric oxygen therapy and autologous platelet concentrate combined increased the rate of bone healing in this experimental model. PMID:24141841

  8. Effect of an oxygen pressure injection (OPI) device on the oxygen saturation of patients during dermatological methyl aminolevulinate photodynamic therapy.

    PubMed

    Blake, E; Allen, J; Thorn, C; Shore, A; Curnow, A

    2013-05-01

    Methyl aminolevulinate photodynamic therapy (MAL-PDT) (a topical treatment used for a number of precancerous skin conditions) utilizes the combined interaction of a photosensitizer (protoporphyrin IX (PpIX)), light of the appropriate wavelength, and molecular oxygen to produce singlet oxygen and other reactive oxygen species which induce cell death. During treatment, localized oxygen depletion occurs and is thought to contribute to decreased efficacy. The aim of this study was to investigate whether an oxygen pressure injection (OPI) device had an effect on localized oxygen saturation levels and/or PpIX fluorescence of skin lesions during MAL-PDT. This study employed an OPI device to apply oxygen under pressure to the skin lesions of patients undergoing standard MAL-PDT. Optical reflectance spectrometry and fluorescence imaging were used to noninvasively monitor the localized oxygen saturation and PpIX fluorescence of the treatment area, respectively. No significant changes in oxygen saturation were observed when these data were combined for the group with OPI and compared to the group that received standard MAL-PDT without OPI. Additionally, no significant difference in PpIX photobleaching or clinical outcome at 3 months between the groups of patients was observed, although the group that received standard MAL-PDT demonstrated a significant increase (p<0.05) in PpIX fluorescence initially and both groups produced a significant decrease (p<0.05) after light irradiation. In conclusion, with this sample size, this OPI device was not found to be an effective method with which to improve tissue oxygenation during MAL-PDT. Further investigation is therefore required to find a more effective method of MAL-PDT enhancement.

  9. The neuroprotective effect of hyperbaric oxygen treatment on laser-induced retinal damage in rats

    NASA Astrophysics Data System (ADS)

    Vishnevskia-Dai, Victoria; Belokopytov, Mark; Dubinsky, Galina; Nachum, Gal; Avni, Isaac; Belkin, Michael; Rosner, Mordechai

    2005-04-01

    Retinal damage induced by mechanical trauma, ischemia or laser photocoagulation increases considerably by secondary degeneration processes. The spread of damage may be ameliorated by neuroprotection that is aimed at reducing the extent of the secondary degeneration and promote healing processes. Hyperbaric oxygen (HBO) treatment consists of inspiration of oxygen at higher than one absolute atmospheric pressure. Improved neural function was observed in patients with acute brain trauma or ischemia treated with HBO. This study was designed to evaluate the neuroprotective effect of hyperbaric oxygen (HBO) on laser induced retinal damage in a rat model. Standard argon laser lesions were created in 25 pigmented rats divided into three groups: Ten rats were treated immediately after the irradiation with HBO three times during the first 24 hr followed by 12 consecutive daily treatments. Five rats received a shorter treatment regimen of 10 consecutive HBO treatments. The control group (10 rats) underwent the laser damage with no additional treatment. The retinal lesions were evaluated 20 days after the injury. All outcome measures were improved by the longer HBO treatment (P<0.01). The shorter HBO treatment was less effective, showing an increase only in nuclei density at the central area of lesion (P< 0.01). Hyperbaric oxygen seems to exert a neuroprotective effect on laser-induced retinal damage in a rat model. In the range of HBO exposures studied, longer exposure provides more neuroprotection. These results encourage further evaluation of the potential therapeutic use of hyperbaric oxygen in diseases and injuries of the retina.

  10. [Oxygen therapy during Argentine-based national and international flights].

    PubMed

    Martínez Fraga, Alejandro; Sívori, Martín; Alonso, Mariana

    2008-01-01

    There are no data about supplemental oxygen in flight in our country. The objective of our study was to evaluate arranging in-flight-oxygen required by a simulated traveler, system of administration and costs, and to compare the results between Argentine-based (A) and international (I) airlines. The questionnaire used was similar to that of Stoller et al12. Data collection consisted of telephone calls placed by one of the authors to all commercial air carriers listed in our two Buenos Aires City airports during July 2007. A structured interview with questions was addressed on issues that an oxygen-using air traveler would need to arrange in-flight oxygen. Of the 25 airlines, 6 were discarded because of lack of information (24%, three A -60%- and one I -16%-). All A allowed in-flight-oxygen vs. 80% of I (p<0.05), 100% of A and 94% of I required a medical certificate (p=NS); 71% of A and 100% of I required previous notification (p<0.05); 50% of A and 87% of I provided patient interphases of oxygen administration (p=NS). Free of charge oxygen could be provided by 100% of A and 50% of I, with airline charge between 70 to 300 dollars. In conclusion, we observed different policies, rules, availability, and a pronounced lack of standardization of airline information. The cost of oxygen was very different between airlines and it was superior on I. It will be necessary to carry out actions to facilitate patient access to oxygentherapy and to standardize medical information among airlines in our country.

  11. Role of Anemia in Home Oxygen Therapy in Chronic Obstructive Pulmonary Disease Patients.

    PubMed

    Copur, Ahmet Sinan; Fulambarker, Ashok; Molnar, Janos; Nadeem, Rashid; McCormack, Charles; Ganesh, Aarthi; Kheir, Fayez; Hamon, Sara

    2015-01-01

    Anemia is a known comorbidity found in chronic obstructive pulmonary disease (COPD) patients. Hypoxemia is common and basically due to ventilation/perfusion (V/Q) mismatch in COPD. Anemia, by decreasing arterial oxygen content, may be a contributing factor for decreased delivery of oxygen to tissues. The objective of this study is to determine if anemia is a factor in qualifying COPD patients for home oxygen therapy. The study was designed as a retrospective, cross-sectional, observational chart review. Patients who were referred for home oxygen therapy evaluation were selected from the computerized patient record system. Demographic data, oxygen saturation at rest and during exercise, pulmonary function test results, hemoglobin level, medications, reason for anemia, comorbid diseases, and smoking status were recorded. The χ tests, independent sample t tests, and logistic regression were used for statistical analysis. Only 356 of total 478 patient referrals had a diagnosis of COPD over a 2-year period. Although 39 of them were excluded, 317 patients were included in the study. The overall rate of anemia was 38% in all COPD patients. Anemia was found significantly more frequent in COPD patients on home oxygen therapy (46%) than those not on home oxygen therapy (18.5%) (P < 0.0001). Mean saturation of peripheral oxygen values were significantly lower in anemic COPD patients both at rest and during exercise (P < 0.0001). Also, in COPD patients, age, Global Initiative for Chronic Obstructive Lung Disease class, smoking status, hemoglobin level, hematocrit, percent of forced expiratory volume in first second, forced expiratory volume in first second/forced vital capacity, residual volume/total lung volume, percent of carbon monoxide diffusion capacity were significantly different between home oxygen therapy and those not on home oxygen therapy (P < 0.05). Multivariate logistic regression showed that anemia remained a strong predictor for long-term oxygen therapy use in

  12. Treating Dyspnea: Is Oxygen Therapy the Best Option for All Patients?

    PubMed

    Baldwin, Jennifer; Cox, Jaclyn

    2016-09-01

    The high prevalence of dyspnea at the end of life carries with it significant health and economic burden. Given the complex mechanism of dyspnea, management should be tailored to the individual patient experience and the underlying disease process. No clear role for supplemental oxygen has been established in the treatment of dyspnea in patients without no hypoxemia, and providers should consider the negative effects of oxygen supplementation. Symptom control with medications, exercise, behavioral therapy, treatment of associated anxiety, and the use of fans may be more effective and less costly than oxygen therapy. Further research is needed in the assessment and treatment of this symptom to more effectively treat patients. PMID:27542431

  13. Enhancement of satellite cell differentiation and functional recovery in injured skeletal muscle by hyperbaric oxygen treatment.

    PubMed

    Horie, Masaki; Enomoto, Mitsuhiro; Shimoda, Manabu; Okawa, Atsushi; Miyakawa, Shumpei; Yagishita, Kazuyoshi

    2014-01-15

    Recently, the use of hyperbaric oxygen (HBO) treatments by elite athletes to accelerate recovery from muscle injuries has become increasingly popular. However, the mechanism of promoting muscle regeneration under HBO conditions has not yet been defined. In this study, we investigated whether HBO treatments promoted muscle regeneration and modulated muscle regulatory factor expression in a rat skeletal muscle injury model. Muscle injury was induced by injecting cardiotoxin (CTX) into the tibialis anterior (TA) muscles. As the HBO treatment, rats were placed in an animal chamber with 100% oxygen under 2.5 atmospheres absolute for 2 h/day, 5 days/wk for 2 wk. We then performed histological analyses, measured the maximum force-producing capacity of the regenerating muscle fibers, and performed quantitative RT-PCR analysis of muscle regulatory factor mRNAs. The cross-sectional areas and maximum force-producing capacity of the regenerating muscle fibers were increased by HBO treatment after injury. The mRNA expression of MyoD, myogenin, and IGF-1 increased significantly in the HBO group at 3 and 5 days after injury. The number of Pax7(+)/MyoD(+), Pax7(-)/MyoD(+), and Pax7(+)/BrdU(+)-positive nuclei was increased by HBO treatment. In this study, we demonstrated that HBO treatment accelerated satellite cell proliferation and myofiber maturation in rat muscle that was injured by a CTX injection. These results suggest that HBO treatment accelerates healing and functional recovery after muscle injury.

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

    PubMed Central

    Peng, Chuan-gang; Zhang, Shu-quan; Wu, Min-fei; Lv, Yang; Wu, Dan-kai; Yang, Qi; Gu, Rui

    2015-01-01

    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. PMID:26604910

  15. A growing fire hazard concern in communities: home oxygen therapy and continued smoking habits.

    PubMed

    Galligan, Catherine J; Markkanen, Pia K; Fantasia, Linda M; Gore, Rebecca J; Sama, Susan R; Quinn, Margaret M

    2015-02-01

    The Safe Home Care Project investigated both qualitatively and quantitatively a range of occupational safety and health hazards, as well as injury and illness prevention practices, among home care aides in Massachusetts. This article reports on a hazard identified by aides during the study's initial focus groups: smoking by home care clients on long-term oxygen therapy. Following the qualitative phase we conducted a cross-sectional survey among 1,249 aides and found that medical oxygen was present in 9 percent of aide visits (314 of aides' 3,484 recent client visits) and that 25 percent of clients on oxygen therapy were described as smokers. Based on our findings, the Board of Health in a local town conducted a pilot study to address fire hazards related to medical oxygen. Medical oxygen combined with smoking or other sources of ignition is a serious fire and explosion hazard that threatens not only workers who visit homes but also communities.

  16. A growing fire hazard concern in communities: home oxygen therapy and continued smoking habits.

    PubMed

    Galligan, Catherine J; Markkanen, Pia K; Fantasia, Linda M; Gore, Rebecca J; Sama, Susan R; Quinn, Margaret M

    2015-02-01

    The Safe Home Care Project investigated both qualitatively and quantitatively a range of occupational safety and health hazards, as well as injury and illness prevention practices, among home care aides in Massachusetts. This article reports on a hazard identified by aides during the study's initial focus groups: smoking by home care clients on long-term oxygen therapy. Following the qualitative phase we conducted a cross-sectional survey among 1,249 aides and found that medical oxygen was present in 9 percent of aide visits (314 of aides' 3,484 recent client visits) and that 25 percent of clients on oxygen therapy were described as smokers. Based on our findings, the Board of Health in a local town conducted a pilot study to address fire hazards related to medical oxygen. Medical oxygen combined with smoking or other sources of ignition is a serious fire and explosion hazard that threatens not only workers who visit homes but also communities. PMID:25816169

  17. Effects of adenosine metabolism in astrocytes on central nervous system oxygen toxicity.

    PubMed

    Chen, Yu-liang; Zhang, Ya-nan; Wang, Zhong-zhuang; Xu, Wei-gang; Li, Run-ping; Zhang, Jun-dong

    2016-03-15

    Hyperbaric oxygen (HBO) is widely used in military operations, especially underwater missions. However, prolonged and continuous inhalation of HBO can cause central nervous system oxygen toxicity (CNS-OT), which greatly limits HBO's application. The regulation of astrocytes to the metabolism of adenosine is involved in epilepsy. In our study, we aimed to observe the effects of HBO exposure on the metabolism of adenosine in the brain. Furthermore, we aimed to confirm the possible mechanism underlying adenosine's mediation of the CNS-OT. Firstly, anesthetized rats exposed to 5 atm absolute HBO for 80 min. The concentrations of extracellular adenosine, ATP, ADP, and AMP were detected. Secondly, free-moving rats were exposed to HBO at the same pressure for 20 min, and the activities of 5'-nucleotidase and ADK in brain tissues were measured. For the mechanism studies, we observed the effects of a series of different doses of drugs related to adenosine metabolism on the latency of CNS-OT. Results showed HBO exposure could increase adenosine content by inhibiting ADK activity and improving 5'-nucleotidase activity. And adenosine metabolism during HBO exposure may be a protective response against HBO-induced CNS-OT. Moreover, the improvement of adenosine concentration, activation of adenosine A1R, or suppression of ADK and adenosine A2AR, which are involved in the prevention of HBO-induced CNS-OT. This is the first study to demonstrate HBO exposure regulated adenosine metabolism in the brain. Adenosine metabolism and adenosine receptors are related to HBO-induced CNS-OT development. These results will provide new potential targets for the termination or the attenuation of CNS-OT. PMID:26806404

  18. Hyperbaric Oxygen Therapy: Don't Be Misled

    MedlinePlus

    ... can be mild (such as sinus pain, ear pressure, painful joints) or serious (such as paralysis, air embolism). Since hyperbaric chambers are oxygen rich environments, there is also a risk of fire. "If you're considering using HBOT, it's essential ...

  19. Randomized Trial of Hyperbaric Oxygen Therapy for Children with Autism

    ERIC Educational Resources Information Center

    Granpeesheh, Doreen; Tarbox, Jonathan; Dixon, Dennis R.; Wilke, Arthur E.; Allen, Michael S.; Bradstreet, James Jeffrey

    2010-01-01

    Autism Spectrum Disorders (ASDs) are characterized by the presence of impaired development in social interaction and communication and the presence of a restricted repertoire of activity and interests. While numerous treatments for ASDs have been proposed, very few have been subjected to rigorous scientific investigation. Hyperbaric oxygen therapy…

  20. Real-time evaluation of tissue vitality by monitoring of microcirculatory blood flow, HbO2, and mitochondrial NADH redox state

    NASA Astrophysics Data System (ADS)

    Deutsch, Assaf; Pevzner, Eliyahu; Jaronkin, Alex; Mayevsky, Avraham

    2004-06-01

    Monitoring of tissue vitality (oxygen supply/demand) in real time is very rare in clinical practice although its use as an early warning alarming system, for clinical care medicine, is very practical. In our previous communication (SPIE 2003) we described the Tissue Spectroscope - TiSpec02, by which tissue microcirculatory blood flow (TBF) and mitochondrial NADH fluorescence were measured using a single light source (390nm). In order to improve the measurement capabilities as well as to decrease dramatically the size and cost of this clinical device, we have changed the TiSpec02 into a multi-wavelength illumination system in the new TiSpec03. In order to measure microcirculatory blood flow by laser Doppler flowmetry we used a 785nm laser diode. For mitochondrial NADH fluorescence measurement we adopted the 370nm LED. For the determination of the oxygenation level of hemoglobin (HbO2) we used the 2-wavelength reflectance technique. This new monitored parameter that was added to the TiSpec03 increases the accuracy of the diagnosis of tissue vitality. The bundle of optical fibers used to connect the tissue to the TiSpec03, was integrated into a special anchoring methodology depending on the monitored tissue or organ. In order to test the performance of the improved TiSpec we have used it in experimental animals brain models exposed to various pathophysiological conditions. Rats and gerbils were anesthetized and the fiber optic probe was located epidurally used dental acrylic cement. During anoxia and ischemia the lack of O2 led to a clear decrease in TBF and HbO2 while NADH shows a large elevation. When brain activation was induced by cortical spreading depression (SD), the elevated O2 consumption was recorded as a large oxidation (decrease) of mitochondrial NADH while TBF increase dramatically. Blood HbO2 was not affected significantly by the SD wave.

  1. The role of high flow oxygen therapy in acute respiratory failure.

    PubMed

    Masclans, J R; Pérez-Terán, P; Roca, O

    2015-11-01

    Acute respiratory failure represents one of the most common causes of intensive care unit admission and oxygen therapy remains the first-line therapy in the management of these patients. In recent years, high-flow oxygen via nasal cannula has been described as a useful alternative to conventional oxygen therapy in patients with acute respiratory failure. High-flow oxygen via nasal cannula rapidly alleviates symptoms of acute respiratory failure and improves oxygenation by several mechanisms, including dead space washout, reduction in oxygen dilution and inspiratory nasopharyngeal resistance, a moderate positive airway pressure effect that may generate alveolar recruitment and an overall greater tolerance and comfort with the interface and the heated and humidified inspired gases. However, the experience in adults is still limited and there are no clinical guidelines to establish recommendations for their use. This article aims to review the existing evidence on the use of high-flow oxygen via nasal cannula in adults with acute respiratory failure and its possible applications, advantages and limitations.

  2. The role of high flow oxygen therapy in acute respiratory failure.

    PubMed

    Masclans, J R; Pérez-Terán, P; Roca, O

    2015-11-01

    Acute respiratory failure represents one of the most common causes of intensive care unit admission and oxygen therapy remains the first-line therapy in the management of these patients. In recent years, high-flow oxygen via nasal cannula has been described as a useful alternative to conventional oxygen therapy in patients with acute respiratory failure. High-flow oxygen via nasal cannula rapidly alleviates symptoms of acute respiratory failure and improves oxygenation by several mechanisms, including dead space washout, reduction in oxygen dilution and inspiratory nasopharyngeal resistance, a moderate positive airway pressure effect that may generate alveolar recruitment and an overall greater tolerance and comfort with the interface and the heated and humidified inspired gases. However, the experience in adults is still limited and there are no clinical guidelines to establish recommendations for their use. This article aims to review the existing evidence on the use of high-flow oxygen via nasal cannula in adults with acute respiratory failure and its possible applications, advantages and limitations. PMID:26429697

  3. Exchange of associated factors directs a switch in HBO1 acetyltransferase histone tail specificity

    PubMed Central

    Lalonde, Marie-Eve; Avvakumov, Nikita; Glass, Karen C.; Joncas, France-Hélène; Saksouk, Nehmé; Holliday, Michael; Paquet, Eric; Yan, Kezhi; Tong, Qiong; Klein, Brianna J.; Tan, Song; Yang, Xiang-Jiao; Kutateladze, Tatiana G.; Côté, Jacques

    2013-01-01

    Histone acetyltransferases (HATs) assemble into multisubunit complexes in order to target distinct lysine residues on nucleosomal histones. Here, we characterize native HAT complexes assembled by the BRPF family of scaffold proteins. Their plant homeodomain (PHD)–Zn knuckle–PHD domain is essential for binding chromatin and is restricted to unmethylated H3K4, a specificity that is reversed by the associated ING subunit. Native BRPF1 complexes can contain either MOZ/MORF or HBO1 as catalytic acetyltransferase subunit. Interestingly, while the previously reported HBO1 complexes containing JADE scaffold proteins target histone H4, the HBO1–BRPF1 complex acetylates only H3 in chromatin. We mapped a small region to the N terminus of scaffold proteins responsible for histone tail selection on chromatin. Thus, alternate choice of subunits associated with HBO1 can switch its specificity between H4 and H3 tails. These results uncover a crucial new role for associated proteins within HAT complexes, previously thought to be intrinsic to the catalytic subunit. PMID:24065767

  4. Exchange of associated factors directs a switch in HBO1 acetyltransferase histone tail specificity.

    PubMed

    Lalonde, Marie-Eve; Avvakumov, Nikita; Glass, Karen C; Joncas, France-Hélène; Saksouk, Nehmé; Holliday, Michael; Paquet, Eric; Yan, Kezhi; Tong, Qiong; Klein, Brianna J; Tan, Song; Yang, Xiang-Jiao; Kutateladze, Tatiana G; Côté, Jacques

    2013-09-15

    Histone acetyltransferases (HATs) assemble into multisubunit complexes in order to target distinct lysine residues on nucleosomal histones. Here, we characterize native HAT complexes assembled by the BRPF family of scaffold proteins. Their plant homeodomain (PHD)-Zn knuckle-PHD domain is essential for binding chromatin and is restricted to unmethylated H3K4, a specificity that is reversed by the associated ING subunit. Native BRPF1 complexes can contain either MOZ/MORF or HBO1 as catalytic acetyltransferase subunit. Interestingly, while the previously reported HBO1 complexes containing JADE scaffold proteins target histone H4, the HBO1-BRPF1 complex acetylates only H3 in chromatin. We mapped a small region to the N terminus of scaffold proteins responsible for histone tail selection on chromatin. Thus, alternate choice of subunits associated with HBO1 can switch its specificity between H4 and H3 tails. These results uncover a crucial new role for associated proteins within HAT complexes, previously thought to be intrinsic to the catalytic subunit.

  5. Synthesis of luminescent 2-(2'-hydroxyphenyl)benzoxazole (HBO) borate complexes.

    PubMed

    Massue, Julien; Frath, Denis; Ulrich, Gilles; Retailleau, Pascal; Ziessel, Raymond

    2012-01-01

    Complexation of boron trifluoride by a series of electron donor/acceptor substituted 2-(2'-hydroxy phenyl)benzoxazole (HBO) derivatives yields luminescent B(III) complexes with an emission wavelength ranging from 385 to 425 nm in dichloromethane or toluene. Appropriate chemical functionalization of these new dyes allows connection to different photoactive subunits (Boranil, BODIPY), endowing an efficient cascade energy transfer.

  6. The bactericidal effect of 470 nm light and hyperbaric oxygen on methicillin-resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Bumah, Violet Vakunseh; Whelan, Harry Thomas; Masson-Meyers, Daniela Santos; Quirk, Brendan; Buchmann, Ellen; Enwemeka, Chukuka Samuel

    2015-01-01

    It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28% bacterial growth, while 470 nm blue light alone suppresses up to 92% methicillin resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470 nm light (55 J/cm2) and HBO will yield 100% bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3×106, 5×106, 7×106, 8×106 or 12×106 CFU/ml and treated each concentration in four groups as follows: (1) Control (no treatment) (2) photo-irradiation only, (3) photo-irradiation then HBO, (4) HBO only, and (5) HBO then photo-irradiation. Bacteria colonies were then quantified. The results showed that at each bacterial concentration, HBO alone was significantly less effective in suppressing MRSA than photo-irradiation or combined HBO and photo-irradiation (p<0.0001). Similarly, at no bacterial concentration did combined HBO and 470 nm light treatment yield a statistically better result than 470 nm light alone (p > 0.05), neither did HBO treatment either before or after irradiation make a difference. Furthermore, at no bacterial concentration was 100% MRSA suppression achieved. Indeed, the maximum bacterial suppression attained was in the mild infection model (3×106 CFU/ml), with blue light producing 97.3±0.2% suppression and HBO +55 J/cm2 yielding 97.5±2.5% suppression. We conclude that: (1) HBO and 470 nm light individually suppress MRSA growth; (2) 470nm blue light is more effective in suppressing MRSA than HBO; and (3) HBO did not act synergistically to heighten the bactericidal effect of 470 nm light. PMID:25700768

  7. An irradiation system for photodynamic therapy with a fiber-optic sensor for measuring tissue oxygen

    NASA Astrophysics Data System (ADS)

    Quintanar, L.; Fabila, D.; Stolik, S.; de la Rosa, J. M.

    2013-11-01

    Photodynamic Therapy is a well known treatment based on the interaction of light of specific wavelength with a photosensitizing drug. In the presence of oxygen molecules, the illumination of the photosensitizer can activate the production of reactive oxygen species, which leads to the death of target cells within the treated tissue. In order to obtain the best therapy response, the tissue oxygen concentration should be measured to adjust the therapy parameters before and during the treatment. In this work, an irradiation system for 5-Aminolevulinic Acid Photodynamic Therapy is presented. It allows the application of visible light radiation of 630 nm using as a light source a high-brightness light emitting diode with an optical-power automatic control considering a light depth-distribution model. A module to measure the tissue oxygen saturation has been implemented into the system. It is based on two light emitting diodes of 660 nm and 940 nm as light sources, a photodiode as a detector and a new handheld fiber optic reflectance pulse oximetry sensor for estimating the blood oxygen saturation within the tissue. The pulse oximetry sensor was modeled through multilayered Monte Carlo simulations to study the behavior of the sensor with changes in skin thickness and melanin content.

  8. Prognostic effect of hyperbaric oxygen therapy starting time for sudden sensorineural hearing loss.

    PubMed

    Yıldırım, Erol; Murat Özcan, K; Palalı, Mehmet; Cetin, Mehmet Ali; Ensari, Serdar; Dere, Hüseyin

    2015-01-01

    Sudden sensorineural hearing loss is one of the otological emergencies whose pathogenesis is uncertain and associated with total or partial loss of hearing function. The aim of this study was to investigate whether the hyperbaric oxygen therapy starting time affects the management of sudden sensorineural hearing loss. Fifty-nine patients with sudden sensorineural hearing loss admitted to our clinic between 2008 and 2012 were retrospectively included in this study. All patients received hyperbaric oxygen therapy. In addition, each patient received intravenous piracetam and 37 patients received steroid therapy. Hyperbaric oxygen therapy was initiated between 1 and 7 days with 20 patients determined as Group A, between 8 and 14 days with 25 patients determined as Group B and between 15 and 28 days with 14 patients determined as Group C. Hearing gains of these three groups were statistically evaluated. Each of them showed statistically significant improvement. Lowest hearing gain was observed in Group C and the gain of this group was statistically less than the other two groups. There was no significant difference between the hearing gains of the Group A and Group B. Starting hyperbaric oxygen therapy in patients with sudden sensorineural hearing loss within the first 14 days has positive effect on the prognosis of the disease.

  9. Self-Monitoring Artificial Red Cells with Sufficient Oxygen Supply for Enhanced Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Luo, Zhenyu; Zheng, Mingbin; Zhao, Pengfei; Chen, Ze; Siu, Fungming; Gong, Ping; Gao, Guanhui; Sheng, Zonghai; Zheng, Cuifang; Ma, Yifan; Cai, Lintao

    2016-03-01

    Photodynamic therapy has been increasingly applied in clinical cancer treatments. However, native hypoxic tumoural microenvironment and lacking oxygen supply are the major barriers hindering photodynamic reactions. To solve this problem, we have developed biomimetic artificial red cells by loading complexes of oxygen-carrier (hemoglobin) and photosensitizer (indocyanine green) for boosted photodynamic strategy. Such nanosystem provides a coupling structure with stable self-oxygen supply and acting as an ideal fluorescent/photoacoustic imaging probe, dynamically monitoring the nanoparticle biodistribution and the treatment of PDT. Upon exposure to near-infrared laser, the remote-triggered photosensitizer generates massive cytotoxic reactive oxygen species (ROS) with sufficient oxygen supply. Importantly, hemoglobin is simultaneously oxidized into the more active and resident ferryl-hemoglobin leading to persistent cytotoxicity. ROS and ferryl-hemoglobin synergistically trigger the oxidative damage of xenograft tumour resulting in complete suppression. The artificial red cells with self-monitoring and boosted photodynamic efficacy could serve as a versatile theranostic platform.

  10. Acute and chronic effects of hyperbaric oxygen therapy on blood circulation of human muscle and tendon in vivo.

    PubMed

    Kubo, Keitaro; Ikebukuro, Toshihiro

    2012-10-01

    This study aimed to investigate the acute and chronic effects of hyperbaric oxygen therapy on blood circulation of human muscle and tendon in vivo. Using near-infrared spectroscopy and red laser lights, we determined acute changes in blood volume (THb) and oxygen saturation (StO2) of the medial gastrocnemius muscle and Achilles tendon during 60 minutes of hyperbaric oxygen therapy (1.3 atm absolute and 50% O2, experiment 1). In addition, we determined the chronic effects of hyperbaric oxygen therapy (60 minutes, 2 times per week, 6 weeks) on THb and StO2 of muscle and tendon (experiment 2). In experiment 1, THb of the muscle increased gradually from resting level, but StO2 did not change. On the other hand, THb and StO2 of the tendon increased during hyperbaric oxygen therapy. In experiment 2, the pattern of changes in the measured variables during 60 minutes of therapy was similar for both the muscle and tendon between the first and last therapies. During resting, THb and StO2 of the tendon were significantly lower after 6 weeks of therapy, although those of the muscle were not. In conclusion, oxygen saturation of the tendon increased during hyperbaric oxygen therapy, whereas that of the muscle did not. This result would be related to the difference in the treated effects between muscle and tendon. However, oxygen saturation of the tendon, but not the muscle, during resting decreased after 6 weeks of therapy.

  11. Combination of positioning therapy and venovenous extracorporeal membrane oxygenation in ARDS patients.

    PubMed

    Kredel, M; Bischof, L; Wurmb, T E; Roewer, N; Muellenbach, R M

    2014-03-01

    Positioning therapy may improve lung recruitment and oxygenation and is part of the standard care in severe acute respiratory distress syndrome (ARDS). Venovenous extracorporeal membrane oxygenation (vvECMO) is a rescue strategy that may ensure sufficient gas exchange in ARDS patients failing conventional therapy. The aim of this case series was to describe the feasibility and pitfalls of combining positioning therapy and vvECMO in patients with severe ARDS. A retrospective cohort of nine patients is described. The patients received 20 (15-86) hours (median, 25(th) and 75(th) percentile) of positioning therapy while being treated with vvECMO. The initial PaO2/FiO2 index was 64 (51-67) mmHg and the arterial carbon dioxide tension was 60 (50-71) mmHg. Positioning therapy included 135 degrees prone, prone positioning and continuous lateral rotational therapy. During the first three days, the oxygenation index improved from 47 (41-47) to 12 (11-14) cmH2O/mmHg. The lung compliance improved from 20 (17-28) to 42 (27-43) ml/cmH2O. Complications related to positioning therapy were facial oedema (n=9); complications related to vvECMO were entrance of air (n=1) and pump failure (n=1). However, investigation of root causes revealed no association with the positioning therapy and had no documented effect on the outcome. The reported cases suggest that positioning therapy can be performed safely in ARDS patients treated with vvECMO, providing appropriate precautions are in place and a very experienced team is present.

  12. Hyperbaric oxygen therapy in the management of two cases of hydrogen sulfide toxicity from liquid manure.

    PubMed

    Belley, Richard; Bernard, Nicolas; Côté, Mario; Paquet, Francois; Poitras, Julien

    2005-07-01

    Hydrogen sulfide is a potent lethal gas. Supportive care, nitrite therapy and hyperbaric oxygen are the treatment modalities reported in the literature in cases of hydrogen sulfide exposure. We describe an industrial exposure in which 6 workers inhaled high concentrations of hydrogen sulfide when they entered a closed spreader tank partially filled with liquid swine manure. Five of the 6 lost consciousness, and 2 were agitated and poorly responsive on arrival to the emergency department despite having already received high-flow oxygen for nearly 1 hour. These 2 patients received nitrite therapy followed by orotracheal intubation and hyperbaric oxygen. All patients were discharged home without sequelae after short stays in hospital. The emergency management of hydrogen sulfide exposure is briefly reviewed.

  13. Perfluorocarbon nanoparticles enhance reactive oxygen levels and tumour growth inhibition in photodynamic therapy.

    PubMed

    Cheng, Yuhao; Cheng, Hao; Jiang, Chenxiao; Qiu, Xuefeng; Wang, Kaikai; Huan, Wei; Yuan, Ahu; Wu, Jinhui; Hu, Yiqiao

    2015-01-01

    Photodynamic therapy (PDT) kills cancer cells by converting tumour oxygen into reactive singlet oxygen ((1)O2) using a photosensitizer. However, pre-existing hypoxia in tumours and oxygen consumption during PDT can result in an inadequate oxygen supply, which in turn hampers photodynamic efficacy. Here to overcome this problem, we create oxygen self-enriching photodynamic therapy (Oxy-PDT) by loading a photosensitizer into perfluorocarbon nanodroplets. Because of the higher oxygen capacity and longer (1)O2 lifetime of perfluorocarbon, the photodynamic effect of the loaded photosensitizer is significantly enhanced, as demonstrated by the accelerated generation of (1)O2 and elevated cytotoxicity. Following direct injection into tumours, in vivo studies reveal tumour growth inhibition in the Oxy-PDT-treated mice. In addition, a single-dose intravenous injection of Oxy-PDT into tumour-bearing mice significantly inhibits tumour growth, whereas traditional PDT has no effect. Oxy-PDT may enable the enhancement of existing clinical PDT and future PDT design.

  14. Perfluorocarbon nanoparticles enhance reactive oxygen levels and tumour growth inhibition in photodynamic therapy

    PubMed Central

    Cheng, Yuhao; Cheng, Hao; Jiang, Chenxiao; Qiu, Xuefeng; Wang, Kaikai; Huan, Wei; Yuan, Ahu; Wu, Jinhui; Hu, Yiqiao

    2015-01-01

    Photodynamic therapy (PDT) kills cancer cells by converting tumour oxygen into reactive singlet oxygen (1O2) using a photosensitizer. However, pre-existing hypoxia in tumours and oxygen consumption during PDT can result in an inadequate oxygen supply, which in turn hampers photodynamic efficacy. Here to overcome this problem, we create oxygen self-enriching photodynamic therapy (Oxy-PDT) by loading a photosensitizer into perfluorocarbon nanodroplets. Because of the higher oxygen capacity and longer 1O2 lifetime of perfluorocarbon, the photodynamic effect of the loaded photosensitizer is significantly enhanced, as demonstrated by the accelerated generation of 1O2 and elevated cytotoxicity. Following direct injection into tumours, in vivo studies reveal tumour growth inhibition in the Oxy-PDT-treated mice. In addition, a single-dose intravenous injection of Oxy-PDT into tumour-bearing mice significantly inhibits tumour growth, whereas traditional PDT has no effect. Oxy-PDT may enable the enhancement of existing clinical PDT and future PDT design. PMID:26525216

  15. Susceptibility weighted imaging of stroke brain in response to normobaric oxygen (NBO) therapy

    NASA Astrophysics Data System (ADS)

    Zhou, Iris Y.; Igarashi, Takahiro; Guo, Yingkun; Sun, Phillip Z.

    2015-03-01

    The neuroprotective effect of oxygen leads to recent interest in normobaric oxygen (NBO) therapy after acute ischemic stroke. However, the mechanism remains unclear and inconsistent outcomes were reported in human studies. Because NBO aims to improve brain tissue oxygenation by enhancing oxygen delivery to ischemic tissue, monitoring the oxygenation level changes in response to NBO becomes necessary to elucidate the mechanism and to assess the efficacy. Susceptibility weighted imaging (SWI) which provides a new MRI contrast by combining the magnitude and phase images is fit for purpose. SWI is sensitive to deoxyhemoglobin level changes and thus can be used to evaluate the cerebral metabolic rate of oxygen. In this study, SWI was used for in vivo monitoring of oxygenation changes in a rat model of permanent middle cerebral artery occlusion (MCAO) before, during and after 30 min of NBO treatment. Regions of interest in ischemic core, penumbra and contralateral normal area were generated based on diffusionweighted imaging and perfusion imaging. Significant differences in SWI indicating different oxygenation levels were generally found: contralateral normal > penumbra > ischemic core. Ischemic core showed insignificant increase in oxygenation during NBO and returned to pre-treatment level after termination of NBO. Meanwhile, the oxygenation levels slightly increased in contralateral normal and penumbra regions during NBO and significantly decreased to a level lower than pre-treatment after termination of NBO, indicating secondary metabolic disruption upon the termination of transient metabolic support from oxygen. Further investigation of NBO effect combined with reperfusion is necessary while SWI can be used to detect hemorrhagic transformation after reperfusion.

  16. Correlation of interactions between NOS3 polymorphisms and oxygen therapy with retinopathy of prematurity susceptibility

    PubMed Central

    Yu, Chunhong; Yi, Jinglin; Yin, Xiaolong; Deng, Yan; Liao, Yujun; Li, Xiaobing

    2015-01-01

    Aim: This study was aimed to detect the correlation of nitric oxide synthase 3 (NOS3) gene polymorphisms (T-786C and G894T) and retinopathy of prematurity (ROP) susceptibility. Interaction between NOS3 gene polymorphisms and the duration of oxygen therapy was also explored in ROP babies. Methods: Genotypes of NOS3 gene polymorphisms were genotyped by MassArray method. Hardy-Weinberg equilibrium (HWE) was used to calculate the representativeness of the cases and controls. Crossover analysis was utilized to explore the gene environment interactions. Relative risk of ROP was presented by odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs). Results: Among the subject features, oxygen therapy had obvious difference between case and control groups (P<0.05). There existed significant association between-786C allele and ROP susceptibility (P=0.049, OR=0.669, 95% CI=0.447-0.999). Genotypes of T-786C polymorphism and genotypes and alleles of G894T polymorphism did not related to the susceptibility of ROP. Interactions were existed between NOS3 gene polymorphisms and oxygen therapy duration. When the duration of oxygen therapy was less than 17 days, both -786CC genotype and 894GT genotype were correlated with ROP susceptibility (P=0.020, OR=0.115, 95% CI=0.014-0.960; P=0.011, OR=0.294, 95% CI=0.100-0.784). Conclusion: -786C allele might have a protective effect for ROP. Interactions of -786CC and 894GT genotype with oxygen therapy duration (less than 17 days) were both protection factors of ROP. PMID:26823875

  17. Highly efficient hierarchical micelles integrating photothermal therapy and singlet oxygen-synergized chemotherapy for cancer eradication.

    PubMed

    Wan, Zhihui; Mao, Huajian; Guo, Miao; Li, Yanli; Zhu, Aijun; Yang, Hong; He, Hui; Shen, Junkang; Zhou, Lijuan; Jiang, Zhen; Ge, Cuicui; Chen, Xiaoyuan; Yang, Xiangliang; Liu, Gang; Chen, Huabing

    2014-01-01

    It is highly desirable to develop theranostic nanoparticles for achieving cancer imaging with enhanced contrast and simultaneously multimodal synergistic therapy. Herein, we report a theranostic micelle system hierarchically assembling cyanine dye (indocyanine green) and chemotherapeutic compound (doxorubicin) (I/D-Micelles) as a novel theranostic platform with high drug loading, good stability and enhanced cellular uptake via clathrin-mediated endocytosis. I/D-Micelles exhibit the multiple functionalities including near-infrared fluorescence (NIRF), hyperthermia and intracellular singlet oxygen from indocyanine green, and simultaneous cytotoxicity from doxorubicin. Upon photoirradiation, I/D-Micelles can induce NIRF imaging, acute photothermal therapy via hyperthermia and simultaneous synergistic chemotherapy via singlet oxygen-triggered disruption of lysosomal membranes, eventually leading to enhanced NIRF imaging and superior tumor eradication without any re-growth. Our results suggest that the hierarchical micelles can act as a superior theranostic platform for cancer imaging and multimodal synergistic therapy.

  18. Dual Antiplatelet Therapy (DAPT) versus No Antiplatelet Therapy and Incidence of Major Bleeding in Patients on Venoarterial Extracorporeal Membrane Oxygenation

    PubMed Central

    Biever, Paul M.; Benk, Christoph; Ahrens, Ingo; Bode, Christoph; Wengenmayer, Tobias

    2016-01-01

    Aims Bleeding is a frequent complication in patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO). An indication for dual antiplatelet therapy due to coronary stent implantation is present in a considerable number of these patients. The objective of this retrospective study was to evaluate if dual antiplatelet therapy (DAPT) significantly increases the high intrinsic bleeding risk in patients on VA-ECMO. Methods and Results A total of 93 patients were treated with VA-ECMO between October 2010 and October 2013. Average time on VA-ECMO was 58.9 ± 1.7 hours. Dual antiplatelet therapy was given to 51.6% of all patients. Any bleeding was recorded in 60.2% of all patients. There was no difference in bleeding incidence in patients on DAPT when compared to those without any antiplatelet therapy including any bleeding (66.7% vs. 57.1%, p = 0.35), BARC3 bleeding (43.8% vs. 33.3%, p = 0.31) or pulmonary bleeding (16.7% vs. 19.0%, p = 0.77). This holds true after adjustment for confounders. Rate of transfusion of red blood cells were similar in patients with or without DAPT (35.4% vs. 28.6%, p = 0.488). Conclusions Bleeding on VA-ECMO is frequent. This registry recorded no statistical difference in bleeding in patients on dual antiplatelet therapy when compared to no antiplatelet therapy. When indicated, DAPT should not be withheld from VA ECMO patients. PMID:27467697

  19. Hyperbaric Oxygen Treatment at Various Stages following Chronic Constriction Injury Produces Different Antinociceptive Effects via Regulation of P2X4R Expression and Apoptosis

    PubMed Central

    Zhao, Bai-Song; Song, Xing-Rong; Hu, Pei-Ying; Meng, Ling-Xin; Tan, Yong-Hong; She, Ying-Jun; Ding, Yuan-Yuan

    2015-01-01

    Purpose The aims of this study were to investigate the effect of hyperbaric oxygen (HBO) treatment at various stages following chronic constriction injury (CCI) and to explore the underlying mechanisms of HBO treatment. Methods Forty adult male Sprague—Dawley rats were randomly assigned to five groups (n = 8 for each group): the sham group, CCI group, HBO1 group, HBO2 group, and HBO3 group. Neuropathic pain was induced by CCI of the sciatic nerve. HBO treatment began on postoperative days 1, 6, and 11 and continued for 5 days. The mechanical withdrawal threshold and thermal withdrawal latency were tested on preoperative day 3 and postoperative days 1, 3, 5, 7, 10, 14, and 21. The expression of P2X4R was determined by immunohistochemistry and western blot analysis. Cell apoptosis was measured using TUNEL staining. The expression of caspase 3 was measured using reverse transcription polymerase chain reaction (RT-PCR). Electron microscopy was used to determine the ultrastructural changes. Results Early HBO treatment beginning on postoperative day 1 produced a persistent antinociceptive effect and inhibited the CCI-induced increase in the expression of P2X4R without changing CCI-induced apoptosis. In contrast, late HBO treatment beginning on postoperative day 11 produced a persistent antinociceptive effect and inhibited CCI-induced apoptosis and upregulation of caspase-3 without changing the expression of P2X4R. In addition, late HBO treatment reduced CCI-induced ultrastructural damage. However, HBO treatment beginning on postoperative day 6 produced a transient antinociceptive effect without changing the expression of P2X4R or CCI-induced apoptosis. Conclusion HBO treatment at various stages following CCI can produce antinociceptive effects via different mechanisms. Early HBO treatment is associated with inhibition of P2X4R expression, and late HBO treatment is associated with inhibition of cell apoptosis. PMID:25789619

  20. Lifetime-resolved photoacoustic (LPA) spectroscopy for monitoring oxygen change and photodynamic therapy (PDT)

    NASA Astrophysics Data System (ADS)

    Jo, Janggun; Lee, Chang Heon; Kopelman, Raoul; Wang, Xueding

    2016-03-01

    The Methylene Blue loaded Polyacrylamide Nanoparticles (MB-PAA NPs) are used for oxygen sensing and Photodynamic therapy (PDT), a promising therapeutic modality employed for various tumors, with distinct advantages of delivery of biomedical agents and protection from other bio-molecules overcoming inherent limitations of molecular dyes. Lifetime-resolved photoacoustic spectroscopy using quenched-phosphorescence method is applied with MB-PAA NPs so as to sense oxygen, while the same light source is used for PDT. The dye is excited by absorbing 650 nm wavelength light from a pump laser to reach triplet state. The probe laser at 810 nm wavelength is used to excite the first triplet state at certain delayed time to measure the dye lifetime which indicates oxygen concentration. The 9L cells (106 cells/ml) incubated with MB-PAA NP solution are used for monitoring oxygen level change during PDT in situ test. The oxygen level and PDT efficacy are confirmed with a commercial oximeter, and fluorescence microscope imaging and flow cytometry results. This technique with the MB-PAA NPs allowed us to demonstrate a potential non-invasive theragnostic operation, by monitoring oxygen depletion during PDT in situ, without the addition of secondary probes. Here, we demonstrate this theragnostic operation, in vitro, performing PDT while monitoring oxygen depletion. We also show the correlation between O2 depletion and cell death.

  1. Conserved Molecular Interactions within the HBO1 Acetyltransferase Complexes Regulate Cell Proliferation

    PubMed Central

    Avvakumov, Nikita; Lalonde, Marie-Eve; Saksouk, Nehmé; Paquet, Eric; Glass, Karen C.; Landry, Anne-Julie; Doyon, Yannick; Cayrou, Christelle; Robitaille, Geneviève A.; Richard, Darren E.; Yang, Xiang-Jiao; Kutateladze, Tatiana G.

    2012-01-01

    Acetyltransferase complexes of the MYST family with distinct substrate specificities and functions maintain a conserved association with different ING tumor suppressor proteins. ING complexes containing the HBO1 acetylase are a major source of histone H3 and H4 acetylation in vivo and play critical roles in gene regulation and DNA replication. Here, our molecular dissection of HBO1/ING complexes unravels the protein domains required for their assembly and function. Multiple PHD finger domains present in different subunits bind the histone H3 N-terminal tail with a distinct specificity toward lysine 4 methylation status. We show that natively regulated association of the ING4/5 PHD domain with HBO1-JADE determines the growth inhibitory function of the complex, linked to its tumor suppressor activity. Functional genomic analyses indicate that the p53 pathway is a main target of the complex, at least in part through direct transcription regulation at the initiation site of p21/CDKN1A. These results demonstrate the importance of ING association with MYST acetyltransferases in controlling cell proliferation, a regulated link that accounts for the reported tumor suppressor activities of these complexes. PMID:22144582

  2. Effects of nocturnal oxygen therapy on heart function in SDB patients undergoing dialysis.

    PubMed

    Nakajima, Fumitaka; Furumatsu, Yoshiyuki; Yurugi, Takatomi; Amari, Yoshifumi; Iida, Takeshi; Uehara, Mitsuru; Fukunaga, Megumu

    2015-06-01

    There is a close relationship between sleep disordered breathing (SDB) and heart failure. We performed home oxygen therapy (HOT) in patients with SAS undergoing dialysis, and investigated its effects on the heart function. The subjects were 10 SDB patients on dialysis. On retiring at night, oxygen was transnasally administered at 1.0 L/min. The human atrial natriuretic peptide (hANP), brain natriuretic peptide (BNP), total protein, Alb, cholesterol and phosphorus levels were measured before the start of oxygen therapy and after 6 weeks. The mean SpO2 increased from 93.5% [91.5, 97.0] to 96.3% [94.8, 97.4] (median [interquartile range]) (p = 0.015). The hANP (p = 0.0039), BNP (p = 0.0098) and serum Alb (p = 0.015) levels significantly improved. There were no significant changes in the cholesterol, phosphorus or total protein levels. These results suggest that nocturnal oxygen therapy improves indices of heart failure, contributing to the prevention and treatment of heart failure in dialysis patients with SDB.

  3. Long-term results of continuous oxygen therapy at sea level.

    PubMed

    Stewart, B N; Hood, C I; Block, A J

    1975-10-01

    Twelve patients with hypoxemia associated with severe chronic obstructive pulmonary disease were treated with continuous portable oxygen therapy and have been followed up for a mean period of 25.2 months at sea level. Pulmonary function testing has revealed no further significant deterioration at long-term follow-up (17 months). After oxygen therapy was initiated, arterial carbon dioxide tension increased slightly, but decreased to pretreatment levels when patients were allowed to breathe room air. The electrocardiogram, which was unchanged at one month, has shown some reversal of cor pulmonale in five patients. Six patients have died, yielding a 56 percent survival rate at two-and-one-half years by the life table analysis. Five patients were autopsied, with possible oxygen toxicity being present in only one. The quality of life in our patients was improved and was especially represented by a reduction in hospital admissions for respiratory illness. We believe that continuous oxygen therapy is beneficial and worthwhile economically in certain patients.

  4. Determinants of Oxygen Therapy in Childhood Pneumonia in a Resource-Constrained Region

    PubMed Central

    Kuti, Bankole Peter; Adegoke, Samuel Ademola; Ebruke, Benard E.; Howie, Stephen; Oyelami, Oyeku Akibu; Ota, Martin

    2013-01-01

    Childhood pneumonia is a leading cause of morbidity and mortality among underfives particularly in the resource-constraint part of the world. A high proportion of these deaths are due to lack of oxygen, thereby making oxygen administration a life-saving adjunctive when indicated. However, many primary health centres that manage most of the cases often lack the adequate manpower and facilities to decide which patient should be on oxygen therapy. Therefore, this study aimed to determine factors that predict hypoxaemia at presentation in children with severe pneumonia. Four hundred and twenty children aged from 2 to 59 months (40% infants) with severe pneumonia admitted to a health centre in rural Gambia were assessed at presentation. Eighty-one of them (19.30%) had hypoxaemia (oxygen saturation < 90%). Children aged 2–11 months, with grunting respiration, cyanosis, and head nodding, and those with cardiomegaly on chest radiograph were at higher risk of hypoxaemia (P < 0.05). Grunting respiration (OR = 5.210, 95% CI 2.287–7.482) and cyanosis (OR = 83.200, 95% CI 5.248–355.111) were independent predictors of hypoxaemia in childhood pneumonia. We conclude that children that grunt and are centrally cyanosed should be preferentially commenced on oxygen therapy even when there is no facility to confirm hypoxaemia. PMID:23819060

  5. Oxygen transport by hemoglobin.

    PubMed

    Mairbäurl, Heimo; Weber, Roy E

    2012-04-01

    Hemoglobin (Hb) constitutes a vital link between ambient O2 availability and aerobic metabolism by transporting oxygen (O2) from the respiratory surfaces of the lungs or gills to the O2-consuming tissues. The amount of O2 available to tissues depends on the blood-perfusion rate, as well as the arterio-venous difference in blood O2 contents, which is determined by the respective loading and unloading O2 tensions and Hb-O2-affinity. Short-term adjustments in tissue oxygen delivery in response to decreased O2 supply or increased O2 demand (under exercise, hypoxia at high altitude, cardiovascular disease, and ischemia) are mediated by metabolically induced changes in the red cell levels of allosteric effectors such as protons (H(+)), carbon dioxide (CO2), organic phosphates, and chloride (Cl(-)) that modulate Hb-O2 affinity. The long-term, genetically coded adaptations in oxygen transport encountered in animals that permanently are subjected to low environmental O2 tensions commonly result from changes in the molecular structure of Hb, notably amino acid exchanges that alter Hb's intrinsic O2 affinity or its sensitivity to allosteric effectors. Structure-function studies of animal Hbs and human Hb mutants illustrate the different strategies for adjusting Hb-O2 affinity and optimizing tissue oxygen supply.

  6. Towards photodynamic therapy with ionizing radiation: nanoparticle-mediated singlet oxygen generation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian; Goldys, Ewa

    2016-03-01

    Photodynamic therapy (PDT) is a clinically approved method for the treatment of cancer by using singlet oxygen, a highly reactive oxygen generated from a photosensitizer drug upon photoactivation. Limited light penetration depth into to the tissue means that PDT is unsuitable for deep tissue cancer treatments. This can be overcome by using X-ray /gamma rays activated nanoparticles able to trigger the photosensitizer drug and generate singlet oxygen. Additionally, inorganic nanoparticles interact more strongly with X and/or gamma rays than the tissue, allowing to concentrate the effects of radiation near nanoparticle surface and they can also be molecularly targeted to cancer cells. In this work we synthesized and characterized CeF3 nanoparticles, a well-known scintillator material. The nanoparticles were conjugated with Verteporfin, a photosensitizer drug by electrostatic interaction. We assessed the performance of CeF3 and the conjugates to generate singlet oxygen exposed to X-ray radiation. The X-ray singlet oxygen quantum yield of the nanoparticle-photosensitizer system was accurately quantified for the first time. This provided realistic estimates of the singlet oxygen dose taking into consideration the dose partition of the radiation between CeF3 and the tissue. Furthermore, we investigated gold nanoparticle-photosensitizer systems. We confirmed that pure gold nanoparticles itself generate singlet oxygen which is attributed to plasmonic effects. We found enhanced singlet oxygen generation from gold-Rose Bengal conjugates and gold nanorod-verteporfin conjugates. These singlet-oxygen-generating nanomaterials add a new dimension to radiation-assisted PDT.

  7. Delayed onset of acute limb compartment syndrome with neuropathy after venoarterial extracorporeal membrane oxygenation therapy.

    PubMed

    Go, Jin Young; Min, Yu-Sun; Jung, Tae-Du

    2014-08-01

    Acute limb compartment syndrome (ALCS) is defined as compound symptoms resulting from poor oxygenation and decreased nutrition supply to muscles and nerves in a tightly confined compartment. The most common cause of ALCS is tibia fracture, followed by blunt trauma to soft tissue. However, non-traumatic causes are rare. We report an iatrogenic, non-traumatic ALCS case after venoarterial extracorporeal membrane oxygen (VA-ECMO) therapy. A 14-year-old male received VA-ECMO therapy due to cardiorespiratory failure after drowning. Although he had no symptoms during therapy, leg swelling appeared 10 hours after ECMO treatment. Two days after the leg swelling, the patient underwent a fasciotomy. Unfortunately, nerve conduction studies and electromyography showed multiple neuropathies in the lower leg. Despite 2 weeks of rehabilitation with electrical stimulation, an exercise program, and physical therapy, there was no definite change in muscle strength. To our knowledge, this is the first reported case of non-traumatic ALCS after VA-ECMO therapy in Korea.

  8. Hyperbaric oxygen therapy as an effective adjunctive treatment for chronic Lyme disease.

    PubMed

    Huang, Chien-Yu; Chen, Yen-Wen; Kao, Tseng-Hui; Kao, Hsin-Kuo; Lee, Yu-Chin; Cheng, Jui-Chun; Wang, Jia-Horng

    2014-05-01

    Lyme disease is the most commonly reported vector-borne illness in the United States, but it is relatively rare in Taiwan. Lyme disease can be treated with antibiotic agents, but approximately 20% of these patients experience persistent or intermittent subjective symptoms, so-called chronic Lyme disease (CLD). The mechanisms of CLD remain unclear and the symptoms related to CLD are difficult to manage. Hyperbaric oxygen therapy (HBOT) was applied in CLD therapy in the 1990s. However, reported information regarding the effectiveness of HBOT for CLD is still limited. Here, we present a patient with CLD who was successfully treated with HBOT.

