An experimental study on the preventive effects of N-acetyl cysteine and ozone treatment against contrast-induced nephropathy

Abstract Purpose: To compare the preventive effects of N-acetyl cysteine (NAC), ozone preconditioning and ozone treatment against contrast-induced nephropathy (CIN) in an experimental rat model. Methods: Thirty adult male Wistar rats were randomly distributed into five groups (n=6 for each group). Group I served as control and Group II had only contrast agent, while Group III received NAC and Group IV received intraperitoneal ozone 6 hours before and 6 hours after introduction of contrast agent. Ozone treatment was applied for 5 days after the contrast agent was introduced in Group V. After induction of CIN, groups were compared in terms of serum levels of urea, creatinine, neutrophil gelatinase associated lipocalin, protein carbonyl, total antioxidant capacity (TAC) as well as degree of renal injury at histopathologic level. Results: Groups II-V displayed more obvious histopathological alterations such as hemorrhage and renal tubular injury compared with Group I. TAC (p=0.043) and creatinine (p=0.046) levels increased significantly in Group II after the intervention. In Group III, protein carbonyl level diminished remarkably (p=0.046), while creatinine level was increased (p=0.046) following the intervention. TAC level was higher in Group IV (p=0.028) and Group V (p=0.026) following the procedure. Conclusion: The N-acetyl cysteine and ozone treatment may alleviate the biochemical and histopathological deleterious effects of contrast-induced nephropathy via enhancement of total antioxidant capacity and decreasing oxidative stress.

The effects of ozone on bacterial growth and thiol-disulphide homeostasis in vascular graft infection caused by MRSA in rats

Abstract: Purpose: To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated. Methods: Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles. Results: There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups. Conclusions: We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.

Antimicrobial activity of ozone and NaF-chlorhexidine on early childhood caries

Abstract An early childhood carie (ECC) is an extremely destructive form of tooth decay. The aim of this study was to investigate the action of ozone (O3), and the association of sodium fluoride (NaF) with chlorhexidine (CHX) on bacteria related to ECC. Overnight culture of the bacteria was performed. On exponential phase the suspension was adjusted (101-108 CFU/mL). A drop (10μL) of each concentration of bacteria was applied on sheep blood agar plates and treated with O3 (2, 20, 200, and 2,000 ppm); after 18 hours, recovery analysis of CFU verified the reduction of bacterial activity. For NaF-CHX, sterile 96-well plates were prepared and divided into groups: G1 (150 µL TSB); G2 (20 µL of bacteria + 25 µL CHX + 25 µL NaF); and G3 (150 µL TSB + 20 µL of bacteria + 50 µL water). The plates were verified by analysis of the optical density (0, 12, 14, 16, and 18 hours). The data from O3 test were submitted to ANOVA and Tukey’s test (p < 0.05). For the data from NaF-CHX, the ANOVA 2-way and Bonferroni’s test (p < 0.05) were used. The number of CFU/mL showed death > 3log10 (99.9%) for all bacteria (ozone ≥ 20ppm), while the combination of NaF-CHX was more effective (p < 0.001) compared to each substance tested alone and the control group. The antimicrobial agents tested were able to inhibit all bacteria tested; O3 seemed to be a good alternative for controlling progression of carious lesions, while the association of NaF-CHX showed to be a good antimicrobial with easy and inexpensive application.

Ozone therapy as an adjuvant for endondontic protocols: microbiological – ex vivo study and citotoxicity analyses

ABSTRACT Objectives This study evaluated the antimicrobial efficacy of ozone therapy in teeth contaminated with Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus using a mono-species biofilm model. Parallel to this, the study aimed to evaluate the cytotoxicity of ozone for human gingival fibroblasts. Material and Methods: One hundred and eighty single-root teeth were contaminated with a mono-species biofilm of Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus. Groups were formed: Group I – control; Group II – standard protocol; Group III – standard protocol + ozone gas at 40 µg/mL; and Group IV – standard protocol + aqueous ozone at 8 µg/mL. In parallel, human gingival fibroblasts were submitted to the MTT test. Cells were plated, then ozone was applied as follows: Group I (control) – broth medium; Group II – aqueous ozone at 2 µg/mL; Group III – aqueous ozone at 5 µg/mL; and Group IV – aqueous ozone at 8 µg/mL. Data were submitted to the Kruskal Wallis test and Bonferroni post hoc analyses to assess microbiology and cytotoxicity, respectively (p<0.05%). Results The results revealed antimicrobial efficacy by Group IV with no CFU count. The cytotoxicity assay showed Groups III and IV to be the most aggressive, providing a decrease in cell viability at hour 0 from 100% to 77.3% and 68.6%, respectively. Such a decrease in cell viability was reverted, and after 72 hours Groups III and IV provided the greatest increase in cell viability, being statistically different from Groups I and II. Conclusion According to the applied methodology and the limitations of this study, it was possible to conclude that ozone therapy improved the decontamination of the root canal ex vivo. Ozone was toxic to the cells on first contact, but cell viability was recovered. Thus, these findings suggest that ozone might be useful to improve root canal results.

