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PubMedDate not supplied

Studies on the biological effects of ozone: 6. Production of transforming growth factor 1 by human blood after ozone treatment.

After exposing human whole blood from normal volunteers to ozone concentrations ranging from 22 to 156 micrograms/ml, we have shown that, upon incubation of up to 8 hours, there is a significant release of transforming growth factor beta (TGF-beta 1). In comparison to TGF-beta 1, TGF-beta 2 production is not influenced by ozone concentrations. In line with our previous findings it appears that blood, in the presence of heparin and 5mM Ca,2+ allows a consistent production of tumor necrosis factor a (TNF alpha) and the release of low and non-hazardous levels of free hemoglobin. These data support the contention that autohemotherapy performed after treating blood with ozone followed by reinfusion into the donor, may represent a valuable therapeutic approach for achieving immunoregulatory effects.

Adult↗

PubMed1997

Effects of ozone on normal and potentially sensitive human subjects. Part I: Airway inflammation and responsiveness to ozone in normal and asthmatic subjects.

We report here the results of a multiphase project to assess the significance of airway responsiveness and airway injury in ozone (O3)* sensitivity. In Phase I, we measured the preexposure methacholine responsiveness of 66 normal subjects and then exposed these subjects to 0.2 ppm O3 for 4 hours with moderate exercise. Preexposure methacholine responsiveness was weakly correlated with O3-induced increases in specific airway resistance (sRaw) but not O3-induced declines in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC). In addition, O3-induced lower respiratory symptoms were not well correlated with O3-induced changes in lung function. In Phase II, we exposed 23 normal subjects to O3, following an identical protocol to that of Phase I, and then performed bronchoscopy with proximal airway lavage (PAL), bronchoalveolar lavage (BAL), and bronchial biopsy at 18 hours after exposure. Ozone-induced increases in percentage of neutrophils and total protein concentration were observed in both bronchial fraction and BAL fluids; increased percentage of neutrophils also was observed in PAL fluid. These increases were correlated with O3-induced increases in sRaw, but not with O3-induced declines in FEV1 or FVC. Ozone also appeared to increase expression of intercellular adhesion molecule-1, an important mediator of neutrophil recruitment, in bronchial mucosa. In Phase III, we exposed a group of 19 asthmatic subjects to O3, following a protocol identical to that of Phase II. We then compared the lower respiratory symptom and lung function responses of the asthmatic subjects to those of the 81 normal subjects who participated in Phase I, Phase II, or both. The changes in the PAL and BAL fluids of the asthmatic subjects were compared with those of the normal subjects who participated in Phase II. Although both the asthmatic and nonasthmatic subjects showed significant O3-induced changes in lower respiratory symptoms, FEV1, FVC, and sRaw, no significant differences were found between the groups. For sRaw, however, a nonsignificant trend toward a greater O3-induced increase was noted for the asthmatic subjects. In contrast, the O3-induced increases in percentage of neutrophils and total protein concentration in BAL fluid were significantly greater for the asthmatic subjects than for the nonasthmatic subjects. These data suggest that although the lower respiratory symptom and lung function responses to O3 are not markedly greater in asthmatic subjects than in healthy subjects, the inflammatory response of the asthmatic lung may be more intense.

Adolescent↗

PubMedDate not supplied

Studies on the biological effects of ozone: 7. Generation of reactive oxygen species (ROS) after exposure of human blood to ozone.