  9. Hyperbaric oxygen therapy as an effective adjunctive treatment for chronic Lyme disease.

    PubMed

    Huang, Chien-Yu; Chen, Yen-Wen; Kao, Tseng-Hui; Kao, Hsin-Kuo; Lee, Yu-Chin; Cheng, Jui-Chun; Wang, Jia-Horng

    2014-05-01

    Lyme disease is the most commonly reported vector-borne illness in the United States, but it is relatively rare in Taiwan. Lyme disease can be treated with antibiotic agents, but approximately 20% of these patients experience persistent or intermittent subjective symptoms, so-called chronic Lyme disease (CLD). The mechanisms of CLD remain unclear and the symptoms related to CLD are difficult to manage. Hyperbaric oxygen therapy (HBOT) was applied in CLD therapy in the 1990s. However, reported information regarding the effectiveness of HBOT for CLD is still limited. Here, we present a patient with CLD who was successfully treated with HBOT. PMID:24726678

  10. Utilization of Hyperbaric Oxygen Therapy and Induced Hypothermia After Hydrogen Sulfide Exposure

    PubMed Central

    Asif, Mir J.; Exline, Matthew C.

    2013-01-01

    Hydrogen sulfide is a toxic gas produced as a byproduct of organic waste and many industrial processes. Hydrogen sulfide exposure symptoms may vary from mild (dizziness, headaches, nausea) to severe lactic acidosis via its inhibition of oxidative phosphorylation, leading to cardiac arrhythmias and death. Treatment is generally supportive. We report the case of a patient presenting with cardiac arrest secondary to hydrogen sulfide exposure treated with both hyperbaric oxygen therapy and therapeutic hypothermia with great improvement in neurologic function. PMID:22004989

  11. Direct Photocontrol of Peptidomimetics: An Alternative to Oxygen-Dependent Photodynamic Cancer Therapy.

    PubMed

    Babii, Oleg; Afonin, Sergii; Garmanchuk, Liudmyla V; Nikulina, Viktoria V; Nikolaienko, Tetiana V; Storozhuk, Olha V; Shelest, Dmytro V; Dasyukevich, Olga I; Ostapchenko, Liudmyla I; Iurchenko, Volodymyr; Zozulya, Sergey; Ulrich, Anne S; Komarov, Igor V

    2016-04-25

    Conventional photodynamic treatment strategies are based on the principle of activating molecular oxygen in situ by light, mediated by a photosensitizer, which leads to the generation of reactive oxygen species and thereby causes cell death. A diarylethene-derived peptidomimetic is presented that is suitable for photodynamic cancer therapy without any involvement of oxygen. This light-sensitive molecule is not a mediator but is itself the cytotoxic agent. As a derivative of the cyclic amphiphilic peptide gramicidin S, the peptidomimetic exists in two thermally stable photoforms that are interconvertible by light of different wavelengths. The isomer generated by visible light shows much stronger toxicity against tumor cells than the UV-generated isomer. First in vivo applications are demonstrated on a tumor animal model to illustrate how the peptidomimetic can be administered in the less toxic form and then activated locally in a solid tumor by visible light.

  12. Light-oxygen effect in cells and its potential applications in tumour therapy (review)

    SciTech Connect

    Zakharov, S D; Ivanov, Andrei V

    1999-12-31

    The light-oxygen effect (POE) represents damage (and at low optical doses, activation) of cells by photogeneration of molecular singlet oxygen from O{sub 2} dissolved in cells, in accordance with the reaction: {sup 3}O{sub 2}+h{nu}{yields}{sup 1}O{sub 2}{yields} biological effect. The phases of evolution of the LOE are similar to the phases, observed in cell experiments, of the photodynamic effect (PDE) the mechanism of which is the basis of the familiar method of photodynamic cancer therapy. The reported proofs of the occurrence of the LOE are in the form of detailed spectra of the biological action of optical radiation on cells recorded in four spectral intervals with the aid of tunable lasers. Allowances are made for the relationships governing a new type of cell excitation, associated with reversible structural transitions in the biomembrane. A demonstration is reported of the same efficiency of cw and pulsed irradiation. An analysis is made of the reasons why the optical doses initiating the PDE and the LOE are comparable. The results are given of the first experimental applications of the LOE in tumour therapy. Identification of the primary photoacceptor (O{sub 2}) in cell biostimulation and photodestruction provides a scientific basis for the development of low-intensity laser light-oxygen cancer therapy methods. (lasers in medicine)

  13. The effects of topical oxygen therapy on equine distal limb dermal wound healing.

    PubMed

    Tracey, Alexandra K; Alcott, Cody J; Schleining, Jennifer A; Safayi, Sina; Zaback, Peter C; Hostetter, Jesse M; Reinertson, Eric L

    2014-12-01

    Topical oxygen therapy (TOT) has been used in human medicine to promote healing in chronic wounds. To test the efficacy and safety of TOT in horses, an experimental wound model was created by making 1 standardized dermal wound on each limb of 4 healthy horses (n = 16). Each wound was fitted with an oxygen delivery cannula and covered with a bandage. One limb of each front and hind pair was randomly assigned to the treatment group (fitted with an oxygen concentrator device), with the contralateral limb assigned to the control group (no device). Wound area, epithelial area, and contraction were measured every 3 to 4 d. Biopsy samples and culture swabs were taken on days 16 and 32 to evaluate angiogenesis, fibroplasia, epithelial hyperplasia, inflammation and bacterial growth. Mean healing time in treated wounds (45 d, range: 38 to 52 d) was not significantly different from that in the paired control wounds (50 d, range: 38 to 62 d). Topical oxygen therapy had little effect on dermal wound healing in this experimental wound model in healthy horses.

  14. The effects of topical oxygen therapy on equine distal limb dermal wound healing

    PubMed Central

    Tracey, Alexandra K.; Alcott, Cody J.; Schleining, Jennifer A.; Safayi, Sina; Zaback, Peter C.; Hostetter, Jesse M.; Reinertson, Eric L.

    2014-01-01

    Topical oxygen therapy (TOT) has been used in human medicine to promote healing in chronic wounds. To test the efficacy and safety of TOT in horses, an experimental wound model was created by making 1 standardized dermal wound on each limb of 4 healthy horses (n = 16). Each wound was fitted with an oxygen delivery cannula and covered with a bandage. One limb of each front and hind pair was randomly assigned to the treatment group (fitted with an oxygen concentrator device), with the contralateral limb assigned to the control group (no device). Wound area, epithelial area, and contraction were measured every 3 to 4 d. Biopsy samples and culture swabs were taken on days 16 and 32 to evaluate angiogenesis, fibroplasia, epithelial hyperplasia, inflammation and bacterial growth. Mean healing time in treated wounds (45 d, range: 38 to 52 d) was not significantly different from that in the paired control wounds (50 d, range: 38 to 62 d). Topical oxygen therapy had little effect on dermal wound healing in this experimental wound model in healthy horses. PMID:25477541

  15. Localized increase of tissue oxygen tension by magnetic targeted drug delivery

    NASA Astrophysics Data System (ADS)

    Liong, Celine; Ortiz, Daniel; Ao-ieong, Eilleen; Navati, Mahantesh S.; Friedman, Joel M.; Cabrales, Pedro

    2014-07-01

    Hypoxia is the major hindrance to successful radiation therapy of tumors. Attempts to increase the oxygen (O2) tension (PO2) of tissue by delivering more O2 have been clinically disappointing, largely due to the way O2 is transported and released by the hemoglobin (Hb) within the red blood cells (RBCs). Systemic manipulation of O2 transport increases vascular resistance due to metabolic autoregulation of blood flow to prevent over oxygenation. This study investigates a new technology to increase O2 delivery to a target tissue by decreasing the Hb-O2 affinity of the blood circulating within the targeted tissue. As the Hb-O2 affinity decreases, the tissue PO2 to satisfy tissue O2 metabolic needs increases without increasing O2 delivery or extraction. Paramagnetic nanoparticles (PMNPs), synthetized using gadolinium oxide, were coated with the cell permeable Hb allosteric effector L35 (3,5-trichlorophenylureido-phenoxy-methylpropionic acid). L35 decreases Hb affinity for O2 and favors the release of O2. The L35-coated PMNPs (L35-PMNPs) were intravenously infused (10 mg kg-1) to hamsters instrumented with the dorsal window chamber model. A magnetic field of 3 mT was applied to localize the effects of the L35-PMNPs to the window chamber. Systemic O2 transport characteristics and microvascular tissue oxygenation were measured after administration of L35-PMNPs with and without magnetic field. The tissue PO2 in untreated control animals was 25.2 mmHg. L35-PMNPs without magnetic field decreased tissue PO2 to 23.4 mmHg, increased blood pressure, and reduced blood flow, largely due to systemic modification of Hb-O2 affinity. L35-PMNPs with magnetic field increased tissue PO2 to 27.9 mmHg, without systemic or microhemodynamic changes. These results indicate that localized modification of Hb-O2 affinity can increase PO2 of target tissue without affecting systemic O2 delivery or triggering O2 autoregulation mechanisms. This technology can be used to treat local hypoxia and to

  16. Hyperbaric oxygen preconditioning protects rats against CNS oxygen toxicity.

    PubMed

    Arieli, Yehuda; Kotler, Doron; Eynan, Mirit; Hochman, Ayala

    2014-06-15

    We examined the hypothesis that repeated exposure to non-convulsive hyperbaric oxygen (HBO) as preconditioning provides protection against central nervous system oxygen toxicity (CNS-OT). Four groups of rats were used in the study. Rats in the control and the negative control (Ctl-) groups were kept in normobaric air. Two groups of rats were preconditioned to non-convulsive HBO at 202 kPa for 1h once every other day for a total of three sessions. Twenty-four hours after preconditioning, one of the preconditioned groups and the control rats were exposed to convulsive HBO at 608 kPa, and latency to CNS-OT was measured. Ctl- rats and the second preconditioned group (PrC-) were not subjected to convulsive HBO exposure. Tissues harvested from the hippocampus and frontal cortex were evaluated for enzymatic activity and nitrotyrosine levels. In the group exposed to convulsive oxygen at 608 kPa, latency to CNS-OT increased from 12.8 to 22.4 min following preconditioning. A significant decrease in the activity of glutathione reductase and glucose-6-phosphate dehydrogenase, and a significant increase in glutathione peroxidase activity, was observed in the hippocampus of preconditioned rats. Nitrotyrosine levels were significantly lower in the preconditioned animals, the highest level being observed in the control rats. In the cortex of the preconditioned rats, a significant increase was observed in glutathione S-transferase and glutathione peroxidase activity. Repeated exposure to non-convulsive HBO provides protection against CNS-OT. The protective mechanism involves alterations in the enzymatic activity of the antioxidant system and lower levels of peroxynitrite, mainly in the hippocampus.

  17. [The morphofunctional changes in the ventricular myocardium in experimental infarct and its treatment by hyperbaric oxygenation and tocopherol acetate].

    PubMed

    Netliukh, M A; Kovalyshyn, V I; Dmytriv, H M

    1995-01-01

    Experimental myocardial infarction was induced in 50 rabbits, 25 of which were subjected to hyperbaric oxygenation (HBO) used as a single procedure or in combination with the antioxidant tocopheroli acetas. HBO was found to promote reduction of the myocardial lesion focus and enhancement of the regeneration processes but in everyday employment over long periods of time it causes dystrophic changes in the remote zones of the myocardium. Administration of tocopheroli acetas before the HBO sessions allows the toxic action of oxygen to be safely prevented.

  18. Hyperbaric oxygen therapy for carcinoma of the cervix - Stages IIB, IIIA, IIIB, and IVA: results of a randomized study by the radiation therapy oncology group

    SciTech Connect

    Brady, L.W.; Plenk,H.P.; Hanley, J.A.

    1981-08-01

    A total of 65 patients with Stage IIB, IIIA, IIIB or IVA carcinoma of the cervix were randomized to receive conventional radiation therapy in air or hyperbaric oxygen therapy with radiation at optimal schedules. Seven patients could not be evaluated. Of the 19 patients treated in oxygen, 14 (73%) were living or had died without evidence of disease. Of the 29 patients treated with radiation alone 15 (52%) were alive or had died without evidence of tumor. Two of 29 patients treated in air and 5 of 19 patients treated in oxygen were dead of complications or intercurrent disease. No significant difference in survival could be demonstrated.

  19. Controlled Evaluation of the Effects of Hyperbaric Oxygen Therapy on the Behavior of 16 Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Jepson, Bryan; Granpeesheh, Doreen; Tarbox, Jonathan; Olive, Melissa L.; Stott, Carol; Braud, Scott; Yoo, J. Helen; Wakefield, Andrew; Allen, Michael S.

    2011-01-01

    Hyperbaric oxygen therapy (HBOT) has been used to treat individuals with autism. However, few studies of its effectiveness have been completed. The current study examined the effects of 40 HBOT sessions at 24% oxygen at 1.3 ATA on 11 topographies of directly observed behavior. Five replications of multiple baselines were completed across a total…

  20. Coupling between intrinsic prefrontal HbO2 and central EEG beta power oscillations in the resting brain.

    PubMed

    Pfurtscheller, Gert; Daly, Ian; Bauernfeind, Günther; Müller-Putz, Gernot R

    2012-01-01

    There is increasing interest in the intrinsic activity in the resting brain, especially that of ultraslow and slow oscillations. Using near-infrared spectroscopy (NIRS), electroencephalography (EEG), blood pressure (BP), respiration and heart rate recordings during 5 minutes of rest, combined with cross spectral and sliding cross correlation calculations, we identified a short-lasting coupling (duration [Formula: see text] s) between prefrontal oxyhemoglobin (HbO2) in the frequency band between 0.07 and 0.13 Hz and central EEG alpha and/or beta power oscillations in 8 of the 9 subjects investigated. The HbO2 peaks preceded the EEG band power peaks by 3.7 s in 6 subjects, with moderate or no coupling between BP and HbO2 oscillations. HbO2 and EEG band power oscillations were approximately in phase with BP oscillations in the 2 subjects with an extremely high coupling (squared coherence [Formula: see text]) between BP and HbO2 oscillation. No coupling was identified in one subject. These results indicate that slow precentral (de)oxyhemoglobin concentration oscillations during awake rest can be temporarily coupled with EEG fluctuations in sensorimotor areas and modulate the excitability level in the brains' motor areas, respectively. Therefore, this provides support for the idea that resting state networks fluctuate with frequencies of between 0.01 and 0.1 Hz (Mantini et.al. PNAS 2007).

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

    PubMed

    ElMoaqet, Hisham; Tilbury, Dawn M; Ramachandran, Satya Krishna

    2015-08-01

    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

  2. Modeling of oxygen transport and cell killing in type-II photodynamic therapy.

    PubMed

    Gkigkitzis, Ioannis; Feng, Yuanming; Yang, Chunmei; Lu, Jun Q; Hu, Xin-Hua

    2012-01-01

    Photodynamic therapy (PDT) provides an effective option for treatment of tumors and other diseases in superficial tissues and attracts attention for in vitro study with cells. In this study, we present a significantly improved model of in vitro cell killing through Type-II PDT for simulation of the molecular interactions and cell killing in time domain in the presence of oxygen transport within a spherical cell. The self-consistency of the approach is examined by determination of conditions for obtaining positive definitive solutions of molecular concentrations. Decay constants of photosensitizers and unoxidized receptors are extracted as the key indices of molecular kinetics with different oxygen diffusion constants and permeability at the cell membrane. By coupling the molecular kinetics to cell killing, we develop a modeling method of PDT cytotoxicity caused by singlet oxygen and obtain the cell survival ratio as a function of light fluence or initial photosensitizer concentration with different photon density or irradiance of incident light and other parameters of oxygen transport. The results show that the present model of Type-II PDT yields a powerful tool to quantitate various events underlying PDT at the molecular and cellular levels and to interpret experimental results of in vitro cell studies.

  3. Protection mechanism of early hyperbaric oxygen therapy in rats with permanent cerebral ischemia.

    PubMed

    Yu, Min; Xue, Yixue; Liang, Weidi; Zhang, Yupeng; Zhang, Zhiqiang

    2015-10-01

    [Purpose] The purpose of this study was to investigate whether early hyperbaric oxygen is useful in rats with permanent cerebral ischemia, and whether its mechanism relates to the inhibition of the tumor necrosis factor-alpha-protein kinase C-alpha pathway. [Subjects] Healthy, male Sprague-Dawley rats (N = 108) were the subjects. [Methods] After middle cerebral artery occlusion models were successfully made, rats were randomly divided into sham-operated, cerebral ischemia, and hyperbaric oxygen groups. At 4 and 12 hours after modeling, the volume of cerebral infarction was determined by triphenyltetrazolium chloride staining, and brain water content was measured using the dry and wet method. The expression of tumor necrosis factor-alpha and protein kinase C-alpha in the ischemic penumbra tissue was measured using Western blot analysis. [Results] The data showed that at 4 and 12 hours after modeling, cerebral infarct volume and brain water content decreased in the hyperbaric oxygen group, and expression of tumor necrosis factor-alpha and phospho-protein kinase C-alpha in the ischemic penumbra tissue also decreased. [Conclusion] Our study demonstrates that early hyperbaric oxygen therapy has protective effects on brain tissue after cerebral ischemia, possibly via inhibition of tumor necrosis factor-alpha and phospho-protein kinase C-alpha.

  4. Applications of Nasal High-Flow Oxygen Therapy in Critically ill Adult Patients.

    PubMed

    Porhomayon, Jahan; El-Solh, Ali A; Pourafkari, Leili; Jaoude, Philippe; Nader, Nader D

    2016-10-01

    The use of nasal high-flow oxygen therapy (NHFOT) has become increasingly common in hospitals across Europe, Asia, and North America. These high utility devices provide an efficient and comfortable access points for providing supplemental oxygen to patients with variety of respiratory disorders. They are relatively easy to set up, and clinicians and patients alike give very positive feedback about their ease of use and comfort for patients in the hospital setting. However, it remains uncertain whether NHFOT improves patient survival or even reduces respiratory complications. Outcome data in adult populations are few and frequently underpowered to guide physicians for their widespread use in hospital setting. In this article, we present a review of the current technology and available studies pertinent to NHFOT. PMID:27142658

  5. Successful Treatment of Lower Limb Complex Regional Pain Syndrome following Three Weeks of Hyperbaric Oxygen Therapy.

    PubMed

    Katznelson, Rita; Segal, Shira C; Clarke, Hance

    2016-01-01

    Hyperbaric oxygen therapy (HBOT) is a treatment that delivers 100% oxygen at increased atmospheric pressures. The efficacy of HBOT for treating pain has been described in various animal pain models and may have clinical efficacy in the treatment of human chronic pain syndromes. We present our experience with posttraumatic Complex Regional Pain Syndrome (CRPS) type 2 in a patient who underwent 15 sessions of HBOT. A 41-year-old male with one-year history of CRPS of left foot followed by left ankle fracture demonstrated less pain, decreased swelling, less allodynia, and improvement in skin color and range of motion of the lower limb after 3 weeks of HBOT. Patient was back to work for the first time in over a year. HBOT may be considered as a valuable therapeutic tool in the treatment of long-standing CRPS. PMID:27445607

  6. Analysis of photochemical oxygen consumption effects in photodynamic therapy (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Foster, Thomas H.; Gibson, Scott L.; Gao, Yongli; Hilf, Russell

    1992-06-01

    Type II photo-oxidation depends on and consumes oxygen. Several factors, including the concentration of photosensitizer and the radiation fluence rate, determine the rate of oxygen consumption in tissue undergoing Photodynamic Therapy. If the tissue capillary density is sparse, as it is in many human tumors, our calculations indicate that for cells sufficiently distant from the nearest capillary, fluence rates commonly used in PDT (50 - 200 mW/cm2) deplete 3O2 levels below those necessary for 1O2 formation. The calculations suggest that under these conditions reduced fluence rates and radiation dose fractionation should be more effective than continuous radiation at high fluence rates in producing 1O2 throughout the treated tissue volume. These predictions are supported by results obtained in vivo. The data and their interpretation have implications for PDT dosimetry and offer the possibility of improved therapeutic ratio.

  7. Applications of Nasal High-Flow Oxygen Therapy in Critically ill Adult Patients.

    PubMed

    Porhomayon, Jahan; El-Solh, Ali A; Pourafkari, Leili; Jaoude, Philippe; Nader, Nader D

    2016-10-01

    The use of nasal high-flow oxygen therapy (NHFOT) has become increasingly common in hospitals across Europe, Asia, and North America. These high utility devices provide an efficient and comfortable access points for providing supplemental oxygen to patients with variety of respiratory disorders. They are relatively easy to set up, and clinicians and patients alike give very positive feedback about their ease of use and comfort for patients in the hospital setting. However, it remains uncertain whether NHFOT improves patient survival or even reduces respiratory complications. Outcome data in adult populations are few and frequently underpowered to guide physicians for their widespread use in hospital setting. In this article, we present a review of the current technology and available studies pertinent to NHFOT.

  8. Successful Treatment of Lower Limb Complex Regional Pain Syndrome following Three Weeks of Hyperbaric Oxygen Therapy

    PubMed Central

    Katznelson, Rita; Segal, Shira C.; Clarke, Hance

    2016-01-01

    Hyperbaric oxygen therapy (HBOT) is a treatment that delivers 100% oxygen at increased atmospheric pressures. The efficacy of HBOT for treating pain has been described in various animal pain models and may have clinical efficacy in the treatment of human chronic pain syndromes. We present our experience with posttraumatic Complex Regional Pain Syndrome (CRPS) type 2 in a patient who underwent 15 sessions of HBOT. A 41-year-old male with one-year history of CRPS of left foot followed by left ankle fracture demonstrated less pain, decreased swelling, less allodynia, and improvement in skin color and range of motion of the lower limb after 3 weeks of HBOT. Patient was back to work for the first time in over a year. HBOT may be considered as a valuable therapeutic tool in the treatment of long-standing CRPS. PMID:27445607

  9. Changes in autophagy in rats after spinal cord injury and the effect of hyperbaric oxygen on autophagy.

    PubMed

    Sun, Yongming; Liu, Dong; Su, Peng; Lin, Fanguo; Tang, Qifeng

    2016-04-01

    The purpose of this study was to explore the effects of Hyperbaric oxygen (HBO) on the autophagic changes after induction of spinal cord injury (SCI) in rats. A total of 75 rats were randomly divided into the sham-operated group, the spinal cord injury group, and the SCI+HBO group. We found that at 7 d and 14 d after surgery, the BBB scores were higher in the SCI+HBO group in comparison to the SCI group. The expression of Beclin-1 and LC3II was upregulated in the SCI and SCI+HBO groups after SCI. Fluorescently stained Beclin-1 and LC3II proteins were barely detectable in the sham group. In contrast, Beclin-l and LC3II expression was observed in neurons and glial cells from the SCI and SCI+HBO groups. Beclin-1 and LC3II expression appeared at 6h after SCI. At each time point, Beclin-1 and LC3II expression was significantly higher in the SCI+HBO group compared to the SCI group. These results suggest that autophagy is activated in rats after SCI and sustained over a period of time. HBO treatment enhances autophagy expression in rats after SCI and accelerates cell repair rate, which may represent one of the mechanisms of action of HBO in the treatment of SCI.

  10. A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation

    PubMed Central

    Ge, Jiechao; Lan, Minhuan; Zhou, Bingjiang; Liu, Weimin; Guo, Liang; Wang, Hui; Jia, Qingyan; Niu, Guangle; Huang, Xing; Zhou, Hangyue; Meng, Xiangmin; Wang, Pengfei; Lee, Chun-Sing; Zhang, Wenjun; Han, Xiaodong

    2014-01-01

    Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen (1O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce 1O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of 1O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility. PMID:25105845

  11. Online Hemoglobin and Oxygen Saturation Sensing During Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation.

    PubMed

    Yessayan, Lenar T; Yee, Jerry; Frinak, Stan; Szamosfalvi, Balazs

    2015-01-01

    Optical hemoglobin and oxygen saturation sensor (OHOS) monitor when used in combination with other hemodynamic tools may be useful for continuous hemodynamic monitoring during ultrafiltration. The stand-alone OHOS monitor can easily be deployed predialyzer into the extracorporeal circuit of continuous renal replacement therapy (CRRT) systems. To maximize the accuracy of the OHOS in 24 hr CRRT systems, clotting in the optical blood chamber and the presensor dilution incurred by replacement fluid should be minimized. Sustained low-efficiency dialysis (SLED) with regional citrate anticoagulation is a therapy that incorporates an OHOS and maintains the overall reliability of hemoglobin (Hb) and saturation sensing. The system operates at a blood flow rate of 60 ml/min and a fixed acid citrate infusion rate of 150 ml/hr. The presensor dilution incurred by concentrated citrate infusion would result in a minimal Hb dilution (<0.7 g/dl) while minimizing optical blood chamber clotting during 24 hr SLED.

  12. A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation.

    PubMed

    Ge, Jiechao; Lan, Minhuan; Zhou, Bingjiang; Liu, Weimin; Guo, Liang; Wang, Hui; Jia, Qingyan; Niu, Guangle; Huang, Xing; Zhou, Hangyue; Meng, Xiangmin; Wang, Pengfei; Lee, Chun-Sing; Zhang, Wenjun; Han, Xiaodong

    2014-01-01

    Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen ((1)O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce (1)O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of (1)O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility.

  13. Reactive oxygen species-responsive protein modification and its intracellular delivery for targeted cancer therapy.

    PubMed

    Wang, Ming; Sun, Shuo; Neufeld, Caleb I; Perez-Ramirez, Bernardo; Xu, Qiaobing

    2014-12-01

    Herein we report a convenient chemical approach to reversibly modulate protein (RNase A) function and develop a protein that is responsive to reactive oxygen species (ROS) for targeted cancer therapy. The conjugation of RNase A with 4-nitrophenyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) benzyl carbonate (NBC) blocks protein lysine and temporarily deactivates the protein. However, the treatment of RNase A-NBC with hydrogen peroxide (one major intracellular ROS) efficiently cleaves the NBC conjugation and restores the RNase A activity. Thus, RNase A-NBC can be reactivated inside tumor cells by high levels of intracellular ROS, thereby restoring the cytotoxicity of RNase A for cancer therapy. Due to higher ROS levels inside tumor cells compared to healthy cells, and the resulting different levels of RNase A-NBC reactivation, RNase A-NBC shows a significant specific cytotoxicity against tumor cells.

  14. A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation

    NASA Astrophysics Data System (ADS)

    Ge, Jiechao; Lan, Minhuan; Zhou, Bingjiang; Liu, Weimin; Guo, Liang; Wang, Hui; Jia, Qingyan; Niu, Guangle; Huang, Xing; Zhou, Hangyue; Meng, Xiangmin; Wang, Pengfei; Lee, Chun-Sing; Zhang, Wenjun; Han, Xiaodong

    2014-08-01

    Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen (1O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce 1O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of 1O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility.

  15. A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation.

    PubMed

    Ge, Jiechao; Lan, Minhuan; Zhou, Bingjiang; Liu, Weimin; Guo, Liang; Wang, Hui; Jia, Qingyan; Niu, Guangle; Huang, Xing; Zhou, Hangyue; Meng, Xiangmin; Wang, Pengfei; Lee, Chun-Sing; Zhang, Wenjun; Han, Xiaodong

    2014-01-01

    Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen ((1)O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce (1)O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of (1)O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility. PMID:25105845

  16. Hyperbaric oxygen therapy in tinnitus with normal hearing in association with combined treatment.

    PubMed

    Holy, Richard; Prazenica, Pavol; Stolarikova, Eva; Dosel, Petr; Fundova, Petra; Kovar, Daniel; Astl, Jaromir

    2016-01-01

    Tinnitus is a phantom perception of sound in the absence of overt acoustic stimulation. The focus of our attention is a combined therapy of tinnitus. In this prospective study (2013-2014) we evaluated the data of normal-hearing patients with tinnitus treated with various treatment modalities. In Group 1 we evaluated the data of 84 patients/124 ears after six weeks of treatment with betahistine dihydrochloride (72 mg). In Group 2, we evaluated the data of 36 patients/ 55 ears unimproved from Group 1 who were then treated for six weeks with hyperbaric oxygen (HBO₂) therapy combined with gingko biloba extract (120 mg). In Group 1, tinnitus disappeared in 9.7%, alleviated in 18.5% and improved overall in 28.2%. Average intensity of tinnitus before/after treatment was 37 decibels (dB)/33 dB. Tinnitus intensities after treatment are statistically significantly lower (p = 0.001) than the values before treatment. In Group 2 tinnitus disappeared in 5.4%, 36.4% achieved alleviation, and 41.8% showed overall improvement. The average intensity of tinnitus before/after treatment was 41dB/ 38dB. The values of tinnitus intensity after combined therapy are statistically significantly lower (p = 0.046). We have shown that both methods treatment of tinnitus are statistically significant. HBO₂therapy was recommended for the general public. PMID:27416687

  17. Investigating the impact of oxygen concentration and blood flow variation on photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Penjweini, Rozhin; Kim, Michele M.; Finlay, Jarod C.; Zhu, Timothy C.

    2016-03-01

    Type II photodynamic therapy (PDT) is used for cancer treatment based on the combined action of a photosensitizer, a special wavelength of light, oxygen (3O2) and generation of singlet oxygen (1O2). Intra-patient and inter-patient variability of oxygen concentration ([3O2]) before and after the treatment as well as photosensitizer concentration and hemodynamic parameters such as blood flow during PDT has been reported. Simulation of these variations is valuable, as it would be a means for the rapid assessment of treatment effect. A mathematical model has been previously developed to incorporate the diffusion equation for light transport in tissue and the macroscopic kinetic equations for simulation of [3O2], photosensitizers in ground and triplet states and concentration of the reacted singlet oxygen ([1O₂]rx) during PDT. In this study, the finite-element based calculation of the macroscopic kinetic equations is done for 2-(1- Hexyloxyethyl)-2-devinyl pyropheophorbide (HPPH)-mediated PDT by incorporating the information of the photosensitizer photochemical parameters as well as the tissue optical properties, photosensitizer concentration, initial oxygen concentration ([3O2]0), blood flow changes and Φ that have been measured in mice bearing radiation-induced fibrosarcoma (RIF) tumors. Then, [1O2]rx calculated by using the measured [3O2] during the PDT is compared with [1O2]rx calculated based on the simulated [3O₂]; both calculations showed a reasonably good agreement. Moreover, the impacts of the blood flow changes and [3O2]0 on [1O2]rx have been investigated, which showed no pronounced effect of the blood flow changes on the long-term 1O2 generation. When [3O2]0 becomes limiting, small changes in [3O₂] have large effects on [1O2]rx.

  18. Investigating the impact of oxygen concentration and blood flow variation on photodynamic therapy

    PubMed Central

    Penjweini, Rozhin; Kim, Michele M.; Finlay, Jarod C.; Zhu, Timothy C.

    2016-01-01

    Type II photodynamic therapy (PDT) is used for cancer treatment based on the combined action of a photosensitizer, a special wavelength of light, oxygen (3O2) and generation of singlet oxygen (1O2). Intra-patient and inter-patient variability of oxygen concentration ([3O2]) before and after the treatment as well as photosensitizer concentration and hemodynamic parameters such as blood flow during PDT has been reported. Simulation of these variations is valuable, as it would be a means for the rapid assessment of treatment effect. A mathematical model has been previously developed to incorporate the diffusion equation for light transport in tissue and the macroscopic kinetic equations for simulation of [3O2], photosensitizers in ground and triplet states and concentration of the reacted singlet oxygen ([1O2]rx) during PDT. In this study, the finite-element based calculation of the macroscopic kinetic equations is done for 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide (HPPH)-mediated PDT by incorporating the information of the photosensitizer photochemical parameters as well as the tissue optical properties, photosensitizer concentration, initial oxygen concentration ([3O2]0), blood flow changes and ϕ that have been measured in mice bearing radiation-induced fibrosarcoma (RIF) tumors. Then, [1O2]rx calculated by using the measured [3O2] during the PDT is compared with [1O2]rx calculated based on the simulated [3O2]; both calculations showed a reasonably good agreement. Moreover, the impacts of the blood flow changes and [3O2]0 on [1O2]rx have been investigated, which showed no pronounced effect of the blood flow changes on the long-term 1O2 generation. When [3O2]0 becomes limiting, small changes in [3O2] have large effects on [1O2]rx. PMID:27453622

  19. [Morphofunctional aspects of the experimental effect of hyperbaric oxygenation on the myocardium of the healthy organism].

    PubMed

    Rossinskaia, V V; Shliapnikov, V N; Uglova, M V

    1978-01-01

    Changes in the myocardium arter numerous treatments with hyperbaric oxygenation (HBO) (PO2 3 technical atmospheres, time of saturation--45 min) were studied by morphological, histochemical and enzymohistochemical methods in 50 rabbits. Three stages were found to occur in the development of these changes: 1) functional-morphological changes (1--3 seanses of HBO), 2) early morphological changes (4--5 seanses), 3) marked morphological lesions (6--8 seanses). The first three treatments produce reversible changes on the part of metabolic processes (a reduction in the content of glycogen and changes in the activity of oxidoreductases: succinate-, malate- and lactate dehydrogenase). Morphological signs of oxygen toxicity in the form of disorders in hemodynamics and microcirculation, and dystrophy of cardiomyocytes appear after 4 seanses of HBO and increase with further treatment. The experimental data permit to recommend short HBO courses (1--3 seanses) for therapeutic application.

  20. Upsides and Downsides of Reactive Oxygen Species for Cancer: The Roles of Reactive Oxygen Species in Tumorigenesis, Prevention, and Therapy

    PubMed Central

    Gupta, Subash C.; Hevia, David; Patchva, Sridevi; Park, Byoungduck; Koh, Wonil

    2012-01-01

    Abstract Significance: Extensive research during the last quarter century has revealed that reactive oxygen species (ROS) produced in the body, primarily by the mitochondria, play a major role in various cell-signaling pathways. Most risk factors associated with chronic diseases (e.g., cancer), such as stress, tobacco, environmental pollutants, radiation, viral infection, diet, and bacterial infection, interact with cells through the generation of ROS. Recent Advances: ROS, in turn, activate various transcription factors (e.g., nuclear factor kappa-light-chain-enhancer of activated B cells [NF-κB], activator protein-1, hypoxia-inducible factor-1α, and signal transducer and activator of transcription 3), resulting in the expression of proteins that control inflammation, cellular transformation, tumor cell survival, tumor cell proliferation and invasion, angiogenesis, and metastasis. Paradoxically, ROS also control the expression of various tumor suppressor genes (p53, Rb, and PTEN). Similarly, γ-radiation and various chemotherapeutic agents used to treat cancer mediate their effects through the production of ROS. Interestingly, ROS have also been implicated in the chemopreventive and anti-tumor action of nutraceuticals derived from fruits, vegetables, spices, and other natural products used in traditional medicine. Critical Issues: These statements suggest both “upside” (cancer-suppressing) and “downside” (cancer-promoting) actions of the ROS. Thus, similar to tumor necrosis factor-α, inflammation, and NF-κB, ROS act as a double-edged sword. This paradox provides a great challenge for researchers whose aim is to exploit ROS stress for the development of cancer therapies. Future Directions: The various mechanisms by which ROS mediate paradoxical effects are discussed in this article. The outstanding questions and future directions raised by our current understanding are discussed. Antioxid. Redox Signal. 16, 1295–1322. PMID:22117137

  1. Hyperbaric Oxygen Therapy for the Adjunctive Treatment of Pyoderma Gangrenosum: A Case Report.

    PubMed

    Chiang, I-Han; Liao, Yi-Shu; Dai, Niann-Tzyy; Chiao, Hao-Yu; Chou, Chang-Yi; Chen, Shyi-Gen; Chen, Tim-Mo; Chang, Shun-Cheng

    2016-05-01

    Pyoderma gangrenosum (PG) is a neutrophilic dermatosis of unknown etiology characterized by an ulcerative skin condition and confirmed through a diagnosis of exclusion. Management usually consists of systemic drug therapy, such as corticosteroids, sulfones, or immunosuppressants, either alone or in combination. Long-term use of these medications often has untold side effects. Hyperbaric oxygen therapy (HBOT) has been shown effective in the treatment of PG, reducing pain and tempering the need for medication. A case is presented of a 54-year-old woman with diabetes, hypertension, and a peptic ulcer who presented with painful, purulent ulcers on her buttocks, hands, and lower extremities of 2 weeks' duration. She was ultimately diagnosed with PG and provided 20 mg/day of oral prednisone for 1 week, tapered to 10 mg/day in the next week and then stopped. In addition, she received 12 sessions of HBOT - she breathed in 100% oxygen under 2.5 atmospheres absolute pressure for 90 minutes over 2 weeks. Her wounds healed without scarring. This excellent outcome including good wound healing, decreased pain, and reduced doses of systemic corticosteroids warrants additional study of the adjunctive use of HBOT for PG. PMID:27192719

  2. Diffuse optical measurements of head and neck tumor hemodynamics for early prediction of radiation therapy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Dong, Lixin; Kudrimoti, Mahesh; Irwin, Daniel; Chen, Li; Shang, Yu; Li, Xingzhe; Stevens, Scott D.; Shelton, Brent J.; Yu, Guoqiang

    2016-03-01

    Radiation therapy is a principal modality for head and neck cancers and its efficacy depends on tumor hemodynamics. Our laboratory developed a hybrid diffuse optical instrument allowing for simultaneous measurements of tumor blood flow and oxygenation. In this study, the clinically involved cervical lymph node was monitored by the hybrid instrument once a week over the treatment period of seven weeks. Based on treatment outcomes within one year, patients were classified into a complete response group (CR) and an incomplete response group (IR) with remote metastasis and/or local recurrence. A linear mixed models was used to compare tumor hemodynamic responses to the treatment between the two groups. Interestingly, we found that human papilloma virus (HPV-16) status largely affected tumor hemodynamic responses. For HPV-16 negative tumors, significant differences in blood flow index (BFI, p = 0.007) and reduced scattering coefficient (μs', p = 0.0005) were observed between the two groups; IR tumors exhibited higher μs' values and a continuous increase in BFI over the treatment period. For HPV-16 positive tumors, oxygenated hemoglobin concentration ([HbO2]) and blood oxygen saturation (StO2) were significant different (p = 0.003 and 0.01, respectively); IR group showed lower [HbO2] and StO2. Our results imply HPV-16 negative tumors with higher density of vasculature (μs') and higher blood flow show poor responses to radiotherapy and HPV-16 positive tumors with lower tissue oxygenation level (lower StO2 and [HbO2]) exhibit poor treatment outcomes. Our diffuse optical measurements show the great potential for early prediction of radiotherapy in head and neck cancers.

  3. Production of reactive oxygen species after photodynamic therapy by porphyrin sensitizers.

    PubMed

    Kolarova, H; Nevrelova, P; Tomankova, K; Kolar, P; Bajgar, R; Mosinger, J

    2008-06-01

    The objectives of this study was to investigate the production of reactive oxygen species (ROS) after photodynamic therapy (PDT) in vitro. We examined second generation sensitizers, porphyrines (TPPS4, ZnTPPS4 and PdTPPS4) and compared their effectivity on ROS generation in G361 cell line. Used porphyrines are very efficient water-soluble aromatic dyes with potential to use in photomedicine and have a high propensity to accumulate in the membranes of intracellular organelles like lysosomes and mitochondria. Interaction between the triplet excited state of the sensitizer and molecular oxygen leads to produce singlet oxygen and other ROS to induce cell death. Production of ROS was verificated by molecular probe CM-H2DCFDA and viability of cells was determined by MTT assay. Our results demonstrated that ZnTPPS4 induces the highest ROS production in cell line compared to TPPS4 and PdTPPS4 at each used concentration and light dose. These results consist with a fact that photodynamic effect depends on sensitizer type, its concentration and light dose.

  4. Antimicrobial strategies centered around reactive oxygen species - bactericidal antibiotics, photodynamic therapy and beyond

    PubMed Central

    Vatansever, Fatma; de Melo, Wanessa C.M.A.; Avci, Pinar; Vecchio, Daniela; Sadasivam, Magesh; Gupta, Asheesh; Chandran, Rakkiyappan; Karimi, Mahdi; Parizotto, Nivaldo A; Yin, Rui; Tegos, George P; Hamblin, Michael R

    2013-01-01

    Reactive oxygen species (ROS) can attack a diverse range of targets to exert antimicrobial activity, which accounts for their versatility in mediating host defense against a broad range of pathogens. Most ROS are formed by the partial reduction of molecular oxygen. Four major ROS are recognized comprising: superoxide (O2•−), hydrogen peroxide (H2O2), hydroxyl radical (•OH), and singlet oxygen (1O2), but they display very different kinetics and levels of activity. The effects of O2•− and H2O2 are less acute than those of •OH and 1O2, since the former are much less reactive and can be detoxified by endogenous antioxidants (both enzymatic and non-enzymatic) that are induced by oxidative stress. In contrast, no enzyme can detoxify •OH or 1O2, making them extremely toxic and acutely lethal. The present review will highlight the various methods of ROS formation and their mechanism of action. Antioxidant defenses against ROS in microbial cells and the use of ROS by antimicrobial host defense systems are covered. Antimicrobial approaches primarily utilizing ROS comprise both bactericidal antibiotics, and non-pharmacological methods such as photodynamic therapy, titanium dioxide photocatalysis, cold plasma and medicinal honey. A brief final section covers, reactive nitrogen species, and related therapeutics, such as acidified nitrite and nitric oxide releasing nanoparticles. PMID:23802986

  5. [Normobaric oxygenation as a first-aid measure in decompression sickness].

    PubMed

    Wendling, J

    1993-12-01

    Most divers and diving medicine specialists know that application of normobaric oxygen as first aid after a bubble disease incident is highly effective. However, as yet technical difficulties acted as a deterrent to using normobaric oxygen at the diving site. This can now be overcome by a newer technique. To be efficient, any therapy of bubble disease should follow three main principles: maximal partial pressure of inhaled oxygen (i.e. 100 kpa in normobaric, and 280 kpa in hyperbaric conditions); minimal partial pressure of inhaled nitrogen, which should ideally be near zero; immediate start of therapy, if possible at the diving site, but not later than 2 hours after the onset of the first symptoms. However, it has to be borne in mind that for an efficient normobaric oxygenation (100%), the standard apparatus design without oxygen reservoir is obsolete, for it offers at most 40% oxygen to the lungs. Currently the following technical approaches for an efficient normobaric oxygenation are available: open one-way systems with tightly fitting mask and oxygen reservoir bag (type Ambu or Leardal, etc.); open systems with on-demand regulation and tightly fitting mouth piece (type SCUBA, or Bird-respirator); closed systems with CO2 absorber (type oxygen rebreathing diving gear). The closed system is a genuine technical advance, because it needs 15 times less oxygen than open systems (about 90 liters oxygen for a 3-hours oxygenation run). Such an apparatus is thus of light weight, far less cumbersome, and nevertheless highly efficient. The therapy should start immediately at the site of the mishap and be maintained during the transport to the next HBO-unit (usually 3 to 6 hours).(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Hyperbaric oxygen therapy in a patient with autosomal dominant polycystic kidney disease with a perinephritic abscess.

    PubMed

    Vega, Jorge; Goecke, Helmuth; Manriquez, Francisco; Escobar, Carlos; Escobar, Max; Videla, Christian; Santamarina, Mario; Echeverria, Carlos; Guarda, Francisco Javier

    2011-02-01

    A 68-year-old female in hemodialysis due to autosomal dominant polycystic kidney disease underwent resection of cysts in her right kidney via a laparoscopic approach due to abdominal pain. Three weeks after surgery, she was admitted with sepsis. A CT scan showed a large abscess around the right kidney. Percutaneous drainage of abscess was performed. The pus smear showed Gram-positive cocci and the culture contained methicillin-resistant Staphylococcus aureus. Ciprofloxacin, clindamycin and vancomycin were given. In the 3 weeks following admission, she remained febrile and septic and showed a progressive deterioration in her general condition, along with malnutrition and persistent drainage of purulent material from her right flank. The antibiotic therapy was changed to vancomycin, metronidazole and meropenem, but no improvement was observed. Because of the high risk associated with carrying out an open nephrectomy, we decided to use hyperbaric oxygen therapy (HBOT) as a potentially useful measure to control her infection. The patient underwent 26 daily sessions of 100% hyperbaric oxygen (2.5 atm). The use of HBOT induced a notable break in the clinical course of this patient's retroperitoneal infection. She was discharged after day 58 without any signs of inflammatory activity, and she has not presented reactivation of infection since then. We think that this case suggests that this therapy could be a new therapeutic tool in the management of patients with similar clinical features when all other therapeutic measures have failed. We did not find any other reports of the use of HBOT in infections of renal cysts.

  7. Improvement of tumor response to photodynamic therapy by manipulation of tumor oxygenation in an in-vivo model system

    NASA Astrophysics Data System (ADS)

    Chen, Qun; Huang, Zheng; Chen, Hua; Shapiro, Howard; Beckers, Jill; Hetzel, Fred W.

    2002-09-01

    Photodynamic therapy (PDT) requires molecular oxygen during light irradiation in order to generate reactive oxygen species. Tumor hypoxia, either pre-existing or induced by PDT, can severely hamper the effectiveness of PDT treatment. Lowering the light irradiation dose rate or fractionating a light dose may improve cell kill of PDT induced hypoxic cells, but will have no effect on pre-existing hypoxic cells. In this study, hyper-oxygenation technique was used during PDT to overcome hypoxia. C3H mice with transplanted mammary carcinoma tumors were injected with 12.5 mg/kg Photofrin and irradiated with 630 nm laser light 24 hours later. Tumor oxygenation was manipulated by subjecting the animals to 3 atp hyperbaric oxygen or normobaric oxygen during PDT light irradiation. The results show a significant improvement in tumor response when PDT was delivered during hyper-oxygenation. With hyper-oxygenation, up to 80% of treated tumors showed no re-growth after 60 days. In comparison, only 20% of tumors treated while animals breathed room air did not re-grow. To explore the effect of hyper-oxygenation on tumor oxygenation, tumor pO2 was measured with microelectrodes positioned in pre-existing hypoxic regions before and during the PDT. The results show that hyper-oxygenation may oxygenate pre-existing hypoxic cells and compensate for oxygen depletion induced by PDT light irradiation. In conclusion, hyper-oxygenation may provide effective ways to improve PDT treatment efficiency by oxygenating both pre-existing and treatment induced cell hypoxia.

  8. Photoacoustically Measured Speeds of Sound of Liquid HBO2: On Unlocking the Fuel Potential of Boron

    SciTech Connect

    Bastea, S; Crowhurst, J; Armstrong, M; ., N T

    2010-03-24

    Elucidation of geodynamic, geochemical, and shock induced processes is often limited by challenges to accurately determine molecular fluid equations of state (EOS). High pressure liquid state reactions of carbon species underlie physiochemical mechanisms such as differentiation of planetary interiors, deep carbon sequestration, propellant deflagration, and shock chemistry. Here we introduce a versatile photoacoustic technique developed to measure accurate and precise speeds of sound (SoS) of high pressure molecular fluids and fluid mixtures. SoS of an intermediate boron oxide, HBO{sub 2} are measured up to 0.5 GPa along the 277 C isotherm. A polarized Exponential-6 interatomic potential form, parameterized using our SoS data, enables EOS determinations and corresponding semi-empirical evaluations of > 2000 C thermodynamic states including energy release from bororganic formulations. Our thermochemical model propitiously predicts boronated hydrocarbon shock Hugoniot results.

  9. Effects of hyperbaric oxygen and irradiation on experimental skin flaps in rats

    SciTech Connect

    Nemiroff, P.M.; Merwin, G.E.; Brant, T.; Cassisi, N.J.

    1985-08-01

    This study investigated the effects of hyperbaric oxygen (HBO) and irradiation (RT) on experimental skin flaps in rats under varying conditions. Animals were assigned at random to 1 of 15 groups that represented all possible ordering effects of HBO, RT, and flap, as well as controls that included flap-only, RT-only, and HBO-only groups. Cranially based skin flaps measuring 3 x 9 cm were elevated on the dorsum. The surviving length was evaluated with fluorescein dye 7 days after the operation. Depending on the treatment condition, HBO was given either 48 hours or 24 hours before flap elevation, or within 4 hours or 48 hours after flap elevation. Rats receiving RT (WCo) were given a single dose of 1000 rads to the dorsum. Results showed that all groups receiving HBO within 4 hours after flap elevation had significantly greater flap survival length, with as much as a 22% greater length of surviving flap. HBO given 48 hours before flap elevation also significantly improved flap survival over controls. RT appeared to have no immediate significant effect on flap survival. However, rats receiving RT, regardless of other factors, gained significantly less weight than did controls. Findings clearly indicate that, to be effective, HBO needs to be given as soon after surgery as possible.

  10. Microvascular oxygen partial pressure during hyperbaric oxygen in diabetic rat skeletal muscle.

    PubMed

    Yamakoshi, Kohei; Yagishita, Kazuyoshi; Tsuchimochi, Hirotsugu; Inagaki, Tadakatsu; Shirai, Mikiyasu; Poole, David C; Kano, Yutaka

    2015-12-15

    Hyperbaric oxygen (HBO) is a major therapeutic treatment for ischemic ulcerations that perforate skin and underlying muscle in diabetic patients. These lesions do not heal effectively, in part, because of the hypoxic microvascular O2 partial pressures (PmvO2 ) resulting from diabetes-induced cardiovascular dysfunction, which alters the dynamic balance between O2 delivery (Q̇o2) and utilization (V̇o2) rates. We tested the hypothesis that HBO in diabetic muscle would exacerbate the hyperoxic PmvO2 dynamics due, in part, to a reduction or slowing of the cardiovascular, sympathetic nervous, and respiratory system responses to acute HBO exposure. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (control) groups. A small animal hyperbaric chamber was pressurized with oxygen (100% O2) to 3.0 atmospheres absolute (ATA) at 0.2 ATA/min. Phosphorescence quenching techniques were used to measure PmvO2 in tibialis anterior muscle of anesthetized rats during HBO. Lumbar sympathetic nerve activity (LSNA), heart rate (HR), and respiratory rate (RR) were measured electrophysiologically. During the normobaric hyperoxia and HBO, DIA tibialis anterior PmvO2 increased faster (mean response time, CONT 78 ± 8, DIA 55 ± 8 s, P < 0.05) than CONT. Subsequently, PmvO2 remained elevated at similar levels in CONT and DIA muscles until normobaric normoxic recovery where the DIA PmvO2 retained its hyperoxic level longer than CONT. Sympathetic nervous system and cardiac and respiratory responses to HBO were slower in DIA vs. CONT. Specifically the mean response times for RR (CONT: 6 ± 1 s, DIA: 29 ± 4 s, P < 0.05), HR (CONT: 16 ± 1 s, DIA: 45 ± 5 s, P < 0.05), and LSNA (CONT: 140 ± 16 s, DIA: 247 ± 34 s, P < 0.05) were greater following HBO onset in DIA than CONT. HBO treatment increases tibialis anterior muscle PmvO2 more rapidly and for a longer duration in DIA than CONT, but not to a greater level. Whereas respiratory, cardiovascular

  11. Low flow oxygen therapy from a portable oxygen concentrator or an oxygen cylinder effectively treats hypoxemia in anesthetized white-tailed deer (Odocoileus virginianus).

    PubMed

    Fahlman, Asa; Caulkett, Nigel; Woodbury, Murray; Duke-Novakovski, Tanya; Wourms, Vincent

    2014-06-01

    For treatment of hypoxemia, delivery of the minimum effective oxygen flow rate is advantageous during field anesthesia because it prolongs the life of the oxygen cylinder. Portable oxygen concentrators as the oxygen source require less logistical considerations than cylinders and are a safer alternative during helicopter field work because they are nonexplosive devices. The objective of this study was to evaluate low oxygen flow rates by continuous or pulsed intranasal delivery for treatment of hypoxemia in anesthetized white-tailed deer (Odocoileus virginianus). Nine captive adult female deer (body mass 56-72 kg) were physically restrained in a drop-floor chute and hand injected intramuscularly with medetomidine (0.1-0.14 mg/kg) and ketamine (2.5-4.3 mg/kg). Intranasal oxygen was delivered from an oxygen cylinder at continuous flow rates of 1 and 2 L/min or from a battery driven oxygen concentrator (EverGo Portable Oxygen Concentrator, Respironics) with pulse-dose delivery (maximum capacity of 1.05 L/min). The pulse-dose setting (pulse volume 12-70 ml) was adjusted according to the respiratory rate. Arterial blood gases were analyzed before, during, and after O2 supplementation. A 10-min washout period was allowed between treatment groups. All three treatments adequately treated hypoxemia. The partial pressure of arterial oxygenation increased significantly from baseline values of 55 +/- 10 to 115 +/- 31 mm Hg during supplementation from the oxygen concentrator, to 138 +/- 21 mm Hg during supplementation from the oxygen cylinder at 1 L/min, and to 201 +/- 42 mm Hg at 2 L/min. In conclusion, low flow rates of intranasal oxygen supplemented continuously from an oxygen cylinder or by pulsed delivery from a portable oxygen concentrator effectively treated hypoxemia in anesthetized white-tailed deer.

  12. Crime, the Media, and Constructions of Reality: Using HBO's "The Wire" as a Frame of Reference

    ERIC Educational Resources Information Center

    Guastaferro, Wendy P.

    2013-01-01

    This article shows how a uniquely situated television show was used as a pedagogical tool to address numerous criminal justice topics in a crime and media course. The show is Home Box Office's (HBO) "The Wire." The first season focused on "the law" and "the street" and how each is affected by drug enforcement,…

  13. John F. Kennedy, Jr., speaks to the media at KSC's HBO premiere 'From the Earth to the Moon.'

    NASA Technical Reports Server (NTRS)

    1998-01-01

    John F. Kennedy, Jr., editor-in-chief of George Magazine, speaks with members of the national media at the Home Box Office (HBO) and Imagine Entertainment premiere of the 12-part miniseries 'From the Earth to the Moon' at Kennedy Space Center (KSC). The series was filmed in part on location at KSC and dramatizes the human aspects of NASA's efforts to launch Americans to the Moon. The miniseries highlights NASA's Apollo program and the events leading up to and including the six successful missions to the Moon. A special 500-seat theater was constructed next to the Apollo/Saturn V Center for the KSC premiere showing. Speakers at the event included KSC Director Roy Bridges (at right); Jeff Bewkes, chairman and CEO for HBO; and John F. Kennedy, Jr. Also attending the event, which featured the episode entitled '1968,' were Buzz Aldrin, Apollo 11 astronaut, and Al Worden, Apollo 15 astronaut. The original miniseries event, created for HBO by actor Tom Hanks and Imagine Entertainment, will premiere on HBO beginning April 5, 1998.

  14. John F. Kennedy, Jr., speaks to invited guests at KSC's HBO premiere 'From the Earth to the Moon.'

    NASA Technical Reports Server (NTRS)

    1998-01-01

    John F. Kennedy, Jr., editor-in-chief of George Magazine, greets invited guests at the Home Box Office (HBO) and Imagine Entertainment premiere of the 12-part miniseries 'From the Earth to the Moon' at Kennedy Space Center (KSC). The series was filmed in part on location at KSC and dramatizes the human aspects of NASA's efforts to launch Americans to the Moon. The miniseries highlights NASA's Apollo program and the events leading up to and including the six successful missions to the Moon. A special 500- seat theater was constructed next to the Apollo/Saturn V Center for the KSC premiere showing. Speakers at the event included KSC Director Roy Bridges (at right); Jeff Bewkes, chairman and CEO for HBO; and John F. Kennedy, Jr. Also attending the event, which featured the episode entitled '1968,' were Buzz Aldrin, Apollo 11 astronaut, and Al Worden, Apollo 15 astronaut. The original miniseries event, created for HBO by actor Tom Hanks and Imagine Entertainment, will premiere on HBO beginning April 5, 1998.