Anti-fungal potential of ozone against some dermatophytes

ABSTRACT Dermatophytes are classified in three genera, Epidermophyton, Microsporum and Trichophyton. They have the capacity to invade keratinized tissue to produce a cutaneous infection known as dermatophytoses. This investigation was performed to study the effect of gaseous ozone and ozonized oil on three specific properties of six different dermatophytes. These properties included sporulation, mycelia leakage of sugar and nutrients and the activity of their hydrolytic enzymes. Generally, ozonized oil was found to be more efficacious than gaseous ozone. Microsporum gypseum and Microsporum canis were the most susceptible, while Trichophyton interdigitale and T. mentagrophytes were relatively resistant. The study revealed a steady decline in spore production of M. gypseum and M. canis on application of ozonated oil. An increase in leakage of electrolytes and sugar was noticed after treatment with ozonized oil in the case of M. gypseum, M. canis, T. interdigitale, T. mentagrophytes and T. rubrum. The results also revealed loss in urease, amylase, alkaline phosphatase, lipase and keratinase enzyme producing capacity of the investigated fungi.

The acute effects of preoperative ozone theraphy on surgical wound healing

ABSTRACT PURPOSE: To investigate the effects of preoperative rectal ozone insufflation on surgical wound healing over the proinflammatory cytokines and histopathological changes. METHODS: Twenty one rabbits were divided into 3 groups. Sham, surgical wound, and ozone applied (6 sessions, every other day 70 µg/mL in 12 mL O2-O3 mixture rectally) surgical wound groups were created. TNF-alpha and IL-6 levels from all rabbits were studied at the basal, 24th hour, and 72nd hour. The histopathological examination was done by removing the surgical scar tissue at the end of 72nd hour. RESULTS: TNF-alfa and IL-6 levels were significantly lower compared to the control group, in the rabbits treated with ozone. The increase in angiogenesis, the decrease in the number of inflammatory cells, epidermal and dermal regeneration, better collagen deposition, and increased keratinisation in stratum corneum were observed in the histopathological examination. It was determined that the wound healing noticeably accelerated in the ozone group. CONCLUSION: Preoperative rectal ozone insufflation had a positive effect on surgical wound healing in acute period.

Effect of ozone on colon anastomoses in rat peritonitis model

PURPOSE: To investigate the effects of medical ozone theraphy on the colon anastomosis of peritonitis model in rats. METHODS: Eighteen rats were randomly assigned into three equal groups; control, cecal punctuation and colon anastomosis and ozone theraphy. Sepsis was performed with a cecal punctuation in groups 2 and 3. The medical ozone theraphy was administered intraperitonealy for three weeks in group 3 while the other rats received saline injection. At the twenty second day serum were obtained for TNF-α and IL-1β, the colonic burst pressures were measured and colonic tissue samples were obtained for MDA and MPO levels. Histolopatological examination was evaluated with H&E stain, and Ki-67, IL-1β and the VEGF immunostaining densities were also compared. RESULTS: Intraperitoneal ozone administration reversed TNF-α, IL-1β, MDA and MPO levels and the colonic burst pressures. There was also a significant difference at immunostaining densities of histopathological examination. CONCLUSION: Medical ozone therapy may contribute to tissue healing by affecting the proliferation and the vascularization thus has benefits on colonic anastomosis at peritonitis in rats.

