Ozone in Medicine. The Low-Dose Ozone Concept and Its Basic Biochemical Mechanisms of Action in Chronic Inflammatory Diseases.

Low-dose ozone acts as a bioregulator in chronic inflammatory diseases, biochemically characterized by high oxidative stress and a blocked regulation. During systemic applications, "Ozone peroxides" are able to replace H2O2 in its specific function of regulation, restore redox signaling, and improve the antioxidant capacity. Two different mechanisms have to be understood. Firstly, there is the direct mechanism, used in topical treatments, mostly via radical reactions. In systemic treatments, the indirect, ionic mechanism is to be discussed: "ozone peroxide" will be directly reduced by the glutathione system, informing the nuclear factors to start the regulation. The GSH/GSSG balance outlines the ozone dose and concentration limiting factor. Antioxidants are regulated, and in the case of inflammatory diseases up-regulated; cytokines are modulated, here downregulated. Rheumatoid arthritis RA as a model for chronic inflammation: RA, in preclinical and clinical trials, reflects the pharmacology of ozone in a typical manner: SOD (superoxide dismutase), CAT (catalase) and finally GSH (reduced glutathione) increase, followed by a significant reduction of oxidative stress. Inflammatory cytokines are downregulated. Accordingly, the clinical status improves. The pharmacological background investigated in a remarkable number of cell experiments, preclinical and clinical trials is well documented and published in internationally peer reviewed journals. This should encourage clinicians to set up clinical trials with chronic inflammatory diseases integrating medical ozone as a complement.

Aqueous ozone therapy improves the standard treatment of leishmaniasis lesions in animals leading to local and systemic alterations.

The current treatment of leishmaniasis presents some problems, such as cell toxicity, parenteral route, and time of treatment. Ozone emerges as an option to accelerate the standard treatment due to the immunomodulatory, antioxidant, and wound healing activity reported in the literature. This work aimed to evaluate the efficacy of aqueous ozone as an adjuvant to the standard treatment of cutaneous lesions caused by Leishmania amazonensis in an experimental model. For in vivo experiments, mice were randomly distributed in 6 groups, which were infected with L. amazonensis and treated in five different schedules using the standard treatment with Glucantime® with or without aqueous ozone. After the last day of treatment, the animals were euthanized and were analyzed: the thickness of lesions; collagen deposition, the parasitic burden of the lesions; blood leukocyte number; NO; and cytokine dosages and arginase activity from peritoneal macrophages. All treated groups showed a decrease in the lesion, but with a significative deposition of collagen in lesions with local ozone treatment. The parasite burden showed that ozone enhanced the leishmanicidal activity of the reference drug. The reduction of NO production and blood leukocyte count and increases in the arginase activity showed an immunomodulatory activity of ozone in the treated animals. Thus, ozone therapy has been shown to work as an adjuvant in the treatment of Leishmania lesions, enhancing leishmanicidal and wound healing activity of standard treatment.

Preoperative topical liposomal ozone dispersion to reduce bacterial colonization in conjunctival sac and periocular skin: Preliminary study in dogs.

Prophylaxis represents a keystone to reduce periocular skin and ocular conjunctiva bacterial load before surgical procedures. Despite many prophylactic agents are available the preferred perioperative ocular surface antimicrobial is still unknown. The purpose of this study was to assess the effectiveness of preoperative liposomal ozone dispersion in reducing bacterial colonization from the conjunctival sac and periocular skin in dogs, in comparison with povidone-iodine and fluoroquinolone. Twenty-two owned dogs consisting with 44 eyes in total scheduled for ophthalmic surgical procedure were enrolled for the study and divided in four groups receiving either ozone dispersion or povidone iodine in eyelid and conjunctiva, fluoroquinolone or placebo. A swab was taken before and after the antisepsis protocol evaluating total microbial count, coagulase positive and negative staphylococci. Statistical analysis revealed a significant decrease in colony forming units (CFU) for total microbial count, coagulase positive and negative staphylococci both for liposomal ozone dispersion and povidone iodine. No statistical differences were detected in median CFU for both one-day placebo and fluoroquinolone preoperative prophylactic topical therapy. The results of this preliminary study demonstrate that liposomal ozone-dispersion is as effective as povidone iodine to reduce preoperative bacterial load in ocular surface.

The Effect of Paravertebral Ozone Injection in the Treatment of Low Back Pain.