  15. Effectiveness of a Short-Term Treatment of Oxygen-Ozone Therapy into Healing in a Posttraumatic Wound

    PubMed Central

    Degli Agosti, Irene; Mazzacane, Bruno; Peroni, Gabriella; Bianco, Sandra; Guerriero, Fabio; Ricevuti, Giovanni

    2016-01-01

    Introduction. A number of studies suggest that oxygen-ozone therapy may have a role in the treatment of chronic, nonhealing, or ischemic wounds for its disinfectant and antibacterial properties. Nonhealing wounds are a significant cause of morbidity. Here we present a case of subcutaneous oxygen-ozone therapy used to treat a nonhealing postoperative wound in a young man during a period of 5 weeks. Case Presentation. A 46-year-old man had a motorcycle accident and underwent amputation of the right tibia and fibula. At the discharge he came to our attention to start rehabilitation treatment. At that time the wound was ulcerated but it was afebrile with no signs of inflammation and negativity to blood tests. At 2 months from the trauma despite appropriate treatment and dressing, the wound was slowly improving and the patient complained of pain. For this reason in addition to standard dressing he underwent oxygen-ozone therapy. After 5 weeks of treatment the wound had healed. Conclusion. In patients with nonhealing wounds, oxygen-ozone therapy could be helpful in speeding the healing and reducing the pain thanks to its disinfectant property and by the increase of endogenous oxygen free radicals' scavenging properties. Compared to standard dressing and other treatments reported in the literature it showed a shorter time of action. PMID:27738434

  16. Hyperbaric oxygen therapy in the treatment of post cardiac surgical strokes--a case series and review of the literature.

    PubMed

    Gibson, A J; Davis, F M

    2010-01-01

    Strokes remain an uncommon but significant complication of cardiac surgery. Cerebral air embolism is the likely aetiology in the majority of cases. Hyperbaric oxygen therapy is the recognised treatment for cerebral air embolism associated with compressed air (SCUBA) diving accidents and is therefore also the standard of care for iatrogenic causes of air embolism. It follows that there is a logic in treating post-cardiac surgical stroke patients with hyperbaric oxygen. The aim of this retrospective review was to examine the outcomes of 12 such patients treated in the Christchurch Hospital hyperbaric unit and to appraise the evidence base for the use of hyperbaric oxygen therapy in this setting. Despite delays of up to 48 hours following surgery before the institution of hyperbaric oxygen therapy, 10 of the 12 patients made a full neurological recovery or were left with mild residual symptoms, with nine returning to their previous level of care. One patient remained hemiplegic and there was one early neurological death. There is a paucity of prospective data in this area, but based on sound pathophysiological principles and clinical experience, we believe that patients suffering a stroke following open cardiac surgery should be considered for hyperbaric oxygen therapy.

  17. Direct imaging of singlet oxygen luminescence generated in blood vessels during photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Lin, Lisheng; Lin, Huiyun; Chen, Defu; Chen, Longchao; Wang, Min; Xie, Shusen; Gu, Ying; Wilson, Brian C.; Li, Buhong

    2014-05-01

    Singlet oxygen (1O2) is commonly recognized to be a major phototoxic component for inducing the biological damage during photodynamic therapy (PDT). In this study, a novel configuration of a thermoelectrically-cooled near-infrared sensitive InGaAs camera was developed for imaging of photodynamically-generated 1O2 luminescence. The validation of 1O2 luminescence images for solution samples was performed with the model photosensitizer Rose Bengal (RB). Images of 1O2 luminescence generated in blood vessels in vivo in a well-controlled dorsal skinfold window chamber model were also recorded during PDT. This study demonstrated the capacity of the newly-developed imaging system for imaging of 1O2 luminescence, and the first reported images of 1O2 luminescence in blood vessels in vivo. This system has potential for elucidating the mechanisms of vascular targeted PDT.

  18. A Population Pharmacokinetic Model for Vancomycin in Adult Patients Receiving Extracorporeal Membrane Oxygenation Therapy.

    PubMed

    Moore, J N; Healy, J R; Thoma, B N; Peahota, M M; Ahamadi, M; Schmidt, L; Cavarocchi, N C; Kraft, W K

    2016-09-01

    The literature on the pharmacokinetics of vancomycin in patients undergoing extracorporeal membrane oxygenation (ECMO) therapy is sparse. A population pharmacokinetic (PK) model for vancomycin in ECMO patients was developed using a nonlinear mixed effects modeling on the concentration-time profiles of 14 ECMO patients who received intravenous vancomycin. Model selection was based on log-likelihood criterion, goodness of fit plots, and scientific plausibility. Identification of covariates was done using a full covariate model approach. The pharmacokinetics of vancomycin was adequately described with a two-compartment model. Parameters included clearance of 2.83 L/hr, limited central volume of distribution 24.2 L, and low residual variability 0.67%. Findings from the analysis suggest that standard dosing recommendations for vancomycin in non-ECMO patients are adequate to achieve therapeutic trough concentrations in ECMO patients. This further shows that ECMO minimally affects the PK of vancomycin in adults including in higher-weight patients. PMID:27639260

  19. Vessel constriction correlated with local singlet oxygen generation during vascular targeted photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Lin, Lisheng; Li, Yirong; Zhang, Jinde; Tan, Zou; Chen, Defu; Xie, Shusen; Gu, Ying; Li, Buhong

    2014-11-01

    In this study, the vessel constriction was measured as a biological indicator of acute vascular response after vascular targeted photodynamic therapy (V-PDT). During V-PDT treatment, the near-infrared (NIR) singlet oxygen (1O2) luminescence at 1270 nm generated in blood vessels in a dorsal skinfold window chamber model in vivo was directly monitored using a custom built high-sensitive NIR imaging system. In order to compare the acute vascular response, various irradiances with the same light dose were utilized for treatments. The obtained results show that the complete arteriole constriction occurred frequently, while some of the larger veins were constricted partially. For the vessels that have significant constriction after V-PDT, our preliminary data suggest that the vasoconstriction in the selected ROIs are roughly correlated with the local cumulative 1O2 luminescence intensities. This study implies that the 1O2 luminescence dosimetry maybe also effective for evaluating V-PDT efficiency.

  20. Hyperbaric oxygen therapy reduces apoptosis after spinal cord injury in rats

    PubMed Central

    Long, Ying; Liang, Fang; Gao, Chunjin; Li, Zhuo; Yang, Jing

    2014-01-01

    Hyperbaric oxygen therapy (HBOT) protects brain tissue from inflammatory injury by suppressing mitochondrial apoptotic pathways. However, its neuroprotective mechanism via anti-apoptosis in spinal cord injury (SCI) is still unclear. In our study, Male Sprague-Dawley rats were randomly divided into three groups: sham-operated (SH), SCI model, and SCI + HBOT. Rats in each group were randomly divided into four sub-groups in a time-dependent manner (1 day, 3 days, 7 days and 14 days after surgery). Expression of adaptor molecule apoptosis-associated speck-like protein (ASC) and caspase-3 was evaluated at the indicated time after injury. Our data showed that HBOT downregulated expression of ASC in SCI rats at the mRNA and protein levels. HBOT mitigated caspase-3 release in injured spinal cord tissue. We conclude that HBOT prevents inflammation apoptosis after SCI, likely through suppression of ASC and caspase-3. PMID:25550916

  1. A Population Pharmacokinetic Model for Vancomycin in Adult Patients Receiving Extracorporeal Membrane Oxygenation Therapy

    PubMed Central

    Healy, JR; Thoma, BN; Peahota, MM; Ahamadi, M; Schmidt, L; Cavarocchi, NC; Kraft, WK

    2016-01-01

    The literature on the pharmacokinetics of vancomycin in patients undergoing extracorporeal membrane oxygenation (ECMO) therapy is sparse. A population pharmacokinetic (PK) model for vancomycin in ECMO patients was developed using a nonlinear mixed effects modeling on the concentration–time profiles of 14 ECMO patients who received intravenous vancomycin. Model selection was based on log‐likelihood criterion, goodness of fit plots, and scientific plausibility. Identification of covariates was done using a full covariate model approach. The pharmacokinetics of vancomycin was adequately described with a two‐compartment model. Parameters included clearance of 2.83 L/hr, limited central volume of distribution 24.2 L, and low residual variability 0.67%. Findings from the analysis suggest that standard dosing recommendations for vancomycin in non‐ECMO patients are adequate to achieve therapeutic trough concentrations in ECMO patients. This further shows that ECMO minimally affects the PK of vancomycin in adults including in higher‐weight patients. PMID:27639260

  2. Hyperbaric oxygen preconditioning attenuates early apoptosis after spinal cord ischemia in rats.

    PubMed

    Wang, Liping; Li, Wenxian; Kang, Zhimin; Liu, Yun; Deng, Xiaoming; Tao, Hengyi; Xu, Weigang; Li, Runping; Sun, Xuejun; Zhang, John H

    2009-01-01

    This study tested the hypothesis that spinal cord ischemic tolerance induced by hyperbaric oxygen preconditioning (HBO-PC) is mediated by inhibition of early apoptosis. Male Sprague-Dawley rats were preconditioned with consecutive 4 cycles of 1-h HBO exposures (2.5 atmospheres absolute [ATA], 100% O(2)) at a 12-h interval. At 24 h after the last HBO pretreatment, rats underwent 9 min of spinal cord ischemia induced by occlusion of the descending thoracic aorta in combination with systemic hypotension (40 mmHg). Spinal cord ischemia produced marked neuronal death and neurological dysfunction in animals. HBO-PC enhanced activities of Mn-superoxide dismutase (Mn-SOD) and catalase, as well as the expression of Bcl-2 in the mitochondria in the normal spinal cord at 24 h after the last pretreatment (before spinal cord ischemia), and retained higher levels throughout the early reperfusion in the ischemic spinal cord. In parallel, superoxide and hydrogen peroxide levels in mitochondria were decreased, cytochrome c release into the cytosol was reduced at 1 h after reperfusion, and activation of caspase-3 and -9 was subsequently attenuated. HBO-PC improved neurobehavioral scores and reduced neuronal apoptosis in the anterior, intermediate, and dorsal gray matter of lumbar segment at 24 h after spinal cord ischemia. HBO-PC increased nitric oxide (NO) production. L-nitroarginine-methyl-ester (L-NAME; 10 mg/kg), a nonselective NO synthase (NOS) inhibitor, applied before each HBO-PC protocol abolished these beneficial effects of HBO-PC. We conclude that HBO-PC reduced spinal cord ischemia-reperfusion injury by increasing Mn-SOD, catalase, and Bcl-2, and by suppressing mitochondrial apoptosis pathway. NO may be involved in this neuroprotection. PMID:19196076

  3. Marriage of scintillator and semiconductor for synchronous radiotherapy and deep photodynamic therapy with diminished oxygen dependence.

    PubMed

    Zhang, Chen; Zhao, Kuaile; Bu, Wenbo; Ni, Dalong; Liu, Yanyan; Feng, Jingwei; Shi, Jianlin

    2015-02-01

    Strong oxygen dependence and limited penetration depth are the two major challenges facing the clinical application of photodynamic therapy (PDT). In contrast, ionizing radiation is too penetrative and often leads to inefficient radiotherapy (RT) in the clinic because of the lack of effective energy accumulation in the tumor region. Inspired by the complementary advantages of PDT and RT, we present herein the integration of a scintillator and a semiconductor as an ionizing-radiation-induced PDT agent, achieving synchronous radiotherapy and depth-insensitive PDT with diminished oxygen dependence. In the core-shell Ce(III)-doped LiYF4@SiO2@ZnO structure, the downconverted ultraviolet fluorescence from the Ce(III)-doped LiYF4 nanoscintillator under ionizing irradiation enables the generation of electron-hole (e(-)-h(+)) pairs in ZnO nanoparticles, giving rise to the formation of biotoxic hydroxyl radicals. This process is analogous to a type I PDT process for enhanced antitumor therapeutic efficacy.

  4. Oxygen Nanocarrier for Combined Cancer Therapy: Oxygen-Boosted ATP-Responsive Chemotherapy with Amplified ROS Lethality.

    PubMed

    Zhao, Pengfei; Zheng, Mingbin; Luo, Zhenyu; Fan, Xiujun; Sheng, Zonghai; Gong, Ping; Chen, Ze; Zhang, Baozhen; Ni, Dapeng; Ma, Yifan; Cai, Lintao

    2016-09-01

    Oxygen nanocarrier (A/D-ONC) with a polymeric core entrapping hemoglobin and a cationic lipid shell absorbing a DOX-intercalating DNA duplex is developed. After endocytosis oxygenated A/D-ONC donates O2 to cancer cells that acts therapeutically by: (1) increasing intracellular ATP content that promotes DOX release, thereby converting ATP to the trigger of detrimental chemotherapy; (2) by synchronously increasing the ROS amount to amplify the lethality to cancer cells.

  5. X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield.

    PubMed

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C; Goldys, Ewa M

    2016-01-01

    Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 10(8) and (2.0 ± 0.1) × 10(9) singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 10(7)-2 × 10(9) singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality.

  6. X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield

    NASA Astrophysics Data System (ADS)

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C.; Goldys, Ewa M.

    2016-01-01

    Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 108 and (2.0 ± 0.1) × 109 singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 107-2 × 109 singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality.

  7. X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield

    PubMed Central

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C.; Goldys, Ewa M.

    2016-01-01

    Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 108 and (2.0 ± 0.1) × 109 singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 107–2 × 109 singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality. PMID:26818819

  8. Breast tumor oxygenation in response to carbogen intervention assessed simultaneously by three oxygen-sensitive parameters

    NASA Astrophysics Data System (ADS)

    Gu, Yueqing; Bourke, Vincent; Kim, Jae Gwan; Xia, Mengna; Constantinescu, Anca; Mason, Ralph P.; Liu, Hanli

    2003-07-01

    Three oxygen-sensitive parameters (arterial hemoglobin oxygen saturation SaO2, tumor vascular oxygenated hemoglobin concentration [HbO2], and tumor oxygen tension pO2) were measured simultaneously by three different optical techniques (pulse oximeter, near infrared spectroscopy, and FOXY) to evaluate dynamic responses of breast tumors to carbogen (5% CO2 and 95% O2) intervention. All three parameters displayed similar trends in dynamic response to carbogen challenge, but with different response times. These response times were quantified by the time constants of the exponential fitting curves, revealing the immediate and the fastest response from the arterial SaO2, followed by changes in global tumor vascular [HbO2], and delayed responses for pO2. The consistency of the three oxygen-sensitive parameters demonstrated the ability of NIRS to monitor therapeutic interventions for rat breast tumors in-vivo in real time.

  9. Paradoxical action of reactive oxygen species in creation and therapy of cancer.

    PubMed

    Kardeh, Sina; Ashkani-Esfahani, Soheil; Alizadeh, Ali Mohammad

    2014-07-15

    A great number of comprehensive literature believe that reactive oxygen species (ROS) and their products play a significant role in cell homeostasis maintenance, tissue protection against further insults by controlling cells proliferation through inducing apoptosis, and defending against cancer. ROS is believed to be like a potential double-edged sword in both cancer progression and prevention. Although at low and moderate levels ROS affect some of the most essential mechanisms of cell survival such as proliferation, angiogenesis and tumor invasion, at higher levels these agents can expose cells to detrimental consequences of oxidative stress including DNA damage and apoptosis that result in therapeutic effects on cancer. Understanding the new aspects on molecular mechanisms and signaling pathways modulating creation and therapy of cancers by ROS is critical in development of therapeutic strategies for patients suffering from cancer. This paper presents a general overview and rationale of paradoxical action of ROS in creation and therapy of cancer, tests to be used, and examples of how it may be applied.

  10. Colloidal gold nanorings for improved photodynamic therapy through field-enhanced generation of reactive oxygen species

    NASA Astrophysics Data System (ADS)

    Hu, Yue; Yang, Yamin; Wang, Hongjun; Du, Henry

    2013-02-01

    Au nanostructures that exhibit strong localized surface plasmon resonance (SPR) have excellent potential for photo-medicine, among a host of other applications. Here, we report the synthesis and use of colloidal gold nanorings (GNRs) with potential for enhanced photodynamic therapy of cancer. The GNRs were fabricated via galvanic replacement reaction of sacrificial Co nanoparticles in gold salt solution with low molecular weight (Mw = 2,500) poly(vinylpyrrolidone) (PVP) as a stabilizing agent. The size and the opening of the GNRs were controlled by the size of the starting Co particles and the concentration of the gold salt. UV-Vis absorption measurements indicated the tunability of the SPR of the GNRs from 560 nm to 780 nm. MTT assay showed that GNRs were non-toxic and biocompatible when incubated with breast cancer cells as well as the healthy counterpart cells. GNRs conjugated with 5-aminolevulinic acid (5-ALA) photosensitizer precursor led to elevated formation of reactive oxygen species and improved efficacy of photodynamic therapy of breast cancer cells under light irradiation compared to 5-ALA alone. These results can be attributed to significantly enhance localized electromagnetic field of the GNRs.

  11. Botulinum toxin therapy for hyperhidrosis: reduction of injection site pain by nitrous oxide/oxygen mixtures.

    PubMed

    Paracka, Lejla; Kollewe, Katja; Dengler, Reinhard; Dressler, Dirk

    2015-09-01

    Injection site pain (ISP) reduces compliance of botulinum toxin (BT) therapy considerably. We wanted to study whether nitrous oxide/oxygen (NOO, Livopan(®), Linde Gas Therapeutics, Unterschleißheim, Germany) can reduce ISP in patients receiving intracutaneous BT injections for axillary or palmar hyperhidrosis (HH). The study followed an open-label design comparing intraindividually ISP in both axillae and/or both palms when NOO was applied or not during BT injections. BT efficacy was measured by the Hyperhidrosis Disease Severity Scale (HDSS) and by a 4-point Self-Assessment Scale. ISP was documented by a Visual Analogue Scale (VAS) and the Verbal Scale of Pain Intensity (VSPI), adverse effects by a Structuralised Interview (SI). Altogether 13 patients (age 34.1 ± 12.4 years, 9 females, 4 males) were studied. 11 BT treatments were for biaxillary and 3 for bipalmar HH. BT reduced biaxillary HH from HDSS 3.7 ± 0.5 to 1.0 ± 0 and bipalmar HH from 3.6 ± 0.6 to 1.0 ± 0. All patients reported ISP reduction by NOO. In axillary HH, NOO reduced ISP from 55.7 ± 12.7 to 12.8 ± 7.5 on the VAS (p < 0.05) and from 4.1 ± 0.3 to 0.7 ± 0.5 on the VSPI (p < 0.05), in bipalmar HH from 60.0 ± 10.0 to 13.3 ± 5.8 on the VAS (p < 0.05) and from 5.0 ± 0 to 1.3 ± 0.5 on the VSPI (p < 0.05). Adverse effects were not identified. NOO is a potent, non-sedative, quickly reversible and safe inhalative analgesic which reduces ISP considerably in patients receiving BT therapy for axillary and palmar HH thus substantially improving compliance of BT therapy.

  12. Involvement of spinal cord opioid mechanisms in the acute antinociceptive effect of hyperbaric oxygen in mice.

    PubMed

    Heeman, Jacqueline H; Zhang, Yangmiao; Shirachi, Donald Y; Quock, Raymond M

    2013-12-01

    Earlier research has demonstrated that treatment with hyperbaric oxygen (HBO2) can elicit an antinociceptive response in models of acute pain. We have demonstrated that this antinociceptive effect is centrally-mediated and is dependent on opioid receptors. The purpose of the present study was to examine the role of endogenous opioid peptides and opioid receptors specifically in the spinal cord in the acute antinociceptive effect of HBO2 in mice. Male NIH Swiss mice were exposed to HBO2 (100% oxygen at 3.5atm absolute) for 11min and their antinociceptive responsiveness was determined using the glacial acetic acid-induced abdominal constriction test. HBO2-induced antinociception was sensitive to antagonism by intrathecal (i.t.) pretreatment with the κ- and μ-selective opioid antagonists norbinaltorphimine and β-funaltrexamine, respectively, but not the δ-selective antagonist naltrindole. The antinociceptive effect of HBO2 was also significantly attenuated by i.t. pretreatment with a rabbit antiserum against rat dynorphin1-13 but not antisera against β-endorphin or methionine-enkephalin. Based on these experimental findings, the acute antinociceptive effect of HBO2 appears to involve neuronal release of dynorphin and activation of κ- and μ-opioid receptors in the spinal cord. PMID:24113418

  13. Hyperbaric Oxygen Therapy Can Diminish Fibromyalgia Syndrome – Prospective Clinical Trial

    PubMed Central

    Efrati, Shai; Golan, Haim; Bechor, Yair; Faran, Yifat; Daphna-Tekoah, Shir; Sekler, Gal; Fishlev, Gregori; Ablin, Jacob N.; Bergan, Jacob; Volkov, Olga; Friedman, Mony; Ben-Jacob, Eshel; Buskila, Dan

    2015-01-01

    Background Fibromyalgia Syndrome (FMS) is a persistent and debilitating disorder estimated to impair the quality of life of 2–4% of the population, with 9:1 female-to-male incidence ratio. FMS is an important representative example of central nervous system sensitization and is associated with abnormal brain activity. Key symptoms include chronic widespread pain, allodynia and diffuse tenderness, along with fatigue and sleep disturbance. The syndrome is still elusive and refractory. The goal of this study was to evaluate the effect of hyperbaric oxygen therapy (HBOT) on symptoms and brain activity in FMS. Methods and Findings A prospective, active control, crossover clinical trial. Patients were randomly assigned to treated and crossover groups: The treated group patients were evaluated at baseline and after HBOT. Patients in the crossover-control group were evaluated three times: baseline, after a control period of no treatment, and after HBOT. Evaluations consisted of physical examination, including tender point count and pain threshold, extensive evaluation of quality of life, and single photon emission computed tomography (SPECT) imaging for evaluation of brain activity. The HBOT protocol comprised 40 sessions, 5 days/week, 90 minutes, 100% oxygen at 2ATA. Sixty female patients were included, aged 21–67 years and diagnosed with FMS at least 2 years earlier. HBOT in both groups led to significant amelioration of all FMS symptoms, with significant improvement in life quality. Analysis of SPECT imaging revealed rectification of the abnormal brain activity: decrease of the hyperactivity mainly in the posterior region and elevation of the reduced activity mainly in frontal areas. No improvement in any of the parameters was observed following the control period. Conclusions The study provides evidence that HBOT can improve the symptoms and life quality of FMS patients. Moreover, it shows that HBOT can induce neuroplasticity and significantly rectify abnormal

  14. Factors influencing the outcome of idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy.

    PubMed

    Körpinar, Sefika; Alkan, Zeynep; Yiğit, Ozgür; Gör, Ayşe Pelin; Toklu, Akin Savaş; Cakir, Burak; Soyuyüce, Ozlem Gedik; Ozkul, Haluk

    2011-01-01

    Idiopathic sudden sensorineural hearing loss (ISSNHL) is an otologic emergency with an incidence of about 5-20 per 100,000 of the population per year. There is no universally accepted standard protocol for the treatment of patients with ISSNHL. Hyperbaric oxygen therapy (HBOT), was first reported to improve the outcome following acute inner ear disorders during the late 1960s by both French and German authors. The increase in perilymph oxygenation produced by HBOT provides logical basis for the use of this treatment modality in ISSNHL. We reviewed the records of 97 cases that received HBOT for SSNHL to identify the factors that may affect the treatment outcomes. The effects of age, gender, affected ear, status of the contralateral ear, symptoms associated with hearing loss, presence of a cardiovascular disease, dyslipidemia, history of diabetes mellitus, seasonal factor, smoking, degree of hearing loss, audiogram type, medical treatments provided prior to HBOT, onset time, and number of HBOT sessions were evaluated. The mean hearing gain in all cases after the HBOT was 29.5 dB. The gains were statistically significant in the following cases: early onset of HBOT (p = 0.016), higher number of HBOT sessions (p < 0.01), steroid usage (p = 0.009), low frequency-ascending and total audiogram configuration (p < 0.01) and profound hearing loss (p = 0.011). The success rate was significantly lower in cases with high frequency-descending audiogram configuration (p < 0.001). The most important factor affected the prognosis favorably was found as steroid therapy. This retrospective study and our clinical experience suggest that HBOT has beneficial effects when administered in the early phase of the disease together with steroids. HBOT is a safe practice when used properly by an experienced hyperbaric team. In the treatment of ISSNHL, 20 sessions of HBOT at 2.5 ATA can be tolerated well besides some minor side effects. HBOT should be considered for the cases

  15. The Effects of Hyperbaric Oxygen Therapy on Post-Training Recovery in Jiu-Jitsu Athletes

    PubMed Central

    Santos, Jonatas Ferreira da Silva; Esteves, João Victor Del Conti

    2016-01-01

    Objectives The present study aimed to evaluate the effects of using hyperbaric oxygen therapy during post-training recovery in jiu-jitsu athletes. Methods Eleven experienced Brazilian jiu-jitsu athletes were investigated during and following two training sessions of 1h30min. Using a cross-over design, the athletes were randomly assigned to passive recovery for 2 hours or to hyperbaric oxygen therapy (OHB) for the same duration. After a 7-day period, the interventions were reversed. Before, immediately after, post 2 hours and post 24 hours, blood samples were collected to examine hormone concentrations (cortisol and total testosterone) and cellular damage markers [creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH)]. Moreover, the rating of perceived exertion (RPE) and recovery (RPR) scales were applied. Results Final lactate [La] values (control: 11.9 ± 1.4 mmol/L, OHB: 10.2 ± 1.4 mmol/L) and RPE [control: 14 (13–17 a.u.), OHB: 18 (17–20 a.u.)] were not significantly different following the training sessions. Furthermore, there was no difference between any time points for blood lactate and RPE in the two experimental conditions (P>0.05). There was no effect of experimental conditions on cortisol (F1,20 = 0.1, P = 0.793, η2 = 0.00, small), total testosterone (F1,20 = 0.03, P = 0.877, η2 = 0.00, small), CK (F1,20 = 0.1, P = 0.759, η2 = 0.01, small), AST (F1,20 = 0.1, P = 0.761, η2 = 0.01, small), ALT (F1,20 = 0.0, P = 0.845, η2 = 0.00, small) or LDH (F1,20 = 0.7, P = 0.413, η2 = 0.03, small). However, there was a difference between the two experimental conditions in RPR with higher values at post 2 h and 24 h in OHB when compared to the control condition (P<0.05). Conclusions Thus, it can be concluded that OHB exerts no influence on the recovery of hormonal status or cellular damage markers. Nonetheless, greater perceived recovery, potentially due to the placebo effect, was evident

  16. Hyperbaric oxygen therapy augments the photodynamic action of methylene blue against bacteria in vitro

    NASA Astrophysics Data System (ADS)

    Bisland, S. K.; Dadani, F. N.; Chien, C.; Wilson, B. C.

    2007-02-01

    Photodynamic therapy (PDT) entails the combination of photosensitizer and light to generate cytotoxic molecules that derive from molecular oxygen (O II). The presence of sufficient O II within the target tissues is critical to the efficiency of PDT. This study investigates the use of hyperbaric oxygen therapy in combination with PDT (HOTPDT) to augment the photodynamic action of methylene blue (MB) or 5-aminolevulinic acid (ALA) against gram positive and gram negative bacterial strains in vitro. Staphylococcus aureus or Pseudomonas aeruginosa were grown in trypticase soy broth as planktonic cultures (~10 8/mL) or as established biofilms in 48 well plates (3 days old) at 32°C. Dark toxicity and PDT response in the presence or absence of HOT (2 atmospheres, 100% O II for 30, 60 or 120 min) was established for both MB (0-0.1 mM) and ALA (0- 1 mM) for a range of incubation times. The number of surviving colonies (CFU/mL) was plotted for each treatment groups. Light treatments (5, 10, 20 or 30 J/cm2) were conducted using an array of halogen bulbs with a red filter providing 90% transmittance over 600-800 nm at 21 mW/cm2. HOT increased the dark toxicity of MB (30 min, 0.1 mM) from < 0.2 log cell kill to 0.5 log cell kill. Dark toxicity of ALA (4 hr, 1 mM) was negligible and did not increase with HOT. For non-dark toxic concentrations of MB or ALA, (0.05 mM and 1 mM respectively) HOT-PDT enhanced the antimicrobial effect of MB against Staphylococcus aureus in culture by >1 and >2 logs of cell kill (CFU/mL) at 5 and 10 J/cm2 light dose respectively as compared to PDT alone. HOT-PDT also increased the anti-microbial effects of MB against Staphylococcus aureus biofilms compared to PDT, albeit less so (> 2 logs) following 10 J/cm2 light dose. Anti-microbial effects of PDT using ALA were not significant for either strain with or without HOT. These data suggest that HOTPDT may be useful for improving the PDT treatment of bacterial infections.

  17. Involvement of brain opioid receptors in the anti-allodynic effect of hyperbaric oxygen in rats with sciatic nerve crush-induced neuropathic pain

    PubMed Central

    Gibbons, Carlee R.; Liu, Shulin; Zhang, Yangmiao; Sayre, Casey L.; Levitch, Briana; Moehlmann, Sarah; Shirachi, Donald Y.; Quock, Raymond M.

    2013-01-01

    Earlier research has demonstrated that hyperbaric oxygen (HBO2) can produce an antinociceptive effect in models of acute pain. Recent studies have revealed that HBO2 can produce pain relief in animal models of chronic pain as well. The purpose of the present investigation was to ascertain whether HBO2 treatment might suppress allodynia in rats with neuropathic pain and whether this effect might be blocked by the opioid antagonist naltrexone (NTX). Male Sprague Dawley rats were subjected to a sciatic nerve crush under anesthesia and mechanical thresholds were assessed using an electronic von Frey anesthesiometer. The time course of the HBO2-induced anti-allodynic effect in different treatment groups was plotted, and the area-under-the-curve (AUC) was determined for each group. Seven days after the nerve crush procedure, rats were treated with HBO2 at 3.5 atmospheres absolute (ATA) for 60 min and exhibited an anti-allodynic effect, compared to nerve crush-only control rats. Twenty-four hours before HBO2 treatment, another group of rats was implanted with Alzet® osmotic minipumps that continuously released NTX into the lateral cerebral ventricle for 7 days. These NTX-infused, HBO2-treated rats exhibited an allodynic response comparable to that exhibited by rats receiving nerve crush only. Analysis of the AUC data showed that HBO2 significantly reduced the nerve crush-induced allodynia; this anti-allodynic effect of HBO2 was reversed by NTX. These results implicate opioid receptors in the pain relief induced by HBO2. PMID:23998986

  18. Visible light-induced singlet oxygen-mediated intracellular disassembly of polymeric micelles co-loaded with a photosensitizer and an anticancer drug for enhanced photodynamic therapy.

    PubMed

    Saravanakumar, Gurusamy; Lee, Junseok; Kim, Jihoon; Kim, Won Jong

    2015-06-21

    Herein, we report a biocompatible amphiphilic block copolymer micelle bearing a singlet oxygen-sensitive vinyldithioether cleavable linker at the core-shell junction, which undergoes singlet oxygen-mediated photocleavage in the presence of visible light. The micelle facilitates the light-responsive release of singlet oxygen and an anticancer drug for enhanced photodynamic therapy. PMID:25998105

  19. Extracorporeal blood oxygenation and ozonation: clinical and biological implications of ozone therapy.

    PubMed

    Di Paolo, N; Gaggiotti, E; Galli, F

    2005-01-01

    Some lines of evidence have suggested that the challenge to antioxidants and biomolecules provoked by pro-oxidants such as ozone may be used to generate a controlled stress response of possible therapeutic relevance in some immune dysfunctions and chronic, degenerative conditions. Immune and endothelial cells have been proposed to be elective targets of the positive molecular effects of ozone and its derived species formed during blood ozonation. On the bases of these underlying principles and against often prejudicial scepticism and concerns about its toxicity, ozone has been used in autohemotherapy (AHT) for four decades with encouraging results. However, clinical application and validation of AHT have been so far largely insufficient. Latterly, a new and more effective therapeutic approach to ozone therapy has been established, namely extracorporeal blood oxygenation and ozonation (EBOO). This technique, first tested in vitro and then in vivo in sheep and humans (more than 1200 treatments performed in 82 patients), is performed with a high-efficiency apparatus that makes it possible to treat with a mixture of oxygen-ozone (0.5-1 microg/ml oxygen) in 1 h of extracorporeal circulation up to 4800 ml of heparinized blood without technical or clinical problems, whereas only 250 ml of blood can be treated with ozone by AHT. The EBOO technique can be easily adapted for use in hemodialysis also. The standard therapeutic cycle lasts for 7 weeks in which 14 treatment sessions of 1 h are performed. After a session of EBOO, the interaction of ozone with blood components results in 4-5-fold increased levels of thiobarbituric acid reactants and a proportional decrease in plasma protein thiols without any appreciable erythrocyte haemolysis. On the basis of preliminary in vitro evidence, these simple laboratory parameters may represent a useful complement in the routine monitoring of biological compliance to the treatment. The clinical experience gained so far confirms the

  20. Enhanced Singlet Oxygen Production by Photodynamic Therapy and a Novel Method for Its Intracellular Measurement

    PubMed Central

    Marin, Gustavo Horacio; Aviles, Kevin; Acuña, Ricardo Cruz; Roque, Gustavo; Nieto, Felipe Rodríguez; Sanchez, Francisco; Tarditi, Adrián; Rivera, Luis; Mansilla, Eduardo

    2014-01-01

    Abstract The generation of singlet oxygen (SO) in the presence of specific photosensitizers (PSs) or semiconductor quantum dots (QDs) and its application in photodynamic therapy (PDT) is of great interest to develop cancer therapies with no need of surgery, chemotherapy, and/or radiotherapy. This work was focused on the identification of the main factors leading to the enhancement of SO production using Rose Bengal (RB), and Methylene Blue (MB) as PS species in organic and aqueous mediums. Subsequently, the capacity of zinc oxide (ZnO), zinc sulfide (ZnS), and ZnO/ZnS core-shell QDs as well as manganese (Mn+2) doped ZnO and ZnS nanoparticles (NPs) as potential PS was also investigated. Many variable parameters such as type of quencher, PSs, NPs, as well as its different concentrations, light source, excitation wavelength, reaction time, distance from light source, and nature of solvent were used. The degradation kinetics of the quenchers generated by SO species and the corresponding quantum yields were determined by monitoring the photo-oxidation of the chemical quencher and measuring its disappearance by fluorometry and spectrophotometry in the presence of NPs. Small intracellular changes of SO induced by these metal Zn (zinc) NPs and PDT could execute and accelerate deadly programs in these leukemic cells, providing in this way an innovative modality of treatment. In order to perform further more specific in vitro cytotoxic studies on B-chronic lymphocytic leukemia cells exposed to Zn NPs and PDT, we needed first to measure and ascertain those possible intracellular SO variations generated by this type of treatment; for this purpose, we have also developed and tested a novel method first described by us. PMID:25490599

  1. Combination therapy with normobaric oxygen (NBO) plus thrombolysis in experimental ischemic stroke

    PubMed Central

    Fujiwara, Norio; Murata, Yoshihiro; Arai, Ken; Egi, Yasuhiro; Lu, Jie; Wu, Ona; Singhal, Aneesh B; Lo, Eng H

    2009-01-01

    Background The widespread use of tissue plasminogen activator (tPA), the only FDA-approved acute stroke treatment, remains limited by its narrow therapeutic time window and related risks of brain hemorrhage. Normobaric oxygen therapy (NBO) may be a useful physiological strategy that slows down the process of cerebral infarction, thus potentially allowing for delayed or more effective thrombolysis. In this study we investigated the effects of NBO started simultaneously with intravenous tPA, in spontaneously hypertensive rats subjected to embolic middle cerebral artery (MCA) stroke. After homologous clot injection, animals were randomized into different treatment groups: saline injected at 1 hour; tPA at 1 hour; saline at 1 hour plus NBO; tPA at 1 hour plus NBO. NBO was maintained for 3 hours. Infarct volume, brain swelling and hemorrhagic transformation were quantified at 24 hours. Outcome assessments were blinded to therapy. Results Upon clot injection, cerebral perfusion in the MCA territory dropped below 20% of pre-ischemic baselines. Both tPA-treated groups showed effective thrombolysis (perfusion restored to nearly 100%) and smaller infarct volumes (379 ± 57 mm3 saline controls; 309 ± 58 mm3 NBO; 201 ± 78 mm3 tPA; 138 ± 30 mm3 tPA plus NBO), showing that tPA-induced reperfusion salvages ischemic tissue and that NBO does not significantly alter this neuroprotective effect. NBO had no significant effect on hemorrhagic conversion, brain swelling, or mortality. Conclusion NBO can be safely co-administered with tPA. The efficacy of tPA thrombolysis is not affected and there is no induction of brain hemorrhage or edema. These experimental results require clinical confirmation. PMID:19604385

  2. An abnormally slow proton transfer reaction in a simple HBO derivative due to ultrafast intramolecular-charge transfer events.

    PubMed

    Alarcos, Noemí; Gutierrez, Mario; Liras, Marta; Sánchez, Félix; Douhal, Abderrazzak

    2015-07-01

    We report on the steady-state, picosecond and femtosecond time-resolved studies of a charge and proton transfer dye 6-amino-2-(2'-hydroxyphenyl)benzoxazole (6A-HBO) and its methylated derivative 6-amino-2-(2'-methoxyphenyl)benzoxazole (6A-MBO), in different solvents. With femtosecond resolution and comparison with the photobehaviour of 6A-MBO, we demonstrate for 6A-HBO in solution, the photoproduction of an intramolecular charge-transfer (ICT) process at S1 taking place in ∼140 fs or shorter, followed by solvent relaxation in the charge transferred species. The generated structure (syn-enol charge transfer conformer) experiences an excited-state intramolecular proton-transfer (ESIPT) reaction to produce a keto-type tautomer. This subsequent proton motion occurs in 1.2 ps (n-heptane), 14 ps (DCM) and 35 ps (MeOH). In MeOH, it is assisted by the solvent molecules and occurs through tunneling for which we got a large kinetic isotope effect (KIE) of about 13. For the 6A-DBO (deuterated sample in CD3OD) the global proton-transfer reaction takes place in 200 ps, showing a remarkable slow KIE regime. The slow ESIPT reaction in DCM (14 ps), not through tunnelling as it is not sensitive to OH/OD exchange, has however to overcome an energy barrier using intramolecular as well as solvent coordinates. The rich ESIPT dynamics of 6A-HBO in the used solutions is governed by an ICT reaction, triggered by the amino group, and it is solvent dependent. Thus, the charge injection to a 6A-HBO molecular frame makes the ICT species more stable, and the phenol group less acidic, slowing down the subsequent ESIPT reaction. Our findings bring new insights into the coupling between ICT and ESIPT reactions on the potential-energy surfaces of several barriers.

  3. Arterial and pulmonary arterial hemodynamics and oxygen delivery/extraction in normal humans exposed to hyperbaric air and oxygen.

    PubMed

    Weaver, Lindell K; Howe, Steve; Snow, Gregory L; Deru, Kayla

    2009-07-01

    Divers and hyperbaric chamber attendants breathe hyperbaric air routinely. Hyperbaric oxygen (HBO(2)) is used therapeutically frequently. Although much is understood about the hemodynamic physiology and gas exchange effects during hyperbaric air and HBO(2) exposure, arterial and pulmonary arterial (PA) catheter data, including blood gas values during hyperbaric air and HBO(2) exposure of normal humans, have not been reported. We exposed 10 healthy volunteers instrumented with arterial and PA catheters to air at 0.85, 3.0, 2.5, 2.0, 1.3 (decompression stop), 1.12 (decompression stop), and 0.85 atm abs (our altitude) and then at identical pressures breathing O(2) followed by atmospheric pressure air while we measured arterial and PA pressures (PAP), cardiac output (Q), and blood gas measurements from both arterial and PA catheters. Although hemodynamic changes occurred during exposure to both hyperbaric air and HBO(2), we observed a greater magnitude of change under HBO(2) conditions: heart rate changes ranged from -9 to -19% (air to O(2)), respiratory rate from -12 to -17%, Q from -7 to -18%, PAP from -18 to -19%, pulmonary vascular resistance from -38 to -48%, and right-to-left shunt fraction from -87 to -107%. Mixed venous CO(2) fell 8% from baseline during HBO(2) despite mixed venous O(2) tensions of several hundred Torr. The stroke volume, O(2) delivery, and O(2) consumption did not change across exposures. The arterial and mixed venous partial pressures of O(2) and contents were elevated, as predicted. O(2) extraction increased 37% during HBO(2).

  4. The influences of hyperbaric oxygen therapy with a lower pressure and oxygen concentration than previous methods on physiological mechanisms in dogs

    PubMed Central

    ISHIBASHI, Maki; HAYASHI, Akiyoshi; AKIYOSHI, Hideo; OHASHI, Fumihito

    2014-01-01

    Recently, hyperbaric oxygen therapy with a lower pressure and oxygen concentration (L-HBOT) than previous methods has been used for dogs in Japan; however, the influences of L-HBOT on dogs have not been clarified. To verify the influences of L-HBOT on physiological mechanism in dogs, we investigated blood gas parameters, glutathione peroxidase (GPx) activity, heart rate variability, stress-related hormones and skin conductance (SC) in 4 clinically normal beagle dogs with catheters in their carotid arteries and jugular veins when they were quiet, after running, after receiving L-HBOT (30% oxygen concentration, 1.3 atmospheres absolute, 30 min) or after not receiving L-HBOT. The results showed there were no changes in blood gas parameters, heart rate variability and catecholamine levels after L-HBOT. GPx activity was significantly higher, and the SC and cortisol level were lower in dogs that received L-HBOT than those when they were quiet. These results suggested that L-HBOT may have a small influence on oxygenation dynamics, activate antioxidant enzymes such as GPx, restrain autonomic nervous activity and control the balance between oxidation and antioxidation inside the body. PMID:25482821

  5. The influences of hyperbaric oxygen therapy with a lower pressure and oxygen concentration than previous methods on physiological mechanisms in dogs.

    PubMed

    Ishibashi, Maki; Hayashi, Akiyoshi; Akiyoshi, Hideo; Ohashi, Fumihito

    2015-03-01

    Recently, hyperbaric oxygen therapy with a lower pressure and oxygen concentration (L-HBOT) than previous methods has been used for dogs in Japan; however, the influences of L-HBOT on dogs have not been clarified. To verify the influences of L-HBOT on physiological mechanism in dogs, we investigated blood gas parameters, glutathione peroxidase (GPx) activity, heart rate variability, stress-related hormones and skin conductance (SC) in 4 clinically normal beagle dogs with catheters in their carotid arteries and jugular veins when they were quiet, after running, after receiving L-HBOT (30% oxygen concentration, 1.3 atmospheres absolute, 30 min) or after not receiving L-HBOT. The results showed there were no changes in blood gas parameters, heart rate variability and catecholamine levels after L-HBOT. GPx activity was significantly higher, and the SC and cortisol level were lower in dogs that received L-HBOT than those when they were quiet. These results suggested that L-HBOT may have a small influence on oxygenation dynamics, activate antioxidant enzymes such as GPx, restrain autonomic nervous activity and control the balance between oxidation and antioxidation inside the body.

  6. Brain tissue oxygen-based therapy and outcome after severe traumatic brain injury: a systematic literature review.

    PubMed

    Nangunoori, Raj; Maloney-Wilensky, Eileen; Stiefel, Michael; Park, Soojin; Andrew Kofke, W; Levine, Joshua M; Yang, Wei; Le Roux, Peter D

    2012-08-01

    Observational clinical studies demonstrate that brain hypoxia is associated with poor outcome after severe traumatic brain injury (TBI). In this study, available medical literature was reviewed to examine whether brain tissue oxygen (PbtO2)-based therapy is associated with improved patient outcome after severe TBI. Clinical studies published between 1993 and 2010 that compared PbtO2-based therapy combined with intracranial and cerebral perfusion pressure (ICP/CPP)-based therapy to ICP/CPP-based therapy alone were identified from electronic databases, Index Medicus, bibliographies of pertinent articles, and expert consultation. For analysis, each selected paper had to have adequate data to determine odds ratios (ORs) and confidence intervals (CIs) of outcome described by the Glasgow outcome score (GOS). Seven studies that compared ICP/CPP and PbtO2- to ICP/CPP-based therapy were identified. There were no randomized studies and no comparison studies in children. Four studies, published in 2003, 2009, and 2010 that included 491 evaluable patients were used in the final analysis. Among patients who received PbtO2-based therapy, 121(38.8%) had unfavorable and 191 (61.2%) had a favorable outcome. Among the patients who received ICP/CPP-based therapy 104 (58.1%) had unfavorable and 75 (41.9%) had a favorable outcome. Overall PbtO2-based therapy was associated with favorable outcome (OR 2.1; 95% CI 1.4-3.1). Summary results suggest that combined ICP/CPP- and PbtO2-based therapy is associated with better outcome after severe TBI than ICP/CPP-based therapy alone. Cross-organizational practice variances cannot be controlled for in this type of review and so we cannot answer whether PbtO2-based therapy improves outcome. However, the potentially large incremental value of PbtO2-based therapy provides justification for a randomized clinical trial.

  7. Considering the oxygen effect: Further development of a volumetric model of tumor response to radiation therapy for cervical cancer

    NASA Astrophysics Data System (ADS)

    Winkler, Stephanie S.

    Mathematical modeling of tumor response to radiation therapy (RT) has great potential for designing therapy plans that are more personalized, more adaptive, and more reliable for outcome predictions. A preexisting model of tumor response to radiation therapy for cervical cancer has been shown to generate model parameters that correlate strongly with both tumor local control and disease-specific survival. This model is further developed through incorporation of another effect of RT not previously accounted for: the oxygen effect. An easily obtainable form of input data, hemoglobin level, enables simulation of the oxygen effect simultaneously with the other major model effects. For the Local Control (LC) patient group, the changes in the model parameters caused by incorporation of the oxygen effect are found to significantly improve the agreement of those parameters with actual patient data. For the Local Failure (LF) group and the overall patient group, the oxygen effect is incorporated without significant change to the agreement between the model-simulated output parameters and the actual patient data. Also, a strategy is presented for solving the main model equations to obtain analytic expressions for surviving cell fraction and regression volume ratio as functions of time.

  8. Secondary hyperbaric oxygen therapy for idiopathic sudden sensorineural hearing loss in the subacute and chronic phases.

    PubMed

    Ohno, Kazuchika; Noguchi, Yoshihiro; Kawashima, Yoshiyuki; Yagishita, Kazuyoshi; Kitamura, Ken

    2010-06-01

    This study investigated the efficacy of hyperbaric oxygen therapy (HBOT) as a secondary treatment for patients with idiopathic sudden sensorineural hearing loss (ISSNHL) in the subacute and chronic phases. Forty-eight ISSNHL patients (HBOT group) who had received primary conventional treatment within 4 weeks after onset and underwent HBOT between 4 and 20 weeks post-onset were retrospectively compared with 44 ISSNHL patients (control group) with primary conventional treatment alone. Mean hearing gain was slight, with gains of 5.2 +/- 8.9 dB in the HBOT group and 2.0 +/- 7.6 dB in the control group. However, no significant difference was recognized between the two groups. In the HBOT group, no significant difference was observed in hearing gain among patients with HBOT initial time at 4-7, 8-11, 12-15 or 16-20 weeks after onset. Meanwhile, hearing gain was significantly higher in patients with profound hearing loss than in the other patients. We conclude that the effectiveness of secondary HBOT for ISSNHL patients in either subacute or chronic phase remains unproven, and thus, the decision administer HBOT should be made with caution.

  9. Nocturnal oxygen therapy in patients with chronic heart failure and sleep apnea: a systematic review.

    PubMed

    Bordier, Philippe; Lataste, Aurelia; Hofmann, Pauline; Robert, Frederic; Bourenane, Ghalia

    2016-01-01

    Chronic heart failure (CHF) is a public health problem which affects >2% of the adult population, with high morbidity, mortality, and financial cost. Sleep apnea, prevalent in >50% of patients with CHF, can aggravate vital prognosis due to worsening of heart failure. It is considered that a decrease in the apnea-hypopnea load may improve outcomes for those patients. Nocturnal non invasive ventilation can be proposed to treat sleep apnea in this situation, there being few alternatives. The present review concerns the use of nocturnal oxygen therapy (NOT) in patients suffering from both CHF and sleep apnea. The interest of NOT in this situation lies in its ability to reduce the central apnea-hypopnea index and to improve nocturnal oximetry disorders related to sleep apnea. Impact on cardiac contractility, patient tolerance, side effects, and costs of NOT are also approached as well as the underlying mechanisms of NOT. In addition, the results of the SERVE-HF trial have shown an increased death rate in patients with CHF and central sleep apnea and who were treated with adaptive servo-ventilation versus control patients. This may lead to renewed interest in NOT in those patients.

  10. Assessment of oxygen and carbogen therapy effect in Meniere's disease according to clinical and electroencephalographic data

    NASA Technical Reports Server (NTRS)

    Boronoyev, A. B.

    1980-01-01

    The method of constructing fields on the basis of EEG data gives a quantitative characterization of bioelectrical activity. Fields of average rates of the change of potentials in healthy people have a well defined configuration, where the greatest rates are found in the occipital zones, lower in the frontal and parietal, and least in the temporal zones. In response to functional loads the form of the field remains the same because of a synchronous change in the average rates in both hemispheres of the cerebrum to the same extent. The configuration of the fields of background bioelectric activity of the cerebrum in people with Meniere's disease is not uniform. On the basis of this investigation, a clear correlation was found between the subjective sensations of patients during oxygen and carbogen therapy and the changes in the spatial characteristics of the field of potentials of the cerebrum. This correlation makes it possible to objectively identify the nature of the vascular disturbances in Meniere's disease, develop a pathogenetic treatment plan, and evaluate its effectiveness.

  11. Targeting mitochondrial reactive oxygen species as novel therapy for inflammatory diseases and cancers

    PubMed Central

    2013-01-01

    There are multiple sources of reactive oxygen species (ROS) in the cell. As a major site of ROS production, mitochondria have drawn considerable interest because it was recently discovered that mitochondrial ROS (mtROS) directly stimulate the production of proinflammatory cytokines and pathological conditions as diverse as malignancies, autoimmune diseases, and cardiovascular diseases all share common phenotype of increased mtROS production above basal levels. Several excellent reviews on this topic have been published, but ever-changing new discoveries mandated a more up-to-date and comprehensive review on this topic. Therefore, we update recent understanding of how mitochondria generate and regulate the production of mtROS and the function of mtROS both in physiological and pathological conditions. In addition, we describe newly developed methods to probe or scavenge mtROS and compare these methods in detail. Thorough understanding of this topic and the application of mtROS-targeting drugs in the research is significant towards development of better therapies to combat inflammatory diseases and inflammatory malignancies. PMID:23442817

  12. Roles of Reactive Oxygen Species in Anticancer Therapy with Salvia miltiorrhiza Bunge.

    PubMed

    Hung, Yu-Chiang; Pan, Tai-Long; Hu, Wen-Long

    2016-01-01

    Cancer is a leading cause of death worldwide. We aim to provide a systematic review about the roles of reactive oxygen species (ROS) in anticancer therapy with Salvia miltiorrhiza Bunge (Danshen). Danshen, including its lipophilic and hydrophilic constituents, is potentially beneficial for treating various cancers. The mechanisms of ROS-related anticancer effects of Danshen vary depending on the specific type of cancer cells involved. Danshen may enhance TNF-α-induced apoptosis, upregulate caspase-3, caspase-8, caspase-9, endoplasmic reticulum stress, P21, P53, Bax/Bcl-2, DR5, and AMP-activated protein kinase, or activate the p38/JNK, mitogen-activated protein kinase, and FasL signaling pathways. Conversely, Danshen may downregulate human telomerase reverse transcriptase mRNA, telomerase, survivin, vascular endothelial growth factor/vascular endothelial growth factor receptor 2, CD31, NF-κB, Erk1/2, matrix metalloproteinases, microtubule assembly, and receptor tyrosine kinases including epidermal growth factor receptors, HER2, and P-glycoprotein and inhibit the PI3K/Akt/mTOR or estrogen receptor signaling pathways. Therefore, Danshen may inhibit cancer cells proliferation through antioxidation on tumor initiation and induce apoptosis or autophagy through ROS generation on tumor progression, tumor promotion, and tumor metastasis. Based on the available evidence regarding its anticancer properties, this review provides new insights for further anticancer research or clinical trials with Danshen. PMID:27579153

  13. Roles of Reactive Oxygen Species in Anticancer Therapy with Salvia miltiorrhiza Bunge

    PubMed Central

    Pan, Tai-Long

    2016-01-01

    Cancer is a leading cause of death worldwide. We aim to provide a systematic review about the roles of reactive oxygen species (ROS) in anticancer therapy with Salvia miltiorrhiza Bunge (Danshen). Danshen, including its lipophilic and hydrophilic constituents, is potentially beneficial for treating various cancers. The mechanisms of ROS-related anticancer effects of Danshen vary depending on the specific type of cancer cells involved. Danshen may enhance TNF-α-induced apoptosis, upregulate caspase-3, caspase-8, caspase-9, endoplasmic reticulum stress, P21, P53, Bax/Bcl-2, DR5, and AMP-activated protein kinase, or activate the p38/JNK, mitogen-activated protein kinase, and FasL signaling pathways. Conversely, Danshen may downregulate human telomerase reverse transcriptase mRNA, telomerase, survivin, vascular endothelial growth factor/vascular endothelial growth factor receptor 2, CD31, NF-κB, Erk1/2, matrix metalloproteinases, microtubule assembly, and receptor tyrosine kinases including epidermal growth factor receptors, HER2, and P-glycoprotein and inhibit the PI3K/Akt/mTOR or estrogen receptor signaling pathways. Therefore, Danshen may inhibit cancer cells proliferation through antioxidation on tumor initiation and induce apoptosis or autophagy through ROS generation on tumor progression, tumor promotion, and tumor metastasis. Based on the available evidence regarding its anticancer properties, this review provides new insights for further anticancer research or clinical trials with Danshen. PMID:27579153

  14. A review of mechanical adjuncts in wound healing: hydrotherapy, ultrasound, negative pressure therapy, hyperbaric oxygen, and electrostimulation.

    PubMed

    Hess, Christopher L; Howard, Michael A; Attinger, Christopher E

    2003-08-01

    Chronic or non-healing wounds may develop in the setting of many diseases and are the source of considerable morbidity as well as health costs. These wounds demand an aggressive, multifactorial approach including surgical debridement, revascularization, antibiotics and dressings. In addition several adjuvant treatment methods have been developed to further stimulate healing. Whirlpool, although used frequently, has not been proven to be of benefit. However, pulsed lavage does show a promising future. Ultrasound has demonstrated beneficial effects but further controlled studies are needed. Subatmospheric pressure therapy is associated with few complications and is fast becoming a mainstay of adjuvant therapy. Hyperbaric oxygen therapy has been shown to be effective for many types of wounds. Unfortunately, cost and access to chambers may prohibit its use on a routine basis. Finally, electrostimulation may be one of the up and coming therapies for the future. Though, more studies are needed to determine the mode of delivery for various types of wounds.