Ozone oxidative preconditioning protects the rat kidney from reperfusion injury via modulation of the TLR4-NF-κB pathway

PURPOSE: To investigate the protective effects of ozone oxidative preconditioning (OzoneOP) were associated with the modulation of TLR4-NF-κB pathway. METHODS: Thirty six rats were subjected to 45 min of renal ischemia, with or without treatment with OzoneOP (1 mg/kg). Blood samples were collected for the detection of blood urea nitrogen and creatinine levels. Histologic examinations were evaluated and immunohistochemistry was also performed for localization of TLR4 and NF-κB. The expression of TNF-α, IL-1β, IL-6, ICAM-1 and MCP-1 were studied by Real-time PCR. Western blot was performed to detect the expression of TLR4 and NF-κB. RESULTS: The results indicated that blood urea nitrogen and creatinine levels increased significantly in I/R group. Rats treated with OzoneOP showed obviously less renal damage. Immunohistochemistry showed that TLR4 were ameliorated by OzoneOP. Realtime PCR showed that OzoneOP could significantly inhibit the increased mRNA levels of TNF-α, IL-1β, IL-6, ICAM-1 and MCP-1 induced by I/R. Western blot indicated that the expression of TLR4 and NF-κB were upregulated in I/R group, but OzoneOP could inhibit this increase. CONCLUSION: These findings indicated that OzoneOP had potent anti-inflammatory properties by the modulation of the TLR4-NF-κB pathway in renal ischemia/reperfusion injury. .

Chemical cystitis developed in experimental animals model: topical effect of intravesical ozone application to bladder

To demonstrate the effects of intravesical ozone treatment on inflammation and epithelial cell damage in chemical cystitis animal model. A total of 30 New Zealand rabbits were divided into six groups. Cystitis was conducted with transurethral intravesical hydrochloric acid instillation on the subjects in Groups IA, IB, IIA, and IIB. Then, Group IA-IB subjects were transurethrally administered intravesical ozone therapy twice a week, while Group IIA-IIB subjects were only given intravesical isotonic NaCl instillation. Group IIIA-IIIB subjects were administered intravesical isotonic NaCl instillation without conducting chemical cystitis in order to create the same stress. Treatment schemes of all groups were arranged in the same manner. Following a 3-week [early period] and 6-week [late period] therapy, the rabbits were sacrificed and histopathologic investigations were carried out in order to demonstrate changes in the urinary bladder. In our study, we observed that the basal membrane and mucosal integrity were maintained, inflammatory cells were suppressed in Group IA-IB [Early and late period], which received ozone therapy. However, it was also observed that mucosal integrity was spoiled, numerous inflammatory cells were accumulated in Group IIA-IIB, which was administered isotonic NaCl. Due to its low cost and minimal side effects; ozone therapy could be a new therapeutic approach in the treatment of interstitial cystitis

Alternative sanitization methods for minimally processed lettuce in comparison to sodium hypochlorite

Lettuce is a leafy vegetable widely used in industry for minimally processed products, in which the step of sanitization is the crucial moment for ensuring a safe food for consumption. Chlorinated compounds, mainly sodium hypochlorite, are the most used in Brazil, but the formation of trihalomethanes from this sanitizer is a drawback. Then, the search for alternative methods to sodium hypochlorite has been emerging as a matter of great interest. The suitability of chlorine dioxide (60 mg L-1/10 min), peracetic acid (100 mg L-1/15 min) and ozonated water (1.2 mg L-1 /1 min) as alternative sanitizers to sodium hypochlorite (150 mg L-1 free chlorine/15 min) were evaluated. Minimally processed lettuce washed with tap water for 1 min was used as a control. Microbiological analyses were performed in triplicate, before and after sanitization, and at 3, 6, 9 and 12 days of storage at 2 ± 1 ºC with the product packaged on LDPE bags of 60 µm. It was evaluated total coliforms, Escherichia coli, Salmonella spp., psicrotrophic and mesophilic bacteria, yeasts and molds. All samples of minimally processed lettuce showed absence of E. coli and Salmonella spp. The treatments of chlorine dioxide, peracetic acid and ozonated water promoted reduction of 2.5, 1.1 and 0.7 log cycle, respectively, on count of microbial load of minimally processed product and can be used as substitutes for sodium hypochlorite. These alternative compounds promoted a shelf-life of six days to minimally processed lettuce, while the shelf-life with sodium hypochlorite was 12 days.

Evaluation of changes in lipid peroxidation, ROS production, surface structures, secondary metabolites and yield of linseed (Linum usitatissimum L.) under individual and combined stress of ultraviolet-B and ozone using open top chambers.