The acceptance of any complementary medical approach is conditioned by the results obtained after the same scientific scrutiny applied in orthodox medicine. Otherwise any claim of efficacy remains in the realm of fiction. In the case of ozone therapy, the mechanisms of action have remained nebulous and in a series of publications we are trying to present the biochemical, immunological and morphological evidence in favour or against ozone therapy. We have now shown that ozone (O3) dissolved in the water of either plasma or serum or physiological saline generates reactive oxygen species (ROS), of which hydrogen peroxide (H2O2) can be unequivocally demonstrated by using specific methods for its detection. Lipids present in plasma preferentially those present in lipoproteins, undergo peroxidation that is somewhat O3-dose dependent and can be observed by the measurement of thiobarbituric acid reactive substances (TBARS). While the generation of H2O2 is crucial in activating both biochemical (hexose monophosphate shunt) and immunological (via the transcription factor NF-kB) mechanisms, the role of lipid oxidation products (LOP) remains to be investigated. We have shown here that there is a small but consistent induction of some cytokines (TNF-alpha, IFN-gamma and IL-2) when human blood is directly exposed to O3 concentrations up to 100 micrograms/ml per g of blood. On the other hand, isolated blood mononuclear cells (PBMC) in tissue culture medium are far more sensitive to the oxidant action of O3 as shown by a progressive reduction of the proliferation index with comparatively far lower O3, concentrations. On the whole, these results support the concept that much of the O3 toxicity is neutralized by the powerful antioxidant system of blood. The minimal hemolysis supports this idea but as far as platelets are concerned, we must mention that they tend to aggregate in heparinized blood, even when it is exposed to an O3 concentration of 40 micrograms/ml. In spite of the lack of side-effects after autohemotherapy, this drawback must be kept in mind and avoided in clinical practice.

Adult↗

PubMed1991

Influence of ozone air pollution on plant-herbivore interactions. Part 1: Biochemical changes in ornamental milkweed (Asclepias curassavica L.; asclepiadaceae) induced by ozone.

A series of fumigation experiments was conducted with bloodflower (Asclepias curassavica L.) in continuous-flow stirred reactors (CSTRs) to elucidate the effects of ozone on foliar concentrations of several primary and secondary plant metabolites relevant to herbivores. Plants 8 weeks of age were subjected to different ozone levels ranging from 0 to 134 nl liter(-1) for exposure periods up to 16 days. Leaves were analyzed for concentration of soluble carbohydrates, starch, free amino acids, soluble protein, total phenolics, and total cardenolides. Significant interactions between the linear effects of ozone concentration and exposure time were found for soluble carbohydrates, amino acids, cardenolides and phenolics. No significant treatment effects could be observed on foliar starch and protein concentration. The metabolic responses of plants to fumigation appeared to be altered by overall plant nutrition. It is possible that the metabolic changes observed in the host plant represent important changes in nutritional quality to insects.

Journal Article↗

PubMed1992

Influence of ozone air pollution on plant-herbivore interactions. Part 2: Effects of ozone on feeding preference, growth and consumption rates of monarch butterflies (Danaus plexippus).

Effects of ozone fumigation of Asclepias curassavica L. and A. syriaca L. on feeding preference, growth, development, and nutritional indices of monarch larvae were investigated in conjunction with changes in specific leaf metabolites. While foliar chemistry was quite variable, fumigation generally decreased sugars and proteins, and increased amino acids and phenolics in A. curassavica. Effects were similar in A. syriaca except that sugars were generally increased while amino acids were usually not affected. On A. curassavica, 3rd instar larvae preferred ozone-treated leaves while 4th instars showed no preference; conversely, on A. syriaca, 3rd instars showed no preference while 4th instars preferred control leaves. Relative growth rate and relative consumption rate of 5th instars were greater on fumigated plants of both species, but other nutritional indices were unaffected. Larvae developed more rapidly on intact fumigated plants of both species than on the respective controls. The results suggest that enhanced feeding stimulation may be the primary cause of the altered behavior and performance on ozone-fumigated plants.

Journal Article↗

PubMed2001

Global tropospheric ozone dynamics. Part I: Tropospheric ozone precursors.

An overview of the tropospheric ozone changes is presented focussing mainly on the tropospheric ozone precursors. The complexity of the problem is shown through the consideration of a great number of relevant substances, like nitrogen compounds, volatile organic compounds, peroxyacetyl nitrate, hydroxyl radical, carbon monoxide, alkyl nitrates. The up-to-date knowledge on the relevant numerical modelling is presented in Part II.

Atmosphere↗

PubMed1992

Cholesterol ozonation products as biomarkers for ozone exposure in rats.