  15. Combined sonodynamic and antimetabolite therapy for the improved treatment of pancreatic cancer using oxygen loaded microbubbles as a delivery vehicle.

    PubMed

    McEwan, Conor; Kamila, Sukanta; Owen, Joshua; Nesbitt, Heather; Callan, Bridgeen; Borden, Mark; Nomikou, Nikolitsa; Hamoudi, Rifat A; Taylor, Mark A; Stride, Eleanor; McHale, Anthony P; Callan, John F

    2016-02-01

    In this manuscript we describe the preparation of an oxygen-loaded microbubble (O2MB) platform for the targeted treatment of pancreatic cancer using both sonodynamic therapy (SDT) and antimetabolite therapy. O2MB were prepared with either the sensitiser Rose Bengal (O2MB-RB) or the antimetabolite 5-fluorouracil (O2MB-5FU) attached to the microbubble (MB) surface. The MB were characterised with respect to size, physical stability and oxygen retention. A statistically significant reduction in cell viability was observed when three different pancreatic cancer cell lines (BxPc-3, MIA PaCa-2 and PANC-1), cultured in an anaerobic cabinet, were treated with both SDT and antimetabolite therapy compared to either therapy alone. In addition, a statistically significant reduction in tumour growth was also observed when ectopic human xenograft BxPC-3 tumours in SCID mice were treated with the combined therapy compared to treatment with either therapy alone. These results illustrate not only the potential of combined SDT/antimetabolite therapy as a stand alone treatment option in pancreatic cancer, but also the capability of O2-loaded MBs to deliver O2 to the tumour microenvironment in order to enhance the efficacy of therapies that depend on O2 to mediate their therapeutic effect. Furthermore, the use of MBs to facilitate delivery of O2 as well as the sensitiser/antimetabolite, combined with the possibility to activate the sensitiser using externally applied ultrasound, provides a more targeted approach with improved efficacy and reduced side effects when compared with conventional systemic administration of antimetabolite drugs alone.

  16. TH-C-17A-05: Cherenkov Excited Phosphorescence Oxygen (CEPhOx) Imaging During Multi-Beam Radiation Therapy

    SciTech Connect

    Zhang, R; Pogue, B; Holt, R; Esipova, T; Vinogradov, S; Gladstone, D

    2014-06-15

    Purpose: Cherenkov radiation is created during external beam radiation therapy that can excite phosphorescence in tissue from oxygen-sensitive, bio-compatible probes. Utilizing the known spatial information of the treatment plan with directed multiple beam angles, Cherenkov Excited Phosphorescence Oxygen (CEPhOx) imaging was realized from the reconstructions of Cherenkov excited phosphorescence lifetime. Methods: Platinum(II)-G4 (PtG4) was used as the oxygen-sensitive phosphorescent probe and added to a oxygenated cylindrical liquid phantom with a oxygenated/deoxygenated cylindrical anomaly. Cherenkov excited phosphorescence was imaged using a time-gated ICCD camera temporallysynchronized to the LINAC pulse output. Lifetime reconstruction was carried out in NIRFAST software. Multiple angles of the incident radiation beam was combined with the location of the prescribed treatment volume (PTV) to improve the tomographic recovery as a function of location. The tissue partial pressure of oxygen (pO2) in the background and PTV was calculated based on the recovered lifetime distribution and Stern-Volmer equation. Additionally a simulation study was performed to examine the accuracy of this technique in the setting of a human brain tumor. Results: Region-based pO2 values in the oxygenated background and oxygenated/deoxygenated PTV were correctly recovered, with the deoxygenated anomaly (15.4 mmHg) easily distinguished from the oxygenated background (143 mmHg). The data acquisition time could be achieved within the normal irradiation time for a human fractionated plan. The simulations indicated that CEPhOx would be a sufficient to sample tumor pO2 sensing from tumors which are larger than 2cm in diameter or within 23mm depth from the surface. Conclusion: CEPhOx could be a novel imaging tool for pO2 assessment during external radiation beam therapy. It is minimally invasive and should work within the established treatment plan of radiation therapy with multiple beams in

  17. COUPLED HBO AND NBO VARIATIONS IN THE Z SOURCE GX 5-1: INNER ACCRETION DISK AS THE LOCATION OF QPOs

    SciTech Connect

    Sriram, K.; Choi, C. S.; Rao, A. R.

    2011-12-20

    The simultaneous and coupled evolution of horizontal branch oscillation (HBO) and normal branch oscillation (NBO) in Z-type sources suggests that the production of HBO is connected to NBO and is caused by changes in the physical/radiative properties of the inner accretion disk, although there is a lack of substantial spectral evidence to support this. In this Letter, we present the results of an analysis of an RXTE observation of the Z source GX 5-1, where the 6 Hz NBO is simultaneously detected along with an HBO at 51 Hz. The variations in the intensity and the associated power density spectrum indicate that the HBO and NBO are strongly coupled, originating from the same location in the inner accretion disk. The absence of HBO and NBO in the lower energy bands, an increase in the rms amplitude with energy, and a smooth transition among them suggest that they are produced in the hot inner regions of the accretion disk. Based on a spectral analysis, we found a signature of changing or physically modified inner disk front during the coupled HBO and NBO evolution. We explore the various models to explain the observed phenomenon and propose that the NBO is affiliated to the oscillations in the thick/puffed-up inner region of the accretion disk.

  18. An anxiolytic-like effect of hyperbaric oxygen in the mouse light/dark exploration test

    PubMed Central

    Carlile, Edina L.; Shirachi, Donald Y.; Quock, Raymond M.

    2011-01-01

    Aims We studied whether hyperbaric oxygen (HBO2) treatment, which is known to increase production of nitric oxide (NO) in the brain, might also produce an NO-dependent anxiolytic-like behavioral response. Main methods Male NIH Swiss mice (20–25 g) were subjected to a 60-min HBO2 treatment at different absolute atmospheres, and anxiety was assessed using the light/dark exploration test at different time intervals following the cessation of HBO2 treatment. To ascertain the underlying mechanism of action, other groups of mice were pretreated with the NO synthase inhibitor NG-monomethyl-L-arginine acetate, the NO scavenger 2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazolyl-1-oxy-3-oxide (carboxy-PTIO), the soluble guanylyl cyclase-inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or the benzodiazepine antagonist flumazenil to determine their influence on the HBO2-induced anxiolytic-like effect. Key findings A 60-min HBO2 treatment at 3.0 absolute atmospheres increased the time spent by mice in the light compartment that lasted up to 90 min following the end of HBO2 treatment. This anxiolytic effect of HBO2 was significantly reduced by pretreatment with L-NMMA, carboxy-PTIO, ODQ and flumazenil. Significance Based on these findings, we conclude that a 60-min HBO2 treatment is capable of inducing an anxiolytic effect that possibly involves NO, cyclic GMP and the benzodiazepine binding site. PMID:22154905

  19. The facilitatory effects of hyperbaric oxygen treatment on membrane bone wound healing in a rat calvarial defect model.

    PubMed

    Hayashi, Kairi; Takahashi, Toshiyuki; Ikegawa, Mai; Horie, Masaki; Oyaizu, Takuya; Enomoto, Mitsuhiro; Shibata, Shunichi; Yagishita, Kazuyoshi; Ueno, Toshiaki

    2016-01-01

    We examined the effect of hyperbaric oxygen (HBO2) treatment on bone wound healing in a rat calvarial defect. Critical-sized defects were created in the calvaria of adult Wistar rats. The animals were divided into four groups--HBO2, normobaric oxygen, hyperbaric air, and no treatment. Treatments were performed five days a week, for two weeks. Micro-computerized tomography and histological analysis were used to evaluate the bone defects. Regenerated bone areas were calculated as the percentage of new bone in the cross-sectional area of defect. The new bone cross-sectional area was significantly greater in the HBO2 group than in the other groups. There were no significant differences in the numbers of nucleated cells in the new bone areas. Although new bone volume per defect volume was significantly greater in the HBO2 group than in the other groups, no significant differences in bone mineral density in the new bone area were observed. These findings indicate the facilitatory role of HBO2 treatment on bone wound healing in the rat calvarial bone defect, and it does not appear to have any negative effects on bone maturity. We propose that HBO2 treatment would be useful in promoting bone regeneration following injury in the orofacial region.

  20. The facilitatory effects of hyperbaric oxygen treatment on membrane bone wound healing in a rat calvarial defect model.

    PubMed

    Hayashi, Kairi; Takahashi, Toshiyuki; Ikegawa, Mai; Horie, Masaki; Oyaizu, Takuya; Enomoto, Mitsuhiro; Shibata, Shunichi; Yagishita, Kazuyoshi; Ueno, Toshiaki

    2016-01-01

    We examined the effect of hyperbaric oxygen (HBO2) treatment on bone wound healing in a rat calvarial defect. Critical-sized defects were created in the calvaria of adult Wistar rats. The animals were divided into four groups--HBO2, normobaric oxygen, hyperbaric air, and no treatment. Treatments were performed five days a week, for two weeks. Micro-computerized tomography and histological analysis were used to evaluate the bone defects. Regenerated bone areas were calculated as the percentage of new bone in the cross-sectional area of defect. The new bone cross-sectional area was significantly greater in the HBO2 group than in the other groups. There were no significant differences in the numbers of nucleated cells in the new bone areas. Although new bone volume per defect volume was significantly greater in the HBO2 group than in the other groups, no significant differences in bone mineral density in the new bone area were observed. These findings indicate the facilitatory role of HBO2 treatment on bone wound healing in the rat calvarial bone defect, and it does not appear to have any negative effects on bone maturity. We propose that HBO2 treatment would be useful in promoting bone regeneration following injury in the orofacial region. PMID:27265990

  1. Involvement of spinal cord opioid mechanisms in the acute antinociceptive effect of hyperbaric oxygen in mice1

    PubMed Central

    Heeman, Jacqueline H.; Zhang, Yangmiao; Shirachi, Donald Y.; Quock, Raymond M.

    2013-01-01

    Earlier research has demonstrated that treatment with hyperbaric oxygen (HBO2) can elicit an antinociceptive response in models of acute pain. We have demonstrated that this antinociceptive effect is centrally-mediated and is dependent on opioid receptors. The purpose of the present study was to examine the role of endogenous opioid peptides and opioid receptors specifically in the spinal cord in the acute antinociceptive effect of HBO2 in mice. Male NIH Swiss mice were exposed to HBO2 (100% oxygen @ 3.5 atmospheres absolute) for 11 min and their antinociceptive responsiveness was determined using the glacial acetic acid-induced abdominal constriction test. HBO2-induced antinociception was sensitive to antagonism by intrathecal (i.t.) pretreatment with the κ- and μ-selective opioid antagonists norbinaltorphimine and β-funalrexamine, respectively, but not the δ-selective antagonist naltrindole. The antinociceptive effect of HBO2 was also significantly attenuated by i.t. pretreatment with a rabbit antiserum against rat dynorphin1-13 but not antisera against β-endorphin or methionine-enkephalin. Based on these experimental findings, the acute antinociceptive effect of HBO2 appears to involve neuronal release of dynorphin and activation of κ and μ opioid receptors in the spinal cord. PMID:24113418

  2. Technical aspects of oxygen saving devices.

    PubMed

    Brambilla, I; Arlati, S; Chiusa, I; Micallef, E

    1990-01-01

    Oxygen economizing devices have been extensively studied, both at rest and during muscular exercise, in an attempt to increase the autonomy of a portable oxygen apparatus. The aim of this study is threefold: first, to suggest a simple method to verify in a simple way the technical accuracy of a demand flow oxygen delivery device; second, to suggest how we can monitor in a simple way the clinical efficacy of an economizer; and third, to remember that we can utilize an oxygen saving device to give a better protection than nasal prongs against the worsening of HbO2 desaturation induced by exercise. PMID:2117198

  3. Hyperbaric oxygen therapy for postoperative spinal dural arterio-venous fistula patients: An observational cohort study.

    PubMed

    Chen, Sichang; Ma, Yongjie; Liang, Peipeng; Wang, Xiaohui; Peng, Chao; Bian, Lisong; Liu, Jiang; Ding, Jianzhang; Zhang, Hongqi; Ling, Feng

    2016-09-01

    Spinal dural arterio-venous fistula (SDAVF) is a common type of spinal vascular malformation. Surgical obliteration of the fistula can cure SDAVF anatomically, but the functional outcome is unsatisfactory.The aim of the study was to evaluate the effect of hyperbaric oxygen therapy (HBOT) on the functional recovery of postoperative SDAVF patients.This prospective cohort study included postoperative SDAVF patients. Patients were divided into control and HBOT groups. Patients in control group received conventional treatment, whereas those in the HBOT group received conventional treatment plus HBOT (2.0 atmospheric pressure absolute, 14 days). Follow-up was done at 1, 3, 6, 12, and 24 months after surgery for evaluation, including symptoms. To assess the effectiveness of HBOT on SDAVF patients, we compared the postoperative magnetic resonance imaging and neurological outcomes of each group with respect to modified Aminoff-Lougue scale and modified Denis Pain and Numbness Scale.From September 1, 2013 to January 31, 2014, 33 SDAVF patients (27 male) treated by microsurgery were included in this study. Sixteen patients were in the HBOT group and 17 patients were in the control group. At 24 months follow-up, the improvement of mDPNS for the HBOT group was significantly larger than those of the control group (2.25 vs 0.88; P = 0.005). In the HBOT group, the average length of hypersignal in magnetic resonance imaging T2 image decrease at 3 months after surgery was 3.25 compared with 2.29 in the control group (P = 0.009). No major adverse effects were reported for all 16 patients who received HBOT.The current findings suggest that HBOT is an effective and safe treatment to relieve lower body pain and numbness for postoperative SDAVF patients. PMID:27631206

  4. LASERS IN MEDICINE: Light-oxygen effect in cells and its potential applications in tumour therapy (review)

    NASA Astrophysics Data System (ADS)

    Zakharov, S. D.; Ivanov, Andrei V.

    1999-12-01

    The light-oxygen effect (POE) represents damage (and at low optical doses, activation) of cells by photogeneration of molecular singlet oxygen from O2 dissolved in cells, in accordance with the reaction: 3O2+hν→1O2→ biological effect. The phases of evolution of the LOE are similar to the phases, observed in cell experiments, of the photodynamic effect (PDE) the mechanism of which is the basis of the familiar method of photodynamic cancer therapy. The reported proofs of the occurrence of the LOE are in the form of detailed spectra of the biological action of optical radiation on cells recorded in four spectral intervals with the aid of tunable lasers. Allowances are made for the relationships governing a new type of cell excitation, associated with reversible structural transitions in the biomembrane. A demonstration is reported of the same efficiency of cw and pulsed irradiation. An analysis is made of the reasons why the optical doses initiating the PDE and the LOE are comparable. The results are given of the first experimental applications of the LOE in tumour therapy. Identification of the primary photoacceptor (O2) in cell biostimulation and photodestruction provides a scientific basis for the development of low-intensity laser light-oxygen cancer therapy methods.

  5. The bactericidal effect of 470-nm light and hyperbaric oxygen on methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Bumah, Violet Vakunseh; Whelan, Harry Thomas; Masson-Meyers, Daniela Santos; Quirk, Brendan; Buchmann, Ellen; Enwemeka, Chukuka Samuel

    2015-04-01

    It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28 % bacterial growth, while 470-nm blue light alone suppresses up to 92 % methicillin-resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470-nm light (55 J/cm(2)) and HBO will yield 100 % bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3 × 10(6), 5 × 10(6), 7 × 10(6), 8 × 10(6), or 12 × 10(6) CFU/ml and treated each concentration in four groups as follows: (1) control (no treatment) (2) photo-irradiation only, (3) photo-irradiation then HBO, (4) HBO only, and (5) HBO then photo-irradiation. Bacteria colonies were then quantified. The results showed that at each bacterial concentration, HBO alone was significantly less effective in suppressing MRSA than photo-irradiation or combined HBO and photo-irradiation (p < 0.0001). Similarly, at no bacterial concentration did combined HBO and 470-nm light treatment yield a statistically better result than 470-nm light alone (p > 0.05), neither did HBO treatment either before or after irradiation make a difference. Furthermore, at no bacterial concentration was 100 % MRSA suppression achieved. Indeed, the maximum bacterial suppression attained was in the mild infection model (3 × 10(6) CFU/ml), with blue light producing 97.3 ± 0.2 % suppression and HBO + 55 J/cm(2) yielding 97.5 ± 2.5 % suppression. We conclude that (1) HBO and 470-nm light individually suppress MRSA growth; (2) 470-nm blue light is more effective in suppressing MRSA than HBO; and (3) HBO did not act synergistically to heighten the bactericidal effect of 470-nm light.

  6. High-Flow Nasal Cannula Oxygen Therapy in Adults: Physiological Benefits, Indication, Clinical Benefits, and Adverse Effects.

    PubMed

    Nishimura, Masaji

    2016-04-01

    High-flow nasal cannula (HFNC) oxygen therapy is carried out using an air/oxygen blender, active humidifier, single heated tube, and nasal cannula. Able to deliver adequately heated and humidified medical gas at flows up to 60 L/min, it is considered to have a number of physiological advantages compared with other standard oxygen therapies, including reduced anatomical dead space, PEEP, constant F(IO2), and good humidification. Although few large randomized clinical trials have been performed, HFNC has been gaining attention as an alternative respiratory support for critically ill patients. Published data are mostly available for neonates. For critically ill adults, however, evidence is uneven because the reports cover various subjects with diverse underlying conditions, such as hypoxemic respiratory failure, exacerbation of COPD, postextubation, preintubation oxygenation, sleep apnea, acute heart failure, and conditions entailing do-not-intubate orders. Even so, across the diversity, many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces the need for respiratory support escalation. Some important issues remain to be resolved, such as definitive indications for HFNC and criteria for timing the starting and stopping of HFNC and for escalating treatment. Despite these issues, HFNC has emerged as an innovative and effective modality for early treatment of adults with respiratory failure with diverse underlying diseases. PMID:27016353

  7. Hyperbaric Oxygen Therapy in Treating Long-Term Gastrointestinal Adverse Effects Caused by Radiation Therapy in Patients With Pelvic Cancer

    ClinicalTrials.gov

    2011-07-14

    Bladder Cancer; Cervical Cancer; Colorectal Cancer; Endometrial Cancer; Gastrointestinal Complications; Long-term Effects Secondary to Cancer Therapy in Adults; Ovarian Cancer; Prostate Cancer; Radiation Toxicity; Sarcoma; Testicular Germ Cell Tumor; Vaginal Cancer

  8. Conscious sedation with inhaled 50% nitrous oxide/oxygen premix in photodynamic therapy sessions for vulvar lichen sclerosus treatment*

    PubMed Central

    Cabete, Joana; Campos, Sara; Lestre, Sara

    2015-01-01

    Photodynamic therapy has been described as an effective therapeutic option in selected cases of anogenital lichen sclerosus that are refractory to first-line treatments. However, procedure-related pain is a limiting factor in patient adherence to treatment. The authors report the case of a 75-year-old woman with highly symptomatic vulvar lichen sclerosus, successfully treated with photodynamic therapy. An inhaled 50% nitrous oxide/oxygen premix was administered during sessions, producing a pain-relieving, anxiolytic, and sedative effect without loss of consciousness. This ready-to-use gas mixture may be a well-tolerated and accepted alternative to classical anesthetics in Photodynamic therapy, facilitating patients' adherence to illumination of pain-prone areas. PMID:25672311

  9. Synthesis of Hemoglobin Conjugated Polymeric Micelle: A ZnPc Carrier with Oxygen Self-Compensating Ability for Photodynamic Therapy.

    PubMed

    Wang, Shasha; Yuan, Fang; Chen, Kui; Chen, Gaojian; Tu, Kehua; Wang, Hongjun; Wang, Li-Qun

    2015-09-14

    Photodynamic therapy (PDT) is a promising singlet oxygen ((1)O2) mediated clinical treatment for many tumors. As the source of (1)O2, oxygen plays an important role in the curative effect of PDT. However, the facts of photochemical depletion of oxygen and the intrinsic hypoxic microenvironment of tumors remain the major challenges. In this work, a novel photosensitizer carrier with oxygen self-compensating ability was designed for PDT. It was synthesized via chemical conjugation of hemoglobin (Hb) to polymeric micelles formed by triblock copolymers of poly(ethylene glycol)-block-poly(acrylic acid)-block-polystyrene (PEG-b-PAA-b-PS). The PEG-b-PAA-b-PS and resultant micelles in aqueous solution were comprehensively characterized by means of FTIR, (1)H NMR, GPC, DLS, TEM, and fluorescence spectroscopy. The oxygen-binding capacity and antioxidative activity of the Hb conjugated micelles were evaluated via UV-vis spectroscopy. In addition, compared with the control micelles without Hb, the Hb conjugated photosensitizer carrier was able to generate more (1)O2 and exert greater photocytotoxicity on Hela cells in vitro.

  10. Noninvasive tumor oxygen imaging by photoacoustic lifetime imaging integrated with photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Shao, Qi; Biel, Merrill A.; Ashkenazi, Shai

    2014-03-01

    Oxygen plays a major role in cancer biology and tumor progression. In PDT, the reduction in efficacy is directly related to lack of oxygen because its molecular mechanism relies on oxygen as an energy mediator. Measuring tumor oxygenation can provide physicians with better diagnosis and optimization of treatment plans. However, clinical tools for directly assessing tissue oxygenation are limited. The gold standard is oxygen needle electrode, which is invasive and measures oxygen level at a single location. We present our work on developing a combined treatment-imaging modality that integrates PDT and photoacoustic oxygen imaging. We propose a system designed for clinical treatments of cancer of the oral cavity. Tissue oxygen imaging is performed by applying Photoacoustic Lifetime Imaging (PALI). This technology relies on photoacoustic probing of oxygen-dependent excitation lifetime of Methylene Blue. The dye is excited by the same wavelength of illumination source for PDT. Once excited, the population of photosensitizer molecules at triplet state has a lifetime depending on the oxygen level. The transition from excited triplet state to ground state can be probe by another laser, which generate photoacoustic signal that is used to map the lifetime. The lifetime map is then converted to pO2 distribution. We expect that PDT efficacy can be improved by applying PALI imaging feedback in real-time to determine, and individually optimize, O2-enriched gas breathing parameters and PDT light-dose during treatment. Successful implementation of PALI in PDT can also drive its application in guiding other cancer treatments that are affected by hypoxia.

  11. Evaluation of results of conservative therapy in patients with transient osteoporosis of hip.

    PubMed

    Guler, Olcay; Ozyurek, Selahattin; Cakmak, Selami; Isyar, Mehmet; Mutlu, Serhat; Mahirogullari, Mahir

    2015-09-01

    The present study aimed to review the general characteristics of 18 cases diagnosed with transient osteoporosis of the hip (TOH) in our hospital within a 3-year period and to present their follow-up results after conservative treatment. A retrospective evaluation was made of the treatment and results of follow-up of TOH cases using physical examination and laboratory findings, hip radiographs and magnetic resonance imaging (MRI) and Harris Hip Scores (HHS). The mean duration of complaints of 6 females (mean age, 34.3±4.3 years) and 12 males (mean age, 40.7±10.5 years) was 6.1±2.7 weeks before the treatment. Three female patients had a history of giving birth by cesarean delivery. None of the patients had any history of trauma. MRI revealed increased intensity in T2 sequences and decreased intensity in T1 sequences in the proximal aspect of the femur. None of the patients had subchondral collapse or intra-articular effusion. For 3 female patients who were breastfeeding, no medical therapy was given, but only hyperbaric oxygen (HBO) therapy and forearm crutches. As standard management, the other patients were prevented from weight-bearing with the use of forearm crutches and medical therapy of diclofenac sodium, acetylsalicylic acid, and risedronate sodium was administered and additional HBO therapy. Clinical and radiological improvements were observed in all patients. None of the patients had avascular necrosis (AVN) of the femoral head. There was no record of therapy-related complications. While HHS was 55.6±7.8 before the treatment, it increased to 88.8±5.8 in the 3rd month and to 96.0±1.8 in the 6th month after the treatment. This change in score over time was found to be significant.

  12. The experiences of parents and nurses of hospitalised infants requiring oxygen therapy for severe bronchiolitis: A phenomenological study.

    PubMed

    Peeler, Alison; Fulbrook, Paul; Kildea, Sue

    2015-06-01

    Bronchiolitis is a major cause of children's admission to hospital. The study aim was to describe the experiences of parents who had, or nurses who cared for, a child admitted to hospital for severe bronchiolitis requiring oxygen therapy. A descriptive phenomenological approach was used to interview 12 mothers and 12 nurses. The findings were clustered into three domains: fear, parent-child interaction and technical caring. The mothers found the experience to be extremely frightening, based on their fear that their child could die. This was compounded by their lack of knowledge and understanding about what was happening and their inability to fulfil their mothering role. Although nurses recognised that parents were anxious, they did not seem to appreciate fully the depth of fear and emotion that mothers were experiencing and tended to describe procedural aspects of their role. The mothers' relationship with their child was focused upon physical contact and the desire to comfort their child. Their ability to do so was significantly impacted upon by the method of oxygen delivery to their child. For nurses, although they recognised the psychosocial dimension, their emphasis was on health and safety aspects of oxygen therapy, both for the child and themselves.

  13. Evaluation of N-acetylcysteine and methylprednisolone as therapies for oxygen and acrolein-induced lung damage

    SciTech Connect

    Critchley, J.A.J.H. ); Beeley, J.M.; Clark, R.J.; Buchanan, J.D. ); Summerfield, M.; Bell, S. ); Spurlock, M.S.; Edginton, J.A.G. )

    1990-04-01

    Reactive oxidizing species are implicated in the etiology of a range of inhalational pulmonary injuries. Consequently, various free radical scavengers have been tested as potential prophylactic agents. The sulfydryl compound, N-acetylcysteine (NAC) is the only such compound clinically available for use in realistic dosages, and it is well established as an effective antidote for the hepatic and renal toxicity of paracetamol. Another approach in pulmonary injury prophylaxis is methylprednisolone therapy. The authors evaluated NAC and methylprednisolone in two rats models of inhalation injury: 40-hr exposure to >97% oxygen at 1.1 bar and 15-min exposure to acrolein vapor (210 ppm). The increases in lung wet/dry weight ratios, seen with both oxygen and acrolein toxicity were reduced with both treatments. However, with oxygen, NAC therapy was associated with considerably increased mortality and histological changes. Furthermore, IP NAC administration resulted in large volumes of ascitic fluid. With acrolein, IV, NAC had no significant effect on mortality or pulmonary histological damage. Methylprednisolone had no beneficial effects on either the mortality or histological damage observed in either toxicity model. They caution against the ad hoc use of NAC in the management of inhalational pulmonary injury.

  14. High-flow nasal cannula oxygen therapy for acute exacerbation of interstitial pneumonia: A case series.

    PubMed

    Horio, Yukihiro; Takihara, Takahisa; Niimi, Kyoko; Komatsu, Masamichi; Sato, Masako; Tanaka, Jun; Takiguchi, Hiroto; Tomomatsu, Hiromi; Tomomatsu, Katsuyoshi; Hayama, Naoki; Oguma, Tsuyoshi; Aoki, Takuya; Urano, Tetsuya; Takagi, Atsushi; Asano, Koichiro

    2016-03-01

    We report 3 cases (all men, age: 69-81 years) of acute exacerbation of interstitial pneumonia (AEIP) that were successfully treated with a high-flow nasal cannula (HFNC), which delivers heated, humidified gas at a fraction of inspired oxygen (FIO2) up to 1.0 (100%). Oxygenation was insufficient under non-rebreathing face masks; however, the introduction of HFNC with an FIO2 of 0.7-1.0 (flow rate: 40 L/min) improved oxygenation and was well-tolerated until the partial pressure of oxygen in blood/FIO2 ratio increased (between 21 and 26 days). Thus, HFNC might be an effective and well-tolerated therapeutic addition to the management of AEIP. PMID:26879483

  15. Ultrasound-mediated destruction of paclitaxel and oxygen loaded lipid microbubbles for combination therapy in ovarian cancer xenografts.

    PubMed

    Liu, Li; Chang, Shufang; Sun, Jiangchuan; Zhu, Shenyin; Yin, Minyue; Zhu, Yi; Wang, Zhigang; Xu, Ronald X

    2015-05-28

    We have synthesized multifunctional oxygen and paclitaxel loaded microbubbles (OPLMBs) for ultrasound mediated delivery of combination therapy in an ovarian cancer xenograft model. In comparison with other therapeutic options, intravenous injection of OPLMBs followed by ultrasound mediation yielded a superior therapeutic outcome. Immunohistochemical analyses of the dissected tumor tissue confirmed the increased tumor apoptosis and the reduced VEGF expression after treatment. Western Blot tests further confirmed the decreased expressions of HIF-1α and P-gp. Our experiment suggests that ultrasound mediation of OPLMBs may provide a promising drug delivery strategy for the combination treatment of ovarian cancer.

  16. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment.

    PubMed

    Topaz, Moris

    2012-05-01

    Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review.

  17. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment.

    PubMed

    Topaz, Moris

    2012-05-01

    Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review. PMID:23162229

  18. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment

    PubMed Central

    Topaz, Moris

    2012-01-01

    Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review. PMID:23162229

  19. A Near-Infrared Triggered Nanophotosensitizer Inducing Domino Effect on Mitochondrial Reactive Oxygen Species Burst for Cancer Therapy.

    PubMed

    Yu, Zhengze; Sun, Qiaoqiao; Pan, Wei; Li, Na; Tang, Bo

    2015-11-24

    Photodynamic therapy (PDT) is a well-established modality for cancer therapy, which locally kills cancer cells when light irradiates a photosensitizer. However, conventional PDT is often limited by the extremely short lifespan and severely limited diffusion distance of reactive oxygen species (ROS) generated by photosensitizer, as well as the penetration depth of visible light activation. Here, we develop a near-infrared (NIR) triggered nanophotosensitizer based on mitochondria targeted titanium dioxide-coated upconversion nanoparticles for PDT against cancer. When irradiated by NIR laser, the nanophotosensitizer could produce ROS in mitochondria, which induced the domino effect on ROS burst. The overproduced ROS accumulated in mitochondria, resulting in mitochondrial collapse and irreversible cell apoptosis. Confocal fluorescence imaging indicated that the mitochondrial targeting and real-time imaging of ROS burst could be achieved in living cells. The complete removal of tumor in vivo confirmed the excellent therapeutic effect of the nanophotosensitizer.

  20. Understanding the pathology and treatment of traumatic brain injury and posttraumatic stress disorder: a therapeutic role for hyperbaric oxygen therapy.

    PubMed

    Guedes, Vivian A; Song, Shuojing; Provenzano, Martina; Borlongan, Cesario V

    2016-01-01

    Traumatic brain injury (TBI) is an intracranial injury caused by external trauma leading to different degrees of brain damage. TBI can cause a wide array of symptoms and range in severity from concussion to coma and death. The link between TBI and posttraumatic stress disorder (PTSD) has received increasing attention due to the high incidence of these conditions in soldiers returning from recent conflicts. TBI has been associated with an increased risk of PTSD. Additionally, TBI and PTSD often demonstrate overlapping symptoms. In this article, we discuss the different forms of TBI and their links to PTSD. We also discuss current therapies for TBI and PTSD, in particular detailing the therapeutic potential of hyperbaric oxygen therapy in the management of these conditions.

  1. Anti-Inflammatory Effects of Hyperbaric Oxygenation during DSS-Induced Colitis in BALB/c Mice Include Changes in Gene Expression of HIF-1α, Proinflammatory Cytokines, and Antioxidative Enzymes

    PubMed Central

    2016-01-01

    Reactive oxygen species (ROS) and nitrogen species have an indispensable role in regulating cell signalling pathways, including transcriptional control via hypoxia inducible factor-1α (HIF-1α). Hyperbaric oxygenation treatment (HBO2) increases tissue oxygen content and leads to enhanced ROS production. In the present study DSS-induced colitis has been employed in BALB/c mice as an experimental model of gut mucosa inflammation to investigate the effects of HBO2 on HIF-1α, antioxidative enzyme, and proinflammatory cytokine genes during the colonic inflammation. Here we report that HBO2 significantly reduces severity of DSS-induced colitis, as evidenced by the clinical features, histological assessment, impaired immune cell expansion and mobilization, and reversal of IL-1β, IL-2, and IL-6 gene expression. Gene expression and antioxidative enzyme activity were changed by the HBO2 and the inflammatory microenvironment in the gut mucosa. Strong correlation of HIF-1α mRNA level to GPx1, SOD1, and IL-6 mRNA expression suggests involvement of HIF-1α in transcriptional regulation of these genes during colonic inflammation and HBO2. This is further confirmed by a strong correlation of HIF-1α with known target genes VEGF and PGK1. Results demonstrate that HBO2 has an anti-inflammatory effect in DSS-induced colitis in mice, and this effect is at least partly dependent on expression of HIF-1α and antioxidative genes.

  2. Anti-Inflammatory Effects of Hyperbaric Oxygenation during DSS-Induced Colitis in BALB/c Mice Include Changes in Gene Expression of HIF-1α, Proinflammatory Cytokines, and Antioxidative Enzymes

    PubMed Central

    2016-01-01

    Reactive oxygen species (ROS) and nitrogen species have an indispensable role in regulating cell signalling pathways, including transcriptional control via hypoxia inducible factor-1α (HIF-1α). Hyperbaric oxygenation treatment (HBO2) increases tissue oxygen content and leads to enhanced ROS production. In the present study DSS-induced colitis has been employed in BALB/c mice as an experimental model of gut mucosa inflammation to investigate the effects of HBO2 on HIF-1α, antioxidative enzyme, and proinflammatory cytokine genes during the colonic inflammation. Here we report that HBO2 significantly reduces severity of DSS-induced colitis, as evidenced by the clinical features, histological assessment, impaired immune cell expansion and mobilization, and reversal of IL-1β, IL-2, and IL-6 gene expression. Gene expression and antioxidative enzyme activity were changed by the HBO2 and the inflammatory microenvironment in the gut mucosa. Strong correlation of HIF-1α mRNA level to GPx1, SOD1, and IL-6 mRNA expression suggests involvement of HIF-1α in transcriptional regulation of these genes during colonic inflammation and HBO2. This is further confirmed by a strong correlation of HIF-1α with known target genes VEGF and PGK1. Results demonstrate that HBO2 has an anti-inflammatory effect in DSS-induced colitis in mice, and this effect is at least partly dependent on expression of HIF-1α and antioxidative genes. PMID:27656047

  3. Apoptosis-related protein expression in rabbits with blast brain injury following early hyperbaric oxygen therapy.

    PubMed

    Xu, Shaonian; Liu, Jiachuan; Zhang, Yongming; Wang, Chunlin; Wang, Jinbiao; Yang, Yanyan; Huo, Jian; Sun, Wenjiang

    2012-06-15

    We treated detonator-explosion-induced craniocerebral injury in rabbits with hyperbaric oxygen 1-24 hours post-injury. Expression of the apoptosis-regulating protein cytochrome c, the pro-apoptotic protein Bax and the apoptosis marker caspase-3 in the tissues surrounding the area of injury was significantly reduced, while that of the anti-apoptotic protein Bcl-2 was significantly increased. Our findings indicate that the curative effects of early hyperbaric oxygen on cortical cell apoptosis is associated with suppression of cytochrome c release from mitochondria. This mechanism underlies the observed reduction in Bax expression and upregulation of Bcl-2 expression.

  4. The fetal circulation, pathophysiology of hypoxemic respiratory failure and pulmonary hypertension in neonates, and the role of oxygen therapy.

    PubMed

    Lakshminrusimha, S; Saugstad, O D

    2016-06-01

    Neonatal hypoxemic respiratory failure (HRF), a deficiency of oxygenation associated with insufficient ventilation, can occur due to a variety of etiologies. HRF can result when pulmonary vascular resistance (PVR) fails to decrease at birth, leading to persistent pulmonary hypertension of newborn (PPHN), or as a result of various lung disorders including congenital abnormalities such as diaphragmatic hernia, and disorders of transition such as respiratory distress syndrome, transient tachypnea of newborn and perinatal asphyxia. PVR changes throughout fetal life, evident by the dynamic changes in pulmonary blood flow at different gestational ages. Pulmonary vascular transition at birth requires an interplay between multiple vasoactive mediators such as nitric oxide, which can be potentially inactivated by superoxide anions. Superoxide anions have a key role in the pathophysiology of HRF. Oxygen (O2) therapy, used in newborns long before our knowledge of the complex nature of HRF and PPHN, has continued to evolve. Over time has come the discovery that too much O2 can be toxic. Recommendations on the optimal inspired O2 levels to initiate resuscitation in term newborns have ranged from 100% (pre 1998) to the currently recommended use of room air (21%). Questions remain about the most effective levels, particularly in preterm and low birth weight newborns. Attaining the appropriate balance between hypoxemia and hyperoxemia, and targeting treatments to the pathophysiology of HRF in each individual newborn are critical factors in the development of improved therapies to optimize outcomes. PMID:27225963

  5. Alteration of blood glucose levels in the rat following exposure to hyperbaric oxygen.

    PubMed

    Eynan, Mirit; Mullokandov, Michael; Krinsky, Nitzan; Biram, Adi; Arieli, Yehuda

    2015-09-01

    Findings regarding blood glucose level (BGL) on exposure to hyperbaric oxygen (HBO) are contradictory. We investigated the influence of HBO on BGL, and of BGL on latency to central nervous system oxygen toxicity (CNS-OT). The study was conducted on five groups of rats: Group 1, exposure to oxygen at 2.5 atmospheres absolute (ATA), 90 min/day for 7 days; Group 2, exposure to oxygen once a week from 2 to 6 ATA in increments of 1 ATA/wk, for a period of time calculated as 60% of the latency to CNS-OT (no convulsions); Group 3, exposure to 6 ATA breathing a gas mixture with a pO2 of 0.21; Group 4, received 10 U/kg insulin to induce hypoglycemia before exposure to HBO; Group 5, received 33% glucose to induce hyperglycemia before exposure to HBO. Blood samples were drawn before and after exposures for measurement of BGL. No change was observed in BGL after exposure to oxygen at 2.5 ATA, 90 min/day for 7 days. BGL was significantly elevated after exposure to oxygen at 6 ATA until the appearance of convulsions, and following exposure to 4, 5, and 6 ATA without convulsions (P < 0.01). No change was observed in BGL after exposure to 6 ATA breathing a gas mixture with a pO2 of 0.21. Hypoglycemia shortened latency to CNS oxygen toxicity, whereas hyperglycemia had no effect. Our results demonstrate an influence of HBO exposure on elevation of BGL, starting at 4 ATA. This implies that BGL may serve as a marker for the generation of CNS-OT.

  6. MRI assessment of changes in tumor oxygenation post hypoxia-targeted therapy

    NASA Astrophysics Data System (ADS)

    Agarwal, Shubhangi; Vidya Shankar, Rohini; Inge, Landon J.; Kodibagkar, Vikram

    2015-03-01

    In the tumor microenvironment, the combination of compromised oxygen supply and high demand results in formation of regions of acute and chronic hypoxia, which promotes metastasis, proliferation, resistance to chemo and radiotherapy and poor prognosis. Targeted, non-invasive in vivo imaging of hypoxia has the potential to determine regions with poor oxygenation in the target and differentiate between normoxic vs hypoxic tissues. MRI provides a powerful platform for generating quantitative maps of hypoxia with the use of a novel pO2 measuring technique PISTOL (Proton imaging of siloxanes to map tissue oxygenation levels) which could impact the therapeutic choices. In the present study, PISTOL was used to determine the changes in oxygenation of tumor in pre-clinical models of NSCLC (H1975) and epidermoid carcinoma (A431) in response to tirapzamine (TPZ), a hypoxia activated chemotherapeutic. The tumor volume measurements indicate that tirapazamine was more effective in slowing the tumor growth in H1975 as compared to A431 tumors, even though lower baseline pO2 was observed in A431 as compared to H1975 tumors. These results indicate that other factors such as tumor perfusion (essential for delivering TPZ) and relative expression of nitroreductases (essential for activating TPZ) may play an important role in conjunction with pO2.

  7. A study of attitudes, beliefs and organisational barriers related to safe emergency oxygen therapy for patients with COPD (chronic obstructive pulmonary disease) in clinical practice and research

    PubMed Central

    O'Driscoll, B Ronan; Bakerly, Nawar Diar; Caress, Ann-Louise; Roberts, June; Gaston, Miriam; Newton, Mark; Yorke, Janelle

    2016-01-01

    Background Patients can be harmed by receiving too little or too much oxygen. There is ongoing disagreement about the use of oxygen in medical emergencies. Methods This was a mixed methods study (survey, telephone interviews and focus groups) involving patients, the public and healthcare professionals (HCPs). Results 62 patients with chronic obstructive pulmonary disease (COPD), 65 members of the public, 68 ambulance crew members, 22 doctors, 22 nurses and 10 hospital managers took part. For five factual questions about oxygen therapy, the average score for correct answers was 28% for patients with COPD, 33% for the general public and 75% for HCPs. The HCPs had an average score of 66% for five technical questions. Patients (79%) and members of the public (68%) were more likely than HCPs (36%) to believe that oxygen was beneficial in most medical emergencies and less likely to have concerns that it might harm some people (35%, 25% and 68%). All groups had complex attitudes about research into oxygen use in medical emergencies. Many participants would not wish for themselves or their loved ones to have their oxygen therapy determined by a randomised protocol, especially if informed consent was not possible in an emergency situation. Conclusions We have found low levels of factual knowledge about oxygen use among patients with COPD and the general public and many false beliefs about the potential benefits and harms of using oxygen. HCPs had a higher level of factual knowledge. All groups had complex attitudes towards research into emergency oxygen use. PMID:27252870

  8. Ultrasound-mediated destruction of oxygen and paclitaxel loaded lipid microbubbles for combination therapy in hypoxic ovarian cancer cells.

    PubMed

    Sun, Jiangchuan; Yin, Mingyue; Zhu, Shenyin; Liu, Li; Zhu, Yi; Wang, Zhigang; Xu, Ronald X; Chang, Shufang

    2016-01-01

    We synthesized oxygen and paclitaxel (PTX) loaded lipid microbubbles (OPLMBs) for ultrasound mediated combination therapy in hypoxic ovarian cancer cells. Our experiments successfully demonstrated that ultrasound induced OPLMBs destruction significantly enhanced the local oxygen release. We also demonstrated that OPLMBs in combination with ultrasound (300 kHz, 0.5 W/cm(2), 15s) yielded anti-proliferative activities of 52.8 ± 2.75% and cell apoptosis ratio of 35.25 ± 0.17% in hypoxic cells at 24h after the treatment, superior to other treatment groups such as PTX only and PTX-loaded MBs (PLMBs) with or without ultrasound mediation. RT-PCR and Western blot tests further confirmed the reduced expression of HIF-1α and MDR-1/P-gp after ultrasound mediation of OPLMBs. Our experiment suggests that ultrasound mediation of oxygen and drug-loaded MBs may be a useful method to overcome chemoresistance in the hypoxic ovarian cancer cells.

  9. Study on a practical robotic follower to support home oxygen therapy patients--questionnaire-based concept evaluation by the patients-.

    PubMed

    Endo, Gen; Iemura, Yu; Fukushima, Edwardo F; Hirose, Shigeo; Iribe, Masatsugu; Ikeda, Ryota; Onishi, Kohei; Maeda, Naoto; Takubo, Toshio; Ohira, Mineko

    2013-06-01

    Home oxygen therapy (HOT) is a medical treatment for the patients suffering from severe lung diseases. Although walking outdoors is recommended for the patients to maintain physical strength, the patients always have to carry a portable oxygen supplier which is not sufficiently light weight for this purpose. Our ultimate goal is to develop a mobile robot to carry an oxygen tank and follow a patient in an urban outdoor environment. We have proposed a mobile robot with a tether interface to detect the relative position of the foregoing patient. In this paper, we report the questionnaire-based evaluation about the two developed prototypes by the HOT patients. We conduct maneuvering experiments, and then obtained questionnaire-based evaluations from the 20 patients. The results show that the basic following performance is sufficient and the pulling force of the tether is sufficiently small for the patients. Moreover, the patients prefer the small-sized prototype for compactness and light weight to the middle-sized prototype which can carry larger payload. We also obtained detailed requests to improve the robots. Finally the results show the general concept of the robot is favorably received by the patients. PMID:24187296

  10. Helmet CPAP versus Oxygen Therapy in Hypoxemic Acute Respiratory Failure: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Luo, Yuwen; Luo, Yan; Li, Yun; Zhou, Luqian; Zhu, Zhe; Chen, Yitai; Huang, Yuxia

    2016-01-01

    Purpose The efficacy of helmet continuous positive airway pressure (CPAP) in hypoxemic acute respiratory failure (hARF) remains unclear. The aim of this meta-analysis was to critically review studies that investigated the effect of helmet CPAP on gas exchange, mortality, and intubation rate in comparison with standard oxygen therapy. Materials and Methods We performed a meta-analysis of randomized controlled trials (RCTs) by searching the PubMed, Embase, Cochrane library, OVID, and CBM databases, and the bibliographies of the retrieved articles. Studies that enrolled adults with hARF who were treated with helmet CPAP and measured at least one of the following parameters were included: gas exchange, intubation rate, in-hospital mortality rate. Results Four studies with 377 subjects met the inclusion criteria and were analyzed. Compared to the standard oxygen therapy, helmet CPAP significantly increased the PaO2/FiO2 [weighted mean difference (WMD)=73.40, 95% confidence interval (95% CI): 43.92 to 102.87, p<0.00001], and decreased the arterial carbon dioxide levels (WMD=-1.92, 95% CI: -3.21 to -0.63, p=0.003), intubation rate [relative risk (RR)=0.21, 95% CI: 0.11 to 0.40, p<0.00001], and in-hospital mortality rate (RR=0.22, 95% CI: 0.09 to 0.50, p=0.0004). Conclusion The results of this meta-analysis suggest that helmet CPAP improves oxygenation and reduces mortality and intubation rates in hARF. However, the significant clinical and statistical heterogeneity of the literature implies that large RCTs are needed to determine the role of helmet CPAP in different hypoxemic ARF populations. PMID:27189288

  11. A retrospective study of outcomes in subjects of head and neck cancer treated with hyperbaric oxygen therapy for radiation induced osteoradionecrosis of mandible at a tertiary care centre: an Indian experience.

    PubMed

    Gupta, Puneet; Sahni, Tarun; Jadhav, G K; Manocha, Sapna; Aggarwal, Shweta; Verma, Sapna

    2013-07-01

    Osteoradionecrosis (ORN) of the mandible is a rare complication of radiation therapy for head and neck cancer. It manifests as an area of exposed necrotic bone failing to heal for at least 3 months. Our study aims to determine the effectiveness of HBO in management of radiation induced mandibular ORN. A retrospective study of 33 subjects of mandibular ORN treated with HBOT during period 2009-2011 was carried out. The mean patient age was 60 years (range 41-80).They were treated in a multiplace hyperbaric chamber at 2.4 ATA, for 90 min once a day for up to 30 sessions. Pre and post treatment improvement in relation to symptoms, healing of intraoral wound and overall wellbeing were evaluated. Out of 33 Subjects, 48 % (n = 16) cases showed complete healing of wound, 18 % (n = 6) had marked healing, slight healing in 24 % (n = 8) cases and 9 % (n = 3) cases had no change in healing. 70 % (23 of 33) cases had significant reduction in pain, 62 % (18 of 29) cases had improved jaw opening, 41 % (11 of 27) cases and 71 % (20 of 28) cases showed improvement in ability to talk and mouth dryness respectively. Overall 85 % (28 of 30) cases showed improvement. Our clinical experience supports the efficacy of HBO treatment for radiation induced mandibular ORN and we recommend additional multicentric, prospective studies to be carried out defining the role of HBOT using at least 30 sessions in such cases. PMID:24427631

  12. Ultrafast heme-ligand recombination in truncated hemoglobin HbO from Mycobacterium tuberculosis: A ligand cage

    NASA Astrophysics Data System (ADS)

    Jasaitis, Audrius; Ouellet, Hugues; Lambry, Jean-Christophe; Martin, Jean-Louis; Friedman, Joel M.; Guertin, Michel; Vos, Marten H.

    2012-03-01

    Truncated hemoglobin HbO from Mycobacterium tuberculosis displays very slow exchange of diatomic ligands with its environment. Using femtosecond spectroscopy, we show that upon photoexcitation, ligands rebind with unusual speed and efficiency. Only ˜1% O2 can escape from the heme pocket and less than 1% NO. Most remarkably, CO rebinding occurs for 95%, predominantly in 1.2 ns. The general CO rebinding properties are unexpectedly robust against changes in the interactions with close by aromatic residues Trp88 (G8) and Tyr36 (CD1). Molecular dynamics simulations of the CO complex suggest that interactions of the ligand with structural water molecules as well as its rotational freedom play a role in the high reactivity of the ligand and the heme. The slow exchange of ligands between heme and environment may result from a combination of hindered ligand access to the heme pocket by the network of distal aromatic residues, and low escape probability from the pocket.

  13. Photoacoustically Measured Speeds of Sound and the Equation of State of HBO2: On Understanding Detonation with Boron Fuel

    SciTech Connect

    Zaug, J M; Bastea, S; Crowhurst, J; Armstrong, M; Fried, L; Teslich, N

    2010-03-09

    Elucidation of geodynamic, geochemical, and shock induced processes is limited by challenges to accurately determine molecular fluid equations of state (EOS). High pressure liquid state reactions of carbon species underlie physiochemical mechanisms such as differentiation of planetary interiors, deep carbon sequestration, propellant deflagration, and shock chemistry. In this proceedings paper we introduce a versatile photoacoustic technique developed to measure accurate and precise speeds of sound (SoS) of high pressure molecular fluids and fluid mixtures. SoS of an intermediate boron oxide, HBO{sub 2} are measured up to 0.5 GPa along the 277 C isotherm. A polarized exponential-6 interatomic potential form, parameterized using our SoS data, enables EOS determinations and corresponding semi-empirical evaluations of >2000 C thermodynamic states including energy release from bororganic formulations. Our thermochemical model propitiously predicts boronated hydrocarbon shock Hugoniot results.

  14. Early Hyperbaric Oxygen Therapy for Reducing Radiotherapy Side Effects: Early Results of a Randomized Trial in Oropharyngeal and Nasopharyngeal Cancer

    SciTech Connect

    Teguh, David N.; Levendag, Peter C.; Noever, Inge; Voet, Peter; Est, Henrie van der; Rooij, Peter van; Dumans, Antoine G.; Boer, Maarten F. de; Huls, Michiel van der; Sterk, Wouter; Schmitz, Paul

    2009-11-01

    Purpose: Comparison of quality of life (QoL) and side effects in a randomized trial for early hyperbaric oxygen therapy (HBOT) after radiotherapy (RT). Methods and Materials: From 2006, 19 patients with tumor originating from the tonsillar fossa and/or soft palate (15), base of tongue (1), and nasopharynx (3) were randomized to receive HBOT or not. HBOT consisted of 30 sessions at 2.5 ATA (15 msw) with oxygen breathing for 90 min daily, 5 days per week, applied shortly after the RT treatment was completed. As of 2005, all patients received validated questionnaires (i.e., the European Organization for Research and Treatment of Cancer [EORTC] QLQ-C30, EORTC QLQ Head and Neck Cancer Module (H and N35), Performance Status Scale): before treatment; at the start of RT treatment; after 46 Gy; at the end of RT treatment; and 2, 4, and 6 weeks and 3, 6, 12, and 18 months after follow-up. Results: On all QoL items, better scores were obtained in patients treated with hyperbaric oxygen. The difference between HBOT vs. non-HBOT was significant for all parameters: EORTC H and N35 Swallowing (p = 0.011), EORTC H and N35 Dry Mouth (p = 0.009), EORTC H and N35, Sticky Saliva (p = 0.01), PSS Eating in Public (p = 0.027), and Pain in Mouth (visual analogue scale; p < 0.0001). Conclusions: Patients randomized for receiving hyperbaric oxygen after the RT had better QoL scores for swallowing, sticky saliva, xerostomia, and pain in mouth.

  15. Glycosylated hemoglobin and hyperbaric oxygen coverage denials.

    PubMed

    Moffat, A D; Worth, E R; Weaver, L K

    2015-01-01

    Some Medicaid and Medicare fiscal intermediaries are denying hyperbaric oxygen (HBO2) therapy for diabetic foot ulcer (DFU) patients if the glycosylated hemoglobin (HbA1c) > 7.0%. We performed multiple PubMed searches for any diabetic wound healing clinical trial that documented HbA1c and had a wound healing endpoint. We scrutinized 30 peer-reviewed clinical trials, representing more than 4,400 patients. The average HbA1c from the intervention side of the studies was 8.6% (7.2% - 9.9%) and the control/sham side was 8.3% (6.0% - 10.6%). Twelve studies made a direct attempt to link HbA1c and wound healing. Four retrospective studies and one prospective cohort study assert that lower HbA1c favors wound healing, but review of the studies reveal design flaws that invalidate these conclusions. In total, 25 studies showed no direct correlation between HbA1c levels and wound healing. There was no randomized controlled trial (RCT) data demonstrating that HbA1c < 7.0% improves diabetic wound healing. In every study reviewed, wounds healed with high HbA1c levels that would be considered poorly controlled by the American Diabetes Association (ADA). Frequently, patients lack optimal blood glucose control when they have a limb-threatening DFU. The evidence supports that denying hyperbaric oxygen to those with HbA1c > 7.0% is unfounded. PMID:26152104

  16. Glycosylated hemoglobin and hyperbaric oxygen coverage denials.

    PubMed

    Moffat, A D; Worth, E R; Weaver, L K

    2015-01-01

    Some Medicaid and Medicare fiscal intermediaries are denying hyperbaric oxygen (HBO2) therapy for diabetic foot ulcer (DFU) patients if the glycosylated hemoglobin (HbA1c) > 7.0%. We performed multiple PubMed searches for any diabetic wound healing clinical trial that documented HbA1c and had a wound healing endpoint. We scrutinized 30 peer-reviewed clinical trials, representing more than 4,400 patients. The average HbA1c from the intervention side of the studies was 8.6% (7.2% - 9.9%) and the control/sham side was 8.3% (6.0% - 10.6%). Twelve studies made a direct attempt to link HbA1c and wound healing. Four retrospective studies and one prospective cohort study assert that lower HbA1c favors wound healing, but review of the studies reveal design flaws that invalidate these conclusions. In total, 25 studies showed no direct correlation between HbA1c levels and wound healing. There was no randomized controlled trial (RCT) data demonstrating that HbA1c < 7.0% improves diabetic wound healing. In every study reviewed, wounds healed with high HbA1c levels that would be considered poorly controlled by the American Diabetes Association (ADA). Frequently, patients lack optimal blood glucose control when they have a limb-threatening DFU. The evidence supports that denying hyperbaric oxygen to those with HbA1c > 7.0% is unfounded.