The individual and interactive effects of supplemental UV-B (sUV-B) (ambient + 7.2 kJ m-2 d-1) and elevated O3 (ambient + 10 ppb) were evaluated under field conditions using open top chambers on two cultivars, Padmini and T-397 of linseed (Linum usitatissimum L.). Mean monthly surface level of O3 concentrations varied from 27.7 ppb to 59.0 ppb during the experimental period. Both UV-B and O3 induced the production of ROS (H2O2 and O2.-), resulting in significant damage of membranes due to lipid peroxidation and electrolyte leakage. Synthesis of secondary metabolites (flavonoids, anthocyanin, lignin and wax) was also enhanced in all the treatments, whereas biomass and yield were reduced. Alterations in frequency of stomata and wax distribution were also observed through scanning electron microscopy (SEM). Cultivar Padmini was found to be more sensitive because of higher damage of membrane vis-a-vis reduction in biomass and seed yield. However, concentrations of flavonoids, anthocyanin, lignin and wax were higher in T-397, suggesting its relative resistance against applied stress. Combined exposure of sUV-B and O3 was less harmful, as compared to their individual treatment. Among the three treatments, O3 was found to be more detrimental for overall growth and sUV-B for economic yield.

Effect of ozone gas on the shear bond strength to enamel

Ozone is an important disinfecting agent, however its influence on enamel adhesion has not yet been clarified. Objective: Evaluate the influence of ozone pretreatment on the shear strength of an etch-and-rinse and a self-etch system to enamel and analyze the respective failure modes. Material and Methods: Sixty sound bovine incisors were used. Specimens were randomly assigned to four experimental groups (n=15): Group G1 (Excite® with ozone) and group G3 (AdheSE® with ozone) were prepared with ozone gas from the HealOzone unit (Kavo®) for 20 s prior to adhesion, and groups G2 (Excite®) and G4 (AdheSE®) were used as control. Teeth were bisected and polished to simulate a smear layer just before the application of the adhesive systems. The adhesives were applied according to the manufacturer's instructions to a standardized 3 mm diameter surface, and a composite (Synergy D6, Coltene Whaledent) cylinder with 2 mm increments was build. Specimens were stored in 100% humidity for 24 h at 37°C and then subjected to a thermal cycling regimen of 500 cycles. Shear bond tests were performed with a Watanabe device in a universal testing machine at 5 mm/min. The failure mode was analyzed under scanning electron microscope. Means and standard deviation of shear bond strength (SBS) were calculated and difference between the groups was analyzed using ANOVA, Kolmogorov-Smirnov, Levene and Bonferroni. Chi-squared statistical tests were used to evaluate the failure modes. Results: Mean bond strength values and failure modes were as follows: G1- 26.85±6.18 MPa (33.3% of adhesive cohesive failure); G2 - 27.95±5.58 MPa (53.8% of adhesive failures between enamel and adhesive); G3 - 15.0±3.84 MPa (77.8% of adhesive failures between enamel and adhesive) and G4 - 13.1±3.68 MPa (36.4% of adhesive failures between enamel and adhesive). Conclusions: Shear bond strength values of both adhesives tested on enamel were not influenced by the previous application of ozone gas.

Ex-vivo Effect of Intracanal Medications Based on Ozone and Calcium Hydroxide in Root Canals Contaminated with Enterococcus faecalis

This ex vivo study evaluated the antibacterial effect of intracanal medications in root canals contaminated with Enterococcus faecalis. Fifty single-rooted human teeth were contaminated with E. faecalis (ATCC 29212) and incubated at 37°C for 21 days. The specimens were randomly divided into 5 groups according to the intracanal medication used: OZ-PG: ozonized propylene glycol; CH/CPMC: calcium hydroxide/camphorated paramonochlorophenol; OZ-PG/CH ozonized PG/CH; PC: positive control group (no medication); and NC: negative control group (no contamination). The samples were collected after 7 days (post-medication) and 14 days (final). Bacterial growth was checked by counting the colony-forming units (CFU). OZ-PG and CH/CPMC reduced significantly the CFU counts compared with PC in the post-medication and final samples, with no statistically significant differences among them. On the other hand, OZ-PG/CH did not reduce significantly the number of bacteria compared with PC. In conclusion, among the evaluated medications OZ-PG and CH/CPMC were the most effective against E. faecalis.

