Short-term exposure of mice to cigarette smoke and/or residual oil fly ash produces proximal airspace enlargements and airway epithelium remodeling

Chronic obstructive pulmonary disease (COPD) is associated with inflammatory cell reactions, tissue destruction and lung remodeling. Many signaling pathways for these phenomena are still to be identified. We developed a mouse model of COPD to evaluate some pathophysiological mechanisms acting during the initial stage of the disease. Forty-seven 6- to 8-week-old female C57/BL6 mice (approximately 22 g) were exposed for 2 months to cigarette smoke and/or residual oil fly ash (ROFA), a concentrate of air pollution. We measured lung mechanics, airspace enlargement, airway wall thickness, epithelial cell profile, elastic and collagen fiber deposition, and by immunohistochemistry transforming growth factor-β1 (TGF-β1), macrophage elastase (MMP12), neutrophils and macrophages. We observed regional airspace enlargements near terminal bronchioles associated with the exposure to smoke or ROFA. There were also increases in airway resistance and thickening of airway walls in animals exposed to smoke. In the epithelium, we noted a decrease in the ciliated cell area of animals exposed to smoke and an increase in the total cell area associated with exposure to both smoke and ROFA. There was also an increase in the expression of TGF-β1 both in the airways and parenchyma of animals exposed to smoke. However, we could not detect inflammatory cell recruitment, increases in MMP12 or elastic and collagen fiber deposition. After 2 months of exposure to cigarette smoke and/or ROFA, mice developed regional airspace enlargements and airway epithelium remodeling, although no inflammation or increases in fiber deposition were detected. Some of these phenomena may have been mediated by TGF-β1.

Indirect effect of neem oil on Podisus nigrispinus (Hemiptera, Pentatomidae): biology and predatory capacity

This study evaluated the effects on the development and predatory capacity of Podisus nigrispinus fed on Spodoptera frugiperda that have ingested different concentrations of neem oil. The predatory capacity of Podisus nigrispinus was assessed, separating nymphs (fourth instar) and adults (males and females). The treatments consisted of S. frugiperda larvae reared in neem oil aqueous solutions (0.077, 0.359 and 0.599%), deltamethrin EC 25 (0.100%) and control arranged in a completely randomized design, with ten replicates. Insects were offered three larval densities (one, three and six), in the third or fourth instars. The predated larvae were examined at 24 and 48 hours after the beginning of the experiment. Biological parameters of Podisus nigrispinus were evaluated in groups of ten second-instar nymphs transferred to pots, in five replicates. Insects were offered 2-6 third and/or fourth-instar larvae reared in the same neem oil concentrations in a completely randomized design. The following parameters were evaluated: duration of each nymph stage (days), nymph mortality (%), weight of fifth-instar nymphs (mg), sex ratio, weight of males and females (mg) and longevity of unfed adults (days). The predatory capacity of nymphs and adults of Podisus nigrispinus was influenced by the neem oil at the concentrations of 0.359% and 0.599% in the highest density. The concentration of 0.359% lengthened the nymphal stage and the concentration of 0.599% reduced the weight of males.

Methodology in the epidemiological research of respiratory diseases and environmental pollution

There are complex and diverse methodological problems involved in the clinical and epidemiological study of respiratory diseases and their etiological factors. The association of urban growth, industrialization and environmental deterioration with respiratory diseases makes it necessary to pay more attention to this research area with a multidisciplinary approach. Appropriate study designs and statistical techniques to analyze and improve our understanding of the pathological events and their causes must be implemented to reduce the growing morbidity and mortality through better preventive actions and health programs. The objective of the article is to review the most common methodological problems in this research area and to present the most available statistical tools used.

Air pollution effects on myocardial infarction

OBJECTIVE: Myocardial infarction is an acute and severe cardiovascular disease that generally leads to patient admissions to intensive care units and few cases are initially admitted to infirmaries. The objective of the study was to assess whether estimates of air pollution effects on myocardial infarction morbidity are modified by the source of health information. METHODS: The study was carried out in hospitals of the Brazilian Health System in the city of São Paulo, Southern Brazil. A time series study (1998-1999) was performed using two outcomes: infarction admissions to infirmaries and to intensive care units, both for people older than 64 years of age. Generalized linear models controlling for seasonality (long and short-term trends) and weather were used. The eight-day cumulative effects of air pollutants were assessed using third degree polynomial distributed lag models. RESULTS: Almost 70% of daily hospital admissions due to myocardial infarction were to infirmaries. Despite that, the effects of air pollutants on infarction were higher for intensive care units admissions. All pollutants were positively associated with the study outcomes but SO2 presented the strongest statistically significant association. An interquartile range increase on SO2 concentration was associated with increases of 13% (95% CI: 6-19) and 8% (95% CI: 2-13) of intensive care units and infirmary infarction admissions, respectively. CONCLUSIONS: It may be assumed there is a misclassification of myocardial infarction admissions to infirmaries leading to overestimation. Also, despite the absolute number of events, admissions to intensive care units data provides a more adequate estimate of the magnitude of air pollution effects on infarction admissions.