  17. Efficient singlet oxygen generation from sugar pendant C60 derivatives for photodynamic therapy.

    PubMed

    Yano, Shigenobu; Naemura, Masami; Toshimitsu, Akio; Akiyama, Motofusa; Ikeda, Atsushi; Kikuchi, Jun-ichi; Shen, Xiande; Duan, Qian; Narumi, Atsushi; Inoue, Masahiro; Ohkubo, Kei; Fukuzumi, Shunichi

    2015-12-01

    The amidation reaction between C60 with an activated ester group (1) and acetylated Glc (AcGlc) with an amino group (2) was performed to yield the target AcGlc-pendant C60 compound (3). The water soluble deacetylated compound, Glc-pendant C60 compound (4), exhibited high photocytotoxicity against HeLa cells due to the more efficient singlet oxygen generation as compared with that of Glc-pendant azafulleroids. PMID:26420023

  18. Pathophysiological Mechanisms in Gaseous Therapies for Severe Malaria.

    PubMed

    Kayano, Ana Carolina A V; Dos-Santos, João Conrado K; Bastos, Marcele F; Carvalho, Leonardo J; Aliberti, Júlio; Costa, Fabio T M

    2016-04-01

    Over 200 million people worldwide suffer from malaria every year, a disease that causes 584,000 deaths annually. In recent years, significant improvements have been achieved on the treatment of severe malaria, with intravenous artesunate proving superior to quinine. However, mortality remains high, at 8% in children and 15% in adults in clinical trials, and even worse in the case of cerebral malaria (18% and 30%, respectively). Moreover, some individuals who do not succumb to severe malaria present long-term cognitive deficits. These observations indicate that strategies focused only on parasite killing fail to prevent neurological complications and deaths associated with severe malaria, possibly because clinical complications are associated in part with a cerebrovascular dysfunction. Consequently, different adjunctive therapies aimed at modulating malaria pathophysiological processes are currently being tested. However, none of these therapies has shown unequivocal evidence in improving patient clinical status. Recently, key studies have shown that gaseous therapies based mainly on nitric oxide (NO), carbon monoxide (CO), and hyperbaric (pressurized) oxygen (HBO) alter vascular endothelium dysfunction and modulate the host immune response to infection. Considering gaseous administration as a promising adjunctive treatment against severe malaria cases, we review here the pathophysiological mechanisms and the immunological aspects of such therapies.

  19. Pathophysiological Mechanisms in Gaseous Therapies for Severe Malaria

    PubMed Central

    Kayano, Ana Carolina A. V.; Dos-Santos, João Conrado K.; Bastos, Marcele F.; Carvalho, Leonardo J.; Aliberti, Júlio

    2016-01-01

    Over 200 million people worldwide suffer from malaria every year, a disease that causes 584,000 deaths annually. In recent years, significant improvements have been achieved on the treatment of severe malaria, with intravenous artesunate proving superior to quinine. However, mortality remains high, at 8% in children and 15% in adults in clinical trials, and even worse in the case of cerebral malaria (18% and 30%, respectively). Moreover, some individuals who do not succumb to severe malaria present long-term cognitive deficits. These observations indicate that strategies focused only on parasite killing fail to prevent neurological complications and deaths associated with severe malaria, possibly because clinical complications are associated in part with a cerebrovascular dysfunction. Consequently, different adjunctive therapies aimed at modulating malaria pathophysiological processes are currently being tested. However, none of these therapies has shown unequivocal evidence in improving patient clinical status. Recently, key studies have shown that gaseous therapies based mainly on nitric oxide (NO), carbon monoxide (CO), and hyperbaric (pressurized) oxygen (HBO) alter vascular endothelium dysfunction and modulate the host immune response to infection. Considering gaseous administration as a promising adjunctive treatment against severe malaria cases, we review here the pathophysiological mechanisms and the immunological aspects of such therapies. PMID:26831465

  20. Hyperbaric oxygen reduces delayed immune-mediated neuropathology in experimental carbon monoxide toxicity

    SciTech Connect

    Thom, Stephen R. . E-mail: sthom@mail.med.upenn.edu; Bhopale, Veena M.; Fisher, Donald

    2006-06-01

    The goal of this investigation was to determine whether exposure to hyperbaric oxygen (HBO{sub 2}) would ameliorate biochemical and functional brain abnormalities in an animal model of carbon monoxide (CO) poisoning. In this model, CO-mediated oxidative stress causes chemical alterations in myelin basic protein (MBP), which initiates an adaptive immunological response that leads to a functional deficit. CO-exposed rats do not show improvements in task performance in a radial maze. We found that HBO{sub 2} given after CO poisoning will prevent this deficit, but not eliminate all of the CO-mediated biochemical alterations in MBP. MBP from HBO{sub 2} treated CO-exposed rats is recognized normally by a battery of antibodies, but exhibits an abnormal charge pattern. Lymphocytes from HBO{sub 2}-treated and control rats do not become activated when incubated with MBP, immunohistological evidence of microglial activation is not apparent, and functional deficits did not occur, unlike untreated CO-exposed rats. The results indicate that HBO{sub 2} prevents immune-mediated delayed neurological dysfunction following CO poisoning.

  1. Remote-Controlled Release of Singlet Oxygen by the Plasmonic Heating of Endoperoxide-Modified Gold Nanorods: Towards a Paradigm Change in Photodynamic Therapy.

    PubMed

    Kolemen, Safacan; Ozdemir, Tugba; Lee, Dayoung; Kim, Gyoung Mi; Karatas, Tugce; Yoon, Juyoung; Akkaya, Engin U

    2016-03-01

    The photodynamic therapy of cancer is contingent upon the sustained generation of singlet oxygen in the tumor region. However, tumors of the most metastatic cancer types develop a region of severe hypoxia, which puts them beyond the reach of most therapeutic protocols. More troublesome, photodynamic action generates acute hypoxia as the process itself diminishes cellular oxygen reserves, which makes it a self-limiting method. Herein, we describe a new concept that could eventually lead to a change in the 100 year old paradigm of photodynamic therapy and potentially offer solutions to some of the lingering problems. When gold nanorods with tethered endoperoxides are irradiated at 808 nm, the endoperoxides undergo thermal cycloreversion, resulting in the generation of singlet oxygen. We demonstrate that the amount of singlet oxygen produced in this way is sufficient for triggering apoptosis in cell cultures. PMID:26845734

  2. Effect of hyperbaric oxygen on glucose utilization in a freeze-traumatized rat brain

    SciTech Connect

    Contreras, F.L.; Kadekaro, M.; Eisenberg, H.M.

    1988-01-01

    Local cerebral glucose utilization was measured with the autoradiographic 2-deoxyglucose technique in rats injured by a focal parietal cortical freeze lesion then treated with hyperbaric oxygen (HBO). The cold lesion depressed glucose utilization in the contralateral as well as in the ipsilateral hemisphere. The largest decreases were observed in ipsilateral cortical areas. Treatment of lesioned animals with HBO at 2 atm for 90 minutes on each of 4 consecutive days tended to increase the overall cerebral glucose utilization measured 5 days after injury when compared to animals exposed to normobaric air. This improvement reached statistical significance in five of the 21 structures studied: the auditory cortex, medial geniculate body, superior olivary nucleus, and lateral geniculate body ipsilateral to the lesion, and the mammillary body. The data indicate that changes in lesioned rats exposed to HBO are not restricted to the period of time that the animals are in the hyperbaric chamber but are persistent.

  3. Oxygen high level laser therapy is efficient in treatment of chronic periodontitis: a clinical and microbiological study using PCR analysis.

    PubMed

    Caccianiga, G; Rey, G; Paiusco, A; Lauritano, D; Cura, F; Ormianer, Z; Carinci, F

    2016-01-01

    In periodontology, lasers have been suggested for the photodynamic therapy (PDT). Such therapy can be defined as the inactivation of cells, microorganisms or molecules induced by light and not by heat. The aim of our study is to assess the effect of Oxygen high-level laser therapy (OHLLT) in removing all bacterial deposits on root or implant surface by means of mechanical instrumentation and laser irradiation. OHLLT has two effects on targeted bacteria and tissues, decontamination and biostimulation. A total of 33 patients were randomly selected with a diagnosis of chronic periodontitis. The patients enrolled were 16 females and 17 males, six smokers and 4 diabetic patients. For each patient a periodontal charting was performed, assessing probing depth, plaque index and bleeding on probing at baseline and after 6 months. Microbiological analysis were performed with PCR Real Time, using paper tips to withdraw gingival fluid in periodontal pockets before and after treatment, at baseline and after 6 months. All patients were treated with OHLLT at baseline, after 1 week, after 2 weeks and every month for 6 months. After 6 months, all periodontal pockets were treated successfully, without complications and no significant differences in results. All clinical parameters showed an improvement, with a decrease both of plaque index (average decrease of 75%), bleeding on probing (average decrease of 62%) and probing depth (average decrease of 1.8 mm). After the treatment, a remarkable decrease in bacteria amount, both for each species and for total bacteria was observed except for Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis demonstrating that this laser protocol is effective on periodontitis treatment. OHLLT is efficient in treatment of chronic periodontitis as demonstrated by clinical and microbiological parameters, going beyond the traditional periodontal therapy.

  4. Oxygen high level laser therapy is efficient in treatment of chronic periodontitis: a clinical and microbiological study using PCR analysis.

    PubMed

    Caccianiga, G; Rey, G; Paiusco, A; Lauritano, D; Cura, F; Ormianer, Z; Carinci, F

    2016-01-01

    In periodontology, lasers have been suggested for the photodynamic therapy (PDT). Such therapy can be defined as the inactivation of cells, microorganisms or molecules induced by light and not by heat. The aim of our study is to assess the effect of Oxygen high-level laser therapy (OHLLT) in removing all bacterial deposits on root or implant surface by means of mechanical instrumentation and laser irradiation. OHLLT has two effects on targeted bacteria and tissues, decontamination and biostimulation. A total of 33 patients were randomly selected with a diagnosis of chronic periodontitis. The patients enrolled were 16 females and 17 males, six smokers and 4 diabetic patients. For each patient a periodontal charting was performed, assessing probing depth, plaque index and bleeding on probing at baseline and after 6 months. Microbiological analysis were performed with PCR Real Time, using paper tips to withdraw gingival fluid in periodontal pockets before and after treatment, at baseline and after 6 months. All patients were treated with OHLLT at baseline, after 1 week, after 2 weeks and every month for 6 months. After 6 months, all periodontal pockets were treated successfully, without complications and no significant differences in results. All clinical parameters showed an improvement, with a decrease both of plaque index (average decrease of 75%), bleeding on probing (average decrease of 62%) and probing depth (average decrease of 1.8 mm). After the treatment, a remarkable decrease in bacteria amount, both for each species and for total bacteria was observed except for Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis demonstrating that this laser protocol is effective on periodontitis treatment. OHLLT is efficient in treatment of chronic periodontitis as demonstrated by clinical and microbiological parameters, going beyond the traditional periodontal therapy. PMID:27469554

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

    PubMed Central

    Huo, Jian; Liu, Jiachuan; Wang, Jinbiao; Zhang, Yongming; Wang, Chunlin; Yang, Yanyan; Sun, Wenjiang; Xu, Shaonian

    2012-01-01

    In the present study, rabbits were treated with hyperbaric oxygen for 1 hour after detonator-blast- induced 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. PMID:25624795

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

    PubMed

    Huo, Jian; Liu, Jiachuan; Wang, Jinbiao; Zhang, Yongming; Wang, Chunlin; Yang, Yanyan; Sun, Wenjiang; Xu, Shaonian

    2012-08-01

    In the present study, rabbits were treated with hyperbaric oxygen for 1 hour after detonator-blast- induced 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.

  7. [The value of systematic monitoring of oxygen consumption in the diagnosis and therapy of septic shock].

    PubMed

    Pilas, V; Cubrilo, M; Bakula, V; Vranjkovic, S; Bakula, B; Bilic, A

    1990-01-01

    In 31 patients with sepsis and multiple organic dysfunction, changes in the systemic oxygen consumption (VO2) during reanimation were observed in order to discover more objective indicators of the course and prognosis of the disease. In a prospective randomized study, 21 live (Group 1) and 11 dead patients (Group 2) were included. The investigation was based upon the application of the invasive tracing of oxygen hemodynamics and transport. The findings of the initially hypovolemic status were compared with those of the stabile normovolemic status obtained by the application of infusions and the blood volume substitute. In the early phase of the disease there were no significant differences in the clinical finding of the circulatory shock and the volume deficit of the circulated blood between these two groups of patients. Group 1 patients had lower values of the cardiac index (CI) and the systemic oxygen transport (DO2). In them there was a greater frequency of acute organic insufficiency, especially pulmonal, renal and hepatal. In the initial status VO2 decreased. In the normovolemic status of Group 1, a significant VO2 was found, while in Group 2 in spite of a DO2 increase and hemodynamics improvement, a more significant VO2 increase was not obtained. As VO2 is an objective indicator of oxidative metabolic reactions of the organism and the circulatory system, the authors maintain that by the VO2 tracing, a better insight into the seriousness and course of the disease is obtained, and that an inadequate VO2 finding during the therapeutic treatment requires a revision of the treatment. PMID:2077821

  8. Reactive oxygen species, Ca(2+) stores and acute pancreatitis; a step closer to therapy?

    PubMed

    Criddle, David N

    2016-09-01

    Disruption of Ca(2+) homeostasis can lead to severe damage of the pancreas, resulting in premature activation of digestive enzymes, vacuolisation and necrotic cell death, features typical of acute pancreatitis (AP). Therefore a fine balance between Ca(2+) release from internal stores, Ca(2+) entry and extrusion mechanisms is necessary to avoid injury. Precipitants of AP induce Ca(2+) overload of the pancreatic acinar cell that causes mitochondrial dysfunction, via formation of the mitochondrial permeability transition pore (MPTP), loss of ATP production and consequent necrosis. Oxidative stress has been shown to occur in the development of AP and may modify Ca(2+) signalling events in the acinar cell. However, the precise pathophysiological involvement is currently unclear and antioxidant therapy in the clinic has largely proved ineffective. Possible reasons for this are discussed, including evidence that ROS generation may determine cell death patterns. In contrast, recent evidence has indicated the potential for AP therapy via the prevention of Ca(2+)-dependent mitochondrial damage. Multiple approaches are indicated from preclinical findings; 1) inhibition of Ca(2+) release by IP3R blockade, 2) inhibition of Ca(2+) entry through Orai1 blockade and 3) prevention of MPTP formation. Clinical trials of drugs which prevent mitochondrial dysfunction induced by Ca(2+) overload of pancreatic acinar cells are imminent and may provide patient benefit for a disease that currently lacks specific therapy. PMID:27229361

  9. Direct observation of breaking of the intramolecular H-bond, and slowing down of the proton motion and tuning its mechanism in an HBO derivative.

    PubMed

    Alarcos, Noemí; Gutiérrez, Mario; Liras, Marta; Sánchez, Félix; Moreno, Miquel; Douhal, Abderrazzak

    2015-06-14

    We report on spectroscopic and photodynamical behaviours of 5-amino-2-(2'-hydroxyphenyl)benzoxazole (5A-HBO) in different solutions. The dye undergoes an ultrafast ICT reaction (<50 fs) (comparable to that observed for its methylated derivative, 5A-MBO), in agreement with the results of TD-DFT theoretical calculations (gas phase). Depending on the used solvent, the ICT reaction can be followed by a reversible/irreversible excited-state intramolecular proton transfer (ESIPT) reaction or by breaking of the intramolecular hydrogen bond (IHB). 5A-HBO in n-heptane solution exhibits an irreversible and slow (20 ps) ESIPT reaction, while that of the parent compound, HBO, takes place in less than 150 fs. Compared to excited HBO behaviour, theoretical calculations on 5A-HBO suggest a higher energy barrier (∼4 kcal mol(-1)) between the relaxed enol and keto tautomers, in addition to a less stabilization of the latter, which is in agreement with experiments in n-heptane. On the other hand, in dichloromethane, after the ICT reaction a subsequent and reversible proton motion occurs in an extraordinary slower regime (ns-time scale). No isotopic effect (OH/OD exchange) was observed in this solvent reflecting that the reversible ESIPT reaction evolves along the IHB and solvent coordinates. Using tetrahydrofurane and acetonitrile, we observed a breaking of the IHB due to specific intermolecular interactions with solvent molecules. This leads to the formation of open-enol forms, which undergo an ICT reaction as it occurs in 5A-MBO. These results bring new findings in the coupled ICT and ESIPT reactions. The photobehaviour of this new dye remarkably changes with the solvent nature, opening up the window for further research and possible applications in sensing polarity or H-bonding of media similar to that of the biological ones.

  10. Mechanisms of oxygen sensing: a key to therapy of pulmonary hypertension and patent ductus arteriosus

    PubMed Central

    Weir, E K; Obreztchikova, M; Vargese, A; Cabrera, J A; Peterson, D A; Hong, Z

    2008-01-01

    Specialized tissues that sense acute changes in the local oxygen tension include type 1 cells of the carotid body, neuroepithelial bodies in the lungs, and smooth muscle cells of the resistance pulmonary arteries and the ductus arteriosus (DA). Hypoxia inhibits outward potassium current in carotid body type 1 cells, leading to depolarization and calcium entry through L-type calcium channels. Increased intracellular calcium concentration ([Ca++]i) leads to exocytosis of neurotransmitters, thus stimulating the carotid sinus nerve and respiration. The same K+ channel inhibition occurs with hypoxia in pulmonary artery smooth muscle cells (PASMCs), causing contraction and providing part of the mechanism of hypoxic pulmonary vasoconstriction (HPV). In the SMCs of the DA, the mechanism works in reverse. It is the shift from hypoxia to normoxia that inhibits K+ channels and causes normoxic ductal contraction. In both PA and DA, the contraction is augmented by release of Ca++ from the sarcoplasmic reticulum, entry of Ca++ through store-operated channels (SOC) and by Ca++ sensitization. The same three ‘executive' mechanisms are partly responsible for idiopathic pulmonary arterial hypertension (IPAH). While vasoconstrictor mediators constrict both PA and DA and vasodilators dilate both vessels, only redox changes mimic oxygen by having directly opposite effects on the K+ channels, membrane potential, [Ca++]i and tone in the PA and DA. There are several different hypotheses as to how redox might alter tone, which remain to be resolved. However, understanding the mechanism will facilitate drug development for pulmonary hypertension and patent DA. PMID:18641675

  11. The use of high-flow nasal oxygen therapy in the management of hypercarbic respiratory failure.

    PubMed

    Millar, Jonathan; Lutton, Stuart; O'Connor, Philip

    2014-04-01

    Hypercarbic respiratory failure, occurring secondary to chronic lung disease, is a frequently encountered problem. These patients present a significant challenge to respiratory and critical care services, as many are unsuitable for mechanical ventilation and most have multiple comorbidities. Recently, noninvasive ventilation (NIV) has become established as the primary modality for respiratory support in this group of patients. Several factors limit patient compliance with NIV, not least comfort and tolerability. A recent innovation in adult critical care is the use of high-flow nasal oxygen (HFNO) devices. These systems are capable of delivering high gas flows via nasal cannulae, with the ability to blend air and oxygen to give a controlled FiO2. Few clinical studies have been conducted in adults, although several are planned. To date the majority of available evidence addresses the use of HFNO in hypoxemic respiratory failure. Here we present a case in which a HFNO system was used to successfully manage hypercarbic respiratory failure in a patient unable to tolerate conventional NIV.

  12. Oxygen measurements in brain stem slices exposed to normobaric hyperoxia and hyperbaric oxygen.

    PubMed

    Mulkey, D K; Henderson, R A; Olson, J E; Putnam, R W; Dean, J B

    2001-05-01

    We previously reported (J Appl Physiol 89: 807-822, 2000) that < or =10 min of hyperbaric oxygen (HBO(2); < or = 2,468 Torr) stimulates solitary complex neurons. To better define the hyperoxic stimulus, we measured PO(2) in the solitary complex of 300-microm-thick rat medullary slices, using polarographic carbon fiber microelectrodes, during perfusion with media having PO(2) values ranging from 156 to 2,468 Torr. Under control conditions, slices equilibrated with 95% O(2) at barometric pressure of 1 atmospheres absolute had minimum PO(2) values at their centers (291 +/- 20 Torr) that were approximately 10-fold greater than PO(2) values measured in the intact central nervous system (10-34 Torr). During HBO(2), PO(2) increased at the center of the slice from 616 +/- 16 to 1,517 +/- 15 Torr. Tissue oxygen consumption tended to decrease at medium PO(2) or = 1,675 Torr to levels not different from values measured at PO(2) found in all media in metabolically poisoned slices (2-deoxy-D-glucose and antimycin A). We conclude that control medium used in most brain slice studies is hyperoxic at normobaric pressure. During HBO(2), slice PO(2) increases to levels that appear to reduce metabolism. PMID:11299283

  13. Topical hyperbaric oxygen and low energy laser therapy for chronic diabetic foot ulcers resistant to conventional treatment.

    PubMed Central

    Landau, Z.; Schattner, A.

    2001-01-01

    Chronic foot ulcers are common in long-standing diabetes, may herald severe complications and are often resistant to therapy. To evaluate the effects of adjunctive topical hyperbaric oxygen treatment (THBO) and low energy laser (LEL) irradiation on ulcer healing, a 100 consecutive patients with chronic diabetic foot ulcers (DFU) refractory to 4.5 +/- 1.2 months of comprehensive treatment, were enrolled in a prospective open study. While conventional treatment was continued as necessary, THBO was administered by pumping 100 percent oxygen into a disposable sealed polythylene hyperbaric chamber (150 min x 2 to 3/wk at up to 1.04 atm). Helium-neon LEL irradiation was given concurrently using a Unilaser Scan Unit at 4 J/cm2 for 20 min. Some patients continued THBO at home or their treatment was confined to THBO at home. Patients were monitored every two weeks revealing 81 percent cure after 25 +/- 13 treatments over 3.2 +/- 1.7 months. On follow-up (median 18 months), only 3/81 (4 percent) had reulceration, which responded to THBO/LEL retreatment. Nonresponders had significantly lower ankle brachial indices (ABI) than patients whose ulcers were healed (0.55 vs. 0.78, p < 0.01) and ultimately required amputation. Patient compliance was full and no adverse events occurred. In conclusion, although the study was open and uncontrolled, an 81 percent healing of DFU in patients who previously did not respond to a comprehensive treatment program, constitutes an intriguing preliminary result. Thus, THBO/LEL therapy may be a safe, simple, and inexpensive early adjunctive treatment for patients with chronic diabetic foot ulcers. Our findings should prompt its evaluation by large randomized controlled trials. PMID:11393266

  14. Explicit dosimetry for 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a-mediated photodynamic therapy: macroscopic singlet oxygen modeling

    NASA Astrophysics Data System (ADS)

    Penjweini, Rozhin; Liu, Baochang; Kim, Michele M.; Zhu, Timothy C.

    2015-12-01

    Type II photodynamic therapy (PDT) is based on the photochemical reactions mediated through an interaction between a photosensitizer, ground-state oxygen ([O]), and light excitation at an appropriate wavelength, which results in production of reactive singlet oxygen ([]rx). We use an empirical macroscopic model based on four photochemical parameters for the calculation of []rx threshold concentration ([]rx,sh) causing tissue necrosis in tumors after PDT. For this reason, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH)-mediated PDT was performed interstitially on mice with radiation-induced fibrosarcoma (RIF) tumors. A linear light source at 665 nm with total energy released per unit length of 12 to 100 J/cm and source power per unit length (LS) of 12 to 150 mW/cm was used to induce different radii of necrosis. Then the amount of []rx calculated by the macroscopic model incorporating explicit PDT dosimetry of light fluence distribution, tissue optical properties, and HPPH concentration was correlated to the necrotic radius to obtain the model parameters and []rx,sh. We provide evidence that []rx is a better dosimetric quantity for predicting the treatment outcome than PDT dose, which is proportional to the time integral of the products of the photosensitizer concentration and light fluence rate.

  15. Explicit dosimetry for 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a-mediated photodynamic therapy: macroscopic singlet oxygen modeling.

    PubMed

    Penjweini, Rozhin; Liu, Baochang; Kim, Michele M; Zhu, Timothy C

    2015-01-01

    Type II photodynamic therapy (PDT) is based on the photochemical reactions mediated through an interaction between a photosensitizer, ground-state oxygen ([(3)O2]), and light excitation at an appropriate wavelength, which results in production of reactive singlet oxygen ([(1)O2]rx). We use an empirical macroscopic model based on four photochemical parameters for the calculation of [(1)O2]rx threshold concentration ([(1)O2]rx,sh) causing tissue necrosis in tumors after PDT. For this reason, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH)-mediated PDT was performed interstitially on mice with radiation-induced fibrosarcoma (RIF) tumors. A linear light source at 665 nm with total energy released per unit length of 12 to 100  J/cm and source power per unit length (LS) of 12 to 150  mW/cm was used to induce different radii of necrosis. Then the amount of [(1)O2]rx calculated by the macroscopic model incorporating explicit PDT dosimetry of light fluence distribution, tissue optical properties, and HPPH concentration was correlated to the necrotic radius to obtain the model parameters and [(1)O2]rx,sh. We provide evidence that [(1)O2]rx is a better dosimetric quantity for predicting the treatment outcome than PDT dose, which is proportional to the time integral of the products of the photosensitizer concentration and light fluence rate. PMID:26720883

  16. Cerebral hemodynamics in patients with obstructive sleep apnea syndrome monitored with near-infrared spectroscopy (NIRS) during positive airways pressure (CPAP) therapy: a pilot study

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Fritschi, Ursula; Lehner, Isabella; Qi, Ming; Khatami, Ramin

    2014-03-01

    In obstructive sleep apnea syndrome (OSA) the periodic reduction or cessation of breathing due to narrowing or occlusion of the upper airway during sleep leads to daytime symptoms and increased cardiovascular risk, including stroke. The higher risk of stroke is related to the impairment in cerebral vascular autoregulation. Continuous positive airways pressure (CPAP) therapy at night is the most effective treatment for OSA. However, there is no suitable bedside monitoring method evaluating the treatment efficacy of CPAP therapy, especially to monitor the recovery of cerebral hemodynamics. NIRS is ideally suited for non-invasive monitoring the cerebral hemodynamics during sleep. In this study, we will for first time assess dynamic changes of cerebral hemodynamics during nocturnal CPAP therapy in 3 patients with OSA using NIRS. We found periodic oscillations in HbO2, HHb, tissue oxygenation index (TOI) and blood volume associated with periodic apnea events without CPAP in all OSA patients. These oscillations were gradually attenuated and finally eliminated with the stepwise increments of CPAP pressures. The oscillations were totally eliminated in blood volume earlier than in other hemodynamic parameters. These results suggested that 1) the cerebral hemodynamic oscillations induced by OSA events can effectively be attenuated by CPAP therapy, and 2) blood flow and blood volume recovered first during CPAP therapy, followed by the recovery of oxygen consumption. Our study suggested that NIRS is a useful tool to evaluate the efficacy of CPAP therapy in patients with OSA bedside and in real time.

  17. The Injury and Therapy of Reactive Oxygen Species in Intracerebral Hemorrhage Looking at Mitochondria

    PubMed Central

    Qu, Jie; Chen, Weixiang; Hu, Rong; Feng, Hua

    2016-01-01

    Intracerebral hemorrhage is an emerging major health problem often resulting in death or disability. Reactive oxygen species (ROS) have been identified as one of the major damaging factors in ischemic stroke. However, there is less discussion about ROS in hemorrhage stroke. Metabolic products of hemoglobin, excitatory amino acids, and inflammatory cells are all sources of ROS, and ROS harm the central nervous system through cell death and structural damage, especially disruption of the blood-brain barrier. We have considered the antioxidant system of the CNS itself and the drugs aiming to decrease ROS after ICH, and we find that mitochondria are key players in all of these aspects. Moreover, when the mitochondrial permeability transition pore opens, ROS-induced ROS release, which leads to extensive liberation of ROS and mitochondrial failure, occurs. Therefore, the mitochondrion may be a significant target for elucidating the problem of ROS in ICH; however, additional experimental support is required. PMID:27293511

  18. The Injury and Therapy of Reactive Oxygen Species in Intracerebral Hemorrhage Looking at Mitochondria.

    PubMed

    Qu, Jie; Chen, Weixiang; Hu, Rong; Feng, Hua

    2016-01-01

    Intracerebral hemorrhage is an emerging major health problem often resulting in death or disability. Reactive oxygen species (ROS) have been identified as one of the major damaging factors in ischemic stroke. However, there is less discussion about ROS in hemorrhage stroke. Metabolic products of hemoglobin, excitatory amino acids, and inflammatory cells are all sources of ROS, and ROS harm the central nervous system through cell death and structural damage, especially disruption of the blood-brain barrier. We have considered the antioxidant system of the CNS itself and the drugs aiming to decrease ROS after ICH, and we find that mitochondria are key players in all of these aspects. Moreover, when the mitochondrial permeability transition pore opens, ROS-induced ROS release, which leads to extensive liberation of ROS and mitochondrial failure, occurs. Therefore, the mitochondrion may be a significant target for elucidating the problem of ROS in ICH; however, additional experimental support is required.

  19. Oxygen free radical damage in the cornea after excimer laser therapy

    PubMed Central

    Hayashi, S.; Ishimoto, S.; Wu, G.; Wee, W.; Rao, N.; McDonnell, P.

    1997-01-01

    AIMS/BACKGROUND—To evaluate the extent of oxygen radical damage in the cornea after excimer laser ablation.
METHODS—The 193 nm argon fluoride excimer laser was programmed for an average fluence of 150 mJ/cm2, with a firing rate of 5 Hz and an ablation zone diameter of 6 mm. Phototherapeutic keratectomy was performed to remove 30 µm of epithelium and 50 µm of stroma from the corneas of New Zealand white rabbits. Oxidative tissue damage after laser was determined by measuring oxidised lipids (conjugated dienes and ketodienes) in corneal lipid extracts, and by fast blue B staining to localise the lipid peroxide in the tissue.
RESULTS—Conjugated diene levels were 3.73 (SD 0.56) nmol per hemicornea in ablated corneas and 1.99 (0.33) nmol per hemicornea in normal corneas (p = 0.0044). Ketodiene levels were 2.72 (0.38) nmol per hemicornea in treated corneas and 0.91 (0.12) nmol per hemicornea in normal corneas (p < 0.001). Fast blue B staining disclosed that the tissue damage occurred primarily on the surface of the ablated cornea.
CONCLUSION—The presence of lipid peroxidation in the superficial corneal stroma in excimer laser treated corneas was demonstrated. This lipid peroxidation could be from oxygen free radicals generated by the infiltrating polymorphonuclear cells at the site of tissue damage.

 PMID:9059249

  20. Enhancement of photodynamic therapy due to hyperbaric hyperoxia: an experimental study of Walker 256 tumors in rats

    NASA Astrophysics Data System (ADS)

    Nicola, Jorge H.; Colussi, Valdir C.; Nicola, Ester M. D.; Metze, Konradin

    1997-05-01

    Photodynamic therapy (PDT), which is now an approved treatment for many types of cancers, is based on the simultaneous involvement of three factors, namely: tumor tissue retention of a specific photosensitizer; local illumination of the lesion with a visible light source and the occurrence of oxygen in the triplet state. Theoretically, a change in any one of these factors may be compensated by a change in the other two factors, leading to the same therapeutic result. In practice, this is not true, since we are dealing with living tissue, but we may expect to find an ideal combination of these three factors which may give the best clinical results. In this work we present experimental results of PDT under Hyperbaric hyperoxia (HBO) in tumor masses of the dorsal subcutaneous tissue of rats. These tumors were created by previous inoculation of 'Walker 256' neoplastic cells Hematoporphyrin Ester (HpE) was administered as the photosensitizer. The rats were pressurized at up to 3 atm with a 100 percent continuous oxygen ventilation environment in a specially designed hyperbaric chamber. The skin area above the tumor was photosensitized for 45 minutes with a 7 mw HeNe laser. Twenty four hours later, the tumor was removed for study. In all the animals treated with PDT/HBO histology revealed a very important reduction in the number of tumor cells as compared with the PDT controls in normal atmospheric condition, showing numerous apoptotic as well as necrotic cells at the border of the radiated area. The observed enhancement in the PDT for this situation is, of course, related to the extra oxygen in the circulatory system.

  1. Induction of Endogenous Reactive Oxygen Species in Mitochondria by Fullerene-Based Photodynamic Therapy.

    PubMed

    Li, Qian; Liu, Chenguang; Li, Hongguang

    2016-06-01

    The production of ROS in mitochondria plays critical role in photodynamic therapy (PDT). The aim of this study was to investigate whether fullerene-based PDT can induce generation of additional endogenous ROS in mitochondria. Chitosan oligosaccharide grafted fullerene conjugate (CS-C60) was synthesized as a model water-soluble fullerene. The relationship among photodynamic cytotoxicity, intracellular ROS and CS-C60 amount demonstrated that low dose fullerene could induce generation of endogenous ROS in human malignant melanoma (A375) cells. Laser scanning microscope (LSM) image shows that considerable amount of endogenous ROS was generated in mitochondria even CS-C60 could not localize into mitochondria. Assay with rotenone shows that PDT-induced endogenous ROS was generated via electron transport chain (ETC).

  2. Induction of Endogenous Reactive Oxygen Species in Mitochondria by Fullerene-Based Photodynamic Therapy.

    PubMed

    Li, Qian; Liu, Chenguang; Li, Hongguang

    2016-06-01

    The production of ROS in mitochondria plays critical role in photodynamic therapy (PDT). The aim of this study was to investigate whether fullerene-based PDT can induce generation of additional endogenous ROS in mitochondria. Chitosan oligosaccharide grafted fullerene conjugate (CS-C60) was synthesized as a model water-soluble fullerene. The relationship among photodynamic cytotoxicity, intracellular ROS and CS-C60 amount demonstrated that low dose fullerene could induce generation of endogenous ROS in human malignant melanoma (A375) cells. Laser scanning microscope (LSM) image shows that considerable amount of endogenous ROS was generated in mitochondria even CS-C60 could not localize into mitochondria. Assay with rotenone shows that PDT-induced endogenous ROS was generated via electron transport chain (ETC). PMID:27427601

  3. How to Get Hyperbaric Oxygen Therapy for Children with Cerebral Palsy or Brain Injury: Navigating Insurance Denials, Red Tape, and Other Challenges

    ERIC Educational Resources Information Center

    Console, Richard P., Jr.

    2010-01-01

    Medical professionals who use hyperbaric oxygen therapy (HBOT) say that recent studies, as well as anecdotal evidence, indicate that this treatment significantly improves the lives of many children with cerebral palsy and other types of chronic brain injury. So why do many children with these diagnoses not have access to this treatment? Simply…

  4. Hyperbaric oxygen therapy for intensive care patients: position statement by the European Committee for Hyperbaric Medicine.

    PubMed

    Mathieu, Daniel; Ratzenhofer-Komenda, Beatrice; Kot, Jacek

    2015-03-01

    Many of the accepted indications for hyperbaric oxygen treatment (HBOT) may occur in critically ill patients. HBOT itself may cause a number of physiological changes which may further compromise the patient's state. Guidelines on the management of critically ill patients in a hyperbaric facility have been founded on the conclusions of the 2007 European Committee for Hyperbaric Medicine (ECHM) meeting. With regard to patient management, HBOT should be included in the overall care of ICU patients only after a risk/benefit assessment related to the specifics of both the hyperbaric centre and the patient's clinical condition and should not delay or interrupt their overall management. Neither patient monitoring nor treatment should be altered or stopped due to HBOT, and any HBOT effects must be strictly evaluated and appropriately mitigated. With regard to the hyperbaric facility itself, the hyperbaric chamber should be specifically designed for ICU patients and should be fully equipped to allow continuation of patient monitoring and treatment. The hyperbaric chamber ideally should be located in, or around the immediate vicinity of the ICU, and be run by a sufficiently large and well-trained team of physicians, nurses, chamber operators and technicians. All devices to be introduced into the chamber should be evaluated, tested and acknowledged as safe for use in a hyperbaric environment and all procedures (standard and emergency) should be tested and written before being implemented.

  5. Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy.

    PubMed

    Poff, A M; Ward, N; Seyfried, T N; Arnold, P; D'Agostino, D P

    2015-01-01

    The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies - the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation - could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (βHB), hyperbaric oxygen (HBOT), or combination therapy (LG+βHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers.

  6. Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy

    PubMed Central

    Poff, A. M.; Ward, N.; Seyfried, T. N.; Arnold, P.; D’Agostino, D. P.

    2015-01-01

    The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies – the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation – could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (βHB), hyperbaric oxygen (HBOT), or combination therapy (LG+βHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers. PMID:26061868

  7. Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy.

    PubMed

    Poff, A M; Ward, N; Seyfried, T N; Arnold, P; D'Agostino, D P

    2015-01-01

    The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies - the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation - could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (βHB), hyperbaric oxygen (HBOT), or combination therapy (LG+βHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers. PMID:26061868

  8. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen Species

    PubMed Central

    Farhan, Mohd; Khan, Husain Yar; Oves, Mohammad; Al-Harrasi, Ahmed; Rehmani, Nida; Arif, Hussain; Hadi, Sheikh Mumtaz; Ahmad, Aamir

    2016-01-01

    Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG) are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS) responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells. PMID:26861392

  9. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen species.

    PubMed

    Farhan, Mohd; Khan, Husain Yar; Oves, Mohammad; Al-Harrasi, Ahmed; Rehmani, Nida; Arif, Hussain; Hadi, Sheikh Mumtaz; Ahmad, Aamir

    2016-02-04

    Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG) are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS) responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells.

  10. Free radicals and other reactive oxygen metabolites: clinical relevance and the therapeutic efficacy of antioxidant therapy.

    PubMed

    Bulkley, G B

    1993-05-01

    As in any new field, justifiable enthusiasm for the potential for antioxidant therapy has led to hyperbole, hastily designed, poorly conceived clinical trials, and premature reporting of uncontrolled, anecdotal indicators of efficacy that have not held up when subjected to close scrutiny or more careful, controlled trial design. This tendency has been augmented by strong pressure for early positive results from a few, but not most, members of the pharmaceutical industry and by a few clinicians in highly competitive fields who were anxious not to be left behind. The sobering reality of negative or, even worse, indeterminate clinical trials has culled the field and educated those that remain. As a result, we are beginning to see the publication of quite promising results from large, well-controlled, carefully designed clinical studies, many, but not all, of which are quite promising. This has been associated with a much better understanding of the basic mechanism of free radical-mediated human disease, without which further substantial progress would be quite limited. Because the manipulation of oxidant-mediated tissue injury represents treating disease at its most basic level, the therapeutic potential of this approach remains not only promising but exciting. PMID:8488463

  11. The acute antinociceptive effect of hyperbaric oxygen is not accompanied by an increase in markers of oxidative stress

    PubMed Central

    Liu, Shulin; Shirachi, Donald Y.; Quock, Raymond M.

    2014-01-01

    Aims Exposure to hyperbaric oxygen (HBO2) causes an antinociceptive response in mice. However, breathing oxygen (O2) at an elevated pressure can potentially cause oxygen toxicity. The aim of this study was to identify the determinants of HBO2 antinociception and the toxicity profile of HBO2. Main methods Male NIH Swiss mice were assessed for acute antinociceptive responsiveness under room air or 100% O2 at 1.0 or 3.5 atmospheres absolute (ATA), using the acetic acid-induced abdominal constriction test. For the oxygen toxicity test, mice were exposed to 3.5 ATA oxygen for 11 min, 60 min, 60 min daily for 2 days (120 min) or 60 min daily for 4 days (240 min), then assessed by analyzing the levels of two oxidative stress markers, MDA (malondialdehyde) and protein carbonyl in brain, spinal cord and lung. Key Findings Only the combination of 100% O2 and 3.5 ATA caused significant antinociception. The antinociceptive effect of 100% O2 was pressure-dependent up to 3.5 ATA. In the oxygen toxicity test, mice exposed to HBO2 for different time intervals had levels of brain, spinal cord and lung MDA and protein carbonyl that were comparable to that of control animals exposed to room air. Significance Treatment with 100% O2 evokes a pressure-dependent antinociceptive effect. Since there was no significant increase in levels of the oxidative stress markers in the tested tissues, it is concluded HBO2 at 3.5 ATA produces antinociception in the absence of oxidative stress in mice. PMID:24418003

  12. Long-Term Oxygen Therapy 24 vs 15 h/day and Mortality in Chronic Obstructive Pulmonary Disease.

    PubMed

    Ahmadi, Zainab; Sundh, Josefin; Bornefalk-Hermansson, Anna; Ekström, Magnus

    2016-01-01

    Long-term oxygen therapy (LTOT) ≥ 15 h/day improves survival in hypoxemic chronic obstructive pulmonary disease (COPD). LTOT 24 h/day is often recommended but may pose an unnecessary burden with no clear survival benefit compared with LTOT 15 h/day. The aim was to test the hypothesis that LTOT 24 h/day decreases all-cause, respiratory, and cardiovascular mortality compared to LTOT 15 h/day in hypoxemic COPD. This was a prospective, observational, population-based study of COPD patients starting LTOT between October 1, 2005 and June 30, 2009 in Sweden. Overall and cause-specific mortality was analyzed using Cox and Fine-Gray regression, controlling for age, sex, prescribed oxygen dose, PaO2 (air), PaCO2 (air), Forced Expiratory Volume in one second (FEV1), WHO performance status, body mass index, comorbidity, and oral glucocorticoids. A total of 2,249 included patients were included with a median follow-up of 1.1 years (interquartile range, 0.6-2.1). 1,129 (50%) patients died and no patient was lost to follow-up. Higher LTOT duration analyzed as a continuous variable was not associated with any change in mortality rate (hazard ratio [HR] 1.00; (95% confidence interval [CI], 0.98 to 1.02) per 1 h/day increase above 15 h/day. LTOT exactly 24 h/day was prescribed in 539 (24%) patients and LTOT 15-16 h/day in 1,231 (55%) patients. Mortality was similar between the groups for all-cause, respiratory and cardiovascular mortality. In hypoxemic COPD, LTOT 24 h/day was not associated with a survival benefit compared with treatment 15-16 h/day. A design for a registry-based randomized trial (R-RCT) is proposed. PMID:27649490

  13. Hyperbaric oxygen therapy as a potential treatment for post-traumatic stress disorder associated with traumatic brain injury

    PubMed Central

    Eve, David J; Steele, Martin R; Sanberg, Paul R; Borlongan, Cesar V

    2016-01-01

    Traumatic brain injury (TBI) describes the presence of physical damage to the brain as a consequence of an insult and frequently possesses psychological and neurological symptoms depending on the severity of the injury. The recent increased military presence of US troops in Iraq and Afghanistan has coincided with greater use of improvised exploding devices, resulting in many returning soldiers suffering from some degree of TBI. A biphasic response is observed which is first directly injury-related, and second due to hypoxia, increased oxidative stress, and inflammation. A proportion of the returning soldiers also suffer from post-traumatic stress disorder (PTSD), and in some cases, this may be a consequence of TBI. Effective treatments are still being identified, and a possible therapeutic candidate is hyperbaric oxygen therapy (HBOT). Some clinical trials have been performed which suggest benefits with regard to survival and disease severity of TBI and/or PTSD, while several other studies do not see any improvement compared to a possibly poorly controlled sham. HBOT has been shown to reduce apoptosis, upregulate growth factors, promote antioxidant levels, and inhibit inflammatory cytokines in animal models, and hence, it is likely that HBOT could be advantageous in treating at least the secondary phase of TBI and PTSD. There is some evidence of a putative prophylactic or preconditioning benefit of HBOT exposure in animal models of brain injury, and the optimal time frame for treatment is yet to be determined. HBOT has potential side effects such as acute cerebral toxicity and more reactive oxygen species with long-term use, and therefore, optimizing exposure duration to maximize the reward and decrease the detrimental effects of HBOT is necessary. This review provides a summary of the current understanding of HBOT as well as suggests future directions including prophylactic use and chronic treatment. PMID:27799776

  14. Long-Term Oxygen Therapy 24 vs 15 h/day and Mortality in Chronic Obstructive Pulmonary Disease

    PubMed Central

    Sundh, Josefin; Bornefalk-Hermansson, Anna; Ekström, Magnus

    2016-01-01

    Long-term oxygen therapy (LTOT) ≥ 15 h/day improves survival in hypoxemic chronic obstructive pulmonary disease (COPD). LTOT 24 h/day is often recommended but may pose an unnecessary burden with no clear survival benefit compared with LTOT 15 h/day. The aim was to test the hypothesis that LTOT 24 h/day decreases all-cause, respiratory, and cardiovascular mortality compared to LTOT 15 h/day in hypoxemic COPD. This was a prospective, observational, population-based study of COPD patients starting LTOT between October 1, 2005 and June 30, 2009 in Sweden. Overall and cause-specific mortality was analyzed using Cox and Fine-Gray regression, controlling for age, sex, prescribed oxygen dose, PaO2 (air), PaCO2 (air), Forced Expiratory Volume in one second (FEV1), WHO performance status, body mass index, comorbidity, and oral glucocorticoids. A total of 2,249 included patients were included with a median follow-up of 1.1 years (interquartile range, 0.6–2.1). 1,129 (50%) patients died and no patient was lost to follow-up. Higher LTOT duration analyzed as a continuous variable was not associated with any change in mortality rate (hazard ratio [HR] 1.00; (95% confidence interval [CI], 0.98 to 1.02) per 1 h/day increase above 15 h/day. LTOT exactly 24 h/day was prescribed in 539 (24%) patients and LTOT 15–16 h/day in 1,231 (55%) patients. Mortality was similar between the groups for all-cause, respiratory and cardiovascular mortality. In hypoxemic COPD, LTOT 24 h/day was not associated with a survival benefit compared with treatment 15–16 h/day. A design for a registry-based randomized trial (R-RCT) is proposed. PMID:27649490

  15. Long-Term Oxygen Therapy 24 vs 15 h/day and Mortality in Chronic Obstructive Pulmonary Disease.

    PubMed

    Ahmadi, Zainab; Sundh, Josefin; Bornefalk-Hermansson, Anna; Ekström, Magnus

    2016-01-01

    Long-term oxygen therapy (LTOT) ≥ 15 h/day improves survival in hypoxemic chronic obstructive pulmonary disease (COPD). LTOT 24 h/day is often recommended but may pose an unnecessary burden with no clear survival benefit compared with LTOT 15 h/day. The aim was to test the hypothesis that LTOT 24 h/day decreases all-cause, respiratory, and cardiovascular mortality compared to LTOT 15 h/day in hypoxemic COPD. This was a prospective, observational, population-based study of COPD patients starting LTOT between October 1, 2005 and June 30, 2009 in Sweden. Overall and cause-specific mortality was analyzed using Cox and Fine-Gray regression, controlling for age, sex, prescribed oxygen dose, PaO2 (air), PaCO2 (air), Forced Expiratory Volume in one second (FEV1), WHO performance status, body mass index, comorbidity, and oral glucocorticoids. A total of 2,249 included patients were included with a median follow-up of 1.1 years (interquartile range, 0.6-2.1). 1,129 (50%) patients died and no patient was lost to follow-up. Higher LTOT duration analyzed as a continuous variable was not associated with any change in mortality rate (hazard ratio [HR] 1.00; (95% confidence interval [CI], 0.98 to 1.02) per 1 h/day increase above 15 h/day. LTOT exactly 24 h/day was prescribed in 539 (24%) patients and LTOT 15-16 h/day in 1,231 (55%) patients. Mortality was similar between the groups for all-cause, respiratory and cardiovascular mortality. In hypoxemic COPD, LTOT 24 h/day was not associated with a survival benefit compared with treatment 15-16 h/day. A design for a registry-based randomized trial (R-RCT) is proposed.

  16. A prospective randomized controlled trial assessing the efficacy of adjunctive hyperbaric oxygen therapy in the treatment of hidradenitis suppurativa.

    PubMed

    Yildiz, Hamza; Senol, Levent; Ercan, Erdinc; Bilgili, Memet Ersan; Karabudak Abuaf, Ozlem

    2016-02-01

    Hyperbaric oxygen therapy (HBOT) appears to enhance wound healing, increase bactericidal activity, and act synergistically with a number of antibiotics. The aim of this study was to evaluate the efficacy of HBOT as an adjunctive therapy in patients with hidradenitis suppurativa (HS) treated with a combination of systemic rifampicin and clindamycin. The study was a prospective, single-center, single-dose, open-label, randomized controlled clinical study of HBOT in patients with moderate to severe HS. Efficacy was measured by modified Sartorius score (SS), HS Severity Index (HSSI), Dermatology Life Quality Index (DLQI), and a visual analog scale (VAS) before treatment and after the completion of 4 and 10 weeks of treatment. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were also measured. Forty-three patients were enrolled in the study. More patients in the HBOT than in the control group showed a decrease of ≥50% from baseline parameters at week 10 for SS (100%), HSSI (100%), DLQI (95.5%), VAS (100%), ESR (100%), and CRP (72.7%). Clinically and statistically significant improvements from baseline were observed at 4 and 10 weeks in HSSI (P = 0.009 at both), SS (P = 0.021 at both), and DLQI (P = 0.044 at week 4, P = 0.009 at week 10). Adjunctive HBOT was considered to be effective in significantly improving antibiotic treatment of HS. The treatment was well tolerated, and no unexpected safety issues were identified.

  17. Time-resolved singlet oxygen luminescence detection under photodynamic therapy relevant conditions: comparison of ex vivo application of two photosensitizer formulations

    NASA Astrophysics Data System (ADS)

    Schlothauer, Jan C.; Hackbarth, Steffen; Jäger, Lutz; Drobniewski, Kai; Patel, Hemantbhai; Gorun, Sergiu M.; Röder, Beate

    2012-11-01

    Singlet oxygen plays a crucial role in photo-dermatology and photodynamic therapy (PDT) of cancer. Its direct observation by measuring the phosphorescence at 1270 nm, however, is still challenging due to the very low emission probability. It is especially challenging for the time-resolved detection of singlet oxygen kinetics in vivo which is of special interest for biomedical applications. Photosensitized generation of singlet oxygen, in pig ear skin as model for human skin, is investigated here. Two photosensitizers (PS) were topically applied to the pig ear skin and examined in a comparative study, which include the amphiphilic pheophorbide-a and the highly hydrophobic perfluoroalkylated zinc phthalocyanine (F64PcZn). Fluorescence microscopy indicates the exclusive accumulation of pheophorbide-a in the stratum corneum, while F64PcZn can also accumulate in deeper layers of the epidermis of the pig ear skin. The kinetics obtained with phosphorescence measurements show the singlet oxygen interaction with the PS microenvironment. Different generation sites of singlet oxygen correlate with the luminescence kinetics. The results show that singlet oxygen luminescence detection can be used as a diagnostic tool, not only for research, but also during treatment. The detection methodology is suitable for the monitoring of chemical quenchers' oxidation as well as O2 saturation at singlet oxygen concentration levels relevant to PDT treatment protocols.

  18. Photosensitizer fluorescence and singlet oxygen luminescence as dosimetric predictors of topical 5-aminolevulinic acid photodynamic therapy induced clinical erythema

    PubMed Central

    Mallidi, Srivalleesha; Anbil, Sriram; Lee, Seonkyung; Manstein, Dieter; Elrington, Stefan; Kositratna, Garuna; Schoenfeld, David; Pogue, Brian; Davis, Steven J.; Hasan, Tayyaba

    2014-01-01

    Abstract. The need for patient-specific photodynamic therapy (PDT) in dermatologic and oncologic applications has triggered several studies that explore the utility of surrogate parameters as predictive reporters of treatment outcome. Although photosensitizer (PS) fluorescence, a widely used parameter, can be viewed as emission from several fluorescent states of the PS (e.g., minimally aggregated and monomeric), we suggest that singlet oxygen luminescence (SOL) indicates only the active PS component responsible for the PDT. Here, the ability of discrete PS fluorescence-based metrics (absolute and percent PS photobleaching and PS re-accumulation post-PDT) to predict the clinical phototoxic response (erythema) resulting from 5-aminolevulinic acid PDT was compared with discrete SOL (DSOL)-based metrics (DSOL counts pre-PDT and change in DSOL counts pre/post-PDT) in healthy human skin. Receiver operating characteristic curve (ROC) analyses demonstrated that absolute fluorescence photobleaching metric (AFPM) exhibited the highest area under the curve (AUC) of all tested parameters, including DSOL based metrics. The combination of dose-metrics did not yield better AUC than AFPM alone. Although sophisticated real-time SOL measurements may improve the clinical utility of SOL-based dosimetry, discrete PS fluorescence-based metrics are easy to implement, and our results suggest that AFPM may sufficiently predict the PDT outcomes and identify treatment nonresponders with high specificity in clinical contexts. PMID:24503639

  19. In vitro study of reactive oxygen species production during photodynamic therapy in ultrasound-pretreated cancer cells.

    PubMed

    Kolárová, H; Bajgar, R; Tománková, K; Krestýn, E; Dolezal, L; Hálek, J

    2007-01-01

    Several recent studies bring evidence of cell death enhancement in photodynamic compound loaded cells by ultrasonic treatment. There are a number of hypotheses suggesting the mechanism of the harmful ultrasonic effect. One of them considers a process in the activation of photosensitizers by ultrasonic energy. Because the basis of the photodynamic damaging effect on cells consists in the production of reactive oxygen species (ROS), we focused our study on whether the ultrasound can increase ROS production within cancer cells. Particularly, we studied ROS formation in ultrasound pretreated breast adenocarcinoma cells during photodynamic therapy in the presence of chloroaluminum phthalocyanine disulfonate (ClAlPcS2). Production of ROS was investigated by the molecular probe CM-H2DCFDA. Our results show that ClAlPcS2 induces higher ROS production in the ultrasound pretreated cell lines at a concentration of 100 microM and light intensity of 2 mW/cm2. We also observed a dependence of ROS production on photosensitizer concentration and light dose. These results demonstrate that the photodynamic effect on breast cancer cells can be enhanced by ultrasound pretreatment.