Resumo Este estudo ex vivo avaliou o efeito antibacteriano de medicações intracanal em canais radiculares contaminados com Enterococcus faecalis. Cinquenta dentes humanos unirradiculares foram contaminados com E. faecalis (ATCC 29212) e incubados a 37°C durante 21 dias. Os espécimes foram aleatoriamente divididos em diferentes grupos de acordo com a medicação intracanal utilizada: PG-OZ: propilenoglicol ozonizado; HC/PMCC: hidróxido de cálcio/paramonoclorofenol canforado; PG-OZ/CH; CP: controle positivo (sem medicação); e CN: controle negativo (sem contaminação). As amostras foram coletadas após 7 dias (pós-medição) e 14 dias (final). O crescimento bacteriano foi verificado através da contagem das unidades formadoras de colônias (UFC). PG-OZ e HC/PMCC reduziram estatisticamente o número de bactérias quando comparados com o CP nas amostras pós-medição e final, sem diferenças estatísticas entre si. Por outro lado, PG-OZ/HC não reduziu significativamente o número de bactérias em comparação com o CP. Em conclusão, entre as medicações avaliadas, PG-OZ e HC/PMCC foram as mais eficazes contra E. faecalis. .

The antimicrobial effect of 0.1 ppm ozonated water on 24-hour plaque microorganisms in situ

Ozone is a known oxidant present in the atmosphere and is commercially produced by simple ozonizer machines. It is a powerful antimicrobial agent in its gaseous and aqueous forms. Ozone readily dissolves in water and retains its antimicrobial property even in the dissolved state. In this study, the effect of 0.1 ppm ozonated water was analyzed on 24-hour supragingival plaque (SP) samples in situ. SP was collected from the two most posterior teeth in the contra-lateral quadrants before and after a 30-second rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). The plaque was used to count the number of total bacteria, total anaerobic bacteria, Streptococcus mutans, and Candida albicans on selective agar media. The statistical analysis of the number of colony forming units (CFUs) obtained demonstrated a significant antimicrobial effect of ozonated water on the total bacteria (p = 0.01) and anaerobes (p = 0.02). A reduction in the post-rinse CFU count for Streptococcus mutans was also observed, but the effect was not statistically significant (p = 0.07). The Candida species was only grown from one sample. Ozonated water at the 0.1 ppm concentration was effective in reducing the load of 24-hour plaque bacteria, but it did not eliminate them completely.

The use of ozone to lighten teeth: An experimental study

Tooth-whitening agents are available for therapeutic use in the dental office or at home. However, whitening more severe stains, such as those caused by systemic ingestion of tetracycline, constitutes a challenge. The aim of this study was to evaluate, in an experimental model of growing rats, the efficacy of using ozone to lighten tetracycline-stained incisors. At weaning, male Wistar rats (n=40) were randomly assigned to one of three groups. Two control groups, C21 and C60 (n=8, each) were used to document the usual age-related color. The third group (n=24) received 0.25 g% of oxytetracycline (O) until 60 days of age. These rats were subsequently divided into three further groups: O0, O3 and O5 (n=8, each). These rats were anesthetized; O3 and O5 groups received ozone application to the lower incisors for 3 (group O3) or 5 minutes (group O5), respectively; while O0 did not receive the ozone treatment. Teeth were then photographed and the incisors from the control (C60) and treatment groups (O0, O3 and O5) were cut, and compared to a standard color guide (there were eight shades numbered 0 to 7, lightest to darkest) to assess the hue visually. The teeth were then placed in phosphoric acid to quantify the color by spectrophotometry. The data (mean ± SD) were analyzed by One-Way Analysis of Variance (ANOVA) followed by Tukey's test or Dunnett test. The visual observation, analyzed blindly by one investigator, showed that O3 and O5 groups had diminished yellowing of the teeth as compared to the untreated O0 group (P<0.001). The color quantified by spectrophotometry also detected significant differences among groups (O3 < O0, P<0.01; O5 < O0,P < 0.001 and O5 < O3, P<0.01). C21 and C60 were significantly different among groups (P<0.001). This is the first experimental study to show that ozone can be successfully used for lightening the yellowish tinge of tetracycline- stained rat incisors. Further studies are required for its potential use in the dental clinic.