AIM: Paravertebral ozone injection is a new treatment method described in the literature for low back pain. The aim of this study was to compare the pre- and post-treatment pain scores of patients undergoing paravertebral ozone/oxygen (O3 /O2 ) injections for low back pain. METHODS: From September 2018 to December 2018, 122 patients who underwent paravertebral ozone injections due to low back pain were examined retrospectively; 62 patients who met the study criteria were included. The patients were injected with 15 µg/mL (50 mL) O3 /O2 gas in the paravertebral space. The subjects were treated every 7 days for 6 total session. The VAS and Oswestry Disability Index (ODI) scores were assessed before treatment and after treatment (first and third months). The patients' body mass indexes (BMIs) were measured before the injections. RESULTS: There were 12 male patients and 50 female patients. The mean age was 51.9 (range 25 to 71) years. The mean duration of pain was 9.1 (3 to 24) months. Significant improvements were observed in the statistical comparison of VAS and ODI scores between the pre-injection and first month controls (P < 0.000). There was no significant difference in the statistical comparison of VAS and ODI scores between the first and third months (P < 0.05). There was no statistically significant difference between BMI and pain scores (P > 0.213). CONCLUSION: Paravertebral O3 /O2 gas is a reliable and effective treatment for the treatment of lumbar disc herniation, radicular pain, and mechanical back pain due to low back pain.

The effect of different concentrations of topical ozone administration on bone formation in orthopedically expanded suture in rats.

BACKGROUND/OBJECTIVE: The aim of this study was to investigate the effects of different concentrations of ozone (O3) therapy on bone regeneration in response to an expansion of the inter-premaxillary suture in rats. MATERIALS AND METHODS: Forty-eight Wistar rats were randomly divided into four groups (n = 12). In groups I, II, and III, 1ml of O3 at 10, 25, and 40 µg/ml was injected at the premaxillary suture, respectively. In group IV (control group), 1ml of saline solution was injected at the same point during the expansion procedure for 5 days. Bone regeneration in the suture was evaluated histomorphometrically. The area of new bone and fibrotic area, the number of osteoblasts and osteoclasts, and the amount of vascularity were measured and compared. The density of the newly formed bone in the expansion area was measured by using cone beam computed tomography. Data were analyzed using the Kruskal-Wallis one-way analysis of variance and post hoc Student-Newman-Keuls tests. RESULTS: New bone area, fibrotic area, osteoblast and osteoclast numbers, and the amount of vascularity were significantly higher in experimental groups compared with the control group (P < 0.001). The density of newly formed bone (P < 0.001), new bone formation (P = 0.009), number of capillaries (P < 0.001), number of osteoclasts (P = 0.016), and number of osteoblasts (P < 0.001) in the maxillary sutures were highest in the 25 µg/ml O3 group compared with the other experimental groups and control group. CONCLUSIONS/IMPLICATIONS: The application of O3 therapy can stimulate bone regeneration in an orthopedically expanded inter-premaxillary suture during both the expansion and retention periods.

A comprehensive analysis of oxidative stress in the ozone-induced lung inflammation mouse model.

Ozone is an oxidizing environmental pollutant that contributes significantly to respiratory health. Exposure to increased levels of ozone has been associated with worsening of symptoms of patients with asthma and COPD (chronic obstructive pulmonary disease). In the present study, we investigated the acute and chronic effects of ozone exposure-induced oxidative stress-related inflammation mechanics in mouse lung. In particular, we investigated the oxidative stress-induced effects on HDAC2 (histone deacetylase 2) modification and activation of the Nrf2 (nuclear factor erythroid-related factor 2) and HIF-1α (hypoxia-inducible factor-1α) signalling pathways. Male C57BL/6 mice were exposed to ozone (3 p.p.m.) for 3 h a day, twice a week for a period of 1, 3 or 6 weeks. Control mice were exposed to normal air. After the last exposure, mice were killed for BAL (bronchoalveolar lavage) fluid and lung tissue collection. BAL total cell counts were elevated at all of the time points studied. This was associated with increased levels of chemokines and cytokines in all ozone-exposed groups, indicating the presence of a persistent inflammatory environment in the lung. Increased inflammation and Lm (mean linear intercept) scores were observed in chronic exposed mice, indicating emphysematous changes were present in lungs of chronic exposed mice. The antioxidative stress response was active (indicated by increased Nrf2 activity and protein) after 1 week of ozone exposure, but this ability was lost after 3 and 6 weeks of ozone exposure. The transcription factor HIF-1α was elevated in 3- and 6-week ozone-exposed mice and this was associated with increased gene expression levels of several HIF-1α target genes including Hdac2 (histone deacetylase 2), Vegf (vascular endothelial growth factor), Keap1 (kelch-like ECH-associated protein 1) and Mif (macrophage migration inhibitory factor). HDAC2 protein was found to be phosphorylated and carbonylated in nuclear and cytoplasm fractions, respectively, and was associated with a decrease in DNA-binding activity and protein expression of HDAC2. Decreased HDAC2 activity, most likely a direct result of protein modification, in combination with the loss of the antioxidative stress response and activation of the HIF-1α pathway, contribute to the inflammatory response and emphysema observed in ozone-exposed mice.