  20. Suppression of Cancer Growth by Nonviral Gene Therapy Based on a Novel Reactive Oxygen Species-responsive Promoter

    PubMed Central

    Policastro, Lucía L; Ibañez, Irene L; Durán, Hebe A; Soria, Gastón; Gottifredi, Vanesa; Podhajcer, Osvaldo L

    2009-01-01

    Increased reactive oxygen species (ROS) production has been reported as a distinctive feature of different pathologies including cancer. Therefore, we assessed whether increased ROS production in the cancer microenvironment could be selectively exploited to develop a selective anticancer therapy. For this purpose, we constructed a novel chimeric promoter, based on a ROS-response motif located in the VEGF gene promoter placed, in turn, downstream of a second ROS-response motif obtained from the early growth response 1 (Egr-1) gene promoter. The activity of the chimeric promoter was largely dependent on variations in intracellular ROS levels and showed a high inducible response to exogenous H2O2. Transient expression of the thymidine kinase (TK) gene driven by the chimeric promoter, followed by gancyclovir (GCV) administration, inhibited human colorectal cancer and melanoma cell growth in vitro and in vivo. Moreover, electrotransfer of the TK gene followed by GCV administration exerted a potent therapeutic effect on established tumors. This response was improved when combined with chemotherapeutic drugs. Thus, we show for the first time that a distinctive pro-oxidant state can be used to develop new selective gene therapeutics for cancer. PMID:19436270

  1. Low shear red cell oxygen transport effectiveness is adversely affected by transfusion and further worsened by deoxygenation in sickle cell disease patients on chronic transfusion therapy

    PubMed Central

    Detterich, Jon; Alexy, Tamas; Rabai, Miklos; Dongelyan, Ani; Coates, Thomas; Wood, John; Meiselman, Herbert

    2012-01-01

    BACKGROUND Simple chronic transfusion therapy (CTT) is a mainstay for stroke prophylaxis in sickle cell anemia, but its effects on hemodynamics are poorly characterized. Transfusion improves oxygen carrying capacity, reducing demands for high cardiac output. While transfusion decreases factors associated with vaso-occlusion, including percent HbS, reticulocyte count and circulating cell-free hemoglobin, it increases blood viscosity, which reduces microvascular flow. The hematocrit to viscosity ratio (HVR) is an index of red cell oxygen transport effectiveness that varies with shear stress and balances the benefits of improved oxygen capacity to viscosity-mediated impairment of microvascular flow. We hypothesized that transfusion would improve HVR at high shear despite increased blood viscosity, but would decrease HVR at low shear. STUDY DESIGN AND METHODS To test this hypothesis, we examined oxygenated and deoxygenated blood samples from 15 sickle cell patients on CTT immediately pre-transfusion and again 12–120 hours post-transfusion. RESULTS Comparable changes in hemoglobin, hematocrit, reticulocyte count and hemoglobin S with transfusion were observed in all subjects. Viscosity, hematocrit and high-shear HVR increased with transfusion while low shear HVR decreased significantly. CONCLUSION Decreased low-shear HVR suggests impaired oxygen transport to low-flow regions and may explain why some complications of sickle cell anemia are ameliorated by chronic transfusion therapy and others may be made worse. PMID:22882132

  2. Is mean blood saturation a useful marker of tissue oxygenation?

    PubMed

    Thorn, Clare E; Matcher, Stephen J; Meglinski, Igor V; Shore, Angela C

    2009-05-01

    Increasingly we are monitoring the distribution of oxygen through the microcirculation using optical techniques such as optical reflectance spectroscopy (ORS) and near-infrared spectroscopy. Mean blood oxygen saturation (S(mb)O(2)) and tissue oxygenation index measured by these two techniques, respectively, evoke a concept of the measurement of oxygen delivery to tissue. This study aims to establish whether S(mb)O(2) is an appropriate indicator of tissue oxygenation. Spontaneous fluctuations in S(mb)O(2) observed as changes in concentration of oxyhemoglobin ([HbO(2)]) and deoxyhemoglobin ([Hb]) were measured by ORS in the skin microcirculation of 30 healthy subjects (15 men, age 21-42 yr). Fourier analysis identified two distinctly different spontaneous falls in S(mb)O(2). The first type of swing, thought to be induced by fluctuations in arterial blood volume, resulted from the effects of respiration, endothelial, sympathetic, and myogenic activity. There was no apparent change in [Hb]. In contrast, a second type of swing resulted from a fall in [HbO(2)] accompanied by a rise in [Hb] and was only induced by endothelial and sympathetic activity. Thus the same fall in S(mb)O(2) can be induced by two distinct responses. A "type I" swing does not suggest an inadequacy in oxygen delivery whereas a "type II" swing may indicate a change in oxygen delivery from blood to tissue. S(mb)O(2) alone cannot therefore be accepted as a definitive marker of tissue oxygenation.

  3. Bridging Theory and Experiment to Address Structural Properties of Truncated Haemoglobins: Insights from Thermobifida fusca HbO.

    PubMed

    Howes, Barry D; Boechi, Leonardo; Boffi, Alberto; Estrin, Dario E; Smulevich, Giulietta

    2015-01-01

    In this chapter, we will discuss the paradigmatic case of Thermobifida fusca (Tf-trHb) HbO in its ferrous and ferric states and its behaviour towards a battery of possible ligands. This choice was dictated by the fact that it has been one of the most extensively studied truncated haemoglobins, both in terms of spectroscopic and molecular dynamics studies. Tf-trHb typifies the structural properties of group II trHbs, as the active site is characterized by a highly polar distal environment in which TrpG8, TyrCD1, and TyrB10 provide three potential H-bond donors in the distal cavity capable of stabilizing the incoming ligands. The role of these residues in key topological positions, and their interplay with the iron-bound ligands, has been addressed in studies carried out on the CO, F(-), OH(-), CN(-), and HS(-) adducts formed with the wild-type protein and a combinatorial set of mutants, in which the distal polar residues, TrpG8, TyrCD1, and TyrB10, have been singly, doubly, or triply replaced by a Phe residue. In this context, such a complete analysis provides an excellent benchmark for the investigation of the relationship between protein structure and function, allowing one to translate physicochemical properties of the active site into the observed functional behaviour. Tf-trHb will be compared with other members of the group II trHbs and, more generally, with members of the other trHb subgroups.

  4. Bridging Theory and Experiment to Address Structural Properties of Truncated Haemoglobins: Insights from Thermobifida fusca HbO.

    PubMed

    Howes, Barry D; Boechi, Leonardo; Boffi, Alberto; Estrin, Dario E; Smulevich, Giulietta

    2015-01-01

    In this chapter, we will discuss the paradigmatic case of Thermobifida fusca (Tf-trHb) HbO in its ferrous and ferric states and its behaviour towards a battery of possible ligands. This choice was dictated by the fact that it has been one of the most extensively studied truncated haemoglobins, both in terms of spectroscopic and molecular dynamics studies. Tf-trHb typifies the structural properties of group II trHbs, as the active site is characterized by a highly polar distal environment in which TrpG8, TyrCD1, and TyrB10 provide three potential H-bond donors in the distal cavity capable of stabilizing the incoming ligands. The role of these residues in key topological positions, and their interplay with the iron-bound ligands, has been addressed in studies carried out on the CO, F(-), OH(-), CN(-), and HS(-) adducts formed with the wild-type protein and a combinatorial set of mutants, in which the distal polar residues, TrpG8, TyrCD1, and TyrB10, have been singly, doubly, or triply replaced by a Phe residue. In this context, such a complete analysis provides an excellent benchmark for the investigation of the relationship between protein structure and function, allowing one to translate physicochemical properties of the active site into the observed functional behaviour. Tf-trHb will be compared with other members of the group II trHbs and, more generally, with members of the other trHb subgroups. PMID:26616516

  5. Partial hypoxia as a cause of radioresistance in a human tumor xenograft: its influence illustrated by the sensitizing effect of misonidazole and hyperbaric oxygen

    SciTech Connect

    Reynaud-Bougnoux, A.; Lespinasse, F.; Malaise, E.P.; Guichard, M.

    1986-08-01

    While previous studies with three human tumor xenografts suggest that contact-resistance plays a major role in the response of these tumors to radiation, it remains possible that partial hypoxia may provide an alternate explanation. The present study was carried out to check this possibility by investigating the influence of misonidazole (MISO) and hyperbaric oxygen (HBO) on both the initial and distal components of the survival curves of HRT18 tumor cells. The effect of a challenge dose of radiation on the initial radioresistance of this tumor was also studied. To assess the effects of MISO and HBO, tumor cell survival was determined by excision assay in two groups of tumor-bearing mice, one given MISO (1 mg/g body weight, i.p.) 45 min before irradiation and the other exposed to HBO (3.5 bars). MISO treatment caused greater sensitization than HBO. The enhancement ratios at the 5.10(-1) level were 1.7 (MISO) and 1.7 (HBO); at the 10(-1) level, they were 1.6 (MISO) and 1.4 (HBO); while at 10(-2), they were 1.6 (MISO) and 1.4 (HBO). These two sensitizing effects favor the hypothesis that solid tumors contain a compartment of partially hypoxic cells. To study the effect of a challenge radiation dose on initial radioresistance, tumors were given a challenge dose of 8 Gy, followed 24-48 hr later by doses ranging from 2-12 Gy. The challenge dose did not modify the shape of the survival curve.

  6. First experimental-based characterization of oxygen ion beam depth dose distributions at the Heidelberg Ion-Beam Therapy Center

    NASA Astrophysics Data System (ADS)

    Kurz, C.; Mairani, A.; Parodi, K.

    2012-08-01

    Over the last decades, the application of proton and heavy-ion beams to external beam radiotherapy has rapidly increased. Due to the favourable lateral and depth dose profile, the superposition of narrow ion pencil beams may enable a highly conformal dose delivery to the tumour, with better sparing of the surrounding healthy tissue in comparison to conventional radiation therapy with photons. To fully exploit the promised clinical advantages of ion beams, an accurate planning of the patient treatments is required. The clinical treatment planning system (TPS) at the Heidelberg Ion-Beam Therapy Center (HIT) is based on a fast performing analytical algorithm for dose calculation, relying, among others, on laterally integrated depth dose distributions (DDDs) simulated with the FLUKA Monte Carlo (MC) code. Important input parameters of these simulations need to be derived from a comparison of the simulated DDDs with measurements. In this work, the first measurements of 16O ion DDDs at HIT are presented with a focus on the determined Bragg peak positions and the understanding of factors influencing the shape of the distributions. The measurements are compared to different simulation approaches aiming to reproduce the acquired data at best. A simplified geometrical model is first used to optimize important input parameters, not known a priori, in the simulations. This method is then compared to a more realistic, but also more time-consuming simulation approach better accounting for the experimental set-up and the measuring process. The results of this work contributed to a pre-clinical oxygen ion beam database, which is currently used by a research TPS for corresponding radio-biological cell experiments. A future extension to a clinical database used by the clinical TPS at HIT is foreseen. As a side effect, the performed investigations showed that the typical water equivalent calibration approach of experimental data acquired with water column systems leads to slight

  7. Effect of in-water oxygen prebreathing at different depths on decompression-induced bubble formation and platelet activation.

    PubMed

    Bosco, Gerardo; Yang, Zhong-jin; Di Tano, Guglielmo; Camporesi, Enrico M; Faralli, Fabio; Savini, Fabio; Landolfi, Angelo; Doria, Christian; Fanò, Giorgio

    2010-05-01

    Effect of in-water oxygen prebreathing at different depths on decompression-induced bubble formation and platelet activation in scuba divers was evaluated. Six volunteers participated in four diving protocols, with 2 wk of recovery between dives. On dive 1, before diving, all divers breathed normally for 20 min at the surface of the sea (Air). On dive 2, before diving, all divers breathed 100% oxygen for 20 min at the surface of the sea [normobaric oxygenation (NBO)]. On dive 3, before diving, all divers breathed 100% O2 for 20 min at 6 m of seawater [msw; hyperbaric oxygenation (HBO) 1.6 atmospheres absolute (ATA)]. On dive 4, before diving, all divers breathed 100% O2 for 20 min at 12 msw (HBO 2.2 ATA). Then they dove to 30 msw (4 ATA) for 20 min breathing air from scuba. After each dive, blood samples were collected as soon as the divers surfaced. Bubbles were measured at 20 and 50 min after decompression and converted to bubble count estimate (BCE) and numeric bubble grade (NBG). BCE and NBG were significantly lower in NBO than in Air [0.142+/-0.034 vs. 0.191+/-0.066 (P<0.05) and 1.61+/-0.25 vs. 1.89+/-0.31 (P<0.05), respectively] at 20 min, but not at 50 min. HBO at 1.6 ATA and 2.2 ATA has a similar significant effect of reducing BCE and NBG. BCE was 0.067+/-0.026 and 0.040+/-0.018 at 20 min and 0.030+/-0.022 and 0.020+/-0.020 at 50 min. NBG was 1.11+/-0.17 and 0.92+/-0.16 at 20 min and 0.83+/-0.18 and 0.75+/-0.16 at 50 min. Prebreathing NBO and HBO significantly alleviated decompression-induced platelet activation. Activation of CD62p was 3.0+/-0.4, 13.5+/-1.3, 10.7+/-0.9, 4.5+/-0.7, and 7.6+/-0.8% for baseline, Air, NBO, HBO at 1.6 ATA, and HBO at 2.2 ATA, respectively. The data show that prebreathing oxygen, more effective with HBO than NBO, decreases air bubbles and platelet activation and, therefore, may be beneficial in reducing the development of decompression sickness.

  8. The apoptosis of peripheral blood lymphocytes promoted by hyperbaric oxygen treatment contributes to attenuate the severity of early stage acute pancreatitis in rats.

    PubMed

    Bai, Xuewei; Song, Zengfu; Zhou, Yanmei; Pan, Shangha; Wang, Feng; Guo, Zuoming; Jiang, Maitao; Wang, Gang; Kong, Rui; Sun, Bei

    2014-01-01

    The aim of this study was to investigate the immunoregulatory effects of hyperbaric oxygen (HBO) via promoting the apoptosis of peripheral blood lymphocytes (PBLs) to attenuate the severity of early stage acute pancreatitis (AP) in rats. Additionally, the persistence of the HBO treatment effects was evaluated. One hundred and twenty male Wistar rats were randomized into four groups: sham, AP, AP + normobaric oxygen (NBO), and AP + HBO. Each group consisted of 30 rats. Four hours after the induction of AP, the 30 rats in the AP + NBO group were given normobaric oxygen treatment with 100 % oxygen at 1 atm for 90 min. The 30 rats in the AP + HBO group received 100 % oxygen at 2.5 atm for 90 min, with a compression/decompression time of 15 min. The 30 rats in the AP group remained untreated. At 6, 12, and 24 h after the induction of AP, surviving rats from each group were sacrificed, and the blood and tissue samples were collected for the following measurements: the partial pressure of oxygen (PaO2) and oxygen saturation (SaO2) of the arterial blood, the levels of serum amylase, lipase, interleukin-2 (IL-2), interferon-γ (IFN-γ), interleukin-10 (IL-10), hepatocyte growth factor (HGF), and reactive oxygen species (ROS), and the mitochondrial membrane potential (∆Ψm) of the PBLs. The expression levels of procaspase-3, caspase-3, procaspase-9, and caspase-9 were also evaluated in the PBLs. Additionally, the apoptosis of PBLs was assessed, and the pancreatic tissues were subjected to a histopathological analysis by pathological grading and scoring. The histopathology of the lung, liver, kidney, duodenum, and heart was also analyzed at 12 h after the induction of AP. Significant differences were found at 6 and 12 h after AP induction. The HBO treatment significantly elevated the PaO2 and SaO2 levels, and the ROS levels in the PBLs. Additionally, HBO downregulated the levels of amylase and lipase. The HBO treatment also reduced the ∆Ψm levels, upregulated the

  9. Effects of hyperbaric oxygen on eye tracking abnormalities in males after mild traumatic brain injury.

    PubMed

    Cifu, David X; Hoke, Kathy W; Wetzel, Paul A; Wares, Joanna R; Gitchel, George; Carne, William

    2014-01-01

    The effects of hyperbaric oxygen (HBO2) on eye movement abnormalities in 60 military servicemembers with at least one mild traumatic brain injury (TBI) from combat were examined in a single-center, randomized, double-blind, sham-controlled, prospective study at the Naval Medicine Operational Training Center. During the 10 wk of the study, each subject was delivered a series of 40, once a day, hyperbaric chamber compressions at a pressure of 2.0 atmospheres absolute (ATA). At each session, subjects breathed one of three preassigned oxygen fractions (10.5%, 75%, or 100%) for 1 h, resulting in an oxygen exposure equivalent to breathing either surface air, 100% oxygen at 1.5 ATA, or 100% oxygen at 2.0 ATA, respectively. Using a standardized, validated, computerized eye tracking protocol, fixation, saccades, and smooth pursuit eye movements were measured just prior to intervention and immediately postintervention. Between and within groups testing of pre- and postintervention means revealed no significant differences on eye movement abnormalities and no significant main effect for HBO2 at either 1.5 ATA or 2.0 ATA equivalent compared with the sham-control. This study demonstrated that neither 1.5 nor 2.0 ATA equivalent HBO2 had an effect on postconcussive eye movement abnormalities after mild TBI when compared with a sham-control.

  10. Effects of hyperbaric oxygen on eye tracking abnormalities in males after mild traumatic brain injury.

    PubMed

    Cifu, David X; Hoke, Kathy W; Wetzel, Paul A; Wares, Joanna R; Gitchel, George; Carne, William

    2014-01-01

    The effects of hyperbaric oxygen (HBO2) on eye movement abnormalities in 60 military servicemembers with at least one mild traumatic brain injury (TBI) from combat were examined in a single-center, randomized, double-blind, sham-controlled, prospective study at the Naval Medicine Operational Training Center. During the 10 wk of the study, each subject was delivered a series of 40, once a day, hyperbaric chamber compressions at a pressure of 2.0 atmospheres absolute (ATA). At each session, subjects breathed one of three preassigned oxygen fractions (10.5%, 75%, or 100%) for 1 h, resulting in an oxygen exposure equivalent to breathing either surface air, 100% oxygen at 1.5 ATA, or 100% oxygen at 2.0 ATA, respectively. Using a standardized, validated, computerized eye tracking protocol, fixation, saccades, and smooth pursuit eye movements were measured just prior to intervention and immediately postintervention. Between and within groups testing of pre- and postintervention means revealed no significant differences on eye movement abnormalities and no significant main effect for HBO2 at either 1.5 ATA or 2.0 ATA equivalent compared with the sham-control. This study demonstrated that neither 1.5 nor 2.0 ATA equivalent HBO2 had an effect on postconcussive eye movement abnormalities after mild TBI when compared with a sham-control. PMID:25436771

  11. Effects of nocturnal oxygen therapy in patients with chronic heart failure and central sleep apnea: CHF-HOT study.

    PubMed

    Nakao, Yoko M; Ueshima, Kenji; Yasuno, Shinji; Sasayama, Shigetake

    2016-02-01

    It was previously reported that nocturnal home oxygen therapy (HOT) significantly improved not only sleep disordered breathing (SDB), but also quality of life (QOL) and left ventricular ejection fraction (LVEF) in two trials. To strengthen the statistical reliability of the above efficacies of HOT and to assess the effects of 12-week nocturnal HOT on suppression of ventricular arrhythmias, we combined the two trials and undertook a post hoc analysis. Ninety-seven patients with chronic heart failure (CHF) and central sleep apnea were assigned to receive HOT (45 patients) or not (52 patients). HOT resulted in greater reduction in the apnea-hypopnea index (AHI) (-11.4 ± 11.0 vs. -0.2 ± 7.6 events/h, p < 0.01), which is associated with greater improvement in the Specific Activity Scale (0.8 ± 1.2 vs. 0.0 ± 0.6, p < 0.01), New York Heart Association (NYHA) functional class (p < 0.01), and LVEF (p = 0.06). Median number of premature ventricular contraction (PVC) at baseline was 17 beats per hour in both the HOT and the control groups. Overall improvements of PVCs were not different either in the HOT group or in the control. However, in 12 patients with NYHA >III and AHI >20 events/h, PVC was significantly improved by HOT with a marked reduction in AHI and a substantial increase in LVEF. In conclusion, among patients with CHF and CSA, HOT improves SDB, QOL, and cardiac function. The effectiveness of HOT for ventricular arrhythmias was not observed in the overall analysis, but only in a limited number of patients with severe CHF and SDB. To clarify the effects of HOT on ventricular arrhythmias in patients with CHF and SDB, a further study is needed.

  12. The risk of burn injury during long-term oxygen therapy: a 17-year longitudinal national study in Sweden

    PubMed Central

    Tanash, Hanan A; Huss, Fredrik; Ekström, Magnus

    2015-01-01

    Background Long-term oxygen therapy (LTOT) improves the survival time in hypoxemic chronic obstructive pulmonary disease. Despite warnings about potential dangers, a considerable number of patients continue to smoke while on LTOT. The incidence of burn injuries related to LTOT is unknown. The aim of this study was to estimate the rate of burn injury requiring health care contact during LTOT. Methods Prospective, population-based, consecutive cohort study of people starting LTOT from any cause between January 1, 1992 and December 31, 2009 in the Swedish National Register of Respiratory Failure (Swedevox). Results In total, 12,497 patients (53% women) were included. The mean (standard deviation) age was 72±9 years. The main reasons for starting LTOT were chronic obstructive pulmonary disease (75%) and pulmonary fibrosis (15%). Only 269 (2%) were active smokers when LTOT was initiated. The median follow-up time to event was 1.5 years (interquartile range, 0.55–3.1). In total, 17 patients had a diagnosed burn injury during 27,890 person-years of LTOT. The rate of burn injury was 61 (95% confidence interval, 36–98) per 100,000 person-years. There was no statistically significant difference in the rate of burn injury between ever-smokers and never-smokers, or between men and women. Conclusion The rate of burn injuries in patients on LTOT seems to be low in Sweden. The strict requirements in Sweden for smoking cessation before LTOT initiation may contribute to this finding. PMID:26622175

  13. Low level laser therapy activates NF-kB via generation of reactive oxygen species in mouse embryonic fibroblasts

    NASA Astrophysics Data System (ADS)

    Chen, Aaron Chih-Hao; Arany, Praveen R.; Huang, Ying-Ying; Tomkinson, Elizabeth M.; Saleem, Taimur; Yull, Fiona E.; Blackwell, Timothy S.; Hamblin, Michael R.

    2009-02-01

    Despite over forty years of investigation on low-level light therapy (LLLT), the fundamental mechanisms underlying photobiomodulation remain unclear. In this study, we isolated murine embryonic fibroblasts (MEF) from transgenic NF-kB luciferase reporter mice and studied their response to 810-nm laser radiation. Significant activation of NFkB was observed for fluences higher than 0.003 J/cm2. NF-kB activation by laser was detectable at 1-hour time point. Moreover, we demonstrated that laser phosphorylated both IKK α/β and NF-kB 15 minutes after irradiation, which implied that laser activates NF-kB via phosphorylation of IKK α/β. Suspecting mitochondria as the source of NF-kB activation signaling pathway, we demonstrated that laser increased both intracellular reactive oxygen species (ROS) by fluorescence microscopy with dichlorodihydrofluorescein and ATP synthesis by luciferase assay. Mitochondrial inhibitors, such as antimycin A, rotenone and paraquat increased ROS and NF-kB activation but had no effect on ATP. The ROS quenchers N-acetyl-L-cysteine and ascorbic acid abrogated laser-induced NF-kB and ROS but not ATP. These results suggested that ROS might play an important role in the signaling pathway of laser induced NF-kB activation. However, the western blot showed that antimycin A, a mitochondrial inhibitor, did not activate NF-kB via serine phosphorylation of IKK α/β as the laser did. On the other hand, LLLT, unlike mitochondrial inhibitors, induced increased cellular ATP levels, which indicates that light also upregulates mitochondrial respiration. ATP upregulation reached a maximum at 0.3 J/cm2 or higher. We conclude that LLLT not only enhances mitochondrial respiration, but also activates the redox-sensitive transcription factor NF-kB by generating ROS as signaling molecules.

  14. Hyperbaric Oxygen Therapy Registry

    ClinicalTrials.gov

    2016-05-18

    Air or Gas Embolism; Carbon Monoxide Poisoning; Clostridial Myositis and Myonecrosis (Gas Gangrene); Crush Injury, Compartment Syndrome & Other Acute Traumatic Ischemias; Decompression Sickness; Peripheral Arterial Insufficiency and Central Retinal Artery Occlusion; Severe Anemia; Intracranial Abscess; Necrotizing Soft Tissue Infections; Osteomyelitis (Refractory); Delayed Radiation Injury (Soft Tissue and Bony Necrosis); Compromised Grafts and Flaps; Acute Thermal Burn Injury; Idiopathic Sudden Sensorineural Hearing Loss

  15. Selective Degeneration of Central Photoreceptors after Hyperbaric Oxygen in Normal and Metallothionein-Knockout Mice

    PubMed Central

    Nachman-Clewner, Michele; Giblin, Frank J.; Kathleen Dorey, C.; Blanks, Robert H. I.; Dang, Loan; Dougherty, Christopher J.; Blanks, Janet C.

    2009-01-01

    Purpose Metallothioneins (MTs) in the brain and retina are believed to bind metals and reduce free radicals, thereby protecting neurons from oxidative damage. This study was undertaken to investigate whether retinal photoreceptor (PR) cells lacking MTs are more susceptible to hyperbaric oxygen (HBO)–induced cell death in vivo. Methods Wild-type (WT) and MT-knockout (MT-KO) mice lacking metallothionein (MT)-1 and MT-2 were exposed to three atmospheres of 100% oxygen for 3 hours, 3 times per week for 1, 3, or 5 weeks. The control animals were not exposed. Histologic analysis of PR viability was performed by counting rows of nuclei in the outer nuclear layer (ONL). Ultrastructure studies verified PR damage. Results HBO exposure produced a major loss of PR cells in the central retinas of WT and MT-KO mice, with no effect on the peripheral retina even at the longest (5 weeks) exposures. The degree of PR damage and cell death increased with duration of HBO exposure. One week of HBO exposure was insufficient to cause PR death, but tissue damage was observed in the inner and outer segments. At 3 weeks, the rows of PR nuclei in the central retina were significantly reduced by 38% in WT and 28% in MT-KO animals. At 5 weeks, PR loss was identical in WT (34%) and MT-KO (34%) animals and was comparable to that in WT at 3 weeks. Conclusions The data suggest that MT-1 and -2 alone are not sufficient for protecting PRs against HBO-induced cell death. The selective degeneration of central PRs may provide clues to mechanisms of oxidative damage in retinal disease. PMID:18579766

  16. Tissue oxygen monitoring by photoacoustic lifetime imaging (PALI) and its application to image-guided photodynamic therapy (PDT)

    NASA Astrophysics Data System (ADS)

    Shao, Qi; Morgounova, Ekaterina; Ashkenazi, Shai

    2015-03-01

    The oxygen partial pressure (pO2), which results from the balance between oxygen delivery and its consumption, is a key component of the physiological state of a tissue. Images of oxygen distribution can provide essential information for identifying hypoxic tissue and optimizing cancer treatment. Previously, we have reported a noninvasive in vivo imaging modality based on photoacoustic lifetime. The technique maps the excited triplet state of oxygen-sensitive dye, thus reflects the spatial and temporal distribution of tissue oxygen. We have applied PALI on tumor on small animals to identify hypoxia area. We also showed that PALI is able monitor changes of tissue oxygen, in an acute ischemia and breathing modulation model. Here we present our work on developing a treatment/imaging modality (PDT-PALI) that integrates PDT and a combined ultrasound/photoacoustic imaging system. The system provides real-time feedback of three essential parameters namely: tissue oxygen, light penetration in tumor location, and distribution of photosensitizer. Tissue oxygen imaging is performed by applying PALI, which relies on photoacoustic probing of oxygen-dependent, excitation lifetime of Methylene Blue (MB) photosensitizer. Lifetime information can also be used to generate image showing the distribution of photosensitizer. The level and penetration depth of PDT illumination can be deduced from photoacoustic imaging at the same wavelength. All images will be combined with ultrasound B-mode images for anatomical reference.

  17. Near-infrared oxymeter prototype for noninvasive analysis of rat brain oxygenation

    NASA Astrophysics Data System (ADS)

    Crespi, Francesco; Donini, Maurizio; Bandera, Andrea; Heidbreder, Christian; Salvatori, Giorgia; Rovati, Luigi

    2004-09-01

    The feasibility of non-invasive analysis of brain activities was studied in the attempt to overcome the major limitation of actual in vivo methodologies i.e. invasiveness. Optic fibre probes were used as optical head of a novel, highly sensitive near infrared continuous wave spectroscopy (CW-NIR) instrument. This prototype was designed for non-invasive analysis of the two main forms of haemoglobin: oxy-haemoglobin (HbO2) and deoxy-haemoglobin (Hb), chromophores present in biological tissues. It was tested in peripheral tissue (human gastrocnemius muscle) and then reset to perform measurement on rat brain. In animal studies, the optical head was firmly placed using stereotaxic apparatus upon the sagittal line of anaesthetised adult rat's head, without any surgery. Then pharmacological treatments with saline (300μl s.c.) amphetamine (2mg/kg) or nicotine (0.4mg/kg) were performed. Within 10-20 min amphetamine substantially increased HbO2 and reduced Hb control levels. Nicotine produced a rapid initial increase followed by a decrease of HbO2. In contrast to amphetamine, nicotine treatment also reduced Hb and blood volume. These results support the capacity of our CW-NIR prototype to measure non-invasively HbO2 and Hb levels in the rat brain, markers of the degree of tissue oxygenation, index of blood level then of the state of brain metabolism.

  18. Effect of hyperbaric oxygen profiles on the bond strength of repaired composite resin

    PubMed Central

    Mossa, Hossam; ElKhatat, Essam; Hassan, Ahmed M.; Baroudi, Kusai; Beshr, Khaled

    2016-01-01

    Objective: This study was performed to evaluate the bond strength of repaired three types of composite resins under various hyperbaric oxygen (HBO) profiles with various session numbers. Materials and Methods: Sixty specimens of three types of composite resin (nanofilled composite, nanohybrid composite and microfilled composite) each type of composite was divided into four group according to various profiles of HBO treatment (control, 2bar, 3 bar and 5 bar). Then, the specimens were repaired; thermocycled, the tensile bond strength were measured. Then the data were analyzed by One-way ANOVA followed by Tukey's post hoc test (α = 0.05). Results: The highest bond strength was obtained for the repaired nanofilled composite resin specimens while; the lowest bond strength was obtained for the repaired microfilled composite resin specimens. The highest tensile bond strength was recorded for the specimens who treated with the highest pressure of HBO. Conclusion: The bond strength of repaired nanofilled composite resins is better than the other types of composite resin. The highest pressure of HBO, the highest bond strength of repaired composite resins. PMID:27195232

  19. Oxygen safety

    MedlinePlus

    COPD - oxygen safety; Chronic obstructive pulmonary disease - oxygen safety; Chronic obstructive airways disease - oxygen safety; Emphysema - oxygen safety; Heart failure - oxygen-safety; Palliative care - oxygen safety; ...

  20. End-Tidal CO2 Tension Is Predictive of Effective Nocturnal Oxygen Therapy in Patients with Chronic Heart Failure and Central Sleep Apnea.

    PubMed

    Sugimura, Koichiro; Shinozaki, Tsuyoshi; Fukui, Shigefumi; Ogawa, Hiromasa; Shimokawa, Hiroaki

    2016-01-01

    Central sleep apnea (CSA) is characterized by recurring cycles of crescendo-decrescendo ventilation during sleep, and enhances sympathetic nerve activity. Thus CSA has a prognostic impact in patients with chronic heart failure (CHF). Although nocturnal oxygen (O2) therapy decreases frequency of CSA and improves functional exercise capacity, it is also known that some non-responders to the therapy exist. We thus aimed to identify predictors of responders to nocturnal O2 therapy in CHF patients with CSA. In 12 CHF patients with CSA hospitalized at our department, sleep study was performed at 2 consecutive nights. Patients nasally inhaled O2 at either the first or second night in a randomized manner. To predict the percentage reduction in apnea-hypopnea index (%ΔAHI) in response to the nocturnal O2 therapy, we performed multiple regression analysis with a stepwise method with variables including age, brain-natriuretic peptide, circulation time, baseline AHI, hypercapnic ventilatory response and end-tidal carbon dioxide tension (PETCO2). Nocturnal O2 therapy significantly decreased AHI (from 32 ± 13 /h to 12 ± 10 /h, P < 0.0001). Among the possible predictors, PETCO2 was the only variable that is predictive of % changes in AHI. Receiver operating characteristics analysis determined 4.25% as the optimal cutoff PETCO2 level to identify responder to nocturnal O2 therapy (> 50% reduction of AHI), with 88.9% of sensitivity and 66.7% of specificity. In conclusion, PETCO2 is useful to predict the efficacy of O2 therapy in CHF patients with CSA, providing important information to the current nocturnal O2 therapy.

  1. Near-infrared spectroscopy measurement of blood oxygenation content and its application in sports practice

    NASA Astrophysics Data System (ADS)

    Xu, Guodong; Gong, Hui; Ge, Xinfa; Luo, Qingming

    2003-12-01

    To research the change characteristics of blood oxygenation content in skeletal muscle, the change regularity between blood oxygenation content and exercise intensity as well as HbO2 and blood lactate acid while taking incremental exercises, we took an in vivo, real-time and continuous measurement on the blood oxygenation content of eight sportsmen when they did incremental exercises of five degrees on a power bicycle using a portable tissue oximeter which is based on the principle of near-infrared spectroscopy(NIRS), simultaneously, we detected the blood lactate acid of subjects after each degree of incremental physical load instantly using a blood lactate analysis equipment. The results showed that the content of HbO2 descended regularly while that of Hb ascended; blood volume decreased; and the density of lactate increased as the intensity of exercises was heightened. The statistics analyses showed that the relationship between HbO2 and blood lactate is rather close (correlation coefficient r=-0.918). With this discovery, a theoretical basis in measuring the relative change of blood oxygenation content non-invasively was evidenced, and a novel technology for assessing the physical situation of sportsman, grasping sports density and evaluating the training effect could be imported.

  2. Raman spectroscopic monitoring of the bioeffects of nitroglycerin on Hb-O II in single red blood cell

    NASA Astrophysics Data System (ADS)

    Chiang, Huihua Kenny; Ruan, Hung-Shiang; Cheng, Hung-You; Fang, Tung-Ting

    2007-02-01

    Raman spectroscopy has been shown to have the potential for providing oxygenated ability of erythrocytes. Raman line at 1638 cm-1 has also been reported as one significant oxygenic indicator for erythrocytes. In this research, we develop the Raman spectroscopic monitoring of the bioeffects of Nitroglycerin on hemoglobin oxygen saturation in a single red blood cell (RBC). Nitroglycerin has been frequently used in the management of angina pectoris. Nitroglycerin liberates nitric oxide (NO) to blood vessels. NO is an oxidizer that easily converts hemoglobin to methemoglobin. The conversion may cause the decrease of oxygenated ability of erythrocytes. In this study, we observed the oxidize state of erythrocytes caused by the over dosage of Nitroglycerin. When the dose of Nitroglycerin exceeds 2x10 -4 M, the oxygenic state of erythrocytes decreases significantly. The Raman spectroscopic results demonstrate the observation of the bioeffects of Nitroglycerin on hemoglobin.

  3. An observational retrospective/horizontal study to compare oxygen-ozone therapy and/or global postural re-education in complicated chronic low back pain.

    PubMed

    Apuzzo, Dario; Giotti, Chiara; Pasqualetti, Patrizio; Ferrazza, Paolo; Soldati, Paola; Zucco, Gesualdo M

    2014-01-01

    Acute low back pain (LBP) is the fifth most common reason for physician visits and about nine out of ten adults experience back pain at some point in their life. In a large number of patients LBP is associated with disc herniation (DH). Recently, oxygen-ozone (O2O3) therapy has been used successfully in the treatment of LBP, reducing pain after the failure of other conservative treatments. The aim of this study was to assess the effects of O2O3 therapy in back pain rehabilitation, comparing three groups of patients suffering from chronic back pain associated with DH submitted to three different treatments: intramuscular O2O3 infiltrations, global postural An observational retrospective/horizontal study to compare oxygen-ozone therapy and/or global postural re-education in complicated chronic low back pain re-education (GPR), or a combination of the two (O2O3+GPR). The data show that pain severity before treatment was significantly lower in the patients treated with GPR alone (VAS score 7.4) than in the O2O3+GPR patients (VAS score 8.5) and the O2O3 patients (VAS score 8.6). At the end of treatment, pain severity was lower in the O2O3 patients than in the GPR-alone patients. After some years of follow-up only the difference between O2O3+GPR and GPR-alone remained significant. PMID:25014047

  4. The role of nitric oxide in the ischemic brain evaluated by spectroscopic monitoring of mitochondrial NADH, microcirculatory blood flow, and HbO2

    NASA Astrophysics Data System (ADS)

    Eibeshitz, Efrat; Barbiro-Michaely, Efrat; Mayevsky, Avraham

    2008-12-01

    Nitric oxide (NO) is involved in the autoregulation of cerebral blood flow and in modulation of the respiratory chain activity in the normal brain. The present study aimed to evaluate the role of NO under two levels of partial brain ischemia induced by unilateral or bilateral carotid artery occlusion (UCO/BCO), for 24 hours and in appropriate control groups. Time-sharing fluorometer/reflectometer was used for the monitoring of mitochondrial NADH, by the fluorometric technique and oxyhemoglobin level by 2 wavelength reflectance method, combined with laser Doppler flowmetry for cerebral blood flow (CBF) monitoring. Systemic blood pressure (MAP) was also monitored. L-NAME was used for the inhibition of NO synthesis while nitrite was used as an exogenous source for NO. In both groups of ischemic animals L-NAME induced an increase in MAP and oxigenation of HbO2 however in the UCO group CBF remained stable and NADH was oxidized whereas in the BCO group CBF decreased with no change in NADH. Following nitrite infusion MAP reversibly decreased, CBF increased, HbO2 and NADH remained low in the BCO group with a slight reversible increase of NADH in the UCO group. In conclusion, it seems that NO plays an important role in the autoregulation of CBF and mitochondrial activity in the partially ischemic brain.

  5. Does the addition of a second daily session of hyperbaric oxygen therapy to intratympanic steroid influence the outcomes of sudden hearing loss?

    PubMed

    Attanasio, G; Covelli, E; Cagnoni, L; Masci, E; Ferraro, D; Mancini, P; Alessandri, E; Cartocci, G; Filipo, R; Rocco, M

    2015-10-01

    The aim of this study is to investigate whether, in addition to intratympanic steroid therapy, additional hyperbaric oxygen therapy (HBOT) sessions per day (twice a day for 5 days) is more useful than one session per day for 10 days in patients affected by severe and profound idiopathic sudden sensorineural hearing loss (ISSNHL). A total of 55 patients affected by unilateral severe and profound ISSNHL were recruited. Two protocols were adopted. In the first, 27 patients (13 with profound and 14 with severe hearing loss) underwent one session of HBOT per day for 10 days, 6 days a week. An HBOT session comprised a period of 14 minutes air compression followed by 90 min at 2.4 atm absolute (ATA) followed by a decompression period of 15 min in oxygen. Patients breathed 100% oxygen through an appropriate mask checked for leaks. Patients were given 0.4 ml of 62.5 mg/ml of intratympanic prednisolone during the first three days of the protocol. In the second protocol, 28 patients (10 with profound and 18 with severe hearing loss) received 10 sessions of HBOT, twice a day for five days, 2.4 ATA 90 min 100% oxygen. The intratympanic injections of prednisolone were given between the two sessions of HBOT during the first three days of the protocol. Since there were no significant differences in hearing outcomes between the two protocols, the present study shows that the protocol of two sessions of HBOT per day is a valid treatment and equally effective as the one HBOT session per day, but with shorter treatment time.

  6. Respiratory care year in review 2011: long-term oxygen therapy, pulmonary rehabilitation, airway management, acute lung injury, education, and management.

    PubMed

    Dunne, Patrick J; Macintyre, Neil R; Schmidt, Ulrich H; Haas, Carl F; Jones-Boggs Rye, Kathy; Kauffman, Garry W; Hess, Dean R

    2012-04-01

    For the busy clinician, educator, or manager, it is becoming an increasing challenge to filter the literature to what is relevant to one's practice and then update one's practice based on the current evidence. The purpose of this paper is to review the recent literature related to long-term oxygen therapy, pulmonary rehabilitation, airway management, acute lung injury and acute respiratory distress syndrome, respiratory care education, and respiratory care management. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care. PMID:22472499

  7. The effectiveness of ground level post-flight 100 percent oxygen breathing as therapy for pain-only altitude Decompression Sickness (DCS)

    NASA Technical Reports Server (NTRS)

    Demboski, John T.; Pilmanis, Andrew A.

    1994-01-01

    In both the aviation and space environments, decompression sickness (DCS) is an operational limitation. Hyperbaric recompression is the most efficacious treatment for altitude DCS. However, the inherent recompression of descent to ground level while breathing oxygen is in itself therapy for altitude DCS. If pain-only DCS occurs during a hypobaric exposure, and the symptoms resolver during descent, ground level post-flight breathing of 100% O2 for 2 hours (GLO2) is considered sufficient treatment by USAF Regulation 161-21. The effectiveness of the GLO2 treatment protocol is defined.

  8. Effect of hyperbaric oxygen treatment on permanent threshold shift in acoustic trauma among rats.

    PubMed

    Kuokkanen, J; Virkkala, J; Zhai, S; Ylikoski, J

    1997-01-01

    Impulse noise from firearms is a common cause of acute acoustic trauma (AAT). Recently hyperbaric oxygen treatment has become available in many hospitals treating AAT. We exposed 39 Wistar rats to intense impulse noise of 60 shots from the assault rifle (162 dB SPL). After the exposure 15 animals were given hyperbaric oxygen treatment (HBO) by 10 treatment cycles of 90 minutes 100% oxygen in 0.25 MPa, one treatment cycle per day. Four weeks after the exposure the hearing thresholds were measured with auditory brainstem response audiometry at frequencies of 1.0, 2.0, 4.0, 6.0, 8.0 and 10.0 kHz. Characteristics for the resulting noise-induced hearing loss were large variations in its severity not only between animals, but also between the ears of a single animal. The largest permanent threshold shifts were found at 6.0, 8.0 and 10.0 kHz. Most of the HBO-treated animals showed less threshold shift than the non-treated animals. The difference between the HBO group and the control group was only slightly statistically significant (p = 0.067). PMID:9288276

  9. Reactive oxygen species induced by non-steroidal anti-inflammatory drugs enhance the effects of photodynamic therapy in gastric cancer cells.

    PubMed

    Ito, Hiromu; Matsui, Hirofumi; Hirayama, Aki; Indo, Hiroko P; Majima, Hideyuki J; Hyodo, Ichinosuke

    2016-05-01

    Photodynamic therapy is useful for the treatment of cancer because it is minimally invasive for patients. Certain porphyrin compounds and their derivatives have been used as the photosensitizer because they accumulate specifically in cancerous tissues. However, the detailed mechanism of this phenomenon has not been clarified. We previously reported that a proton-coupled folate transporter, HCP1, transported porphyrins and that regulation of the protein was associated with cancer-specific reactive oxygen species from mitochondria (mitROS). Therefore, over-generation of mitROS could increase HCP1 expression and the effect of photodynamic therapy. We investigated whether pretreatment with indomethacin influenced photodynamic therapy by using a rat normal gastric mucosal cell line, RGM1, its cancer-like mutated cell line, RGK1, and a manganese superoxide dismutase (MnSOD)-overexpressing RGK cell line, RGK-MnSOD. Indomethacin promotes the generation of cellular mitROS by inhibiting the electron transport chain, and MnSOD scavenges the mitROS. We elucidated that indomethacin enhanced cancer-specific mitROS generation and increased HCP1 expression. Furthermore, RGK1 cells showed higher cellular incorporation of hematoporphyrin and better therapeutic effect with indomethacin treatment whereas RGK-MnSOD cells did not show a difference. Thus, we concluded that indomethacin improved the effect of photodynamic therapy by inducing increased mitROS generation in cancer cells.

  10. The Appropriate Use of Oxygen

    PubMed Central

    Lubin, Stan

    1988-01-01

    The scientific evidence for the efficacy of oxygen therapy in acute hypoxemia is limited. In chronic hypoxemia continuous oxygen therapy appears to decrease mortality. Current indications for oxygen treatment are PaO2 less than 60 in acute hypoxemia and less than 55 in chronic hypoxemia. Physical and physiological hazards of oxygen are reviewed. Three syndromes of pulmonary oxygen toxicity are described: tracheobronchitis, adult respiratory distress syndrome, and bronchopulmonary dysplasia. PMID:21253258

  11. An association between vasomotion and oxygen extraction

    PubMed Central

    Kyte, Hayley; Slaff, Dick W.; Shore, Angela C.

    2011-01-01

    Vasomotion is defined as a spontaneous local oscillation in vascular tone whose function is unclear but may have a beneficial effect on tissue oxygenation. Optical reflectance spectroscopy and laser Doppler fluximetry provide unique insights into the possible mechanisms of vasomotion in the cutaneous microcirculation through the simultaneous measurement of changes in concentration of oxyhemoglobin ([HbO2]), deoxyhemoglobin ([Hb]), and mean blood saturation (SmbO2) along with blood volume and flux. The effect of vasomotion at frequencies <0.02 Hz attributed to endothelial activity was studied in the dorsal forearm skin of 24 healthy males. Fourier analysis identified periodic fluctuations in SmbO2 in 19 out of 24 subjects, predominantly where skin temperatures were >29.3°C (X2 = 6.19, P < 0.02). A consistent minimum threshold in SmbO2 (mean: 39.4%, range: 24.0–50.6%) was seen to precede a sudden transient surge in flux, inducing a fast rise in SmbO2. The integral increase in flux correlated with the integral increase in [HbO2] (Pearson's correlation r2 = 0.50, P < 0.001) and with little change in blood volume suggests vasodilation upstream, responding to a low SmbO2 downstream. This transient surge in flux was followed by a sustained period where blood volume and flux remained relatively constant and a steady decrease in [HbO2] and equal and opposite increase in [Hb] was considered to provide a measure of oxygen extraction. A measure of this oxygen extraction has been approximated by the mean half-life of the decay in SmbO2 during this period. A comparison of the mean half-life in the 8 normal subjects [body mass index (BMI) <26.0 kg/m2] of 12.2 s and the 11 obese subjects (BMI >29.5 kg/m2) of 18.8 s was statistically significant (Mann Whitney, P < 0.004). The SmbO2 fluctuated spontaneously in this saw tooth manner by an average of 9.0% (range 4.0–16.2%) from mean SmbO2 values ranging from 30 to 52%. These observations support the hypothesis that red blood

  12. Nano-photosensitizers Engineered to Generate a Tunable Mix of Reactive Oxygen Species, for Optimizing Photodynamic Therapy, Using a Microfluidic Device

    PubMed Central

    Yoon, Hyung Ki; Lou, Xia; Chen, Yu-Chih; Koo Lee, Yong-Eun; Yoon, Euisik; Kopelman, Raoul

    2014-01-01

    This work is aimed at engineering photosensitizer embedded nanoparticles (NPs) that produce optimal amount of reactive oxygen species (ROS) for photodynamic therapy (PDT). A revised synthetic approach, coupled with improved analytical tools, resulted in more efficient PDT. Specifically, methylene blue (MB) conjugated polyacrylamide nanoparticles (PAA NPs), with a polyethylene glycol dimethacrylate (PEGDMA, Mn 550) cross-linker, were synthesized so as to improve the efficacy of cancer PDT. The long cross-linker chain, PEGDMA, increases the distance between the conjugated MB molecules so as to avoid self-quenching of the excited states or species, and also enhances the oxygen permeability of the NP matrix, when compared to the previously used shorter cross-linker. The overall ROS production from the MB–PEGDMA PAA NPs was evaluated using the traditional way of monitoring the oxidation rate kinetics of anthracence-9,10-dipropionic acid (ADPA). We also applied singlet oxygen sensor green (SOSG) so as to selectively derive the singlet oxygen (1O2) production rate. This analysis enabled us to investigate the ROS composition mix based on varied MB loading. To effectively obtain the correlation between the ROS productivity and the cell killing efficacy, a microfluidic chip device was employed to provide homogeneous light illumination from an LED for rapid PDT efficacy tests, enabling simultaneous multiple measurements while using only small amounts of NPs sample. This provided multiplexed, comprehensive PDT efficacy assays, leading to the determination of a near optimal loading of MB in a PAA matrix for high PDT efficacy by measuring the light-dose-dependent cell killing effects of the various MB–PEGDMA PAA NPs using C6 glioma cancer cells. PMID:24701030

  13. Reduction in the level of immobilization in forced swim test and ethanol intake in rats by oxygen therapy.

    PubMed

    Kampov-Polevoy, A B; Dubtchenko, V V; Crosby, R D; Halikas, J A

    1993-01-01

    Experiments replicated the previous finding that rats with high immobilization time in the forced swim test (passive rats) consumed more 15% ethanol solution in a free choice situation with tap water than rats with active behavior (active rats). Exposure of passive rats to oxygen under normal and elevated (2 ata) pressure resulted in the decrease in immobilization scores in the forced swim test as well as reduction in alcohol consumption and preference.

  14. Oxygenated hemoglobin diffuse reflectance ratio for in vitro detection of human gastric pre-cancer

    NASA Astrophysics Data System (ADS)

    Li, L. Q.; Wei, H. J.; Guo, Z. Y.; Yang, H. Q.; Wu, G. Y.; Xie, S. S.; Zhong, H. Q.; Li, X. Y.; Zhao, Q. L.; Guo, X.

    2010-07-01

    Oxygenated hemoglobin diffuse reflectance (DR) ratio (R540/R575) method based on DR spectral signatures is used for early diagnosis of malignant lesions of human gastric epithelial tissues in vitro. The DR spectra for four different kinds of gastric epithelial tissues were measured using a spectrometer with an integrating sphere detector in the spectral range from 400 to 650 nm. The results of measurement showed that the average DR spectral intensity for the epithelial tissues of normal stomach is higher than that for the epithelial tissues of chronic and malignant stomach and that for the epithelial tissues of chronic gastric ulcer is higher than that for the epithelial tissues of malignant stomach. The average DR spectra for four different kinds of gastric epithelial tissues show dips at 542 and 577 nm owing to absorption from oxygenated Hemoglobin (HbO2). The differences in the mean R540/R575 ratios of HbO2 bands are 6.84% between the epithelial tissues of normal stomach and chronic gastric ulcer, 14.7% between the epithelial tissues of normal stomach and poorly differentiated gastric adenocarcinoma and 22.6% between the epithelial tissues of normal stomach and undifferentiated gastric adenocarcinoma. It is evident from results that there were significant differences in the mean R540/R575 ratios of HbO2 bands for four different kinds of gastric epithelial tissues in vitro ( P < 0.01).

  15. 99mTc-ECD brain perfusion SPECT imaging for the assessment of brain perfusion in cerebral palsy (CP) patients with evaluation of the effect of hyperbaric oxygen therapy

    PubMed Central

    Asl, Mina Taghizadeh; Yousefi, Farzaneh; Nemati, Reza; Assadi, Majid

    2015-01-01

    Objective: The present study was carried out to evaluate cerebral perfusion in different types of cerebral palsy (CP) patients. For those patients who underwent hyperbaric oxygen therapy, brain perfusion before and after the therapy was compared. Methods: A total of 11 CP patients were enrolled in this study, of which 4 patients underwent oxygen therapy. Before oxygen therapy and at the end of 40 sessions of oxygen treatment, 99mTc-ECD brain perfusion single photon emission computed tomography (SPECT) was performed , and the results were compared. Results: A total of 11 CP patients, 7 females and 4 males with an age range of 5-27 years participated in the study. In brain SPECT studies, all the patients showed perfusion impairments. The region most significantly involved was the frontal lobe (54.54%), followed by the temporal lobe (27.27%), the occipital lobe (18.18%), the visual cortex (18.18%), the basal ganglia (9.09%), the parietal lobe (9.09%), and the cerebellum (9.09%). Frontal-lobe hypoperfusion was seen in all types of cerebral palsy. Two out of 4 patients (2 males and 2 females) who underwent oxygen therapy revealed certain degree of brain perfusion improvement. Conclusion: This study demonstrated decreased cerebral perfusion in different types of CP patients. The study also showed that hyperbaric oxygen therapy improved cerebral perfusion in a few CP patients. However, it could keep the physiological discussion open and strenghten a link with other areas of neurology in which this approach may have some value. PMID:25785099

  16. Poly(D, L-lactide-co-glycolide) nanoparticles as delivery agents for photodynamic therapy: enhancing singlet oxygen release and photototoxicity by surface PEG coating

    NASA Astrophysics Data System (ADS)

    Boix-Garriga, Ester; Acedo, Pilar; Casadó, Ana; Villanueva, Angeles; Stockert, Juan Carlos; Cañete, Magdalena; Mora, Margarita; Lluïsa Sagristá, Maria; Nonell, Santi

    2015-09-01

    Poly(D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) are being considered as nanodelivery systems for photodynamic therapy. The physico-chemical and biological aspects of their use remain largely unknown. Herein we report the results of a study of PLGA NPs for the delivery of the model hydrophobic photosensitizer ZnTPP to HeLa cells. ZnTPP was encapsulated in PLGA with high efficiency and the NPs showed negative zeta potentials and diameters close to 110 nm. Poly(ethylene glycol) (PEG) coating, introduced to prevent opsonization and clearance by macrophages, decreased the size and zeta potential of the NPs by roughly a factor of two and improved their stability in the presence of serum proteins. Photophysical studies revealed two and three populations of ZnTPP and singlet oxygen in uncoated and PEGylated NPs, respectively. Singlet oxygen is confined within the NPs in bare PLGA while it is more easily released into the external medium after PEG coating, which contributes to a higher photocytotoxicity towards HeLa cells in vitro. PLGA NPs are internalized by endocytosis, deliver their cargo to lysosomes and induce cell death by apoptosis upon exposure to light. In conclusion, PLGA NPs coated with PEG show high potential as delivery systems for photodynamic applications.

  17. Pain reduction in patients after applying a nitrous oxide/oxygen mixture (Livopan) during photodynamic therapy: study protocol for an observational study (Livopan study)

    PubMed Central

    Gholam, Patrick; Fink, Christine; Uhlmann, Lorenz; Enk, Alexander

    2015-01-01

    Introduction Photodynamic therapy (PDT) is an effective treatment option for extensively photodamaged skin with multiple actinic kerastosis. However, the main drawback of PDT is the intensive pain experienced during its application, which makes it frequently necessary to interrupt or even terminate the process resulting in incomplete treatment. Several strategies for controlling pain during PDT have been studied but few effective methods are currently available. Alternative options are urgently needed. Livopan, a nitrous oxide/oxygen mixture, is indicated for the treatment of short-term pain conditions when rapid analgesic onset and offset effects are wanted. But so far, there are no studies evaluating the effect of Livopan on pain intensity during PDT. Therefore, it remains unclear whether patients benefit from this inhalation analgesia. Within the Livopan study, this issue will be evaluated for the first time. Methods and analysis The Livopan study is a prospective, single-centre, explorative, controlled, observational study to investigate the pain reduction in patients after applying a nitrous oxide/oxygen mixture (Livopan) during PDT according to the visual analogue scale in 60 patients. Ethics and dissemination Ethics approval was provided by the ethics committee of the medical faculty of the University of Heidelberg. Ethics approval number S-169/2014. Trial registration number German Clinical Trial Register (DRKS): DRKS00006054. PMID:25823443

  18. Fatal fires associated with smoking during long-term oxygen therapy--Maine, Massachusetts, New Hampshire, and Oklahoma, 2000-2007.