Los agentes blanqueadores dentales estan disponibles para tratamientos que se realizan en el consultorio odontologico o en el domicilio. Sin embargo, aclarar manchas severas, como las causadas por la ingestion sistemica de tetraciclina, constituyen un desafio. El objetivo de este estudio fue evaluar en un modelo experimental de ratas en crecimiento, la eficiencia del uso de ozono para aclarar los incisivos oscurecidos por el uso de tetraciclina. Ratas macho Wistar al destete (N=40) fueron asignadas aleatoriamente a uno de tres grupos. Dos de ellos grupos controles, C21 y C60 (N=8, cada uno), para documentar el color habitual de los incisivos, correspondiente a la edad del animal. El tercer grupo (N = 24) recibio 0,25 % de oxitetraciclina (O) hasta los 60 dias de edad. Entonces, el grupo O se dividio aleatoriamente en tres grupos O0, O3 y O5 (N = 8, cada uno) y las ratas se anestesiaron. Los grupos O3 y O5 recibieron en los incisivos inferiores la aplicacion de ozono durante 3 y 5 minutos, respectivamente; mientras que O0 no recibio tratamiento. Los incisivos de C60, O0, O3 y O5 fueron fotografiados. Luego se cortaron y se contrastaron con una guia estandar de ocho colores (ordenados de 0 a 7, desde el mas claro a mas oscuro) para cuantificar visualmente el color de los incisivos. Luego, se colocaron en acido fosforico para cuantificar el color por espectrofotometria. Los resultados (media ± SD) se analizaron por medio de ANOVA y prueba de Tukey o Dunnett (α =0.05) para determinar el efecto del tratamiento. El analisis visual de las imagenes mostro que los grupos O3 y O5 disminuyeron el color amarillo intenso respecto a O0. Dicha diferencia de color fue evaluada a traves de la guia (G) y cuantificada mediante espectrofotometria (E). Segun G, la mayor diferencia de color respecto a C60 fue para O0 (P<0.001), disminuyo en O3 (P<0.001) y aun mas en O5 (P<0.01). De acuerdo a E, O3

Analysis of the bactericidal effect of ozone pneumoperitoneum / Análise do efeito bactericida do pneumoperitônio de ozônio

PURPOSE: To assess the bactericidal action of ozone pneumoperitonium, and to compare the results with CO2. METHODS: It was used 36 Wistar rats. The animals, under anesthesia, were inoculated with 2ml of E. coli ATCC at a concentration of 10(10)UFC, and 1ml of BaSO4, into the peritoneal cavity. They were divided into three groups: Group 1, CO2 pneumoperitoneum was performed for 15 minutes; Group 2, ozone pneumoperitoneum was performed for 5 minutes at a concentration of 42µg/ml, and Group 3, ozone pneumoperitoneum was performed for 5 minutes at a concentration of 62µg/ml. Six animals from each group were sacrificed after the experiment, and the remaining 6 observed for 24 hours. Material was collected from the cavity of all animals for microbiological study. RESULTS: Ozone presented a greater bactericidal effect than CO2 in those animals sacrificed immediately after pneumoperitoneum. In the animals studied 24 hours after pneumoperitoneum evidenced no difference in bactericidal effect between the two gases. Moreover, no difference in mortality was observed. CONCLUSION: Ozone has a more potent bactericidal effect than carbon dioxide gas, although this did not influence survival of the animals.

OBJETIVO: Avaliar a ação bactericida do pneumoperitônio de ozônio comparando-o à ação do CO2. MÉTODOS: Foram utilizados 36 ratos Wistar. Após anestesia e inoculação de 2ml de E. coli ATCC na concentração de 10(10) UFC e 1ml de BaSO4 na cavidade peritoneal, os animais foram divididos em três grupos: Grupo 1, realização de pneumoperitônio de CO2 por 15 minutos; Grupo 2, realização de pneumoperitônio de ozônio durante 5 minutos na concentração de 42µg/ml, e Grupo 3, realização de pneumoperitônio de ozônio durante 5 minutos na concentração de 62µg/ml. Seis animais de cada grupo foram sacrificados após experimento e os outros seis foram observados por 24 horas. Em todos os animais colheu-se material da cavidade para estudo microbiológico. RESULTADOS: O ozônio teve maior efeito bactericida em comparação ao CO2 nos animais sacrificados logo após pneumoperitônio. Nos animais estudados após 24 horas não houve diferença do efeito bactericida entre os gases. Também não se observou alteração da mortalidade. CONCLUSÃO: O ozônio tem efeito bactericida mais potente que o gás carbônico, embora não tenha influenciado a sobrevida dos animais.