Ozone co-exposure modifies cardiac responses to fine and ultrafine ambient particulate matter in mice: concordance of electrocardiogram and mechanical responses.

BACKGROUND: Studies have shown a relationship between air pollution and increased risk of cardiovascular morbidity and mortality. Due to the complexity of ambient air pollution composition, recent studies have examined the effects of co-exposure, particularly particulate matter (PM) and gas, to determine whether pollutant interactions alter (e.g. synergistically, antagonistically) the health response. This study examines the independent effects of fine (FCAPs) and ultrafine (UFCAPs) concentrated ambient particles on cardiac function, and determine the impact of ozone (O3) co-exposure on the response. We hypothesized that UFCAPs would cause greater decrement in mechanical function and electrical dysfunction than FCAPs, and that O3 co-exposure would enhance the effects of both particle-types. METHODS: Conscious/unrestrained radiotelemetered mice were exposed once whole-body to either 190 µg/m³ FCAPs or 140 µg/m³ UFCAPs with/without 0.3 ppm O3; separate groups were exposed to either filtered air (FA) or O3 alone. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure, and cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 hrs post-exposure. RESULTS: FCAPs alone caused a significant decrease in baseline left ventricular developed pressure (LVDP) and contractility, whereas UFCAPs did not; neither FCAPs nor UFCAPs alone caused any ECG changes. O3 co-exposure with FCAPs caused a significant decrease in heart rate variability when compared to FA but also blocked the decrement in cardiac function. On the other hand, O3 co-exposure with UFCAPs significantly increased QRS-interval, QTc and non-conducted P-wave arrhythmias, and decreased LVDP, rate of contractility and relaxation when compared to controls. CONCLUSIONS: These data suggest that particle size and gaseous interactions may play a role in cardiac function decrements one day after exposure. Although FCAPs + O3 only altered autonomic balance, UFCAPs + O3 appeared to be more serious by increasing cardiac arrhythmias and causing mechanical decrements. As such, O3 appears to interact differently with FCAPs and UFCAPs, resulting in varied cardiac changes, which suggests that the cardiovascular effects of particle-gas co-exposures are not simply additive or even generalizable. Additionally, the mode of toxicity underlying this effect may be subtle given none of the exposures described here impaired post-ischemia recovery.

In vitro assessment of the recurrent doses of topical gaseous ozone in the removal of Enterococcus faecalis biofilms in root canals.

AIM: To evaluate the potential antibacterial effect of recurrent doses of topical gaseous ozone on the Enterococcus faecalis biofilms0 growth in human root canals in vitro. MATERIALS AND METHODS: One hundred and thirty four human single-rooted mandibular premolars were enlarged to a size 35 K-File. Each root canal were inoculated with an overnight culture of Enterococcus faecalis 0ATCC 29212 in tryptic soy broth for 24 hours and incubated for 7 days at 37°C. At 7-day interval, 4 specimens were prepared for Scanning Electron Microscope (SEM) analysis to confirm the presence and purity of biofilms whilst the other contaminated root canals were irrigated and disinfected. One hundred root canals of total 134 specimens were selected to create the experimental groups and divided into 5 subgroups. In each experimental group ( n = 20) root canals), recurrent ozone doses were applied with different irrigation and disinfection protocols in 5 different time intervals. Bacterial growth was analyzed by counting viable E. faecalis on tryptic soy agar plates. RESULTS: According to intergroup comparison results observed in the final sample collection analysis, the amount of remaining bacteria in the positive control group were found to be significantly higher compared to Groups 1, 2, 3, 4, 5 and the material control group ( P < 0.01). The remaining amount of bacteria in the last count of Group 1 were found to be significantly higher compared to Group 2 ( P < 0.05), Group 4 ( P < 0.01), Group 5 (P < 0.05) and the material control group (P < 0.01). CONCLUSION: The application of topical gaseous ozone in recurrent doses provides a positive effect in the removal of E. faecalis biofilm from root canals. However, during disinfection procedure, the combined use of recurrent doses of topical gaseous ozone with 2% NaOCl enhanced its antibacterial effect against E. faecalis biofilm.

[Effect on performance ozonized perftoran cytokine profile in generalized peritonitis].

The article analyzes the results of surgical treatment of 78 patients with generalized peritonitis (GP) between the ages of 18 to 76 years. Severity was assessed by RP Mannheim peritoneal index (MPI). The study was conducted according to a comparative evaluation of the method of treatment in both groups. In the comparison group included 38 patients who received conventional therapy without immune complex. In 40 patients of the study group on the background of complex therapeutic measures in pre- and postoperative additionally used concomitant local and systemic ozone therapy (OT) with ozonatedperftoran (OP). All patients in the dynamics of blood prior to surgery, on the 3rd and 7th day after surgery was determined TNF-α, IL-4 and IL-8 by IFA. In general, patients in both groups at admission were identified imbalance between pro- and anti-inflammatory cytokines. Patients of the main group on the complex background of basic therapy combined local and systemic administration of OP positive effect in terms of acceleration available cytokine imbalance. The complex therapeutic interventions GP application of local and systemic OT with OP accelerates elimination of imbalances in the cytokine profile.

[Effect of combined and local cytokine- and ozone therapy on the indices of lipid peroxidation, endogenous intoxication and ferroproteins in diffuse peritonitis].

The article analyzes the results of effect of combined and local cytokine- and ozone therapy on the indices of lipid peroxidation, endogenous intoxication and ferroproteins in 111 patients with diffuse peritonitis. It was shown, that combined sequential local and systemic cytokine and ozone therapy allows correcting the expression of endogenous intoxication and lipid peroxidation in diffuse peritonitis. This method suppresses an inflammation in the abdominal cavity. At the same time, it accelerates the elimination of intestine atony and thereby potentiates the possibilities of traditional methods of treatment.

[Ozone therapy and tamsulosin in the treatment of cystitis].

Treatment of cystitis remains an urgent problem in urology due to its prevalence, physical and social disadaptation of patients, and not always satisfactory treatment results. The article presents the results of treatment of 40 women aged 41.5 +/- 12.4 years with chronic cystitis. 20 patients received ozone therapy, 20 patients--ozone therapy in combination with alpha-adrenoblocker tamsulosin. Effectiveness of the treatment was evaluated using clinical data, data of bladder diaries, IPSS score, and uroflowmetry data. Dynamics of all the parameters in patients treated with ozone therapy in combination with tamsulosin was significantly higher in comparison with that in patients treated with ozone therapy only. As a result of the treatment, increased urine flow rate was accompanied by an increase in urination. Combination therapy with the use of ozone therapy and tamsulosin can be successfully and safely used in the treatment of patients with cystitis.

Treatment of radiculopathies: a study of efficacy and tollerability of paravertebral oxygen-ozone injections compared with pharmacological anti-inflammatory treatment.

The study was performed to evaluate the effectiveness of lumbar paravertebral injections of a gas mixture of Oxygen and Ozone in patients with lumbar radiculopathies caused by L4-L5 or L5-S1 disk herniations compared to a pharmacological therapy based on non-steroidal anti-inflammatory drugs. Lumbar radiculopathy caused by disc herniation is widely spread. Many therapeutic options are available before steering patients to the surgery. Low back pain and sciatica represent some of the most frequent causes of antinflammatory-analgesic drugs overuse. Recent findings have shown that medical Ozone can be used in the treatment of radicular syndrome caused by herniated intervertebral discs. Although widely spread, there are insufficient published data supporting the effectiveness of this approach in clinical practice. We studied 38 affected patients with acute L5 or S1 radicolopathy. The patients were randomly divided in two groups: A) 20 patients treated with lumbar paravertebral injections of Oxygen and Ozone; B) 18 patients treated pharmacologically with antinflammatory-analgesic drugs. All patients underwent a clinical and neurological examination at baseline (T1) and after 1 (T2), 2 (T3), 4 weeks (T4) and after 3 (T5) and 6 months (T6). An MRI and EMG examination were performed at baseline and after 6 months. The intensity of pain and the outcome of treatments were evaluated in all patients with the Visual Analogue Scale and with the Oswestry Disability Index. We found a reduction of pain and discomfort soon after one week with oxygen-ozone injections compared with pharmacological treatment, but this difference of response became statistically significant after two weeks (50 percent vs 16.6 percent) and is confirmed after 3 and 6 months, when 80 percent of patients treated with injections turned out pain free compared with half of the patients treated pharmacologically. No statistical difference were found in MRI and EMG examinations. No adverse effects were found in any patient of group A. We hypothesize that oxygen-ozone injections in paravertebral regions can induce a direct reduction of root inflammation with a corresponding reduction of pain. The paravertebral injections of oxygen-ozone represent a rapidly effective therapy, easily practicable and secure, in patients with lumbar radicolopathies secondary to disc herniation.

Prediction of lung function response for populations exposed to a wide range of ozone conditions.

CONTEXT: A human exposure-response (E-R) model previously demonstrated to accurately predict population mean FEV1 response to ozone exposure has been proposed as the foundation for future risk assessments for ambient ozone. OBJECTIVE: Fit the original and related models to a larger data set with a wider range of exposure conditions and assess agreement between observed and population mean predicted values. MATERIALS AND METHODS: Existing individual E-R data for 23 human controlled ozone exposure studies with a wide range of concentrations, activity levels, and exposure patterns have been obtained. The data were fit to the original model and to a version of the model that contains a threshold below which no response occurs using a statistical program for fitting nonlinear mixed models. RESULTS: Mean predicted FEV1 responses and the predicted proportions of individuals experiencing FEV1 responses greater than 10, 15, and 20% were found to be in agreement with observed responses across a wide range of exposure conditions for both models. The threshold model, however, provided a better fit to the data than the original, particularly at the lowest levels of exposure. CONCLUSION: The models identified in this manuscript predict population FEV1 response characteristics for 18-35-year-old individuals exposed to ozone over a wide range of conditions and represent a substantial improvement over earlier E-R models. Because of its better fit to the data, particularly at low levels of exposure, the threshold model is likely to provide more accurate estimates of risk in future risk assessments of ozone-induced FEV1 effects.

[Medical applications of ozone for the rehabilitation of the patients presenting with chronic bronchitis and arterial hypertension].

Of paramount importance at the stage of rehabilitative treatment of the patients presenting with combined cardiorespiratory pathology are therapeutic measures aimed at eliminating the principal components of pathogenesis of a given disease and correcting the concomitant immunometabolic disturbances. Our investigations have demonstrated that ozone therapy given to the patients with chronic bronchitis and hypertension produces lipid-lowering, hypoglycemic and fibrinolytic effects. Its combination with anti-hypoxic treatment helps to normalize the functioning capabilities of all organs and systems of the body. Immunomodulatory effects of ozone therapy is attributable to the disintoxicative and anti-hypoxic actions of medical ozone as well as activation of the "lipid peroxidation--antioxidant protection" system.

The effect of rectal ozone on the portal vein oxygenation and pharmacokinetics of propranolol in liver cirrhosis (a preliminary human study).

AIM: The aim of this study was to investigate the effect of rectal ozone on portal vein oxygenation and the pharmacokinetic changes of propranolol in patients with liver cirrhosis. METHODS: Fifteen patients with liver cirrhosis were included They were given a fixed oral dose of propranolol 80mg on the morning of day 1 after overnight fasting. Blood samples were collected at fixed time intervals for 24h. Patients were given 12 sessions of rectal ozone of 300ml of 40% ozone/oxygen mixture. On day 14 another oral dose of 80mg propranolol was given and blood samples were collected as on day 1. Plasma concentrations of propranolol were measured by HPLC. Portal vein oxygen tension and saturation were measured before and after rectal ozone. RESULTS: Plasma concentrations of propranolol were reduced after ozone therapy with pronounced decreases in the maximum plasma concentration and the area under the plasma concentration-time curve. The changes were consistent with a decrease in propranolol bioavailability. There was a decrease in the elimination half-life and mean residence time. Portal vein oxygenation significantly increased after rectal ozone. CONCLUSIONS: The changes in the pharmacokinetics of propranolol probably reflect an increase in the rate and extent of its metabolism resulting from improved portal vein oxygenation attributable to the ozone therapy. The present work highlights that ozone can be an alternative medical measure to improve portal vein oxygenation in liver cirrhosis.

[Rectal ozone therapy for patients with pulmonary emphysema]. / La ozonoterapia en pacientes con enfisema pulmonar.

BACKGROUND: Ozone therapy may stimulate antioxidant systems and protect against free radicals. It has not been used formerly in patients with pulmonary emphysema. AIM: To assess the effects of rectal ozone therapy in patients with pulmonary emphysema. MATERIAL AND METHODS: Sixty four patients with pulmonary emphysema, aged between 40 and 69 years, were randomly assigned to receive rectal ozone in 20 daily sessions, rectal medicinal oxygen or no treatment. Treatments were repeated three months later in the first two groups. At baseline and at the end of the study, spirometry and a clinical assessment were performed. RESULTS: fifty patients completed the protocol, 20 receiving ozone therapy, 20 receiving rectal oxygen and 10 not receiving any therapy. At baseline, patients on ozone therapy had significantly lower values of forced expiratory volume in the first second (fEV1) and fEV1/forced vital capacity. At the end of the treatment period, these parameters were similar in the three treatment groups, therefore they only improved significantly in the group on ozone therapy. No differences were observed in other spirometric parameters. CONCLUSIONS: Rectal ozone therapy may be useful in patients with pulmonary emphysema.

Ozone ultrafine bubble water inhibits the early formation of Candida albicans biofilms.

This study aimed to investigate the effect of ozone ultrafine bubble water (OUFBW) on the formation and growth of Candida albicans (C. albicans) biofilms and surface properties of denture base resins. OUFBWs were prepared under concentrations of 6 (OUFBW6), 9 (OUFBW9), and 11 ppm (OUFBW11). Phosphate buffered saline and ozone-free electrolyte aqueous solutions (OFEAS) were used as controls. Acrylic resin discs were made according to manufacturer instructions, and C. albicans was initially cultured on the discs for 1.5 h. A colony forming unit (CFU) assay was performed by soaking the discs in OUFBW for 5 min after forming a 24-h C. albicans biofilm. The discs after initial attachment for 1.5 h were immersed in OUFBW and then cultured for 0, 3, and 5 h. CFUs were subsequently evaluated at each time point. Moreover, a viability assay, scanning electron microscopy (SEM), Alamar Blue assay, and quantitative real-time polymerase chain reaction (qRT-PCR) test were performed. To investigate the long-term effects of OUFBW on acrylic resin surface properties, Vickers hardness (VH) and surface roughness (Ra) were measured. We found that OUFBW9 and OUFBW11 significantly degraded the formed 24-h biofilm. The time point CFU assay showed that C. albicans biofilm formation was significantly inhibited due to OUFBW11 exposure. Interestingly, fluorescence microscopy revealed that almost living cells were observed in all groups. In SEM images, the OUFBW group had lesser number of fungi and the amount of non-three-dimensional biofilm than the control group. In the Alamar Blue assay, OUFBW11 was found to suppress Candida metabolic function. The qRT-PCR test showed that OUFBW down-regulated ALS1 and ALS3 expression regarding cell-cell, cell-material adhesion, and biofilm formation. Additionally, VH and Ra were not significantly different between the two groups. Overall, our data suggest that OUFBW suppressed C. albicans growth and biofilm formation on polymethyl methacrylate without impairing surface properties.

Effect of preconditioned hyperbaric oxygen and ozone on ischemia-reperfusion induced tourniquet in skeletal bone of rats.