Cholesterol, 1, which is present in both the lung lining fluid and cell membranes of lung tissue, reacts with ozone in aqueous systems to give 3 beta-hydroxy-5-oxo-5,6-secocholestan-6-al (2) as the major product. Reaction of 2 with 2,4-dinitrophenyl hydrazine (DNPH) in aqueous solutions, liposomes or lung extracts affords the anti and syn DNPH derivatives of 2 (3b and 3c) and of the rearrangement product 3,5-dihydroxy-B-norcholestane-6-carboxaldehyde (3a). These derivatives also are detected in lung tissue extracts from rats exposed to 1.3 ppm ozone for 12 hr.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed2003

Assessing plant response to ambient ozone: growth of ozone-sensitive loblolly pine seedlings treated with ethylenediurea or sodium erythorbate.

One-year-old seedlings from an ozone-sensitive half-sib family of loblolly pine (Pinus taeda L.) were transplanted into replicated plots in blocks in a large forest clearing near Nacogdoches, Texas. Seedlings were either non-treated (controls) or treated bi-weekly with foliar sprays of ethylenediurea (EDU), at 150, 300 or 450 ppm or sodium erythorbate (NaE), at 515, 1030, or 1545 ppm, for three growing seasons. Results from the final third year harvest indicated that both EDU and NaE increased all growth parameters, with significant differences only for EDU at 450 ppm. Both EDU and NaE would be useful for long-term studies on assessing the effects of ambient ozone on established native plants.

Air Pollutants↗

PubMed1999

Studies on the biological effects of ozone: 10. Release of factors from ozonated human platelets.

In a previous work we have shown that heparin, in the presence of ozone (O3), promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF), transforming growth factor beta1 (TGF-beta1) and interleukin-8 (IL-8) are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limb ischemia treated with O3 autohaemoteraphy (O3-AHT).

Adenosine Diphosphate↗

PubMed2005

Localized ozone fumigation system for studying ozone effects on photosynthesis, respiration, electron transport rate and isoprene emission in field-grown Mediterranean oak species.

We used a localized ozone (O3) fumigation (LOF) system to study acute and short-term O(3) effects on physiological leaf traits. The LOF system enabled investigation of primary and secondary metabolic responses of similarly and differently aged leaves on the same plant to three different O3 concentrations ([O3]), unconfounded by other influences on O3 sensitivity, such as genetic, meteorological and soil factors. To simulate the diurnal cycle of O3 formation, current-year and 1-year-old Quercus ilex (L.) and Quercus pubescens (L.) leaves were fumigated with O3 at different positions (and hence, different leaf ages) on the same branch over three consecutive days. The LOF system supplied a high [O3] (300+/-50 ppb) on leaves appressed to the vents, and an intermediate, super-ambient [O3] (varying between 120 and 280 ppb) on leaves less than 30 cm from the vent. Leaves more than 60 cm from the O3 vent were exposed to an [O3] comparable with the ambient concentration, with a 100 ppb peak during the hottest hours of the day. Only leaves exposed to the high [O3] were affected by the 3-day treatment, confirming that Mediterranean oak are tolerant to ambient and super-ambient [O3], but may be damaged by acute exposure to high [O3]. Stomatal and mesophyll conductance and photosynthesis were all reduced immediately after fumigation with high [O3], but recovered to control values within 72 h. Both the intercellular and chloroplast CO2 concentrations ([CO2]) remained constant throughout the experiment. Thus, although treatment with a high [O3] may have induced stomatal closure and consequent down-regulation of photosynthesis, we found no evidence that photosynthesis was limited by low [CO2] at the site of fixation. One-year-old leaves of Q. ilex were much less sensitive to O3 than current-year leaves, suggesting that the low stomatal conductance observed in aging leaves limited O3 uptake. No similar effect of leaf age was found in Q. pubescens. Dark respiration decreased during the treatment period, but a similar decrease was observed in leaves exposed to low [O3], and therefore may not be an effect of O3 treatment. Light respiration, on the other hand, was mostly constant in ozone-treated leaves and increased only in leaves in which photosynthesis was temporarily inhibited by high [O3], preventing them from acting as strong sinks that recycle respiratory CO2 in the leaves. There was no evidence of photochemical damage in Q. ilex leaves, whereas Q. pubescens leaves exposed to a high [O3] showed limited photochemical damage, but recovered rapidly. Biochemical markers were affected by the high [O3], indicating accumulation of reactive oxygen species (ROS) and increased denaturation of lipid membranes, followed by activation of isoprene biosynthesis in Q. pubescens leaves. We speculate that the high isoprene emissions helped quench ROS and normalize membrane stability in leaves recovering from O3 stress.