Changes in PEP Carboxylase, Rubisco and Rubisco activase mRNA levels from maize (Zea mays) exposed to a chronic ozone stress

We quantified the ozone impact on levels of Zea mays L. cv. Chambord mRNAs encoding C4-phosphoenolpyruvate carboxylase (C4-PEPc), ribulose-l,5-bisphosphate carboxylase/oxygenase small and large subunits (Rubisco-SSU and Rubisco-LSU, respectively) and Rubisco activase (RCA) using real-time RT-PCR. Foliar pigment content, PEPc and Rubisco protein amounts were simultaneously determined. Two experiments were performed to study the ozone response of the 5th and the 10th leaf. For each experiment, three ozone concentrations were tested in open-top chambers: non-filtered air (NF, control) and non-filtered air containing 40 (+40) and 80 nL L-1 (+80) ozone. Regarding the 5th leaf, +40 atmosphere induced a loss in pigmentation, PEPc and Rubisco activase mRNAs. However, it was unable to notably depress carboxylase protein amounts and mRNAs encoding Rubisco. Except for Rubisco mRNAs, all other measured parameters from 5th leaf were depressed by +80 atmosphere. Regarding the 10th leaf, +40 atmosphere increased photosynthetic pigments and transcripts encoding Rubisco and Rubisco activase. Rubisco and PEPc protein amounts were not drastically changed, even if they tended to be increased. Level of C4-PEPc mRNA remained almost stable. In response to +80 atmosphere, pigments and transcripts encoding PEPc were notably decreased. Rubisco and PEPc protein amounts also declined to a lesser extent. Conversely, the level of transcripts encoding both Rubisco subunits and Rubisco activase that were not consistently disturbed tended to be slightly augmented. So, the present study suggests that maize leaves can respond differentially to a similar ozone stress.

Antimicrobial potential of ozone in an ultrasonic cleaning system against Staphylococcus aureus

O objetivo deste estudo foi avaliar a capacidade do ozônio associado a três diferentes soluções usadas em um sistema de limpeza ultra-sônica em inativar Staphylococcus aureus. Cento e vinte mL de suspensão com S. aureus foram misturadas em 6 L das soluções experimentais (água destilada esterilizada, vinagre de maça, e água destilada esterilizada + Endozime AWpluz) utilizadas no sistema de limpeza ultra-sônica. O ozônio foi produzido por descarga elétrica através de uma corrente de oxigênio com valor de 7g/h de ozônio (1,2%) dentro das suspensões microbianas. Um total de 10 mL de cada solução experimental foram coletados e realizadas cinco diluições em 9 mL de BHI e incubadas a 37°C por 48 h. O crescimento bacteriano foi avaliado pela turbidade do meio de cultura. Ao mesmo tempo, 1 mL das amostras bacterianas foram coletadas e inoculadas em placas contendo BHIA. Após o período de incubação a 37ºC por 48 h, realizou-se a contagem de unidades formadoras de colônias (ufc/mL). No teste de diluição em tubos com BHI e placas com BHIA (ufc/mL), quando o ozônio foi empregado, o crescimento bacteriano não foi observado em nenhuma das soluções experimentais. Nas condições deste estudo, a aplicação do ozônio nas soluções experimentais presentes no sistema de limpeza ultra-sônica mostrou atividade antibacteriana sobre S. aureus.

Effects of ozonated water on Candida albicans oral isolates / Efeitos da água de ozônio no isolamento da Cândida albicans bucal

Forty-nine C. albicans freshly isolated strains and C. albicans ATCC 18804 were included in the study. Initially, suspensions containing 5 x 108 viable cells/ml were prepared. This suspension was submitted to a concentration of 3.3 mg/ml of ozone for 20s, 40s, 60s, 80s, 100s 120s, 140s, 160s, 180s and 300s. Before the experiment and also after each period of exposition, 0.1 ml of dilutions of the final suspension was plated on Sabouraud dextrose agar and incubated at 37°C for 24-48 h. After this period, the number of colony formingunits was calculated. Data were statistically analyzed by PearsonÆs correlation test. A reduction of the microorganismÆs concentration during the contact time with ozone was observed. Complete inactivation was observed only for standard strain after 5 min. Freshlyisolated C. albicans strains showed higher resistance to ozone. A linear correlation between the logarithm of yeast concentration and period of contact was found in both cases, being the linear correlation coefficients significant in the experiments