BACKGROUND: The aim of the study was to investigate effect of I/R injury on bone tissue and protective role of hyperbaric oxygen precondition (HBO-PC) and ozone precondition (O(3)-PC) on I/R injury by using biochemical analysis. MATERIALS AND METHODS: Thirty-two rats were included in study. The animals were divided into four equal groups: sham operation, I/R, I/R+HBO and I/R+O(3). One session of 60 min, 3 ATA, 3-4 L/min, 100% oxygenation was defined as one dose of HBO. First dose of HBO was administrated 72 h before ischemia. Subsequent, one-dose of HBO administrated per 12 hours until ischemia time (total seven doses); 0.7 mg/kg ozone/oxygen mixture intraperitoneally was defined as one dose of ozone. First dose of O(3) was administered 72 h before ischemia (total four doses). I/R model was induced in anesthetized rats by unilateral (right) femoral artery clipping for 2 h followed by 22 h of reperfusion. The right tibia and were harvested. Tissue was assayed for levels of malondialdehyde (MDA) and protein carbonyl (PCO), activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). RESULTS: MDA and PCO levels were increased in I/R group. SOD activity was increased; GSH-Px activity was decreased in I/R group. MDA and PCO levels were decreased, SOD and GSH-Px activities were increased in both HBO+I/R and O(3)+I/R groups. CONCLUSION: It has been shown that levels of MDA and PCO in bone were increased followed by 2 h of ischemia and 22 h of reperfusion period. Ozone-PC and HBO-PC has protective effect against skeletal bone I/R injury by decreasing levels of MDA and PCO, increasing activities of SOD and GSH-Px in rats.

6.6-hour inhalation of ozone concentrations from 60 to 87 parts per billion in healthy humans.

RATIONALE: Identification of the minimal ozone (O(3)) concentration and/or dose that induces measurable lung function decrements in humans is considered in the risk assessment leading to establishing an appropriate National Ambient Air Quality Standard for O(3) that protects public health. OBJECTIVES: To identify and/or predict the minimal mean O(3) concentration that produces a decrement in FEV(1) and symptoms in healthy individuals completing 6.6-hour exposure protocols. METHODS: Pulmonary function and subjective symptoms were measured in 31 healthy adults (18-25 yr, male and female, nonsmokers) who completed five 6.6-hour chamber exposures: filtered air and four variable hourly patterns with mean O(3) concentrations of 60, 70, 80, and 87 parts per billion (ppb). MEASUREMENTS AND MAIN RESULTS: Compared with filtered air, statistically significant decrements in FEV(1) and increases in total subjective symptoms scores (P < 0.05) were measured after exposure to mean concentrations of 70, 80, and 87 ppb O(3). The mean percent change in FEV(1) (+/-standard error) at the end of each protocol was 0.80 +/- 0.90, -2.72 +/- 1.48, -5.34 +/- 1.42, -7.02 +/- 1.60, and -11.42 +/- 2.20% for exposure to filtered air and 60, 70, 80, and 87 ppb O(3), respectively. CONCLUSIONS: Inhalation of 70 ppb O(3) for 6.6 hours, a concentration below the current 8-hour National Ambient Air Quality Standard of 75 ppb, is sufficient to induce statistically significant decrements in FEV(1) in healthy young adults.

Concentrated ambient fine particles and not ozone induce a systemic interleukin-6 response in humans.

Epidemiological studies have established significant associations between ambient pollutants, including fine particulate matter (PM(2.5)) and ozone (O(3)), and cardiopulmonary morbidity and mortality. One mechanism that has been proposed is a pulmonary/systemic inflammatory response. Although controlled human exposure studies have examined the independent inflammatory responses of PM(2.5) and O(3), no studies have previously examined their joint effects. The study objective was to examine the independent and combined associations between ambient PM(2.5) and O(3) and acute respiratory/inflammatory responses. Using their concentrated ambient particle (CAP) facility for PM(2.5), the authors studied 10 mild asthmatic and 13 nonasthmatic individuals. The 2-h exposures included CAP (range 48-199 microg/m(3)) and filtered air (FA), with/without O(3) (120 ppb), in a randomized block design. Response measures included pulmonary function and inflammatory indices in induced sputum (interleukin [IL]-6, cytology) and blood (IL-6, tumor necrosis factor [TNF]-alpha) measured before and after exposures. Three hours post exposure, there was an increase in blood levels of IL-6, but only after CAP alone exposures; the IL-6 increase was associated with increasing PM(2.5) mass concentration (p = .005). Some individuals switched to shallow breathing during CAP+O(3), possibly accounting for an attenuation of the resultant blood IL-6 response. Asthmatic and nonasthmatic responses were similar. There were no adverse changes in pulmonary function or other inflammatory measures. The study demonstrated an acute IL-6 response to PM(2.5), providing evidence to support the epidemiological findings of associations between ambient levels of particles and cardiopulmonary morbidity and mortality.