    PubMed

    2008-08-01

    Approximately 1 million persons in the United States receive long-term oxygen therapy (LTOT) annually through the Medicare program, most often for smoking-related lung disease. At 2:10 a.m. on December 14, 2007, a fire occurred in a public housing project for the elderly in Westbrook, Maine. Approximately 60 residents were evacuated; six were transported to a hospital for smoke inhalation. The fire was caused unintentionally by a woman aged 57 years who was an overnight guest of a relative who lived in the housing project. The visitor had ignited the fire while simultaneously smoking and using an oxygen concentrator. After this incident, the Maine Department of Health and Human Services, in collaboration with three other states, attempted to determine 1) how often this type of event results in fatalities and 2) factors common to these incidents that might be amenable to prevention. This report describes the results of that study, which found that, during 2000-2007, of the 38 deaths identified in the four states, 37 occurred in private residences, and the median age of the decedents was 67 years. Prevention of this type of fatality is dependent on smoking cessation, careful assessment of the need for LTOT, and strategies to prevent injuries from fires, such as smoke alarms and sprinklers. PMID:18685553

  19. Cardiac resynchronization therapy and AV optimization increase myocardial oxygen consumption, but increase cardiac function more than proportionally☆

    PubMed Central

    Kyriacou, Andreas; Pabari, Punam A.; Mayet, Jamil; Peters, Nicholas S.; Davies, D. Wyn; Lim, P. Boon; Lefroy, David; Hughes, Alun D.; Kanagaratnam, Prapa; Francis, Darrel P.; I.Whinnett, Zachary

    2014-01-01

    Background The mechanoenergetic effects of atrioventricular delay optimization during biventricular pacing (“cardiac resynchronization therapy”, CRT) are unknown. Methods Eleven patients with heart failure and left bundle branch block (LBBB) underwent invasive measurements of left ventricular (LV) developed pressure, aortic flow velocity-time-integral (VTI) and myocardial oxygen consumption (MVO2) at 4 pacing states: biventricular pacing (with VV 0 ms) at AVD 40 ms (AV-40), AVD 120 ms (AV-120, a common nominal AV delay), at their pre-identified individualised haemodynamic optimum (AV-Opt); and intrinsic conduction (LBBB). Results AV-120, relative to LBBB, increased LV developed pressure by a mean of 11(SEM 2)%, p = 0.001, and aortic VTI by 11(SEM 3)%, p = 0.002, but also increased MVO2 by 11(SEM 5)%, p = 0.04. AV-Opt further increased LV developed pressure by a mean of 2(SEM 1)%, p = 0.035 and aortic VTI by 4(SEM 1)%, p = 0.017. MVO2 trended further up by 7(SEM 5)%, p = 0.22. Mechanoenergetics at AV-40 were no different from LBBB. The 4 states lay on a straight line for Δexternal work (ΔLV developed pressure × Δaortic VTI) against ΔMVO2, with slope 1.80, significantly > 1 (p = 0.02). Conclusions Biventricular pacing and atrioventricular delay optimization increased external cardiac work done but also myocardial oxygen consumption. Nevertheless, the increase in cardiac work was ~ 80% greater than the increase in oxygen consumption, signifying an improvement in cardiac mechanoenergetics. Finally, the incremental effect of optimization on external work was approximately one-third beyond that of nominal AV pacing, along the same favourable efficiency trajectory, suggesting that AV delay dominates the biventricular pacing effect — which may therefore not be mainly “resynchronization”. PMID:24332598

  20. An observational retrospective/horizontal study to compare oxygen-ozone therapy and/or global postural re-education in complicated chronic low back pain

    PubMed Central

    Apuzzo, Dario; Giotti, Chiara; Pasqualetti, Patrizio; Ferrazza, Paolo; Soldati, Paola; Zucco, Gesualdo M.

    2014-01-01

    Summary Acute low back pain (LBP) is the fifth most common reason for physician visits and about nine out of ten adults experience back pain at some point in their life. In a large number of patients LBP is associated with disc herniation (DH). Recently, oxygen-ozone (O2O3) therapy has been used successfully in the treatment of LBP, reducing pain after the failure of other conservative treatments. The aim of this study was to assess the effects of O2O3 therapy in back pain rehabilitation, comparing three groups of patients suffering from chronic back pain associated with DH submitted to three different treatments: intramuscular O2O3 infiltrations, global postural re-education (GPR), or a combination of the two (O2O3+GPR). The data show that pain severity before treatment was significantly lower in the patients treated with GPR alone (VAS score 7.4) than in the O2O3+GPR patients (VAS score 8.5) and the O2O3 patients (VAS score 8.6). At the end of treatment, pain severity was lower in the O2O3 patients than in the GPR-alone patients. After some years of follow-up only the difference between O2O3+GPR and GPR-alone remained significant. PMID:25014047

  1. Catalytic therapy of cancer by ascorbic acid involves redox cycling of exogenous/endogenous copper ions and generation of reactive oxygen species.

    PubMed

    Hadi, S M; Ullah, M F; Shamim, U; Bhatt, S H; Azmi, A S

    2010-01-01

    Catalytic therapy is a cancer treatment modality based on the generation of reactive oxygen species (ROS) through administration of ascorbate/medicinal herbal extracts and copper. It is known that antioxidants such as ascorbate also exhibit prooxidant activity in the presence of transition metals such as copper. Based on our work and that in the literature, in this review we propose a mechanism for the cytotoxic action of ascorbate against cancer cells. It involves redox cycling of exogenous/endogenous copper ions and the consequent generation of ROS leading to oxidative DNA breakage. Using human peripheral lymphocytes and the Comet assay, we have shown that ascorbic acid is able to cause oxidative breakage in cellular DNA. Such DNA degradation is inhibited by neocuproine (a Cu(I) sequestering agent) and scavengers of ROS indicating that the cellular DNA breakage involves the generation of Cu(I) and formation of ROS. Similar results are also obtained with plant polyphenol antioxidants that are important constituents of medicinal herbal extracts. Copper is an essential component of chromatin and can take part in redox reactions. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and ascorbate/plant polyphenols to generate ROS. In this review we cite evidence to indicate that in catalytic therapy cytotoxic action against cancer cells involves redox cycling of exogenous/endogenous copper ions.

  2. Near-infrared oxymeter biosensor prototype for non-invasive in vivo analysis of rat brain oxygenation: effects of drugs of abuse

    NASA Astrophysics Data System (ADS)

    Crespi, F.; Donini, M.; Bandera, A.; Congestri, F.; Formenti, F.; Sonntag, V.; Heidbreder, C.; Rovati, L.

    2006-07-01

    The feasibility of non-invasive analysis of brain activities was studied in the attempt to overcome the major limitation of actual in vivo methodologies, i.e. invasiveness. Optic fibre probes were used as the optical head of a novel, highly sensitive near-infrared continuous wave spectroscopy (CW-NIR) instrument. This prototype was designed for non-invasive analysis of the two main forms of haemoglobin: oxy-haemoglobin (HbO2) and deoxy-haemoglobin (Hb), chromophores present in biological tissues. It was tested in peripheral tissue (human gastrocnemius muscle) and then reset to perform the measurement on rat brain. In animal studies, the optical head was firmly placed using stereotaxic apparatus upon the sagittal line of the head of anaesthetized adult rats, without any surgery. Then pharmacological treatments with saline (300 µl s.c.) amphetamine (2 mg kg-1) or nicotine (0.4 mg kg-1) were performed. Within 10-20 min amphetamine substantially increased HbO2 and reduced Hb control levels. Nicotine produced a rapid initial increase followed by a decrease in HbO2. In contrast to amphetamine, nicotine treatment also reduced Hb and blood volume. These results support the capacity of our CW-NIR prototype to measure non-invasively HbO2 and Hb levels in the rat brain, that are markers of the degree of tissue oxygenation, thus providing an index of blood levels and therefore of brain metabolism.

  3. The Effects of Pulsed Radiation Therapy on Tumor Oxygenation in 2 Murine Models of Head and Neck Squamous Cell Carcinoma

    SciTech Connect

    Wobb, Jessica; Krueger, Sarah A.; Kane, Jonathan L.; Galoforo, Sandra; Grills, Inga S.; Wilson, George D.; Marples, Brian

    2015-07-15

    Purpose: To evaluate the efficacy of low-dose pulsed radiation therapy (PRT) in 2 head and neck squamous cell carcinoma (HNSCC) xenografts and to investigate the mechanism of action of PRT compared with standard radiation therapy (SRT). Methods and Materials: Subcutaneous radiosensitive UT-SCC-14 and radioresistant UT-SCC-15 xenografts were established in athymic NIH III HO female mice. Tumors were irradiated with 2 Gy/day by continuous standard delivery (SRT: 2 Gy) or discontinuous low-dose pulsed delivery (PRT: 0.2 Gy × 10 with 3-min pulse interval) to total doses of 20 Gy (UT14) or 40 Gy (UT15) using a clinical 5-day on/2-day off schedule. Treatment response was assessed by changes in tumor volume, {sup 18}F-fluorodeoxyglucose (FDG) (tumor metabolism), and {sup 18}F-fluoromisonidazole (FMISO) (hypoxia) positron emission tomography (PET) imaging before, at midpoint, and after treatment. Tumor hypoxia using pimonidazole staining and vascular density (CD34 staining) were assessed by quantitative histopathology. Results: UT15 and UT14 tumors responded similarly in terms of growth delay to either SRT or PRT. When compared with UT14 tumors, UT15 tumors demonstrated significantly lower uptake of FDG at all time points after irradiation. UT14 tumors demonstrated higher levels of tumor hypoxia after SRT when compared with PRT as measured by {sup 18}F-FMISO PET. By contrast, no differences were seen in {sup 18}F-FMISO PET imaging between SRT and PRT for UT15 tumors. Histologic analysis of pimonidazole staining mimicked the {sup 18}F-FMISO PET imaging data, showing an increase in hypoxia in SRT-treated UT14 tumors but not PRT-treated tumors. Conclusions: Differences in {sup 18}F-FMISO uptake for UT14 tumors after radiation therapy between PRT and SRT were measurable despite the similar tumor growth delay responses. In UT15 tumors, both SRT and PRT were equally effective at reducing tumor hypoxia to a significant level as measured by {sup 18}F-FMISO and pimonidazole.

  4. Inhaled hydrogen gas therapy for prevention of noise-induced hearing loss through reducing reactive oxygen species.

    PubMed

    Kurioka, Takaomi; Matsunobu, Takeshi; Satoh, Yasushi; Niwa, Katsuki; Shiotani, Akihiro

    2014-12-01

    Reactive oxygen species (ROS) that form in the inner ear play an important role in noise-induced hearing loss (NIHL). Recent studies have revealed that molecular hydrogen (H2) has great potential for reducing ROS. In this study, we examined the potential of hydrogen gas to protect against NIHL. We tested this hypothesis in guinea pigs with 0.5%, 1.0% and 1.5% H2 inhalation in air for 5h a day after noise exposure, for five consecutive days. All animals underwent measurements for auditory brainstem response after the noise exposure; the results revealed that there was a better improvement in the threshold shift for the 1.0% and 1.5% H2-treated groups than the non-treated group. Furthermore, outer hair cell (OHC) loss was examined 7 days after noise exposure. A significantly higher survival rate of OHCs was observed in the 1.0% and 1.5% H2-treated group as compared to that of the non-treated group in the basal turn. Immunohistochemical analyses for 8-hydroxy-2'-deoxyguanosine (8-OHdG) were performed to examine the amount of oxidative DNA damage. While strong immunoreactivities against 8-OHdG were observed of the non-treated group, the H2-treated group showed decreased immunoreactivity for 8-OHdG. These findings strongly suggest that inhaled hydrogen gas protects against NIHL.

  5. Simultaneous NIR-EPR spectroscopy of rat brain oxygenation.

    PubMed

    Sakata, Yasuko S; Grinberg, Oleg Y; Grinberg, Stalina; Springett, Roger; Swartz, Harold M

    2005-01-01

    Changes in cerebral oxygenation were simultaneously monitored by electric paramagnetic resonance (EPR) oximetry and near-infrared spectroscopy (NIRS). The tissue oxygen tension (t-pO2) was measured with an L-band (1.2 GHz) EPR spectrometer with an external loop resonator and the concentration of oxyhemoglobin [HbO2] and deoxyhemoglobin [Hb] were measured with a full-spectral NIRS system. Mean cerebral hemoglobin saturation (SmcO2) was calculated from the absolute [HbO2] and [Hb]. Six adult male rats were implanted with lithium phthalocyanine (LiPc) crystals into the left cerebral cortex. The change in oxygenation of the brain was induced by altering the inspired oxygen fraction (FiO2) in air from 0.30 at baseline to 0.0, 0.05, 0.10, and 0.15 for 1, 2, 5, and 5 minutes, respectively, followed by reoxygenation with an FiO2 = 0.30. Although both t-pO2 and SmcO2 values showed a decrease during reduced FiO2 followed by recovery on reoxygenation, it was found that SmcO2 recovered more rapidly than t-PO2 during the recovery phase. The recovery of t-pO2 is not only related to blood oxygenation, but also to delivery, consumption, and diffusion of oxygen into the tissue from the vascular system. Further studies will be required to determine the exact mechanisms for the delay between the recovery of SmcO2 and t-pO2. PMID:16594173

  6. KAT7/HBO1/MYST2 Regulates CENP-A Chromatin Assembly by Antagonizing Suv39h1-Mediated Centromere Inactivation.

    PubMed

    Ohzeki, Jun-Ichirou; Shono, Nobuaki; Otake, Koichiro; Martins, Nuno M C; Kugou, Kazuto; Kimura, Hiroshi; Nagase, Takahiro; Larionov, Vladimir; Earnshaw, William C; Masumoto, Hiroshi

    2016-06-01

    Centromere chromatin containing histone H3 variant CENP-A is required for accurate chromosome segregation as a foundation for kinetochore assembly. Human centromere chromatin assembles on a part of the long α-satellite (alphoid) DNA array, where it is flanked by pericentric heterochromatin. Heterochromatin spreads into adjacent chromatin and represses gene expression, and it can antagonize centromere function or CENP-A assembly. Here, we demonstrate an interaction between CENP-A assembly factor M18BP1 and acetyltransferase KAT7/HBO1/MYST2. Knocking out KAT7 in HeLa cells reduced centromeric CENP-A assembly. Mitotic chromosome misalignment and micronuclei formation increased in the knockout cells and were enhanced when the histone H3-K9 trimethylase Suv39h1 was overproduced. Tethering KAT7 to an ectopic alphoid DNA integration site removed heterochromatic H3K9me3 modification and was sufficient to stimulate new CENP-A or histone H3.3 assembly. Thus, KAT7-containing acetyltransferases associating with the Mis18 complex provides competence for histone turnover/exchange activity on alphoid DNA and prevents Suv39h1-mediated heterochromatin invasion into centromeres. PMID:27270040

  7. Quantitative in-vivo measurements of blood oxygen saturation using multiwavelength photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Laufer, J.; Zhang, E.; Beard, P.

    2007-02-01

    Multiwavelength photoacoustic imaging was used to make spatially resolved measurements of blood oxygen saturation (sO2) in vivo. 2D cross-sectional images of the initial absorbed optical energy distribution in the finger were acquired at near-infrared wavelengths using a photoacoustic imaging system. Using the structural information from these images, a 2D finite element forward model of the light transport was formulated to calculate the absorbed energy density in the tissue as a function of the concentrations of the tissue chromophores and scatters. Separate oxy- (HbO2) and deoxyhaemoglobin (HHb) concentrations were assigned to locations within the mesh that corresponded to the locations of blood vessels in the detected photoacoustic image. The surrounding tissue was regarded as a homogeneous medium with optical properties that were determined by the concentrations of water, lipids, optical scatters, and HbO2 and HHb in the capillary bed. The concentrations of the individual chromophores were the variable input parameters of the forward model. By varying their values in a minimisation procedure in order to fit the output of the model to the measured multiwavelength images, the HbO2 and HHb concentrations, and hence blood sO2, within the blood vessels were determined.

  8. Hyperbaric oxygen treatment of dogs has no effect on red cell deformability but causes an acute fluid shift.

    PubMed

    Martindale, V E; McKay, K

    1995-01-01

    Red blood cells respond to a number of perturbations, including hypoxia, with a reduction in deformability. Local hypoxia may become self-reinforcing, as hypoxic cells block capillaries preventing perfusion by oxygenated cells. Hyperbaric oxygen (HBO) is frequently used to treat conditions involving some degree of local hypoxia, but does it have a direct effect on deformability? To investigate this, 12 normal dogs received a 10 week "clinical" course of HBO: one 90 min treatment per weekday at 2.4 ATA (243 kPa), 100% O2. On Mondays and Fridays, a blood sample was drawn into EDTA, centrifuged, and the packed red blood cells resuspended in medium to a dilution of 2 x 10(6) to 5 x 10(6) cells/ml, and filtered under constant of 1.08 kPa through a precalibrated Nucleopore Hemafil Polycarbonate membrane. Filtrate was collected for one minute and weighed, and the red blood cell "incremental volume" calculated according to Engstrom (Engstrom and Ohlsson, Pediatric Res. 27:220-226, 1990). No significant change was seen in filtration rates, indicating that HBO itself neither improves nor impairs dog red blood cell deformability. Changes in other commonly measured blood parameters remained within clinical norms. An acute fluid shift out of red blood cells and into plasma was indicated.

  9. Nonthermal Ablation by Using Intravascular Oxygen Radical Generation with WST11: Dynamic Tissue Effects and Implications for Focal Therapy.

    PubMed

    Kimm, Simon Y; Tarin, Tatum V; Monette, Sébastien; Srimathveeravalli, Govindarajan; Gerber, Daniel; Durack, Jeremy C; Solomon, Stephen B; Scardino, Peter T; Scherz, Avigdor; Coleman, Jonathan

    2016-10-01

    Purpose To examine the hypothesis that vascular-targeted photodynamic therapy (VTP) with WST11 and clinically relevant parameters can be used to ablate target tissues in a non-tumor-bearing large-animal model while selectively sparing blood vessels and collagen. Materials and Methods By using an institutional animal care and use committee-approved protocol, 68 ablations were performed in the kidneys (cortex and medulla) and livers of 27 adult pigs. Posttreatment evaluation was conducted with contrast material-enhanced computed tomography in the live animals at 24 hours. Immunohistochemistry was evaluated and histologic examination with hematoxylin-eosin staining was performed at 4 hours, 24 hours, and 7 days. Intravenous infusion of WST11 (4 mg per kilogram of body weight) was followed by using near-infrared illumination (753 nm for 20 minutes) through optical fibers prepositioned in target tissues by using a fixed template. Treated areas were scanned, measured, and statistically analyzed by using the Student t test and two-way analysis of variance. Results Focal WST11 VTP treatment in the liver and kidney by using a single optical fiber resulted in well-demarcated cylindrical zones of nonthermal necrosis concentrically oriented around the light-emitting diffuser, with no intervening viable parenchymal cells. The radius of ablated tissue increased from approximately 5 mm at 150 mW to approximately 7 mm at 415 mW (P < .01). Illumination through fiber triads at 1-cm separation resulted in confluent homogeneous necrosis. Patterns of acute injury within 24 hours were consistent with microcirculatory flow arrest and collagen preservation (demonstrated with trichrome staining). In the peripheral ablation zone, blood vessels at least 40 μm in diameter were selectively preserved and remained functional at 7 days. Ablated tissues exhibited progressive fibrosis and chronic inflammatory cell infiltrates. No histologic changes consistent with thermal injury were observed in

  10. Nonthermal Ablation by Using Intravascular Oxygen Radical Generation with WST11: Dynamic Tissue Effects and Implications for Focal Therapy.

    PubMed

    Kimm, Simon Y; Tarin, Tatum V; Monette, Sébastien; Srimathveeravalli, Govindarajan; Gerber, Daniel; Durack, Jeremy C; Solomon, Stephen B; Scardino, Peter T; Scherz, Avigdor; Coleman, Jonathan

    2016-10-01

    Purpose To examine the hypothesis that vascular-targeted photodynamic therapy (VTP) with WST11 and clinically relevant parameters can be used to ablate target tissues in a non-tumor-bearing large-animal model while selectively sparing blood vessels and collagen. Materials and Methods By using an institutional animal care and use committee-approved protocol, 68 ablations were performed in the kidneys (cortex and medulla) and livers of 27 adult pigs. Posttreatment evaluation was conducted with contrast material-enhanced computed tomography in the live animals at 24 hours. Immunohistochemistry was evaluated and histologic examination with hematoxylin-eosin staining was performed at 4 hours, 24 hours, and 7 days. Intravenous infusion of WST11 (4 mg per kilogram of body weight) was followed by using near-infrared illumination (753 nm for 20 minutes) through optical fibers prepositioned in target tissues by using a fixed template. Treated areas were scanned, measured, and statistically analyzed by using the Student t test and two-way analysis of variance. Results Focal WST11 VTP treatment in the liver and kidney by using a single optical fiber resulted in well-demarcated cylindrical zones of nonthermal necrosis concentrically oriented around the light-emitting diffuser, with no intervening viable parenchymal cells. The radius of ablated tissue increased from approximately 5 mm at 150 mW to approximately 7 mm at 415 mW (P < .01). Illumination through fiber triads at 1-cm separation resulted in confluent homogeneous necrosis. Patterns of acute injury within 24 hours were consistent with microcirculatory flow arrest and collagen preservation (demonstrated with trichrome staining). In the peripheral ablation zone, blood vessels at least 40 μm in diameter were selectively preserved and remained functional at 7 days. Ablated tissues exhibited progressive fibrosis and chronic inflammatory cell infiltrates. No histologic changes consistent with thermal injury were observed in

  11. Sphingosine 1-phosphate receptor 2 (S1P2) attenuates reactive oxygen species formation and inhibits cell death: implications for otoprotective therapy.

    PubMed

    Herr, Deron R; Reolo, Marie J Y; Peh, Yee Xin; Wang, Wei; Lee, Chang-Wook; Rivera, Rich; Paterson, Ian C; Chun, Jerold

    2016-04-15

    Ototoxic drugs, such as platinum-based chemotherapeutics, often lead to permanent hearing loss through apoptosis of neuroepithelial hair cells and afferent neurons of the cochlea. There is no approved therapy for preventing or reversing this process. Our previous studies identified a G protein-coupled receptor (GPCR), S1P2, as a potential mediator of otoprotection. We therefore sought to identify a pharmacological approach to prevent cochlear degeneration via activation of S1P2. The cochleae of S1pr2(-/-) knockout mice were evaluated for accumulation of reactive oxygen species (ROS) with a nitro blue tetrazolium (NBT) assay. This showed that loss of S1P2 results in accumulation of ROS that precedes progressive cochlear degeneration as previously reported. These findings were supported by in vitro cell-based assays to evaluate cell viability, induction of apoptosis, and accumulation of ROS following activation of S1P2 in the presence of cisplatin. We show for the first time, that activation of S1P2 with a selective receptor agonist increases cell viability and reduces cisplatin-mediated cell death by reducing ROS. Cumulatively, these results suggest that S1P2 may serve as a therapeutic target for attenuating cisplatin-mediated ototoxicity.

  12. [Impact of acute respiratory failure on survival of COPD patients managed with long-term non-invasive ventilation and oxygen therapy].

    PubMed

    Perrin, C; Vandenbos, F; Tamisier, R; Lemoigne, F; Blaive, B

    2000-02-01

    Our study aimed to assess the impact of acute respiratory failure (ARF) on survival of patients with chronic obstructive pulmonary disease (COPD) receiving long-term oxygen therapy (LTOT) plus nasal intermittent positive pressure ventilation (NIPPV). Survival was analysed retrospectively in 24 patients with severe COPD initiated to NIPPV in addition to LTOT. Fourteen patients were established on NIPPV following exacerbation of acute respiratory failure which has required mechanical ventilation (group 1). Ten patients (group 2) have never been hospitalized for ARF. Comparison of clinical details at baseline, 6 months, 1, 2, and 3 years for the two groups failed to reveal any difference with the exception of prior episodes of ARF. The probability of survival at 3 years was 65% (95% confidence interval [CI] 43-86) for the overall population, 46% (95% CI 15-77) in group 1, and 74% (95% CI 42-105) in group 2. The difference between the two groups was statistically significant. We show that ARF requiring mechanical ventilation appears to be a factor that is negatively correlated with survival for patients treated by LTOT plus NIPPV. This data suggests that NIPPV should be tried before ARF arising in COPD patients who present a deterioration in chronic respiratory failure with hypercapnia. PMID:10756560

  13. Sphingosine 1-phosphate receptor 2 (S1P2) attenuates reactive oxygen species formation and inhibits cell death: implications for otoprotective therapy

    PubMed Central

    Herr, Deron R.; Reolo, Marie J. Y.; Peh, Yee Xin; Wang, Wei; Lee, Chang-Wook; Rivera, Rich; Paterson, Ian C.; Chun, Jerold

    2016-01-01

    Ototoxic drugs, such as platinum-based chemotherapeutics, often lead to permanent hearing loss through apoptosis of neuroepithelial hair cells and afferent neurons of the cochlea. There is no approved therapy for preventing or reversing this process. Our previous studies identified a G protein-coupled receptor (GPCR), S1P2, as a potential mediator of otoprotection. We therefore sought to identify a pharmacological approach to prevent cochlear degeneration via activation of S1P2. The cochleae of S1pr2−/− knockout mice were evaluated for accumulation of reactive oxygen species (ROS) with a nitro blue tetrazolium (NBT) assay. This showed that loss of S1P2 results in accumulation of ROS that precedes progressive cochlear degeneration as previously reported. These findings were supported by in vitro cell-based assays to evaluate cell viability, induction of apoptosis, and accumulation of ROS following activation of S1P2 in the presence of cisplatin. We show for the first time, that activation of S1P2 with a selective receptor agonist increases cell viability and reduces cisplatin-mediated cell death by reducing ROS. Cumulatively, these results suggest that S1P2 may serve as a therapeutic target for attenuating cisplatin-mediated ototoxicity. PMID:27080739

  14. Hyperbaric Oxygen Therapy for Late Radiation-Associated Tissue Necroses: Is It Safe in Patients With Locoregionally Recurrent and Then Successfully Salvaged Head-and-Neck Cancers?

    SciTech Connect

    Lin, H.-Y.; Ku, C.-H.; Liu, D.-W.; Chao, H.-L.; Lin, C.-S.; Jen, Y.-M.

    2009-07-15

    Purpose: To test, in a retrospective matched-pair study, whether necrosis-rescuing hyperbaric oxygen therapy (HBOT) increases the risk of cancer re-recurrence in patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers. Methods and materials: Between January 1995 and July 2004, we retrospectively identified 22 patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers. We defined two groups: the HBOT group, 11 patients with HBOT for rescuing late radiation-associated tissue necroses; and the non-HBOT group, the other 11 matched-pair patients without HBOT. Between the two groups, the following four factors were matched for case pairing: primary cancer subsite, initial cancer stage, age, and gender. Results: Three findings indicate that HBOT increases the risk of cancer re-recurrence. First, we observed more cancer re-recurrences in the HBOT group than in the non-HBOT group: 9 of 11 vs. 4 of 11, with 5-year disease-free survival rates after salvage of 32.7% vs. 70.0% (hazard ratio 3.2; 95% confidence interval 1.03-10.7; p = 0.048). Second, re-recurrences developed rapidly after HBOT in 6 patients. Third, 3 patients had unusual cancer re-recurrences after HBOT. Remarkably, of 9 patients with cancer re-recurrences in the HBOT group, 4 patients had cancer disease-free intervals of 9 months or less before HBOT. Conclusions: Necrosis-rescuing HBOT should be given with caution in patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers; if it cannot be omitted entirely, deferring HBOT 9 months or longer after cancer re-treatment may be prudent.

  15. A prospective, randomized clinical study evaluating the effect of transdermal continuous oxygen therapy on biological processes and foot ulcer healing in persons with diabetes mellitus.

    PubMed

    Driver, Vickie R; Yao, Min; Kantarci, Alpdogan; Gu, Guosheng; Park, Nanjin; Hasturk, Hatice

    2013-11-01

    Hypoxia is a major factor in delayed wound healing. The aim of this prospective, randomized, clinical trial was to compare outcomes of treatment in persons with chronic diabetic foot ulcers (DFUs) randomly assigned to transdermal continuous oxygen therapy (TCOT) for 4 weeks as an adjunct to standard care (debridement, offloading, and moisture). Nine patients (age 58.6±7.1, range 38-73 years) received TCOT (treatment group) and eight patients (age 59.9±12.6, range 35-76 years) received standard care alone (control group). Most patients (12) were male, and all had a Wagner I or II foot ulcer for an average of 14 (control group) or 20 months (treatment group). Weekly wound measurements and wound tissue biopsies were obtained and wound fluid collected. Levels of pro-inflammatory cytokines and proteases in wound fluid samples were analyzed using Luminex-based multiplex assays. Tissue-resident macrophages were quantified by immunohistochemistry. At week 4, average wound size reduction was 87% (range 55.7% to 100%) in the treatment group compared to 46% (15% to 99%) in the control group (P <0.05). Changes in cytokine levels (IL-6, IL-8) and proteinases (MMP-1,-2,-9, TIMP-1) at weeks 2 to 4 in wound fluid correlated with clinical findings. CD68+ macrophage counts showed statistically significant reduction in response to TCOT compared to the control group (P <0.01). The results of this study show that TCOT may facilitate healing of DFUs by reversing the inflammatory process through reduction in pro-inflammatory cytokines and tissue-degrading proteases. Additional research to elucidate the effects of this treatment on complete healing and increase understanding about the role of wound fluid analysis is needed.

  16. Cerebral and Muscle Tissue Oxygenation During Incremental Cycling in Male Adolescents Measured by Time-Resolved Near-Infrared Spectroscopy.

    PubMed

    Ganesan, Goutham; Leu, Szu-Yun; Cerussi, Albert; Tromberg, Bruce; Cooper, Dan M; Galassetti, Pietro

    2016-05-01

    Near-infrared spectroscopy has long been used to measure tissue-specific O2 dynamics in exercise, but most published data have used continuous wave devices incapable of quantifying absolute Hemoglobin (Hb) concentrations. We used time-resolved near-infrared spectroscopy to study exercising muscle (Vastus Lateralis, VL) and prefrontal cortex (PFC) Hb oxygenation in 11 young males (15.3 ± 2.1 yrs) performing incremental cycling until exhaustion (peak VO2 = 42.7 ± 6.1 ml/min/kg, mean peak power = 181 ± 38 W). Time-resolved near-infrared spectroscopy measurements of reduced scattering (μs´) and absorption (μa) at three wavelengths (759, 796, and 833 nm) were used to calculate concentrations of oxyHb ([HbO2]), deoxy Hb ([HbR]), total Hb ([THb]), and O2 saturation (stO2). In PFC, significant increases were observed in both [HbO2] and [HbR] during intense exercise. PFC stO2% remained stable until 80% of total exercise time, then dropped (-2.95%, p = .0064). In VL, stO2% decreased until peak time (-6.8%, p = .01). Segmented linear regression identified thresholds for PFC [HbO2], [HbR], VL [THb]. There was a strong correlation between timing of second ventilatory threshold and decline in PFC [HbO2] (r = .84). These findings show that time-resolved near-infrared spectroscopy can be used to study physiological threshold phenomena in children during maximal exercise, providing insight into tissue specific hemodynamics and metabolism. PMID:26451845

  17. MRI of brain tissue oxygen tension under hyperbaric conditions.

    PubMed

    Muir, Eric R; Cardenas, Damon P; Duong, Timothy Q

    2016-06-01

    The brain depends on a continuous supply of oxygen to maintain its structural and functional integrity. This study measured T1 from MRI under normobaric air, normobaric oxygen, hyperbaric air, and hyperbaric oxygen (HBO) conditions as a marker of tissue pO2 since dissolved molecular oxygen acts as an endogenous contrast agent. Brain tissue T1 decreased corresponding to increased pO2 with increasing inhaled oxygen concentrations, and tissue oxygenation was estimated from the T1 changes between different inhaled oxygen levels. Tissue pO2 difference maps between different oxygen conditions showed heterogeneous pO2 changes in the brain. MRI-derived tissue pO2 was markedly lower than the arterial pO2 but was slightly higher than venous pO2. Additionally, for comparison with published extracellular tissue pO2 data obtained using oxygen electrodes and other invasive techniques, a model was used to estimate extracellular and intracellular pO2 from the MRI-derived mean tissue pO2. This required multiple assumptions, and so the effects of the assumptions and parameters used in modeling brain pO2 were evaluated. MRI-derived pO2 values were strongly dependent on assumptions about the extra- and intracellular compartments but were relatively less sensitive to variations in the relaxivity constant of oxygen and contribution from oxygen in the cerebral blood compartment. This approach may prove useful in evaluating tissue oxygenation in disease states such as stroke.

  18. Local changes in arterial oxygen saturation induced by visible and near-infrared light radiation.

    PubMed

    Yesman, S S; Mamilov, S O; Veligotsky, D V; Gisbrecht, A I

    2016-01-01

    In this study, we investigate the efficiency of laser radiation on oxyhemoglobin (HbO2) rate in blood vessels and its wavelength dependence. The results of in vivo experimental measurements of the laser-induced photodissociation of HbO2 in cutaneous blood vessels in the visible and near-infrared (IR) spectral range are presented. Arterial oxygen saturation (SpO2) was measured by a method of fingertip pulse oximetry, which is based on the measurement of the modulated pulse wave of the blood. The light irradiating the finger was provided by corresponding light-emitting diodes (LED) at 15 wavelengths in the 400-940 nm spectrum range. Statistical results with a value of p < 0.05 were viewed as being significant for all volunteers. The results show that there is a decrease in SpO2 in the blood under the influence of the transcutaneous laser irradiation. Three maxima in the spectral range (530, 600, and 850 nm) are revealed, wherein decrease in the relative concentration of SpO2 reaches 5 % ± 0.5 %. Near-IR radiation plays a dominant role in absorption of laser radiation by oxyhemoglobin in deeper layers of tissue blood vessels. The obtained data correlate with the processes of light propagation in biological tissue. The observed reduction in SpO2 indicates the process of photodissociation of HbO2 in vivo and may result in local increase in O2 in the tissue. Such laser-induced enrichment of tissue oxygenation can be used in phototherapy of pathologies, where the elimination of local tissue hypoxia is critical. PMID:26637304

  19. Local changes in arterial oxygen saturation induced by visible and near-infrared light radiation.

    PubMed

    Yesman, S S; Mamilov, S O; Veligotsky, D V; Gisbrecht, A I

    2016-01-01

    In this study, we investigate the efficiency of laser radiation on oxyhemoglobin (HbO2) rate in blood vessels and its wavelength dependence. The results of in vivo experimental measurements of the laser-induced photodissociation of HbO2 in cutaneous blood vessels in the visible and near-infrared (IR) spectral range are presented. Arterial oxygen saturation (SpO2) was measured by a method of fingertip pulse oximetry, which is based on the measurement of the modulated pulse wave of the blood. The light irradiating the finger was provided by corresponding light-emitting diodes (LED) at 15 wavelengths in the 400-940 nm spectrum range. Statistical results with a value of p < 0.05 were viewed as being significant for all volunteers. The results show that there is a decrease in SpO2 in the blood under the influence of the transcutaneous laser irradiation. Three maxima in the spectral range (530, 600, and 850 nm) are revealed, wherein decrease in the relative concentration of SpO2 reaches 5 % ± 0.5 %. Near-IR radiation plays a dominant role in absorption of laser radiation by oxyhemoglobin in deeper layers of tissue blood vessels. The obtained data correlate with the processes of light propagation in biological tissue. The observed reduction in SpO2 indicates the process of photodissociation of HbO2 in vivo and may result in local increase in O2 in the tissue. Such laser-induced enrichment of tissue oxygenation can be used in phototherapy of pathologies, where the elimination of local tissue hypoxia is critical.

  20. Construction of near-infrared light-triggered reactive oxygen species-sensitive (UCN/SiO2-RB + DOX)@PPADT nanoparticles for simultaneous chemotherapy and photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Zhou, Fang; Zheng, Bin; Zhang, Ying; Wu, Yudong; Wang, Hanjie; Chang, Jin

    2016-06-01

    Combined therapy now plays a major role in cancer therapy due to the outcome of huge amounts of scientific experiments in recent years. However, all systems designed previously have been unable to simultaneously deliver therapy effects using several methods to produce a greater overall therapeutic effect. To solve the problem, we constructed a delivery system of near-infrared light (NIR)-triggered reactive oxygen species (ROS)-sensitive nanoparticles (NPs) for simultaneous chemotherapy and photodynamic therapy (PDT). The inner NP was assembled from a hydrophobic upconverting nanoparticle (UCN) core, with a thin silica shell linked with rose bengal (RB). Finally, a type of ROS-induced biodegradable polymer named poly-(1, 4-phenyleneacetone dimethylenethioketal) (PPADT) was self-assembled to form the NP as an outer shell to load the inner NP and doxorubicin (DOX). As the results show, the UCN core works as a transducer to convert deeply penetrating NIR to visible light for activating the photosensitizer RB for PDT under NIR excitation. In the meantime, the redundant ROS caused PPADT to biodegrade to release the loaded DOX, realizing simultaneous chemotherapy and PDT. Properties such as structure, size distribution, morphology, Fourier transform infrared spectroscopy, ROS production test, cell uptake test and combined therapy treatment effect in vitro were evaluated to prove NIR triggered ROS-sensitive (UCN/SiO2-RB + DOX)@PPADT NPs. Based on our data, this delivery system could provide an effective means to realize simultaneous chemotherapy and PDT through external NIR-triggered ROS sensitivity.

  1. Construction of near-infrared light-triggered reactive oxygen species-sensitive (UCN/SiO2-RB + DOX)@PPADT nanoparticles for simultaneous chemotherapy and photodynamic therapy.

    PubMed

    Zhou, Fang; Zheng, Bin; Zhang, Ying; Wu, Yudong; Wang, Hanjie; Chang, Jin

    2016-06-10

    Combined therapy now plays a major role in cancer therapy due to the outcome of huge amounts of scientific experiments in recent years. However, all systems designed previously have been unable to simultaneously deliver therapy effects using several methods to produce a greater overall therapeutic effect. To solve the problem, we constructed a delivery system of near-infrared light (NIR)-triggered reactive oxygen species (ROS)-sensitive nanoparticles (NPs) for simultaneous chemotherapy and photodynamic therapy (PDT). The inner NP was assembled from a hydrophobic upconverting nanoparticle (UCN) core, with a thin silica shell linked with rose bengal (RB). Finally, a type of ROS-induced biodegradable polymer named poly-(1, 4-phenyleneacetone dimethylenethioketal) (PPADT) was self-assembled to form the NP as an outer shell to load the inner NP and doxorubicin (DOX). As the results show, the UCN core works as a transducer to convert deeply penetrating NIR to visible light for activating the photosensitizer RB for PDT under NIR excitation. In the meantime, the redundant ROS caused PPADT to biodegrade to release the loaded DOX, realizing simultaneous chemotherapy and PDT. Properties such as structure, size distribution, morphology, Fourier transform infrared spectroscopy, ROS production test, cell uptake test and combined therapy treatment effect in vitro were evaluated to prove NIR triggered ROS-sensitive (UCN/SiO2-RB + DOX)@PPADT NPs. Based on our data, this delivery system could provide an effective means to realize simultaneous chemotherapy and PDT through external NIR-triggered ROS sensitivity.

  2. The history of extracorporeal oxygenators.

    PubMed

    Lim, M W

    2006-10-01

    Extracorporeal oxygenators are artificial devices that substitute for anatomical lungs by delivering oxygen to, and extracting carbon dioxide from, blood. They were first conceptualised by the English scientist Robert Hooke (1635-1703) and developed into practical extracorporeal oxygenators by French and German experimental physiologists in the 19th century. Indeed, most of the extracorporeal oxygenators used until the late 1970s were derived from von Schroder's 1882 bubble oxygenator and Frey and Gruber's 1885 film oxygenator. As there is no intervening barrier between blood and oxygen, these are called 'direct contact' oxygenators; they contributed significantly to the development and practice of cardiac surgery till the 1980s. Membrane extracorporeal oxygenators introduce a gas-permeable interface between blood and oxygen. This greatly decreased the blood trauma of direct-contact extracorporeal oxygenators, and enabled extracorporeal oxygenators to be used in longer-term applications such as the intensive therapy of respiratory distress syndrome; this was demonstrably beneficial for neonates but less so for older patients. Much work since the 1960s focused on overcoming the gas exchange handicap of the membrane barrier, leading to the development of high-performance microporous hollow-fibre oxygenators that eventually replaced direct-contact oxygenators in cardiac theatres. PMID:16978315

  3. The history of extracorporeal oxygenators.

    PubMed

    Lim, M W

    2006-10-01

    Extracorporeal oxygenators are artificial devices that substitute for anatomical lungs by delivering oxygen to, and extracting carbon dioxide from, blood. They were first conceptualised by the English scientist Robert Hooke (1635-1703) and developed into practical extracorporeal oxygenators by French and German experimental physiologists in the 19th century. Indeed, most of the extracorporeal oxygenators used until the late 1970s were derived from von Schroder's 1882 bubble oxygenator and Frey and Gruber's 1885 film oxygenator. As there is no intervening barrier between blood and oxygen, these are called 'direct contact' oxygenators; they contributed significantly to the development and practice of cardiac surgery till the 1980s. Membrane extracorporeal oxygenators introduce a gas-permeable interface between blood and oxygen. This greatly decreased the blood trauma of direct-contact extracorporeal oxygenators, and enabled extracorporeal oxygenators to be used in longer-term applications such as the intensive therapy of respiratory distress syndrome; this was demonstrably beneficial for neonates but less so for older patients. Much work since the 1960s focused on overcoming the gas exchange handicap of the membrane barrier, leading to the development of high-performance microporous hollow-fibre oxygenators that eventually replaced direct-contact oxygenators in cardiac theatres.

  4. Quantitative assessment of brain tissue oxygenation in porcine models of cardiac arrest and cardiopulmonary resuscitation using hyperspectral near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Lotfabadi, Shahin S.; Toronov, Vladislav; Ramadeen, Andrew; Hu, Xudong; Kim, Siwook; Dorian, Paul; Hare, Gregory M. T.

    2014-03-01

    Near-infrared spectroscopy (NIRS) is a non-invasive tool to measure real-time tissue oxygenation in the brain. In an invasive animal experiment we were able to directly compare non-invasive NIRS measurements on the skull with invasive measurements directly on the brain dura matter. We used a broad-band, continuous-wave hyper-spectral approach to measure tissue oxygenation in the brain of pigs under the conditions of cardiac arrest, cardiopulmonary resuscitation (CPR), and defibrillation. An additional purpose of this research was to find a correlation between mortality due to cardiac arrest and inadequacy of the tissue perfusion during attempts at resuscitation. Using this technique we measured the changes in concentrations of oxy-hemoglobin [HbO2] and deoxy-hemoglobin [HHb] to quantify the tissue oxygenation in the brain. We also extracted cytochrome c oxidase changes Δ[Cyt-Ox] under the same conditions to determine increase or decrease in cerebral oxygen delivery. In this paper we proved that applying CPR, [HbO2] concentration and tissue oxygenation in the brain increase while [HHb] concentration decreases which was not possible using other measurement techniques. We also discovered a similar trend in changes of both [Cyt-Ox] concentration and tissue oxygen saturation (StO2). Both invasive and non-invasive measurements showed similar results.

  5. When should I be considering home oxygen for my patients?

    PubMed

    Suntharalingam, Jay; Hippolyte, Sabrine; Knowles, Vikki; Freeman, Daryl; Patel, Irem; Hardinge, Maxine

    2016-01-01

    The ability to provide oxygen in a patient's home can offer enormous benefits, including improvements in life expectancy when given in the appropriate setting. Confusingly, however, home oxygen is available in many forms, including long-term oxygen therapy (LTOT), ambulatory oxygen therapy (AOT), palliative oxygen therapy (POT) and short-burst oxygen therapy (SBOT)-each with varying degrees of supporting evidence. The British Thoracic Society (BTS) has recently published new guidance on home oxygen therapy, after collating the available evidence. This article aims to summarise those guidelines, focusing on who should and should not be considered for oxygen therapy. Although the BTS guidelines target a UK audience, many of the principles covered below are applicable internationally, even if the availability of certain oxygen modalities and supporting service arrangements may vary between different healthcare systems. PMID:26742088

  6. Influence of hyperbaric oxygen on left ventricular contractility, total coronary blood flow, and myocardial oxygen consumption in the conscious dog.

    PubMed

    Savitt, M A; Rankin, J S; Elberry, J R; Owen, C H; Camporesi, E M

    1994-06-01

    It is known that hyperbaric oxygenation (HBO) decreases total coronary blood flow (TCBF) and cardiac output (CO). To determine whether this is related to an alteration in myocardial contractility, 10 chronically instrumented conscious dogs were studied during pharmacologic autonomic blockade. Left ventricular (LV) volume was measured with ultrasonic transducers, LV transmural pressure with micromanometers, TCBF with Doppler-flow probes, and coronary AVO2 difference (A-CSO2) was calculated from direct LV and coronary sinus (CS) sampling. To evaluate the effect of increased oxygenation, data were obtained during resting control conditions and during dynamic vena caval occlusions (VCO), at 1 atmosphere of pressure, while breathing air (1 bar/0.21); at 3 atmospheres, breathing compressed air (3 bar/0.21), and at 3 atmospheres breathing 100% oxygen (3 bar/1.0). Because of autonomic blockade, heart rate (HR) was not statistically different in the three conditions. With increasing oxygenation, arterial oxygen tension (PaO2) increased from 85 +/- 5 mmHg (mean +/- SD) at 1 bar/0.21, to 1374 +/- 201 mmHg at 3 bar/1.0 whereas arterial carbon dioxide tension (PaCO2) and pH values were not statistically different. Arterial oxygen content (AO2 content) and CSO2 content increased significantly (both P < 0.05) with increasing PaO2. LV stroke volume (SV), CO, coronary blood flow, and myocardial oxygen consumption (MVO2) were all significantly reduced (P < 0.05) with increasing levels of oxygenation. Intrinsic myocardial function, as measured by the stroke-work/end-diastolic volume relationship was unchanged from 1 bar/0.21 to 3 bar/0.21, and to 3 bar/1.0 (P < 0.20). Thus, the diminished TCBF, CO, and MVO2 associated with HBO do not seem to be associated with a primary alteration in myocardial contractility, but rather may result from a physiologic autoregulation of the myocardium to increasing levels of PaO2. PMID:8061558

  7. Development and clinical evaluation of noninvasive near-infrared monitoring of cerebral oxygenation

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Yappa A.; Rolfe, Peter J.; Palmer, Keith; Watkins, S.; Spencer, S. A.; Doyle, M.; O'Brien, S.; Walker, A.; Rice, C.; Smallpeice, C.

    1994-02-01

    Near infrared spectroscopy (NIRS) is a relatively new method which is suitable for monitoring oxygenation in blood and tissue in the brain of the fetus and the neonate. The technique involves in-vivo determination of the absorption of light in the wavelength range 775 to 900 nm through such tissue and converting such changes in absorbance to provide information about the changes in the concentration of oxygenated and de-oxygenated haemoglobin (HbO2 and Hb). Recent developments of the methodology now enable the calculation of changes in cerebral blood volume (CBV) as well as absolute CBV and cerebral blood flow (CBF). The attraction of this method is its applicability to monitor cerebral function in a wide variety of patient groups. Although primarily developed for neonatal use it is today applied on the fetus to investigate fetal hypoxia and on adults undergoing surgery.

  8. Oxygen analyzer

    DOEpatents

    Benner, William H.

    1986-01-01

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  9. Relationship between blood oxygenation and lactate in human skeletal muscle revealed by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Xu, Guodong; Luo, Qingming; Ge, Xinfa; Gong, Hui; Zeng, Shaoqun

    2002-04-01

    Near-infrared spectroscopy (NIRS) is a focus of attention in the research field of biomedical photonics. The concentration of HbO2 in human skeletal muscle has been measured noninvasive NIRS using a portable tissue oximeter continuously when the subjects did incremental exercises on a power bicycle. Blood lactate is one of traditional physical research subjects which is applied most widely. We study blood volume in the tissue of sportsmen when they are subjected by the incremental physical load, simultaneously detecting some parameters such as the heart rate, maximal oxygen absorption and the concentration of blood lactate. As the intensity of exercises was heightened, the concentration of blood lactate and blood volume in tissue increased, while the concentration of HbO2 decreased. Thus the rudimental characteristics of energy consumption and supply during hypoxia and aerobic exercises are investigated. By discovering the relationship between blood lactate in human skeletal muscle and blood oxygenation, a novel approach for measuring blood lactate noninvasively and assessing the sports ability could be provided. Furthermore, it is possible to assess the fatigue state with tissue oximeter to monitor the human sports intensity noninvasively and dynamically.

  10. Delayed radiation injury to the retrobulbar optic nerves and chiasm. Clinical syndrome and treatment with hyperbaric oxygen and corticosteroids

    SciTech Connect

    Roden, D.; Bosley, T.M.; Fowble, B.; Clark, J.; Savino, P.J.; Sergott, R.C.; Schatz, N.J. )

    1990-03-01

    Thirteen patients with delayed radiation injury to the optic nerves and chiasm were treated with hyperbaric oxygen (HBO) and corticosteroids. These patients experienced painless, abrupt loss of vision in one (6 patients) or both (7 patients) eyes between 4 and 35 months after receiving radiation doses of at least 4500 cGy to the region of the chiasm. Diagnostic evaluation including neuro-imaging and lumbar puncture showed no recurrent tumor and no other cause for visual loss. No patient's vision improved during treatment or follow-up lasting between 1 and 4 years. There were no serious complications of treatment.

  11. Phase II Trial of Radiotherapy After Hyperbaric Oxygenation With Multiagent Chemotherapy (Procarbazine, Nimustine, and Vincristine) for High-Grade Gliomas: Long-Term Results

    SciTech Connect

    Ogawa, Kazuhiko; Ishiuchi, Shogo; Inoue, Osamu; Yoshii, Yoshihiko; Saito, Atsushi; Watanabe, Takashi; Iraha, Shiro; Toita, Takafumi; Kakinohana, Yasumasa; Ariga, Takuro; Kasuya, Goro; Murayama, Sadayuki

    2012-02-01

    Purpose: To analyze the long-term results of a Phase II trial of radiotherapy given immediately after hyperbaric oxygenation (HBO) with multiagent chemotherapy in adults with high-grade gliomas. Methods and Materials: Patients with histologically confirmed high-grade gliomas were administered radiotherapy in daily 2 Gy fractions for 5 consecutive days per week up to a total dose of 60 Gy. Each fraction was administered immediately after HBO, with the time interval from completion of decompression to start of irradiation being less than 15 minutes. Chemotherapy consisting of procarbazine, nimustine, and vincristine and was administered during and after radiotherapy. Results: A total of 57 patients (39 patients with glioblastoma and 18 patients with Grade 3 gliomas) were enrolled from 2000 to 2006, and the median follow-up of 12 surviving patients was 62.0 months (range, 43.2-119.1 months). All 57 patients were able to complete a total radiotherapy dose of 60 Gy immediately after HBO with one course of concurrent chemotherapy. The median overall survival times in all 57 patients, 39 patients with glioblastoma and 18 patients with Grade 3 gliomas, were 20.2 months, 17.2 months, and 113.4 months, respectively. On multivariate analysis, histologic grade alone was a significant prognostic factor for overall survival (p < 0.001). During treatments, no patients had neutropenic fever or intracranial hemorrhage, and no serious nonhematologic or late toxicities were seen in any of the 57 patients. Conclusions: Radiotherapy delivered immediately after HBO with multiagent chemotherapy was safe, with virtually no late toxicities, and seemed to be effective in patients with high-grade gliomas.

  12. Oxygen analyzer

    DOEpatents

    Benner, W.H.

    1984-05-08

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N/sub 2/), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable obtained by decomposing the sample at 1135/sup 0/C, or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135/sup 0/C as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N/sub 2/, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  13. 5-Aminolevulinic Acid-Mediated Sonodynamic Therapy Promotes Phenotypic Switching from Dedifferentiated to Differentiated Phenotype via Reactive Oxygen Species and p38 Mitogen-Activated Protein Kinase in Vascular Smooth Muscle Cells.

    PubMed

    Dan, Juhua; Sun, Xin; Li, Wanlu; Zhang, Yun; Li, Xuesong; Xu, Haobo; Li, Zhitao; Tian, Zhen; Guo, Shuyuan; Yao, Jianting; Gao, Weidong; Tian, Ye

    2015-06-01

    Sonodynamic therapy (SDT) has been found to inhibit in-stent restenosis in animal models. However, the mechanism is not fully elucidated. Here, we investigated the effects of 5-aminolevulinic acid (ALA)-mediated SDT (ALA-SDT) on vascular smooth muscle cells (VSMCs), a cause of restenosis, with a focus on SDT-induced phenotypic switching. Serum-induced dedifferentiated VSMCs were cultured with ALA (1 mm, 24 h) and exposed to ultrasound (0.8 W/cm(2)) for 5 min. Results indicated that ALA-SDT inhibited the migration and proliferation of VSMCs and enhanced the expression of differentiated phenotypic markers in VSMCs. Additionally, ALA-SDT increased intracellular reactive oxygen species accumulation and phosphorylated p38 mitogen-activated protein kinase in VSMCs. Inhibition of reactive oxygen species elevation or p38 mitogen-activated protein kinase activity abolished the expression of smooth muscle 22α (SM22α) in VSMCs induced by ALA-SDT. Taken together, these results suggest that ALA-SDT promotes transformation of the VSMC phenotype from the dedifferentiated to differentiated status via reactive oxygen species and activated p38 mitogen-activated protein kinase.

  14. A critical role of acute bronchoconstriction in the mortality associated with high-dose sarin inhalation: Effects of epinephrine and oxygen therapies

    SciTech Connect

    Gundavarapu, Sravanthi; Zhuang, Jianguo; Barrett, Edward G.; Xu, Fadi; Russell, Robert G.; Sopori, Mohan L.

    2014-01-15

    Sarin is an organophosphate nerve agent that is among the most lethal chemical toxins known to mankind. Because of its vaporization properties and ease and low cost of production, sarin is the nerve agent with a strong potential for use by terrorists and rouge nations. The primary route of sarin exposure is through inhalation and, depending on the dose, sarin leads to acute respiratory failure and death. The mechanism(s) of sarin-induced respiratory failure is poorly understood. Sarin irreversibly inhibits acetylcholine esterase, leading to excessive synaptic levels of acetylcholine and, we have previously shown that sarin causes marked ventilatory changes including weakened response to hypoxia. We now show that LD{sub 50} sarin inhalation causes severe bronchoconstriction in rats, leading to airway resistance, increased hypoxia-induced factor-1α, and severe lung epithelium injury. Transferring animals into 60% oxygen chambers after sarin exposure improved the survival from about 50% to 75% at 24 h; however, many animals died within hours after removal from the oxygen chambers. On the other hand, if LD{sub 50} sarin-exposed animals were administered the bronchodilator epinephrine, > 90% of the animals survived. Moreover, while both epinephrine and oxygen treatments moderated cardiorespiratory parameters, the proinflammatory cytokine surge, and elevated expression of hypoxia-induced factor-1α, only epinephrine consistently reduced the sarin-induced bronchoconstriction. These data suggest that severe bronchoconstriction is a critical factor in the mortality induced by LD{sub 50} sarin inhalation, and epinephrine may limit the ventilatory, inflammatory, and lethal effects of sarin. - Highlights: • Inhalation exposure of rats to LD{sub 50} sarin causes death through respiratory failure. • Severe bronchoconstriction is the major cause of sarin-induced respiratory failure. • Transfer of sarin exposed rats to 60% oxygen improves the mortality temporarily.