The effects of air pollution on cardiovascular diseases: lag structures

OBJECTIVE: To assess the lag structure between air pollution exposure and elderly cardiovascular diseases hospital admissions, by gender. METHODS: Health data of people aged 64 years or older was stratified by gender in São Paulo city, Southeastern Brazil, from 1996 to 2001. Daily levels of air pollutants (CO, PM10, O3, NO2, and SO2) , minimum temperature, and relative humidity were also analyzed. It were fitted generalized additive Poisson regressions and used constrained distributed lag models adjusted for long time trend, weekdays, weather and holidays to assess the lagged effects of air pollutants on hospital admissions up to 20 days after exposure. RESULTS: Interquartile range increases in PM10 (26.21 mug/m³) and SO2 (10.73 mug/m³) were associated with 3.17% (95% CI: 2.09-4.25) increase in congestive heart failure and 0.89% (95% CI: 0.18-1.61) increase in total cardiovascular diseases at lag 0, respectively. Effects were higher among female group for most of the analyzed outcomes. Effects of air pollutants for different outcomes and gender groups were predominately acute and some "harvesting" were found. CONLUSIONS: The results show that cardiovascular diseases in São Paulo are strongly affected by air pollution.

Principal components and generalized linear modeling in the correlation between hospital admissions and air pollution

OBJECTIVE To analyze the association between concentrations of air pollutants and admissions for respiratory causes in children. METHODS Ecological time series study. Daily figures for hospital admissions of children aged < 6, and daily concentrations of air pollutants (PM10, SO2, NO2, O3 and CO) were analyzed in the Região da Grande Vitória, ES, Southeastern Brazil, from January 2005 to December 2010. For statistical analysis, two techniques were combined: Poisson regression with generalized additive models and principal model component analysis. Those analysis techniques complemented each other and provided more significant estimates in the estimation of relative risk. The models were adjusted for temporal trend, seasonality, day of the week, meteorological factors and autocorrelation. In the final adjustment of the model, it was necessary to include models of the Autoregressive Moving Average Models (p, q) type in the residuals in order to eliminate the autocorrelation structures present in the components. RESULTS For every 10:49 μg/m3 increase (interquartile range) in levels of the pollutant PM10 there was a 3.0% increase in the relative risk estimated using the generalized additive model analysis of main components-seasonal autoregressive – while in the usual generalized additive model, the estimate was 2.0%. CONCLUSIONS Compared to the usual generalized additive model, in general, the proposed aspect of generalized additive model − principal component analysis, showed better results in estimating relative risk and quality of fit.

Air pollution and its impacts on health in Vitoria, Espirito Santo, Brazil

ABSTRACT OBJECTIVE To analyze the impact of air pollution on respiratory and cardiovascular morbidity of children and adults in the city of Vitoria, state of Espirito Santo. METHODS A study was carried out using time-series models via Poisson regression from hospitalization and pollutant data in Vitoria, ES, Southeastern Brazil, from 2001 to 2006. Fine particulate matter (PM10), sulfur dioxide (SO2), and ozone (O3) were tested as independent variables in simple and cumulative lags of up to five days. Temperature, humidity and variables indicating weekdays and city holidays were added as control variables in the models. RESULTS For each increment of 10 µg/m3 of the pollutants PM10, SO2, and O3, the percentage of relative risk (%RR) for hospitalizations due to total respiratory diseases increased 9.67 (95%CI 11.84-7.54), 6.98 (95%CI 9.98-4.17) and 1.93 (95%CI 2.95-0.93), respectively. We found %RR = 6.60 (95%CI 9.53-3.75), %RR = 5.19 (95%CI 9.01-1.5), and %RR = 3.68 (95%CI 5.07-2.31) for respiratory diseases in children under the age of five years for PM10, SO2, and O3, respectively. Cardiovascular diseases showed a significant relationship with O3, with %RR = 2.11 (95%CI 3.18-1.06). CONCLUSIONS Respiratory diseases presented a stronger and more consistent relationship with the pollutants researched in Vitoria. A better dose-response relationship was observed when using cumulative lags in polynomial distributed lag models.

Comparative study of the topical effectiveness of the andiroba oil (Carapa guianensis) and DEET 50% as repellent for Aedes sp

DEET (N,N-diethyl-3-methylbenzamide) is nowadays the most effective mosquito repellent available, however, its use can present some topical and systemic side effects. Some botanical compositions, as Andiroba (Carapa guianensis), have been proved repellent properties at low cost and toxicity. An experimental study was driven involving four volunteers submitting their forearms covered with Andiroba oil at 100%, DEET 50%, refined soy oil, Andiroba oil 15% and in the absence of products, directly to healthy females of Aedes sp. The times of first and third bites were checked. The results showed that the median of the first bite without any product was 17.5s and the third bite, 40.0s. In the soy oil, the bites happened in 60.0s and 101.5s, in the presence of Andiroba oil 100%, in 56.0s and 142.5s and in Andiroba oil 15%, in 63.0s and 97.5s. The volunteers using DEET 50% had not received bites after 3600s in most of the experiments (p < 0.001 Wilcoxon). Pure Andiroba oil compared to the soy oil, forearm without product and Andiroba oil 15%, showed discreet superiority (p < 0.001 Wilcoxon). Our conclusion is that this study demonstrated that the pure Andiroba oil presents discreet repellent effect against bite of Aedes sp., being significantly inferior to DEET 50%.

Some ultrastructural superficial changes in house fly (Diptera: Muscidae) and blow fly (Diptera: Calliphoridae) larvae induced by eucalyptol oil

The ultrastructural superficial changes in third instar house fly (Musca domestica) and blow fly (Chrysomya megacephala) induced by eucalyptol oil were observed using scanning electron microscopy. Dipped in 0.902 g/ml eucalyptol for 30 sec, the larvae integument of both species showed significant aberrant appearance of the body surface, particularly swelling integument, bleb formation, partial breach and deformation of spines.

Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis

To date, there are no vaccines against Leishmania, and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice used for leishmaniasis therapy are significantly toxic, expensive and with a growing frequency of refractory infections. Because of these limitations, a combination therapy is the better hope. This work demonstrates that the essential oil from Chenopodium ambrosioides shows a synergic activity after incubation in conjunction with pentamidine against promastigotes of Leishmania amazonensis. However, an indifferent effect has been found for combinations of meglumine antimoniate or amphotericin B and the essential oil.

ULTRASTRUCTURAL CHANGES IN Schistosoma mansoni MALE WORMS AFTER in vitro INCUBATION WITH THE ESSENTIAL OIL OF Mentha x villosa Huds

Introduction: The essential oil Mentha x villosa (MVEO) has a wide range of actions, including antibacterial, antifungal, antiprotozoal and schistosomicidal actions. The present study aimed to investigate the ultrastructural changes of MVEO on the tegument of adult Schistosoma mansoni. Materials and Methods: Different concentrations of MVEO were tested on S. mansoni adult worms in vitro. Ultrastructural changes on the tegument of these adult worms were evaluated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: The MVEO caused the death of all worms at 500 μg mL-1 after 24 h. After 24h of 500 μg mL-1 MVEO treatment, bubble lesions were observed over the entire body of worms and they presented loss of tubercles in some regions of the ventral portion. In the evaluation by TEM, S. mansoni adult worms treated with MVEO, 500 μg mL-1, presented changes in the tegument and vacuoles in the syncytial matrix region. Glycogen granules close to the muscle fibers were visible. Conclusion: The ability of MVEO to cause extensive ultrastructural damage to S. mansoni adult worms correlates with its schistosomicidal effects and confirms earlier findings with S. mansoni.

Larvicidal activity of oil-resin fractions from the Brazilian medicinal plant Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) against Aedes aegypti (Diptera, Culicidae)

Oil-resin fractions from Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) were evaluated for larvicidal activity on third larval instars of Aedes aegypti, in searching for alternative control methods for this mosquito. The bioactive fractions were chemically monitored by thin-layer chromatography, ¹H and 13C nuclear magnetic resonance and mass spectrometry. Bioassays were performed using five repetitions, at a temperature of 28 ± 1°C, relative humidity of 80 ± 5% and light and dark cycles of 12h. Mortality was indicated by darkening of the cephalic capsule after 24h of exposure of the larvae to the solutions. The most active fractions were CRM1-4 (sesquiterpenes) and CRM5-7 (labdane diterpenes), which showed LC50 values of 0.2 and 0.8ppm, respectively.

Effects of Rosmarinus officinalis essential oil on germ tube formation by Candida albicans isolated from denture wearers

Introduction The aim of this study was to investigate the effects of Rosmarinus officinalis essential oil on germ tube formation by Candida albicans isolated from denture wearers. Methods Ten C. albicans isolates recovered from denture wearers were tested using 10% fetal bovine serum with or without 4% R. officinalis essential oil. Results The essential oil from R. officinalis completely inhibited germ tube formation in the investigated C. albicans isolates. Conclusions The results demonstrate that the essential oil of R. officinalis modulates C. albicans pathogenicity through its primary virulence factor (i.e., germ tube formation was suppressed).