Butadienes↗

PubMed1976

[Animal experiment studies on the use of ozone in irradiated and non-irradiated tumors. I. Intravenous ozone therapy of Crocker's sarcoma 180 and Ehrlich carcinoma in the white mouse].

The fractionated tangential local X-ray therapy, in cases of sarcoma 180 in white mice with a total dose of 1500 R, effects a shrinking of the tumours as well as a certain number of cures. Intravenous administration of ozone in a total dose of 0.15 times 10(-7)g, 1.5 times 10(-7)g, and 15 times 10(-7)g - by itself or together with irradiation - has as consequence neither an inhibitory effect on the tumour growth, nor an increase in radiation effect that are surpassing the diffusion width of the model and are reproducible in an exact manner. It has been possible to prove an inhibition of the tumour growth in the solid Ehrlich's carcinoma of white mice after a fractionated 2000 R irradiation, but also in these cases, no effect of the ozone application was stated.

Animals↗

PubMed1999

Studies on the biological effects of ozone: 9. Effects of ozone on human platelets.

During the course of ozonated autohaemotherapy (O3-AHT) using heparin as an anticoagulant, it was occasionally observed that a few clots were retained in the filter during blood reinfusion. This observation prompted an investigation on the effect of ozone (O3) on human platelets. We have now shown, both by biochemical and morphological criteria, that heparin in the presence of O3 can promote platelet aggregation. In contrast, after Ca(2+) chelation with citrate, platelet aggregation is much reduced. The potential role of the transient formation of hydrogen peroxide (H2O2) in the presence of Ca2+ with the possible expression of adhesion molecules is briefly discussed.

Journal Article↗

PubMed2003

Susceptibility to oxidative stress: proteomic analysis of bronchoalveolar lavage from ozone-sensitive and ozone-resistant strains of mice.

Previous studies have shown that the pulmonary response to ozone (O(3)) varies greatly among strains of mice, but the factor(s) and the mechanism(s) that are responsible for this differential susceptibility have not yet been clearly identified. The present study explores the molecular bases for this differential O(3) susceptibility by studying the expression of proteins associated to the epithelial lining fluid (ELF) from two strains of mice, C57BL/6J and the C3H/HeJ, respectively described as O(3)-sensitive and O(3)-resistant. The ELF proteins of these two strains were displayed by two-dimensional gel electrophoresis (2-DE) of bronchoalveolar lavage fluids (BALFs) and the protein patterns obtained with BALF samples of both strains were compared. Two major differences were observed between the BALF 2-DE protein maps obtained from C57BL/6J and C3H/HeJ strains. First, two isoforms of the antioxidant protein 2 (AOP2) were detected in a strain-dependent manner: C3J/HeJ possesses only AOP2a (isoelectric point 5.7) and C57BL/6J exhibits only AOP2b (isoelectric point 6.0). Second, the levels of anti-inflammatory and immunosuppressive Clara cell protein-16 (CC16) were 1.3 times higher in the BALF from resistant C3H/HeJ than from sensitive C57BL/6 mice. Moreover, two 6 kDa isoforms of CC16 with isoelectric points of 4.9 (CC16a) and 5.2 (CC16b) are detected in both strains. Interestingly, the C57BL/6J strain had a twice decreased level of the acidic isoform of CC16 compared to C3H/HeJ. Our results suggest that AOP2 and CC16 might participate in the protection of the pulmonary tract to O(3)-induced lung injury. The possible differential contribution of specific protein isoforms in the differential susceptibility to oxidative stress is discussed.

Alleles↗

PubMed1994

Effect of ozonation products on phospholipase A2 hydrolytic activity: use of bis(1-hydroxyheptyl)peroxide as a precursor of the ozonation product 1-hydroxy-1-hydroperoxyheptane.

Bis(1-hydroxyheptyl)peroxide (BisC7) upon spontaneous hydrolysis affords the difficult-to-isolate ozonation product 1-hydroxy-1-hydroperoxyheptane along with heptanal. PLA2 hydrolytic activity is enhanced when the BisC7 hydrolysis products are incorporated in the membrane of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine liposomes, suggesting they cause a pronounced alteration in the bilayer packing order. Conversely, inhibition is observed when PLA2 is incubated with BisC7 hydrolytic products prior to incubation with the liposomes, suggesting that these products are capable of reacting with and modifying the enzyme when present in solution.

Alcohols↗

PubMed1995

Ozone adaptation in rats after chronic exposure to a simulated urban profile of ozone.

Studies in both humans and rats have indicated that certain pulmonary responses induced by exposure to an acute provocative concentration of ozone (O3) will eventually attenuate if the exposure is repeated on a daily basis. This phenomenon is commonly referred to as O3 adaptation. Whether or not a "state" of adaptation develops due to long-term low level O3 exposure is unknown. Two human studies have reported adaptation in subjects living in Los Angeles during periods when ambient O3 concentrations have been relatively high. At present, however, we are not aware of comparable information from rats. This study assessed O3 adaptation in rats following chronic (12 or 18 months) exposure and after a 4-month recovery period. A chronic exposure pattern, similar to that found in an urban area during the summer (0.06 ppm O3 for 13 hr/day, 7 days/week; Monday-Friday, peak to 0.25 ppm O3, over 9 hr), was used. To assess whether adaptation had occurred and/or persisted, awake rats were challenged with high provocative concentrations of O3 for up to 2 hr. During a challenge, rats were monitored for typical O3-induced alterations in spontaneous breathing parameters (e.g., increase in breathing frequency and decrease in tidal volume). Adaptation was defined as attenuation of breathing response during the challenge in rats chronically exposed to O3 as compared to that in "control" rats (chronically exposed to air). Adaptation was found in the rats within 8 hr following the chronic O3 exposure but not after the 4-month recovery period. Spontaneous breathing parameters that were significantly attenuated in the chronically exposed rats were breathing frequency, tidal volume, inspiratory and expiratory times, and maximum expiratory flow. We conclude that rats demonstrated adaptation to O3 after long-term exposure to an urban-type O3 profile and that the adaptation was not seen 4 months postexposure. These results suggest that exposure to environmental O3 in Los Angeles air may have been responsible for the adaptation found in residential subjects.

Adaptation, Physiological↗

PubMed1986

Synergistic interaction of ozone and respirable aerosols on rat lungs. II. Synergy between ammonium sulfate aerosol and various concentrations of ozone.

Pulmonary responses after continuous exposure of rats to concentrations of ozone (O3) ranging from 0.12 to 0.64 ppm were quantified by measuring tissue collagen synthesis rate, tissue protein and DNA content, and various constituents of bronchoalveolar lavage fluid. After 7 days of exposure to 0.64 ppm of O3, lung collagen synthesis rate and tissue content of protein and DNA were elevated. After shorter durations of exposure to 0.64 ppm of O3, significant elevations were observed in the protein content and the activities of lactate dehydrogenase, acid phosphatase, and N-acetyl-beta-D-glucosaminidase from lavage fluid. After exposure of rats to 0.20 ppm of O3 for 7 days, changes could be detected in both lung collagen synthesis rate and tissue protein content. Total lavagable protein content, a sensitive indicator for O3-induced effects upon the lung, was significantly elevated in lungs of rats exposed to 0.12 or 0.20 ppm of O3. To examine whether a synergistic interaction occurred between 0.20 or 0.64 ppm of O3 and acid aerosols, rats were continuously exposed to O3 with and without concurrent exposure to 5 mg/m3 of ammonium sulfate. A synergistic interaction between 0.20 ppm of O3 and ammonium sulfate aerosol was observed by measurement of total lavagable protein and of lung collagen synthesis rate. These results demonstrate that ammonium sulfate aerosol interacts synergistically with O3 at concentrations of O3 that approach ambient levels.

Aerosols↗

PubMed1987

Synergistic interaction of ozone and respirable aerosols on rat lungs. III. Ozone and sulfuric acid aerosol.

Previously we have demonstrated that a synergistic interaction, as evaluated by several biochemical, toxicological, and morphological responses of the lung, results from exposure of rats to ozone (O3) in conjunction with moderate concentrations of acidic, but not neutral, aerosols. To extend these studies, groups of rats were continuously exposed to either O3 or sulfuric acid aerosol alone, or to combinations of these pollutants. Pulmonary responses from these rats were measured by assay, after exposures for 6 hr to 7 days, of total lavageable protein content, total lung tissue protein content after 5, 7, or 9 days of exposure, or apparent collagen synthesis rates from lung tissue after 7 days of exposure. While the lavageable protein content from rats exposed for 3 days to 0.1 or 1.0 mg/m3 of sulfuric acid aerosol alone was not different from control values, significant elevations from control values were observed from groups exposed to 0.12, 0.20, or 0.64 ppm of O3. Synergy was demonstrated by this assay upon exposure of rats to 0.20 ppm of O3 in conjunction with 0.1, 0.5, or 1.0 mg/m3 of sulfuric acid aerosol. Similarly, the tissue protein content from rats exposed to 0.1 or 1.0 mg/m3 of sulfuric acid aerosol alone was indistinguishable from control values. Significant elevations from control values were observed by this assay from groups of rats exposed to 0.64 or 0.20 ppm of O3, and a synergistic interaction was demonstrated between 0.64 ppm of O3 and 1.0 mg/m3 of sulfuric acid aerosol. Furthermore, synergy was observed by quantification of increased total lung protein between 0.20 ppm of O3 + 40 micrograms/m3 and higher concentrations of sulfuric acid aerosol. Values of the lung collagen synthesis rate from rats exposed to 0.1, but not 1.0, 0.5, or 0.04 mg/m3 of sulfuric acid aerosol were significantly higher than values from lungs of control animals. Significant elevations from control values were also observed by this assay from groups of rats exposed to 0.64 or 0.20 ppm of O3. A synergistic interaction was demonstrated by the collagen synthesis rate assay between groups of rats exposed to 0.64 ppm of O3 + 0.20 mg/m3 and higher concentrations of sulfuric acid aerosol or between groups exposed to 0.20 ppm of O3 + 40 micrograms/m3 and higher concentrations of sulfuric acid aerosol. These results demonstrate synergy between O3 and sulfuric acid aerosol upon exposure to concentrations of each pollutant at or near peak hourly ambient levels in polluted urban atmospheres.

Aerosols↗

PubMed2004

Intra-specific variability of ozone sensitivity in Centaurea jacea L., a potential bioindicator for elevated ozone concentrations.

Brown knapweed (Centaurea jacea L.) has been suggested as a potential bioindicator for tropospheric ozone (O3), but little is known about the intra-specific variation in O3 sensitivity in this wild species. The aim of this study was to quantify the differences in O3 sensitivity among and within five populations, and to relate the differences to morphological, phenological, and genetic characteristics. These parameters were periodically recorded in two consecutive experiments on a total of 357 plants from five different European countries (Norway, Hungary, Switzerland, Italy, Slovenia). They were grown from seed in natural soil under ambient conditions at a site with seasonally elevated O3 concentrations (Cadenazzo, southern Switzerland). The populations differed significantly both in frequency and extent of O3 injury, as well as in phenological development. The observed degree of O3 injury was highest in the Slovenian and the Swiss populations, while only few Hungarian and Norwegian plants showed slight symptoms of injury. Plants were generally most sensitive to O3 when reaching the reproductive stage, and insensitive at the rosette stage. Amplified fragment length polymorphism analysis (AFLP) demonstrated genetic distinctiveness of the five C. jacea populations. All individuals of four of the five populations were correctly assigned to the respective populations based on principal component analysis. Cluster analysis quite accurately reflected the geographic origin of each population. Overall, the analysis revealed a high degree of intra-specific variability in O3 sensitivity in C. jacea, and underlined the important influence of the climate-dependent population-specific plant development on O3 sensitivity. These observations may constrain the development of a standardized biomonitoring system.

Air Pollutants↗