  15. Noninvasive optical quantification of absolute blood flow, blood oxygenation, and oxygen consumption rate in exercising skeletal muscle

    NASA Astrophysics Data System (ADS)

    Gurley, Katelyn; Shang, Yu; Yu, Guoqiang

    2012-07-01

    This study investigates a method using novel hybrid diffuse optical spectroscopies [near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS)] to obtain continuous, noninvasive measurement of absolute blood flow (BF), blood oxygenation, and oxygen consumption rate (\\Vdot O2) in exercising skeletal muscle. Healthy subjects (n=9) performed a handgrip exercise to increase BF and \\Vdot O2 in forearm flexor muscles, while a hybrid optical probe on the skin surface directly monitored oxy-, deoxy-, and total hemoglobin concentrations ([HbO2], [Hb], and THC), tissue oxygen saturation (StO2), relative BF (rBF), and relative oxygen consumption rate (r\\Vdot O2). The rBF and r\\Vdot O2 signals were calibrated with absolute baseline BF and \\Vdot O2 obtained through venous and arterial occlusions, respectively. Known problems with muscle-fiber motion artifacts in optical measurements during exercise were mitigated using a novel gating algorithm that determined muscle contraction status based on control signals from a dynamometer. Results were consistent with previous findings in the literature. This study supports the application of NIRS/DCS technology to quantitatively evaluate hemodynamic and metabolic parameters in exercising skeletal muscle and holds promise for improving diagnosis and treatment evaluation for patients suffering from diseases affecting skeletal muscle and advancing fundamental understanding of muscle and exercise physiology.

  16. Plasmon-mediated generation of reactive oxygen species from near-infrared light excited gold nanocages for photodynamic therapy in vitro.

    PubMed

    Gao, Liang; Liu, Ru; Gao, Fuping; Wang, Yaling; Jiang, Xinglu; Gao, Xueyun

    2014-07-22

    We have performed fundamental assays of gold nanocages (AuNCs) as intrinsic inorganic photosensitizers mediating generation of reactive oxygen species (ROS) by plasmon-enabled photochemistry under near-infrared (NIR) one/two-photon irradiation. We disclosed that NIR light excited hot electrons transform into either ROS or hyperthermia. Electron spin resonance spectroscopy was applied to demonstrate the production of three main radical species, namely, singlet oxygen ((1)O2), superoxide radical anion (O2(-•)), and hydroxyl radical ((•)OH). The existence of hot electrons from irradiated AuNCs was confirmed by a well-designed photoelectrochemical experiment based on a three-electrode system. It could be speculated that surface plasmons excited in AuNCs first decay into hot electrons, and then the generated hot electrons sensitize oxygen to form ROS through energy and electron transfer modes. We also compared AuNCs' ROS generation efficiency in different surface chemical environments under one/two-photon irradiation and verified that, compared with one-photon irradiation, two-photon irradiation could bring about much more ROS. Furthermore, in vitro, under two-photon irradiation, ROS can trigger mitochondrial depolarization and caspase protein up-regulation to initiate tumor cell apoptosis. Meanwhile, hyperthermia mainly induces tumor cell necrosis. Our findings suggest that plasmon-mediated ROS and hyperthermia can be facilely regulated for optimized anticancer phototherapy. PMID:24992260

  17. A critical role of acute bronchoconstriction in the mortality associated with high-dose sarin inhalation: effects of epinephrine and oxygen therapies.

    PubMed

    Gundavarapu, Sravanthi; Zhuang, Jianguo; Barrett, Edward G; Xu, Fadi; Russell, Robert G; Sopori, Mohan L

    2014-01-15

    Sarin is an organophosphate nerve agent that is among the most lethal chemical toxins known to mankind. Because of its vaporization properties and ease and low cost of production, sarin is the nerve agent with a strong potential for use by terrorists and rouge nations. The primary route of sarin exposure is through inhalation and, depending on the dose, sarin leads to acute respiratory failure and death. The mechanism(s) of sarin-induced respiratory failure is poorly understood. Sarin irreversibly inhibits acetylcholine esterase, leading to excessive synaptic levels of acetylcholine and, we have previously shown that sarin causes marked ventilatory changes including weakened response to hypoxia. We now show that LD50 sarin inhalation causes severe bronchoconstriction in rats, leading to airway resistance, increased hypoxia-induced factor-1α, and severe lung epithelium injury. Transferring animals into 60% oxygen chambers after sarin exposure improved the survival from about 50% to 75% at 24h; however, many animals died within hours after removal from the oxygen chambers. On the other hand, if LD50 sarin-exposed animals were administered the bronchodilator epinephrine, >90% of the animals survived. Moreover, while both epinephrine and oxygen treatments moderated cardiorespiratory parameters, the proinflammatory cytokine surge, and elevated expression of hypoxia-induced factor-1α, only epinephrine consistently reduced the sarin-induced bronchoconstriction. These data suggest that severe bronchoconstriction is a critical factor in the mortality induced by LD50 sarin inhalation, and epinephrine may limit the ventilatory, inflammatory, and lethal effects of sarin.

  18. Extracorporeal shockwave therapy for avascular necrosis of femoral head.

    PubMed

    Wang, Ching-Jen; Cheng, Jai-Hong; Huang, Chung-Cheng; Yip, Han-Kan; Russo, Sergio

    2015-12-01

    The etiology of osteonecrosis of the femoral head (ONFH) is multifactorial. Treatment of ONFH is disease stage dependent. For early stages, femoral head preservation procedures are preferred including core decompression, muscle pedicle grafting and de-rotational osteotomy. Core decompression with bone grafting is considered the gold standard. However, the results are inconsistence and unpredictable. An effective non-invasive method of treatment is imperative. Recently, extracorporeal shockwave therapy (ESWT) has shown beneficial effects in ONFH. ESWT improves pain and function of the hip and regression of the ONFH lesion. ESWT is more effective than core decompression with or without bone grafting, cocktail therapy that combined HBO, ESWT and oral alendronate is shown effective for patients with early osteonecrosis. The purpose of the article is to review, update and summarize the clinical treatment of ONFH using shockwave therapy.

  19. Evidence of a heterogeneous tissue oxygenation: renal ischemia/reperfusion injury in a large animal model

    NASA Astrophysics Data System (ADS)

    Crane, Nicole J.; Huffman, Scott W.; Alemozaffar, Mehrdad; Gage, Frederick A.; Levin, Ira W.; Elster, Eric A.

    2013-03-01

    Renal ischemia that occurs intraoperatively during procedures requiring clamping of the renal artery (such as renal procurement for transplantation and partial nephrectomy for renal cancer) is known to have a significant impact on the viability of that kidney. To better understand the dynamics of intraoperative renal ischemia and recovery of renal oxygenation during reperfusion, a visible reflectance imaging system (VRIS) was developed to measure renal oxygenation during renal artery clamping in both cooled and warm porcine kidneys. For all kidneys, normothermic and hypothermic, visible reflectance imaging demonstrated a spatially distinct decrease in the relative oxy-hemoglobin concentration (%HbO2) of the superior pole of the kidney compared to the middle or inferior pole. Mean relative oxy-hemoglobin concentrations decrease more significantly during ischemia for normothermic kidneys compared to hypothermic kidneys. VRIS may be broadly applicable to provide an indicator of organ ischemia during open and laparoscopic procedures.

  20. Appreciating Oxygen

    ERIC Educational Resources Information Center

    Weiss, Hilton M.

    2008-01-01

    Photosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that…

  1. Validation of a New NIRS Method for Measuring Muscle Oxygenation During Rhythmic Handgrip Exercise

    NASA Technical Reports Server (NTRS)

    Hagan, R. Donald; Soller, Babs R.; Soyemi, Olusola; Landry, Michelle; Shear, Michael; Wu, Jacqueline

    2006-01-01

    Near infrared spectroscopy (NIRS) is commonly used to measure muscle oxygenation during exercise and recovery. Current NIRS algorithms do not account for variation in water content and optical pathlength during exercise. The current effort attempts to validate a newly developed NIRS algorithm during rhythmic handgrip exercise and recovery. Six female subjects, aver age 28 +/- 6 yrs, participated in the study. A venous catheter was placed in the retrograde direction in the antecubital space. A NIRS sensor with 30 mm source-detector separation was placed on the flexor digitorum profundus. Subjects performed two 5-min bouts of rhythmic handgrip exercise (2 s contraction/1 s relaxation) at 15% and 30% of maximal voluntary contraction. Venous blood was sampled before each bout, during the last minute of exercise, and after 5 minutes of recovery. Venous oxygen saturation (SvO2) was measured with a I-stat CG-4+ cartridge. Spectra were collected between 700-900 nm. A modified Beer's Law formula was used to calculate the absolute concentration of oxyhemoglobin (HbO2), deoxyhemoglobin (Hb) and water, as well as effective pathlength for each spectrum. Muscle oxygen saturation (SmO2) was calculated from the HbO2 and Hb results. The correlation between SvO2 and SmO2 was determined. Optical pathlength and water varied significantly during each exercise bout, with pathlength increasing approximately 20% and water increasing about 2%. R2 between blood and muscle SO2 was found to be 0.74, the figure shows the relationship over SvO2 values between 22% and 82%. The NIRS measurement was, on average, 6% lower than the blood measurement. It was concluded that pathlength changes during exercise because muscle contraction causes variation in optical scattering. Water concentration also changes, but only slightly. A new NIRS algorithm which accounts for exercise-induced variation in water and pathlength provided an accurate assessment of muscle oxygen saturation before, during and after

  2. Episodes of apnea and bradycardia in the preterm newborn: impact on cerebral oxygenation measured by near-infrared spectrophotometry

    NASA Astrophysics Data System (ADS)

    Van Huffel, Sabine; Craemers, Johan; Lenaerts, Bart; Daniels, Hans; Naulaers, Gunnar; Casaer, Paul

    1998-12-01

    The objective of this study is to evaluate the effect of episodes of apneas and/or mild bradycardia (heart rate decreases of 10 to 20% or more) on cerebral oxyhemoglobin (HbO2) and reduced hemoglobin (Hb) concentration as measured by Near Infrared Spectrophotometry (NIRS). Measurements were carried out on 7 preterm infants who experienced apneic and bradycardiac events. It is shown how to characterize these events using time-frequency analysis. In addition to NIRS (performed with a NIRO-500 from Hamamatsu, Japan), the heart rate, ECG, peripheral arterial oxygen saturation (measured at the foot) and respiration (abdominal and thoracic pressure, and nasal airflow) were continuously recorded. The impact of apneic events and periodic breathing on these measurements reveals the clinical relevance of NIRS. In particular, we investigate whether these changes in heart rate and respiration also influence HbO2 and reduced Hb concentration in neonatal brain. These changes are characterized, as well as their relationships with the other simultaneously recorded signals such as peripheral arterial oxygen saturation.

  3. The complex interplay of iron metabolism, reactive oxygen species, and reactive nitrogen species: insights into the potential of various iron therapies to induce oxidative and nitrosative stress.

    PubMed

    Koskenkorva-Frank, Taija S; Weiss, Günter; Koppenol, Willem H; Burckhardt, Susanna

    2013-12-01

    Production of minute concentrations of superoxide (O2(*-)) and nitrogen monoxide (nitric oxide, NO*) plays important roles in several aspects of cellular signaling and metabolic regulation. However, in an inflammatory environment, the concentrations of these radicals can drastically increase and the antioxidant defenses may become overwhelmed. Thus, biological damage may occur owing to redox imbalance-a condition called oxidative and/or nitrosative stress. A complex interplay exists between iron metabolism, O2(*-), hydrogen peroxide (H2O2), and NO*. Iron is involved in both the formation and the scavenging of these species. Iron deficiency (anemia) (ID(A)) is associated with oxidative stress, but its role in the induction of nitrosative stress is largely unclear. Moreover, oral as well as intravenous (iv) iron preparations used for the treatment of ID(A) may also induce oxidative and/or nitrosative stress. Oral administration of ferrous salts may lead to high transferrin saturation levels and, thus, formation of non-transferrin-bound iron, a potentially toxic form of iron with a propensity to induce oxidative stress. One of the factors that determine the likelihood of oxidative and nitrosative stress induced upon administration of an iv iron complex is the amount of labile (or weakly-bound) iron present in the complex. Stable dextran-based iron complexes used for iv therapy, although they contain only negligible amounts of labile iron, can induce oxidative and/or nitrosative stress through so far unknown mechanisms. In this review, after summarizing the main features of iron metabolism and its complex interplay with O2(*-), H2O2, NO*, and other more reactive compounds derived from these species, the potential of various iron therapies to induce oxidative and nitrosative stress is discussed and possible underlying mechanisms are proposed. Understanding the mechanisms, by which various iron formulations may induce oxidative and nitrosative stress, will help us

  4. Trends in brain oxygenation during mental and physical exercise measured using near-infrared spectroscopy (NIRS): potential for early detection of Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Allen, Monica S.; Allen, Jeffery W.; Mikkilineni, Shweta; Liu, Hanli

    2005-04-01

    Motivation: Early diagnosis of Alzheimer's disease (AD) is crucial because symptoms respond best to available treatments in the initial stages of the disease. Recent studies have shown that marked changes in brain oxygenation during mental and physical tasks can be used for noninvasive functional brain imaging to detect Alzheimer"s disease. The goal of our study is to explore the possibility of using near infrared spectroscopy (NIRS) and mapping (NIRM) as a diagnostic tool for AD before the onset of significant morphological changes in the brain. Methods: A 16-channel NIRS brain imager was used to noninvasively measure spatial and temporal changes in cerebral hemodynamics induced during verbal fluency task and physical activity. The experiments involved healthy subjects (n = 10) in the age range of 25+/-5 years. The NIRS signals were taken from the subjects' prefrontal cortex during the activities. Results and Conclusion: Trends of oxygenated and deoxygenated hemoglobin in the prefrontal cortex of the brain were observed. During the mental stimulation, the subjects showed significant increase in oxygenated hemoglobin [HbO2] with a simultaneous decrease in deoxygenated hemoglobin [Hb]. However, physical exercise caused a rise in levels of HbO2 with small variations in Hb. This study basically demonstrates that NIRM taken from the prefrontal cortex of the human brain is sensitive to both mental and physical tasks and holds potential to serve as a diagnostic means for early detection of Alzheimer's disease.

  5. Role of mitochondria and NADPH oxidase derived reactive oxygen species in hyperoxaluria induced nephrolithiasis: therapeutic intervention with combinatorial therapy of N-acetyl cysteine and Apocynin.

    PubMed

    Sharma, Minu; Kaur, Tanzeer; Singla, S K

    2016-03-01

    The interactions between the main cellular sources of ROS, such as mitochondria and NADPH oxidase, are known to play an imperative role in the pathogenesis of hyperoxaluria-induced nephrolithiasis. The present study was designed to investigate the protective effect of a combinatorial therapy based on the attenuation of oxidative stress with antioxidant (N-acetyl cysteine), and NADPH oxidase inhibitor (apocynin), that might be required to effectively eliminate hyperoxaluric manifestations. Hyperoxaluria was induced in male Wistar rats by administering 0.4% ethylene glycol with 1% ammonium chloride in drinking water for 9 days. Hyperoxaluria accentuated renal oxidative stress in terms of increased ROS production and lipid peroxidation. Mitochondrial dysfunction, a central deleterious event in renal stone crystallization, was evident by decreased activities of electron transport chain complex I, II and IV, augmented mitochondrial ROS, reduced GSH/GSSG ratio, which resulted in the mitochondrial permeability transition pore (mPTP) opening as indicated by increased mitochondrial swelling in hyperoxaluric rats. Furthermore, NADPH oxidase activity was significantly increased, with raised expression of NOX1, NOX2, NOX4, p38MAPK and MnSOD, in the renal tissue of hyperoxaluric rats compared to control. However, combinatorial therapy with N-acetyl cysteine (50mg/kg/day) and apocynin (200mg/kg/day), intraperitoneally, significantly improved renal functions in hyperoxaluric rats and considerably ameliorated mitochondrial dysfunction. NAC with apocynin was also found to be effective in reducing the redundant activity of NADPH oxidase in renal tissue of hyperoxaluric rats. Hence, our investigation provides novel mechanistic insights that combinatorial approaches using targeted modulators of ROS offer therapeutic benefits in hyperoxaluria-induced nephrolithiasis.

  6. Oxygen binding properties of backswimmer (Notonectidae, Anisops) haemoglobin, determined in vivo.

    PubMed

    Matthews, Philip G D; Seymour, Roger S

    2011-12-01

    Aquatic backswimmers (Anisops spp.) collect oxygen from the atmosphere in order to breathe underwater, carrying it within a bubble of air on the ventral surface of their body and bound within haemoglobin-filled cells inside their abdomen. These oxygen stores are interconnected via the abdominal spiracles and the tracheal system. Fibre optic oxygen probes were used to measure PO(2) changes within the air bubbles of submerged backswimmers (Anisops deanei) and these measurements were transformed into in vivo haemoglobin-oxygen equilibrium curves (OECs) using a biotonometric approach. The haemoglobin displayed a triphasic, highly sigmoid OEC with a P(50) of 3.90 kPa. Comparisons made with a previous in vitro analysis of Anisops haemoglobin demonstrate that while the apparent cooperativity and oxygen affinity are considerably higher in vivo, both measurements share unusual Hb-O(2) binding characteristics. The affinity and cooperativity of the backswimmers' haemoglobin appears adaptive as it lengthens dives and promotes neutral buoyancy. While there are limitations associated with biotonometry, the in vivo OEC accurately represents the loading and unloading of biologically available oxygen within the backswimmers' haemoglobin cells. Potential errors associated with determining the OEC are small, as evaluated with sensitivity analyses in numerical models.

  7. Lack of conventional oxygen-linked proton and anion binding sites does not impair allosteric regulation of oxygen binding in dwarf caiman hemoglobin

    PubMed Central

    Fago, Angela; Malte, Hans; Storz, Jay F.; Gorr, Thomas A.

    2013-01-01

    In contrast to other vertebrate hemoglobins (Hbs) whose high intrinsic O2 affinities are reduced by red cell allosteric effectors (mainly protons, CO2, organic phosphates, and chloride ions), crocodilian Hbs exhibit low sensitivity to organic phosphates and high sensitivity to bicarbonate (HCO3−), which is believed to augment Hb-O2 unloading during diving and postprandial alkaline tides when blood HCO3− levels and metabolic rates increase. Examination of α- and β-globin amino acid sequences of dwarf caiman (Paleosuchus palpebrosus) revealed a unique combination of substitutions at key effector binding sites compared with other vertebrate and crocodilian Hbs: β82Lys→Gln, β143His→Val, and β146His→Tyr. These substitutions delete positive charges and, along with other distinctive changes in residue charge and polarity, may be expected to disrupt allosteric regulation of Hb-O2 affinity. Strikingly, however, P. palpebrosus Hb shows a strong Bohr effect, and marked deoxygenation-linked binding of organic phosphates (ATP and DPG) and CO2 as carbamate (contrasting with HCO3− binding in other crocodilians). Unlike other Hbs, it polymerizes to large complexes in the oxygenated state. The highly unusual properties of P. palpebrosus Hb align with a high content of His residues (potential sites for oxygenation-linked proton binding) and distinctive surface Cys residues that may form intermolecular disulfide bridges upon polymerization. On the basis of its singular properties, P. palpebrosus Hb provides a unique opportunity for studies on structure-function coupling and the evolution of compensatory mechanisms for maintaining tissue O2 delivery in Hbs that lack conventional effector-binding residues. PMID:23720132

  8. Oxygen supplies during a mass casualty situation.

    PubMed

    Ritz, Ray H; Previtera, Joseph E

    2008-02-01

    Mass casualty and pandemic events pose a substantial challenge to the resources available in our current health care system. The ability to provide adequate oxygen therapy is one of the systems that could be out-stripped in certain conditions. Natural disasters can disrupt manufacturing or delivery, and pandemic events can increase consumption beyond the available supply. Patients may require manual resuscitation, basic oxygen therapy, or positive-pressure ventilation during these scenarios. Available sources of oxygen include bulk liquid oxygen systems, compressed gas cylinders, portable liquid oxygen (LOX) systems, and oxygen concentrators. The last two are available in a variety of configurations, which include personal and home systems that are suitable for individual patients, and larger systems that can provide oxygen to multiple patients or entire institutions. Bulk oxygen systems are robust and are probably sustainable during periods of high consumption, but are at risk if manufacturing or delivery is disrupted. Compressed gas cylinders offer support during temporary periods of need but are not a solution for extended periods of therapy. Personal oxygen concentrators and LOX systems are limited in their application during mass casualty scenarios. Large-capacity oxygen concentrators and LOX systems may effectively provide support to alternative care sites or larger institutions. They may also be appropriate selections for governmental emergency-response scenarios. Careful consideration of the strengths and limitations of each of these options can reduce the impact of a mass casualty event. PMID:18218152

  9. Oxygen Delivering Biomaterials for Tissue Engineering

    PubMed Central

    Farris, Ashley L.; Rindone, Alexandra N.; Grayson, Warren L.

    2016-01-01

    Tissue engineering (TE) has provided promising strategies for regenerating tissue defects, but few TE approaches have been translated for clinical applications. One major barrier in TE is providing adequate oxygen supply to implanted tissue scaffolds, since oxygen diffusion from surrounding vasculature in vivo is limited to the periphery of the scaffolds. Moreover, oxygen is also an important signaling molecule for controlling stem cell differentiation within TE scaffolds. Various technologies have been developed to increase oxygen delivery in vivo and enhance the effectiveness of TE strategies. Such technologies include hyperbaric oxygen therapy, perfluorocarbon- and hemoglobin-based oxygen carriers, and oxygen-generating, peroxide-based materials. Here, we provide an overview of the underlying mechanisms and how these technologies have been utilized for in vivo TE applications. Emerging technologies and future prospects for oxygen delivery in TE are also discussed to evaluate the progress of this field towards clinical translation. PMID:27453782

  10. Oxygen-Concentrating Cell

    NASA Technical Reports Server (NTRS)

    Buehler, K.

    1986-01-01

    High-purity oxygen produced from breathing air or from propellantgrade oxygen in oxygen-concentrating cell. Operating economics of concentrator attractive: Energy consumption about 4 Wh per liter of oxygen, slightly lower than conventional electrochemical oxygen extractors.

  11. [ELECTRIC STIMULATION OF VAGUS NERVE MODULATES A PROPAGATION OF OXYGEN EPILEPSY IN RABBITS].

    PubMed

    Zhilyaev, S Yu; Moskvin, A N; Platonova, T F; Demchenko, I T

    2015-11-01

    The activation of autonomic afferents (achieved through the vagus nerve (VN) electrical stimulation) on CNS O2 toxicity and cardiovascular function was investigated. In conscious rabbits at 5 ATA 02, prodromal signs of CNS O2 toxicity and convulsion latency were determined with and without vagus nerve (VN) stimulation. EEG, ECG and respiration were also recorded. In rabbits at 5 ATA, sympathetic overdrive and specific patterns on the EEG (synchronization of slow-waves), ECG (tachycardia) and respiration (respiratory minute volume increase) preceded motor convulsions. Vagus nerve stimulation increased parasympathetic component of autonomic drive and significantly delayed prodromal signs of oxygen toxicity and convulsion latency. Autonomic afferent input to the brain is a novel target for preventing CNS toxicity in HBO2. PMID:26995956

  12. Reversible Oxygenation of Oxygen Transport Proteins.

    ERIC Educational Resources Information Center

    Drain, C. M.; Corden, Barry B.

    1987-01-01

    Describes a lecture demonstration which illustrates changes in the visible spectra of oxygen transport proteins upon reversible oxygen binding. Provides a comparison of the physical characteristics of oxygen storage and transport proteins. Reviews essentials for preparation of the materials. (ML)

  13. Performance of Multiple Risk Assessment Tools to Predict Mortality for Adult Respiratory Distress Syndrome with Extracorporeal Membrane Oxygenation Therapy: An External Validation Study Based on Chinese Single-center Data

    PubMed Central

    Huang, Lei; Li, Tong; Xu, Lei; Hu, Xiao-Min; Duan, Da-Wei; Li, Zhi-Bo; Gao, Xin-Jing; Li, Jun; Wu, Peng; Liu, Ying-Wu; Wang, Song; Lang, Yu-Heng

    2016-01-01

    Background: There has been no external validation of survival prediction models for severe adult respiratory distress syndrome (ARDS) with extracorporeal membrane oxygenation (ECMO) therapy in China. The aim of study was to compare the performance of multiple models recently developed for patients with ARDS undergoing ECMO based on Chinese single-center data. Methods: A retrospective case study was performed, including twenty-three severe ARDS patients who received ECMO from January 2009 to July 2015. The PRESERVE (Predicting death for severe ARDS on VV-ECMO), ECMOnet, Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score, a center-specific model developed for inter-hospital transfers receiving ECMO, and the classical risk-prediction scores of Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) were calculated. In-hospital and six-month mortality were regarded as the endpoints and model performance was evaluated by comparing the area under the receiver operating characteristic curve (AUC). Results: The RESP and APACHE II scores showed excellent discriminate performance in predicting survival with AUC of 0.835 (95% confidence interval [CI], 0.659–1.010, P = 0.007) and 0.762 (95% CI, 0.558–0.965, P = 0.035), respectively. The optimal cutoff values were risk class 3.5 for RESP and 35.5 for APACHE II score, and both showed 70.0% sensitivity and 84.6% specificity. The excellent performance of these models was also evident for the pneumonia etiological subgroup, for which the SOFA score was also shown to be predictive, with an AUC of 0.790 (95% CI, 0.571–1.009, P = 0.038). However, the ECMOnet and the score developed for externally retrieved ECMO patients failed to demonstrate significant discriminate power for the overall cohort. The PRESERVE model was unable to be evaluated fully since only one patient died six months postdischarge. Conclusions: The RESP, APCHAE II, and SOFA scorings

  14. Effect of increased cardiac output on liver blood flow, oxygen exchange and metabolic rate during longterm endotoxin-induced shock in pigs

    PubMed Central

    Šantak, Borislav; Radermacher, Peter; Adler, Jens; Iber, Thomas; Rieger, Karen M; Wachter, Ulrich; Vogt, Josef; Georgieff, Michael; Träger, Karl

    1998-01-01

    We investigated hepatic blood flow, O2 exchange and metabolism in porcine endotoxic shock (Control, n=8; Endotoxin, n=10) with administration of hydroxyethylstarch to maintain arterial pressure (MAP)>60 mmHg. Before and 12, 18 and 24 h after starting continuous i.v. endotoxin we measured portal venous and hepatic arterial blood flow, intracapillary haemoglobin O2 saturation (Hb-O2%) of the liver surface and arterial, portal and hepatic venous lactate, pyruvate, glyercol and alanine concentrations. Glucose production rate was derived from the plasma isotope enrichment during infusion of [6,6-2H2]-glucose. Despite a sustained 50% increase in cardiac output endotoxin caused a progressive, significant fall in MAP. Liver blood flow significantly increased, but endotoxin affected neither hepatic O2 delivery and uptake nor mean intracapillary Hb-O2% and Hb-O2% frequency distributions. Endotoxin nearly doubled endogenous glucose production rate while hepatic lactate, alanine and glycerol uptake rates progressively decreased significantly. The lactate uptake rate even became negative (P<0.05 vs Control). Endotoxin caused portal and hepatic venous pH to fall significantly concomitant with significantly increased arterial, portal and hepatic venous lactate/pyruvate ratios. During endotoxic shock increased cardiac output achieved by colloid infusion maintained elevated liver blood flow and thereby macro- and microcirculatory O2 supply. Glucose production rate nearly doubled with complete dissociation of hepatic uptake of glucogenic precursors and glucose release. Despite well-preserved capillary oxygenation increased lactate/pyruvate ratios reflecting impaired cytosolic redox state suggested deranged liver energy balance, possibly due to the O2 requirements of gluconeogenesis. PMID:9756385

  15. Improved cerebral oxygenation response and executive performance as a function of cardiorespiratory fitness in older women: a fNIRS study.

    PubMed

    Albinet, Cédric T; Mandrick, Kevin; Bernard, Pierre Louis; Perrey, Stéphane; Blain, Hubert

    2014-01-01

    Cardiorespiratory fitness has been shown to protect and enhance cognitive and brain functions, but little is known about the cortical mechanisms that underlie these changes in older adults. In this study, functional near infrared spectroscopy (fNIRS) was used to investigate variations in oxyhemoglobin [HbO2] and in deoxyhemoglobin [HHb] in the dorsolateral prefrontal cortex (DLPFC) during the performance of an executive control task in older women with different levels of cardiorespiratory fitness (VO2max). Thirty-four women aged 60-77 years were classified as high-fit and low-fit based on VO2max measures. They all performed a control counting (CNT) task and the Random Number Generation (RNG) task at two different paces (1 number/1 s and 1 number/1.5 s), allowing to manipulate task difficulty, while hemodynamic responses in the bilateral DLPFCs were recorded using continuous-wave NIRS. The behavioral data revealed that the high-fit women showed significantly better performance on the RNG tasks compared with the low-fit women. The high-fit women showed significant increases in [HbO2] responses in both left and right DLPFCs during the RNG task, while the low-fit women showed significantly less activation in the right DLPFC compared with the right DLPFC of the high-fit women and compared with their own left DLPFC. At the level of the whole sample, increases in the [HbO2] responses in the right DLPFC were found to mediate in part the relationship between VO2max level and executive performance during the RNG task at 1.5 s but not at 1 s. These results provide support for the cardiorespiratory fitness hypothesis and suggest that higher levels of aerobic fitness in older women are related to increased cerebral oxygen supply to the DLPFC, sustaining better cognitive performance. PMID:25339900

  16. Improved cerebral oxygenation response and executive performance as a function of cardiorespiratory fitness in older women: a fNIRS study

    PubMed Central

    Albinet, Cédric T.; Mandrick, Kevin; Bernard, Pierre Louis; Perrey, Stéphane; Blain, Hubert

    2014-01-01

    Cardiorespiratory fitness has been shown to protect and enhance cognitive and brain functions, but little is known about the cortical mechanisms that underlie these changes in older adults. In this study, functional near infrared spectroscopy (fNIRS) was used to investigate variations in oxyhemoglobin [HbO2] and in deoxyhemoglobin [HHb] in the dorsolateral prefrontal cortex (DLPFC) during the performance of an executive control task in older women with different levels of cardiorespiratory fitness (VO2max). Thirty-four women aged 60–77 years were classified as high-fit and low-fit based on VO2max measures. They all performed a control counting (CNT) task and the Random Number Generation (RNG) task at two different paces (1 number/1 s and 1 number/1.5 s), allowing to manipulate task difficulty, while hemodynamic responses in the bilateral DLPFCs were recorded using continuous-wave NIRS. The behavioral data revealed that the high-fit women showed significantly better performance on the RNG tasks compared with the low-fit women. The high-fit women showed significant increases in [HbO2] responses in both left and right DLPFCs during the RNG task, while the low-fit women showed significantly less activation in the right DLPFC compared with the right DLPFC of the high-fit women and compared with their own left DLPFC. At the level of the whole sample, increases in the [HbO2] responses in the right DLPFC were found to mediate in part the relationship between VO2max level and executive performance during the RNG task at 1.5 s but not at 1 s. These results provide support for the cardiorespiratory fitness hypothesis and suggest that higher levels of aerobic fitness in older women are related to increased cerebral oxygen supply to the DLPFC, sustaining better cognitive performance. PMID:25339900

  17. Comparable Cerebral Oxygenation Patterns in Younger and Older Adults during Dual-Task Walking with Increasing Load

    PubMed Central

    Fraser, Sarah A.; Dupuy, Olivier; Pouliot, Philippe; Lesage, Frédéric; Bherer, Louis

    2016-01-01

    The neuroimaging literature on dual-task gait clearly demonstrates increased prefrontal cortex (PFC) involvement when performing a cognitive task while walking. However, findings from direct comparisons of the cerebral oxygenation patterns of younger (YA) and older (OA) adults during dual-task walking are mixed and it is unclear how YA and OA respond to increasing cognitive load (difficulty) while walking. This functional near infra-red (fNIRS) study examined cerebral oxygenation of YA and OA during self-paced dual-task treadmill walking at two different levels of cognitive load (auditory n-back). Changes in accuracy (%) as well as oxygenated (HbO) and deoxygenated (HbR) hemoglobin were examined. For the HbO and HbR measures, eight regions of interest (ROIs) were assessed: the anterior and posterior dorsolateral and ventrolateral PFC (aDLPFC, pDLPFC, aVLPFC, pVLPFC) in each hemisphere. Nineteen YA (M = 21.83 years) and 14 OA (M = 66.85 years) walked at a self-selected pace while performing auditory 1-back and 2-back tasks. Walking alone (single motor: SM) and performing the cognitive tasks alone (single cognitive: SC) were compared to dual-task walking (DT = SM + SC). In the behavioural data, participants were more accurate in the lowest level of load (1-back) compared to the highest (2-back; p < 0.001). YA were more accurate than OA overall (p = 0.009), and particularly in the 2-back task (p = 0.048). In the fNIRS data, both younger and older adults had task effects (SM < DT) in specific ROIs for ΔHbO (three YA, one OA) and ΔHbR (seven YA, eight OA). After controlling for walk speed differences, direct comparisons between YA and OA did not reveal significant age differences, but did reveal a difficulty effect in HbO in the left aDLPFC (p = 0.028) and significant task effects (SM < DT) in HbR for six of the eight ROIs. Findings suggest that YA and OA respond similarly to manipulations of cognitive load when walking on a treadmill at a self-selected pace. PMID

  18. Monitoring oxygenation.

    PubMed

    Severinghaus, John W

    2011-06-01

    Cyanosis was used for a century after dentists began pulling teeth under 100% N(2)O in 1844 because brief (2 min) severe hypoxia is harmless. Deaths came with curare and potent anesthetic respiratory arrest. Leland Clark's invention of a polarographic blood oxygen tension electrode (1954) was introduced for transcutaneous PO2 monitoring to adjust PEEP and CPAP PO2 to prevent premature infant blindness from excess O2 (1972). Oximetry for warning military aviators was tried after WW II but not used for routine monitoring until Takuo Aoyagi (1973) discovered an equation to measure SaO2 by the ratio of ratios of red and IR light transmitted through tissue as it changed with arterial pulses. Pulse oximetry (1982) depended on simultaneous technology improvements of light emitting red and IR diodes, tiny cheap solid state sensors and micro-chip computers. Continuous monitoring of airway anesthetic concentration and oxygen also became very common after 1980. Death from anesthesia fell 10 fold between 1985 and 2000 as pulse oximetry became universally used, but no proof of a causative relationship to pulse oximetry exists. It is now assumed that all anesthesiologist became much more aware of the dangers of prolonged hypoxia, perhaps by using the pulse oximeters. PMID:21717228

  19. Cardiogenic Shock: Failure of Oxygen Delivery and Oxygen Utilization.

    PubMed

    Lim, Hoong Sern

    2016-08-01

    Cardiogenic shock remains a highly lethal condition. Conventional therapy including revascularization and mechanical circulatory support aims to improve cardiac output and oxygen delivery, but increasing basic and clinical observations indicate wider circulatory and cellular abnormalities, particularly at the advanced stages of shock. Progressive cardiogenic shock is associated with microcirculatory and cellular abnormalities. Cardiogenic shock is initially characterized by a failure to maintain global oxygen delivery; however, progressive cardiogenic shock is associated with the release of pro-inflammatory cytokines, derangement of the regulation of regional blood flow, microcirculatory abnormalities, and cellular dysoxia. These abnormalities are analogous to septic shock and may not be reversed by increase in oxygen delivery, even to supranormal levels. Earlier mechanical circulatory support in cardiogenic shock may limit the development of microcirculatory and cellular abnormalities. PMID:27509355

  20. Cardiogenic Shock: Failure of Oxygen Delivery and Oxygen Utilization.

    PubMed

    Lim, Hoong Sern

    2016-08-01

    Cardiogenic shock remains a highly lethal condition. Conventional therapy including revascularization and mechanical circulatory support aims to improve cardiac output and oxygen delivery, but increasing basic and clinical observations indicate wider circulatory and cellular abnormalities, particularly at the advanced stages of shock. Progressive cardiogenic shock is associated with microcirculatory and cellular abnormalities. Cardiogenic shock is initially characterized by a failure to maintain global oxygen delivery; however, progressive cardiogenic shock is associated with the release of pro-inflammatory cytokines, derangement of the regulation of regional blood flow, microcirculatory abnormalities, and cellular dysoxia. These abnormalities are analogous to septic shock and may not be reversed by increase in oxygen delivery, even to supranormal levels. Earlier mechanical circulatory support in cardiogenic shock may limit the development of microcirculatory and cellular abnormalities.

  1. Root Effect Haemoglobins in Fish May Greatly Enhance General Oxygen Delivery Relative to Other Vertebrates.

    PubMed

    Rummer, Jodie L; Brauner, Colin J

    2015-01-01

    The teleost fishes represent over half of all extant vertebrates; they occupy nearly every body of water and in doing so, occupy a diverse array of environmental conditions. We propose that their success is related to a unique oxygen (O2) transport system involving their extremely pH-sensitive haemoglobin (Hb). A reduction in pH reduces both Hb-O2 affinity (Bohr effect) and carrying capacity (Root effect). This, combined with a large arterial-venous pH change (ΔpHa-v) relative to other vertebrates, may greatly enhance tissue oxygen delivery in teleosts (e.g., rainbow trout) during stress, beyond that in mammals (e.g., human). We generated oxygen equilibrium curves (OECs) at five different CO2 tensions for rainbow trout and determined that, when Hb-O2 saturation is 50% or greater, the change in oxygen partial pressure (ΔPO2) associated with ΔpHa-v can exceed that of the mammalian Bohr effect by at least 3-fold, but as much as 21-fold. Using known ΔpHa-v and assuming a constant arterial-venous PO2 difference (Pa-vO2), Root effect Hbs can enhance O2 release to the tissues by 73.5% in trout; whereas, the Bohr effect alone is responsible for enhancing O2 release by only 1.3% in humans. Disequilibrium states are likely operational in teleosts in vivo, and therefore the ΔpHa-v, and thus enhancement of O2 delivery, could be even larger. Modeling with known Pa-vO2 in fish during exercise and hypoxia indicates that O2 release from the Hb and therefore potentially tissue O2 delivery may double during exercise and triple during some levels of hypoxia. These characteristics may be central to performance of athletic fish species such as salmonids, but may indicate that general tissue oxygen delivery may have been the incipient function of Root effect Hbs in fish, a trait strongly associated with the adaptive radiation of teleosts. PMID:26436414

  2. A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes.

    PubMed

    Randall, D J; Rummer, J L; Wilson, J M; Wang, S; Brauner, C J

    2014-04-15

    Teleost fishes constitute 95% of extant aquatic vertebrates, and we suggest that this is related in part to their unique mode of tissue oxygenation. We propose the following sequence of events in the evolution of their oxygen delivery system. First, loss of plasma-accessible carbonic anhydrase (CA) in the gill and venous circulations slowed the Jacobs-Stewart cycle and the transfer of acid between the plasma and the red blood cells (RBCs). This ameliorated the effects of a generalised acidosis (associated with an increased capacity for burst swimming) on haemoglobin (Hb)-O2 binding. Because RBC pH was uncoupled from plasma pH, the importance of Hb as a buffer was reduced. The decrease in buffering was mediated by a reduction in the number of histidine residues on the Hb molecule and resulted in enhanced coupling of O2 and CO2 transfer through the RBCs. In the absence of plasma CA, nearly all plasma bicarbonate ultimately dehydrated to CO2 occurred via the RBCs, and chloride/bicarbonate exchange was the rate-limiting step in CO2 excretion. This pattern of CO2 excretion across the gills resulted in disequilibrium states for CO2 hydration/dehydration reactions and thus elevated arterial and venous plasma bicarbonate levels. Plasma-accessible CA embedded in arterial endothelia was retained, which eliminated the localized bicarbonate disequilibrium forming CO2 that then moved into the RBCs. Consequently, RBC pH decreased which, in conjunction with pH-sensitive Bohr/Root Hbs, elevated arterial oxygen tensions and thus enhanced tissue oxygenation. Counter-current arrangement of capillaries (retia) at the eye and later the swim bladder evolved along with the gas gland at the swim bladder. Both arrangements enhanced and magnified CO2 and acid production and, therefore, oxygen secretion to those specialised tissues. The evolution of β-adrenergically stimulated RBC Na(+)/H(+) exchange protected gill O2 uptake during stress and further augmented plasma disequilibrium states

  3. Root Effect Haemoglobins in Fish May Greatly Enhance General Oxygen Delivery Relative to Other Vertebrates

    PubMed Central

    Rummer, Jodie L.; Brauner, Colin J.

    2015-01-01

    The teleost fishes represent over half of all extant vertebrates; they occupy nearly every body of water and in doing so, occupy a diverse array of environmental conditions. We propose that their success is related to a unique oxygen (O2) transport system involving their extremely pH-sensitive haemoglobin (Hb). A reduction in pH reduces both Hb-O2 affinity (Bohr effect) and carrying capacity (Root effect). This, combined with a large arterial-venous pH change (ΔpHa-v) relative to other vertebrates, may greatly enhance tissue oxygen delivery in teleosts (e.g., rainbow trout) during stress, beyond that in mammals (e.g., human). We generated oxygen equilibrium curves (OECs) at five different CO2 tensions for rainbow trout and determined that, when Hb-O2 saturation is 50% or greater, the change in oxygen partial pressure (ΔPO2) associated with ΔpHa-v can exceed that of the mammalian Bohr effect by at least 3-fold, but as much as 21-fold. Using known ΔpHa-v and assuming a constant arterial-venous PO2 difference (Pa-vO2), Root effect Hbs can enhance O2 release to the tissues by 73.5% in trout; whereas, the Bohr effect alone is responsible for enhancing O2 release by only 1.3% in humans. Disequilibrium states are likely operational in teleosts in vivo, and therefore the ΔpHa-v, and thus enhancement of O2 delivery, could be even larger. Modeling with known Pa-vO2 in fish during exercise and hypoxia indicates that O2 release from the Hb and therefore potentially tissue O2 delivery may double during exercise and triple during some levels of hypoxia. These characteristics may be central to performance of athletic fish species such as salmonids, but may indicate that general tissue oxygen delivery may have been the incipient function of Root effect Hbs in fish, a trait strongly associated with the adaptive radiation of teleosts. PMID:26436414

  4. Root Effect Haemoglobins in Fish May Greatly Enhance General Oxygen Delivery Relative to Other Vertebrates.

    PubMed

    Rummer, Jodie L; Brauner, Colin J

    2015-01-01

    The teleost fishes represent over half of all extant vertebrates; they occupy nearly every body of water and in doing so, occupy a diverse array of environmental conditions. We propose that their success is related to a unique oxygen (O2) transport system involving their extremely pH-sensitive haemoglobin (Hb). A reduction in pH reduces both Hb-O2 affinity (Bohr effect) and carrying capacity (Root effect). This, combined with a large arterial-venous pH change (ΔpHa-v) relative to other vertebrates, may greatly enhance tissue oxygen delivery in teleosts (e.g., rainbow trout) during stress, beyond that in mammals (e.g., human). We generated oxygen equilibrium curves (OECs) at five different CO2 tensions for rainbow trout and determined that, when Hb-O2 saturation is 50% or greater, the change in oxygen partial pressure (ΔPO2) associated with ΔpHa-v can exceed that of the mammalian Bohr effect by at least 3-fold, but as much as 21-fold. Using known ΔpHa-v and assuming a constant arterial-venous PO2 difference (Pa-vO2), Root effect Hbs can enhance O2 release to the tissues by 73.5% in trout; whereas, the Bohr effect alone is responsible for enhancing O2 release by only 1.3% in humans. Disequilibrium states are likely operational in teleosts in vivo, and therefore the ΔpHa-v, and thus enhancement of O2 delivery, could be even larger. Modeling with known Pa-vO2 in fish during exercise and hypoxia indicates that O2 release from the Hb and therefore potentially tissue O2 delivery may double during exercise and triple during some levels of hypoxia. These characteristics may be central to performance of athletic fish species such as salmonids, but may indicate that general tissue oxygen delivery may have been the incipient function of Root effect Hbs in fish, a trait strongly associated with the adaptive radiation of teleosts.

  5. A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes.

    PubMed

    Randall, D J; Rummer, J L; Wilson, J M; Wang, S; Brauner, C J

    2014-04-15

    Teleost fishes constitute 95% of extant aquatic vertebrates, and we suggest that this is related in part to their unique mode of tissue oxygenation. We propose the following sequence of events in the evolution of their oxygen delivery system. First, loss of plasma-accessible carbonic anhydrase (CA) in the gill and venous circulations slowed the Jacobs-Stewart cycle and the transfer of acid between the plasma and the red blood cells (RBCs). This ameliorated the effects of a generalised acidosis (associated with an increased capacity for burst swimming) on haemoglobin (Hb)-O2 binding. Because RBC pH was uncoupled from plasma pH, the importance of Hb as a buffer was reduced. The decrease in buffering was mediated by a reduction in the number of histidine residues on the Hb molecule and resulted in enhanced coupling of O2 and CO2 transfer through the RBCs. In the absence of plasma CA, nearly all plasma bicarbonate ultimately dehydrated to CO2 occurred via the RBCs, and chloride/bicarbonate exchange was the rate-limiting step in CO2 excretion. This pattern of CO2 excretion across the gills resulted in disequilibrium states for CO2 hydration/dehydration reactions and thus elevated arterial and venous plasma bicarbonate levels. Plasma-accessible CA embedded in arterial endothelia was retained, which eliminated the localized bicarbonate disequilibrium forming CO2 that then moved into the RBCs. Consequently, RBC pH decreased which, in conjunction with pH-sensitive Bohr/Root Hbs, elevated arterial oxygen tensions and thus enhanced tissue oxygenation. Counter-current arrangement of capillaries (retia) at the eye and later the swim bladder evolved along with the gas gland at the swim bladder. Both arrangements enhanced and magnified CO2 and acid production and, therefore, oxygen secretion to those specialised tissues. The evolution of β-adrenergically stimulated RBC Na(+)/H(+) exchange protected gill O2 uptake during stress and further augmented plasma disequilibrium states

  6. Brain Tissue Oxygen Monitoring in Neurocritical Care.

    PubMed

    De Georgia, Michael A

    2015-12-01

    Brain injury results from ischemia, tissue hypoxia, and a cascade of secondary events. The cornerstone of neurocritical care management is optimization and maintenance of cerebral blood flow (CBF) and oxygen and substrate delivery to prevent or attenuate this secondary damage. New techniques for monitoring brain tissue oxygen tension (PtiO2) are now available. Brain PtiO2 reflects both oxygen delivery and consumption. Brain hypoxia (low brain PtiO2) has been associated with poor outcomes in patients with brain injury. Strategies to improve brain PtiO2 have focused mainly on increasing oxygen delivery either by increasing CBF or by increasing arterial oxygen content. The results of nonrandomized studies comparing brain PtiO2-guided therapy with intracranial pressure/cerebral perfusion pressure-guided therapy, while promising, have been mixed. More studies are needed including prospective, randomized controlled trials to assess the true value of this approach. The following is a review of the physiology of brain tissue oxygenation, the effect of brain hypoxia on outcome, strategies to increase oxygen delivery, and outcome studies of brain PtiO2-guided therapy in neurocritical care.

  7. pO polarography, contrast enhanced color duplex sonography (CDS), [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography: validated methods for the evaluation of therapy-relevant tumor oxygenation or only bricks in the puzzle of tumor hypoxia?

    PubMed Central

    Gagel, Bernd; Piroth, Marc; Pinkawa, Michael; Reinartz, Patrick; Zimny, Michael; Kaiser, Hans J; Stanzel, Sven; Asadpour, Branka; Demirel, Cengiz; Hamacher, Kurt; Coenen, Heinz H; Scholbach, Thomas; Maneschi, Payam; DiMartino, Ercole; Eble, Michael J

    2007-01-01

    Background The present study was conducted to analyze the value of ([18F] fluoromisonidazole (FMISO) and [18F]-2-fluoro-2'-deoxyglucose (FDG) PET as well as color pixel density (CPD) and tumor perfusion (TP) assessed by color duplex sonography (CDS) for determination of therapeutic relevant hypoxia. As a standard for measuring tissue oxygenation in human tumors, the invasive, computerized polarographic needle electrode system (pO2 histography) was used for comparing the different non invasive measurements. Methods Until now a total of 38 Patients with malignancies of the head and neck were examined. Tumor tissue pO2 was measured using a pO2-histograph. The needle electrode was placed CT-controlled in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO2 readings, with values ≤ 2.5, ≤ 5.0 and ≤ 10.0 mmHg, as well as mean and median pO2 were stated. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. FMISO tumor to muscle ratios (FMISOT/M) and tumor to blood ratios (FMISOT/B) were calculated. FDG PET of the lymph node metastases was performed 71 ± 17 min after intravenous administration. To visualize as many vessels as possible by CDS, a contrast enhancer (Levovist®, Schering Corp., Germany) was administered. Color pixel density (CPD) was defined as the ratio of colored to grey pixels in a region of interest. From CDS signals two parameters were extracted: color hue – defining velocity (v) and color area – defining perfused area (A). Signal intensity as a measure of tissue perfusion (TP) was quantified as follows: TP = vmean × Amean. Results In order to investigate the degree of linear association, we calculated the Pearson correlation coefficient. Slight (|r| > 0.4) to moderate (|r| > 0.6) correlation was found between the parameters of pO2 polarography (pO2 readings with values ≤ 2.5, ≤ 5

  8. Event-related changes of the prefrontal cortex oxygen delivery and metabolism during driving measured by hyperspectral fNIRS.

    PubMed

    Nosrati, Reyhaneh; Vesely, Kristin; Schweizer, Tom A; Toronov, Vladislav

    2016-04-01

    Recent technological advancements in optical spectroscopy allow for the construction of hyperspectral (broadband) portable tissue oximeters. In a series of our recent papers we have shown that hyperspectral NIRS (hNIRS) has similar or better capabilities in the absolute tissue oximetry as frequency-domain NIRS, and that hNIRS is also very efficient in measuring temporal changes in tissue hemoglobin concentration and oxygenation. In this paper, we extend the application of hNIRS to the measurement of event-related hemodynamic and metabolic functional cerebral responses during simulated driving. In order to check if hNIRS can detect event-related changes in the brain, we measured the concentration changes of oxygenated (HbO2) and deoxygenated (HHb) hemoglobin and of the oxidized state of cytochrome c oxidase, on the right and left prefrontal cortices (PFC) simultaneously during simulated driving on sixteen healthy right-handed participants (aged between 22-32). We used our in-house hNIRS system based on a portable spectrometer with cooled CCD detector and a driving simulator with a fully functional steering wheel and foot pedals. Each participant performed different driving tasks and participants were distracted during some driving conditions by asking general knowledge true/false questions. Our findings suggest that more complex driving tasks (non-distracted) deactivate PFC while distractions during driving significantly activate PFC, which is in agreement with previous fMRI results. Also, we found the changes in the redox state of the cytochrome C oxidase to be very consistent with those in the concentrations of HbO2 and HHb. Overall our findings suggest that in addition to the suitability of absolute tissue oximetry, hyperspectral NIRS may also offer advantages in functional brain imaging. In particular, it can be used to measure the metabolic functional brain activity during actual driving. PMID:27446658

  9. Event-related changes of the prefrontal cortex oxygen delivery and metabolism during driving measured by hyperspectral fNIRS

    PubMed Central

    Nosrati, Reyhaneh; Vesely, Kristin; Schweizer, Tom A.; Toronov, Vladislav

    2016-01-01

    Recent technological advancements in optical spectroscopy allow for the construction of hyperspectral (broadband) portable tissue oximeters. In a series of our recent papers we have shown that hyperspectral NIRS (hNIRS) has similar or better capabilities in the absolute tissue oximetry as frequency-domain NIRS, and that hNIRS is also very efficient in measuring temporal changes in tissue hemoglobin concentration and oxygenation. In this paper, we extend the application of hNIRS to the measurement of event-related hemodynamic and metabolic functional cerebral responses during simulated driving. In order to check if hNIRS can detect event-related changes in the brain, we measured the concentration changes of oxygenated (HbO2) and deoxygenated (HHb) hemoglobin and of the oxidized state of cytochrome c oxidase, on the right and left prefrontal cortices (PFC) simultaneously during simulated driving on sixteen healthy right-handed participants (aged between 22–32). We used our in-house hNIRS system based on a portable spectrometer with cooled CCD detector and a driving simulator with a fully functional steering wheel and foot pedals. Each participant performed different driving tasks and participants were distracted during some driving conditions by asking general knowledge true/false questions. Our findings suggest that more complex driving tasks (non-distracted) deactivate PFC while distractions during driving significantly activate PFC, which is in agreement with previous fMRI results. Also, we found the changes in the redox state of the cytochrome C oxidase to be very consistent with those in the concentrations of HbO2 and HHb. Overall our findings suggest that in addition to the suitability of absolute tissue oximetry, hyperspectral NIRS may also offer advantages in functional brain imaging. In particular, it can be used to measure the metabolic functional brain activity during actual driving. PMID:27446658

  10. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    PubMed

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB. PMID:26742253

  11. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    PubMed

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB.

  12. A hyperbaric oxygen chamber for animal experimental purposes.

    PubMed

    Djasim, U M; Spiegelberg, L; Wolvius, E B; van der Wal, K G H

    2012-02-01

    Facilities for hyperbaric oxygen therapy that are suitable for animal experimental research are scarce. In this paper, the authors introduce a hyperbaric oxygen chamber that was developed specifically for animal experimental purposes. The hyperbaric oxygen chamber was designed to meet a number of criteria regarding safety and ease of use. The hyperbaric oxygen chamber conforms to 97/23/EC (Pressure Equipment Directive), Conformity Assessment Module G Product Group 1. It provides easy access, and can be run in manual mode, semi-automatic mode and full-automatic mode. Sensors for pressure level, oxygen level, temperature, humidity and carbon dioxide level allow full control. This state-of-the-art hyperbaric oxygen chamber for animal experimental purposes permits the investigation of the biological mechanisms through which hyperbaric oxygen therapy acts at a fundamental level.

  13. Accelerators for Cancer Therapy

    DOE R&D Accomplishments Database

    Lennox, Arlene J.

    2000-05-30

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy.