Understanding yellow fever-associated myocardial injury: an autopsy study

BACKGROUND

Yellow fever (YF) is a viral hemorrhagic fever, endemic in parts of South America and Africa. There is scarce evidence about the pathogenesis of the myocardial injury. The objective of this study is to evaluate the cardiac pathology in fatal cases of YF.

METHODS

This retrospective autopsy study included cases from the São Paulo (Brazil) epidemic of 2017-2019. We reviewed medical records and performed cardiac tissue histopathological evaluation, electron microscopy, immunohistochemical assays, RT-qPCR for YF virus (YFV)-RNA, and proteomics analysis on inflammatory and endothelial biomarkers.

FINDINGS

Seventy-three confirmed YF cases with a median age of 48 (34-60) years were included. We observed myocardial fibrosis in 68 (93.2%) patients; cardiomyocyte hypertrophy in 68 (93.2%); endothelial alterations in 67 (91.8%); fiber necrosis in 50 (68.5%); viral myocarditis in 9 (12.3%); and secondary myocarditis in 5 (6.8%). Four out of five patients with 17DD vaccine-associated viscerotropic disease presented with myocarditis. The cardiac conduction system showed edema, hemorrhages and endothelial fibrinoid necrosis. Immunohistochemistry detected CD68-positive inflammatory interstitial cells and YFV antigens in endothelial and inflammatory cells. YFV-RNA was detected positive in 95.7% of the cardiac samples. The proteomics analysis demonstrated that YF patients had higher levels of multiple inflammatory and endothelial biomarkers in comparison to cardiovascular controls, and higher levels of interferon gamma-induced protein 10 (IP-10) in comparison to sepsis (p = 0.01) and cardiovascular controls (p < 0.001) in Dunn test.

INTERPRETATION

Myocardial injury is frequent in severe YF, due to multifactorial mechanisms, including direct YFV-mediated damage, endothelial cell injury, and inflammatory response, with a possible prominent role for IP-10.

FUNDING

This study was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo, Bill and Melinda Gates Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.

Ultrasound assessment of pulmonary fibroproliferative changes in severe COVID-19: a quantitative correlation study with histopathological findings

PURPOSE

This study was designed to evaluate the usefulness of lung ultrasound (LUS) imaging to characterize the progression and severity of lung damage in cases of COVID-19.

METHODS

We employed a set of combined ultrasound parameters and histopathological images obtained simultaneously in 28 patients (15 women, 0.6-83 years) with fatal COVID-19 submitted to minimally invasive autopsies, with different times of disease evolution from initial symptoms to death (3-37 days, median 18 days). For each patient, we analysed eight post-mortem LUS parameters and the proportion of three histological patterns (normal lung, exudative diffuse alveolar damage [DAD] and fibroproliferative DAD) in eight different lung regions. The relationship between histopathological and post-mortem ultrasonographic findings was assessed using various statistical approaches.

RESULTS

Statistically significant positive correlations were observed between fibroproliferative DAD and peripheral consolidation (coefficient 0.43, p = 0.02) and pulmonary consolidation (coefficient 0.51, p = 0.005). A model combining age, time of evolution, sex and ultrasound score predicted reasonably well (r = 0.66) the proportion of pulmonary parenchyma with fibroproliferative DAD.

CONCLUSION

The present study adds information to previous studies related to the use of LUS as a tool to assess the severity of acute pulmonary damage. We provide a histological background that supports the concept that LUS can be used to characterize the progression and severity of lung damage in severe COVID-19.

Tracking the time course of pathological patterns of lung injury in severe COVID-19

BACKGROUND

Pulmonary involvement in COVID-19 is characterized pathologically by diffuse alveolar damage (DAD) and thrombosis, leading to the clinical picture of Acute Respiratory Distress Syndrome. The direct action of SARS-CoV-2 in lung cells and the dysregulated immuno-coagulative pathways activated in ARDS influence pulmonary involvement in severe COVID, that might be modulated by disease duration and individual factors. In this study we assessed the proportions of different lung pathology patterns in severe COVID-19 patients along the disease evolution and individual characteristics.

METHODS

We analysed lung tissue from 41 COVID-19 patients that died in the period March-June 2020 and were submitted to a minimally invasive autopsy. Eight pulmonary regions were sampled. Pulmonary pathologists analysed the H&E stained slides, performing semiquantitative scores on the following parameters: exudative, intermediate or advanced DAD, bronchopneumonia, alveolar haemorrhage, infarct (%), arteriolar (number) or capillary thrombosis (yes/no). Histopathological data were correlated with demographic-clinical variables and periods of symptoms-hospital stay.

RESULTS

Patient´s age varied from 22 to 88 years (18f/23 m), with hospital admission varying from 0 to 40 days. All patients had different proportions of DAD in their biopsies. Ninety percent of the patients presented pulmonary microthrombosis. The proportion of exudative DAD was higher in the period 0-8 days of hospital admission till death, whereas advanced DAD was higher after 17 days of hospital admission. In the group of patients that died within eight days of hospital admission, elderly patients had less proportion of the exudative pattern and increased proportions of the intermediate patterns. Obese patients had lower proportion of advanced DAD pattern in their biopsies, and lower than patients with overweight. Clustering analysis showed that patterns of vascular lesions (microthrombosis, infarction) clustered together, but not the other patterns. The vascular pattern was not influenced by demographic or clinical parameters, including time of disease progression.

CONCLUSION

Patients with severe COVID-19 present different proportions of DAD patterns over time, with advanced DAD being more prevalent after 17 days, which seems to be influenced by age and weight. Vascular involvement is present in a large proportion of patients, occurs early in disease progression, and does not change over time.

Periodontal tissues are targets for Sars-Cov-2: a post-mortem study

Background: The ability of coronavirus SARS-CoV-2 to spread is one of the determinants of the COVID-19 pandemic status. Until June 2020, global COVID-19 cases surpassed 10 million. Asymptomatic patients, with no respiratory impairment, are believed to be responsible for more than 80% of the transmission. Other viruses have been consistently detected in periodontal tissues. Objective: The aim of this study was to investigate the presence of SARS-CoV-2 in periodontal tissue. Methods: We conducted video-endoscope minimally invasive post-mortem biopsy in seven fatal cases of COVID-19, using a regular endoscope video system associated with a smartphone to locate periodontal tissue. We analyzed the samples using RT-PCR, to identify the SARS-CoV-2 RNA and histopathological analysis. Results: The seven studied autopsies with positive laboratory tests for COVID-19 included 57.14% of female patients at the average age of 47.4 (range 8 to 74). In five cases, periodontal tissue was positive for SARS-CoV-2 (RT-PCR). Histopathologic analyses showed morphologic alterations in the keratinocytes of the junctional epithelium, a vacuolization of the cytoplasm and nucleus and nuclear pleomorphism. Conclusion: We presented a biomolecular analysis obtained from minimally invasive autopsies. This is the first study to demonstrate the presence of SARS-CoV-2 in periodontal tissue in COVID-19 positive patients.

The role of artificial intelligence and machine learning in harmonization of high-resolution post-mortem MRI (virtopsy) with respect to brain microstructure

Enhanced resolution of 7 T magnetic resonance imaging (MRI) scanners has considerably advanced our knowledge of structure and function in human and animal brains. Post-industrialized countries are particularly prone to an ever-increasing number of ageing individuals and ageing-associated neurodegenerative diseases. Neurodegenerative diseases are associated with volume loss in the affected brain. MRI diagnoses and monitoring of subtle volume changes in the ageing/diseased brains have the potential to become standard diagnostic tools. Even with the superior resolution of 7 T MRI scanners, the microstructural changes comprising cell types, cell numbers, and cellular processes, are still undetectable. Knowledge of origin, nature, and progression for microstructural changes are necessary to understand pathogenetic stages in the relentless neurodegenerative diseases, as well as to develop therapeutic tools that delay or stop neurodegenerative processes at their earliest stage. We illustrate the gap in resolution by comparing the identical regions of the post-mortem in situ 7 T MR images (virtual autopsy or virtopsy) with the histological observations in serial sections through the same brain. We also described the protocols and limitations associated with these comparisons, as well as the necessity of supercomputers and data management for "Big data". Analysis of neuron and/or glial number by using a body of mathematical tools and guidelines (stereology) is time-consuming, cumbersome, and still restricted to trained human investigators. Development of tools based on machine learning (ML) and artificial intelligence (AI) could considerably accelerate studies on localization, onset, and progression of neuron loss. Finally, these observations could disentangle the mechanisms of volume loss into stages of reversible atrophy and/or irreversible fatal cell death. This AI- and ML-based cooperation between virtopsy and histology could bridge the present gap between virtual reality and neuropathology. It could also culminate in the creation of an imaging-associated comprehensive database. This database would include genetic, clinical, epidemiological, and technical aspects that could help to alleviate or even stop the adverse effects of neurodegenerative diseases on affected individuals, their families, and society.

Evaluation of peak expiratory flow in adolescents and its association with inhalable particulate in a Brazilian medium-sized city

ABSTRACT: Introduction: High particulate matter (PM10) concentrations are associated with increased incidence of respiratory symptoms and decreased lung function. This study evaluates the air pollution effects in children’s and adolescents’ lung function using peak expiratory flow (PEF) measurements over a given period, in an area exposed to industrial emissions. Methodology: This was a panel study. The effects of air pollution on respiratory symptoms and PEF were investigated in 117 children and adolescents from three public schools in areas of exposure to air pollution from a mining company in a Brazilian medium-sized city, from 2008 to 2009. The average daily PM10, temperature and humidity were recorded by the monitoring network in the region. Association between daily records of PEF and PM10 was assessed in mixed-effect regression models, controlling for temperature, humidity, and body mass index. Results: About 60,000 PEF measurements were performed. Increases of 14µg/m3 in PM10 were associated with decreased PEF in the morning (-1.04%, 95%CI -1.32; -0.77) and evening (-1.2%, 95%CI -1.49, -0.92). Discussion: We found a significant negative association between particulate matter and peak expiratory flow rate in this population, and these remained significant even after adjusted for temperature, humidity, body mass index, coughing, wheezing and coryza. Conclusion: Adverse effects were found and it suggests an association between increase in PM10 and reduced lung function.

An approach to using heart rate monitoring to estimate the ventilation and load of air pollution exposure

BACKGROUND

The effects of air pollution on health are associated with the amount of pollutants inhaled which depends on the environmental concentration and the inhaled air volume. It has not been clear whether statistical models of the relationship between heart rate and ventilation obtained using laboratory cardiopulmonary exercise test (CPET) can be applied to an external group to estimate ventilation.

OBJECTIVES

To develop and evaluate a model to estimate respiratory ventilation based on heart rate for inhaled load of pollutant assessment in field studies.

METHODS

Sixty non-smoking men; 43 public street workers (public street group) and 17 employees of the Forest Institute (park group) performed a maximum cardiopulmonary exercise test (CPET). Regression equation models were constructed with the heart rate and natural logarithmic of minute ventilation data obtained on CPET. Ten individuals were chosen randomly (public street group) and were used for external validation of the models (test group). All subjects also underwent heart rate register, and particulate matter (PM2.5) monitoring for a 24-hour period.

RESULTS

For the public street group, the median difference between estimated and observed data was 0.5 (CI 95% -0.2 to 1.4) l/min and for the park group was 0.2 (CI 95% -0.2 to 1.2) l/min. In the test group, estimated values were smaller than the ones observed in the CPET, with a median difference of -2.4 (CI 95% -4.2 to -1.8) l/min. The mixed model estimated values suggest that this model is suitable for situations in which heart rate is around 120-140bpm.

CONCLUSION

The mixed effect model is suitable for ventilation estimate, with good accuracy when applied to homogeneous groups, suggesting that, in this case, the model could be used in field studies to estimate ventilation. A small but significant difference in the median of external validation estimates was observed, suggesting that the applicability of the model to external groups needs further evaluation.

The effect of air pollution on pneumonia-related emergency department visits in a region of extensive sugar cane plantations: a 30-month time-series study

BACKGROUND

In Brazil, many cities are surrounded by sugar cane plantations, and when these plantations are burnt prior to harvesting, millions of people are exposed to the smoke from these fires from May to November every year.

METHODS

A daily time-series regression analysis was conducted in a city located in the sugar cane plantation region of São Paulo State, Brazil, between 1 February 2005 and 31 July 2007. The percentage increase in the number of pneumonia-related emergency department visits (PEDV) associated with a 10 µg/m(3) increase in the total suspended particles (TSP) concentration was measured, including any effects that were delayed for up to 6 days.

RESULTS

A total of 1505 PEDV (a median of two events per day) were analysed. During the burning period, there was an acute effect that began on the day of exposure and remained for 2 days. An increase of 6% (95% CI 2.4 to 9.9) in PEDV was observed for the 2 days following the TSP increase. This pattern and the size of the effect were similar to those observed for the whole period and also during the non-burning period.

CONCLUSIONS

Increases in TSP concentrations were found to be associated with increased PEDV in a region affected by air pollution from sugar cane burning. This finding reinforces the need for polices and efforts to ban sugar cane burning prior to harvesting.

Risk assessment of PM(2.5) to child residents in Brazilian Amazon region with biofuel production

BACKGROUND

Exposure to fine fractions of particulate matter (PM(2.5)) is associated with increased hospital admissions and mortality for respiratory and cardiovascular disease in children and the elderly. This study aims to estimate the toxicological risk of PM(2.5) from biomass burning in children and adolescents between the age of 6 and 14 in Tangará da Serra, a municipality of Subequatorial Brazilian Amazon.

METHODS

Risk assessment methodology was applied to estimate the risk quotient in two scenarios of exposure according to local seasonality. The potential dose of PM(2.5) was estimated using the Monte Carlo simulation, stratifying the population by age, gender, asthma and Body Mass Index (BMI).

RESULTS

Male asthmatic children under the age of 8 at normal body rate had the highest risk quotient among the subgroups. The general potential average dose of PM(2.5) was 1.95 μg/kg.day (95% CI: 1.62 - 2.27) during the dry scenario and 0.32 μg/kg.day (95% CI: 0.29 - 0.34) in the rainy scenario. During the dry season, children and adolescents showed a toxicological risk to PM(2.5) of 2.07 μg/kg.day (95% CI: 1.85 - 2 .30).

CONCLUSIONS

Children and adolescents living in the Subequatorial Brazilian Amazon region were exposed to high levels of PM(2.5) resulting in toxicological risk for this multi-pollutant. The toxicological risk quotients of children in this region were comparable or higher to children living in metropolitan regions with PM(2.5) air pollution above the recommended limits to human health.

In utero exposure to air pollution lowers erythrocyte antioxidant defense and decreases weight in adult mice

In this study, we tested the influence of ambient air pollution on different phases of development of adult mice. With respect to adult weight, the animals that had spent their in utero period exposed to pollution showed less weight gain over their lifetime, as well as lower activity levels of the antioxidant enzymes catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx). Our study suggests that contact with atmospheric pollutants during the foetal period produces important changes on enzymatic erythrocyte antioxidant defense and weight in adult mice.

The association between air pollution and blood pressure in traffic controllers in Santo André, São Paulo, Brazil

BACKGROUND

Urban air pollutants are associated with cardiovascular events. Traffic controllers are at high risk for pollution exposure during outdoor work shifts.

OBJECTIVE

The purpose of this study was to evaluate the relationship between air pollution and systemic blood pressure in traffic controllers during their work shifts.

METHODS

This cross-sectional study enrolled 19 male traffic controllers from Santo André city (São Paulo, Brazil) who were 30-60 years old and exposed to ambient air during outdoor work shifts. Systolic and diastolic blood pressure readings were measured every 15 min by an Ambulatory Arterial Blood Pressure Monitoring device. Hourly measurements (lags of 0-5h) and the moving averages (2-5h) of particulate matter (PM(10)), ozone (O(3)) ambient concentrations and the acquired daily minimum temperature and humidity means from the São Paulo State Environmental Agency were correlated with both systolic and diastolic blood pressures. Statistical methods included descriptive analysis and linear mixed effect models adjusted for temperature, humidity, work periods and time of day.

RESULTS

Interquartile increases of PM(10) (33 μg/m(3)) and O(3) (49 μg/m(3)) levels were associated with increases in all arterial pressure parameters, ranging from 1.06 to 2.53 mmHg. PM(10) concentration was associated with early effects (lag 0), mainly on systolic blood pressure. However, O(3) was weakly associated most consistently with diastolic blood pressure and with late cumulative effects.

CONCLUSIONS

Santo André traffic controllers presented higher blood pressure readings while working their outdoor shifts during periods of exposure to ambient pollutant fluctuations. However, PM(10) and O(3) induced cardiovascular effects demonstrated different time courses and end-point behaviors and probably acted through different mechanisms.

A review of low-level air pollution and adverse effects on human health: implications for epidemiological studies and public policy

The aim of this study was to review original scientific articles describing the relationship between atmospheric pollution and damage to human health. We also aimed to determine which of these studies mentioned public policy issues. Original articles relating to atmospheric pollution and human health published between 1995 and 2009 were retrieved from the PubMed database and analyzed. This study included only articles dealing with atmospheric pollutants resulting primarily from vehicle emissions. Three researchers were involved in the final selection of the studies, and the chosen articles were approved by at least two of the three researchers. Of the 84 non-Brazilian studies analyzed, 80 showed an association between atmospheric pollution and adverse effects on human health. Moreover, 66 showed evidence of adverse effects on human health, even at levels below the permitted emission standards. Three studies mentioned public policies aimed at changing emission standards. Similarly, the 29 selected Brazilian studies reported adverse associations with human health, and 27 showed evidence of adverse effects even at levels below the legally permitted emission standards. Of these studies, 16 mentioned public policies aimed at changing emission standards. Based on the Brazilian and non-Brazilian scientific studies that have been conducted, it can be concluded that, even under conditions that are compliant with Brazilian air quality standards, the concentration of atmospheric pollutants in Brazil can negatively affect human health. However, as little discussion of this topic has been generated, this finding demonstrates the need to incorporate epidemiological evidence into decisions regarding legal regulations and to discuss the public policy implications in epidemiological studies.

The effects of chronic exposure to traffic derived air pollution on the ocular surface

OBJECTIVES

The purpose of this study was to explore the clinical relevance of chronic exposure to ambient levels of traffic derived air pollution on the ocular surface.

METHODS

A panel study involving 55 volunteers was carried out in São Paulo, Brazil. We measured the mean individual levels of nitrogen dioxide (NO(2)) exposure for 7 days. All subjects answered the Ocular Symptom Disease Index (OSDI) and a symptoms inventory. Subsequently, subjects underwent Schirmer I test, biomicroscopy, vital staining and tear breakup time (TBUT) assessment. Subject's mean daily exposure to NO(2) was categorized in quartiles. Statistical analysis was performed using one-way ANOVA, Tukey HSD and Chi-Square tests.

RESULTS

A dose-response pattern was detected between OSDI scores and NO(2) quartiles (p<0.05). There was a significant association between NO(2) quartiles and reported ocular irritation (Chi(2)=9.2, p<0.05) and a significant negative association between TBUT and NO(2) exposure (p<0.05, R=-0.316, Spearman's correlation). There was a significant increase in the frequency of meibomitis in subjects exposed to higher levels of NO(2) (p<0.05).

CONCLUSIONS

Subjects exposed to higher levels of traffic derived air pollution reported more ocular discomfort symptoms and presented greater tear film instability, suggesting that the ocular discomfort symptoms and tear breakup time could be used as convenient bioindicators of the adverse health effects of traffic derived air pollution exposure.

Homocysteine and cysteine concentrations are modified by recent exposure to environmental air pollution in São Paulo, Brazil

Millions of people worldwide are affected by anthropogenic air pollution derived from the combustion of fossil fuels. In this work, we tested the effects of fetal, lactation and post-weaning ambient air pollution exposure on total homocysteine (tHcy) concentrations and on a downstream pathway element, the plasma cysteine (Cys) concentration. Two similar exposure chambers (polluted and filtered chamber) were located near an area with heavy traffic in São Paulo, Brazil, and male Swiss mice were housed there from the pre-natal period until 3 months of age. Groups during fetal, lactation and adult periods of exposure were apportioned, and tHcy and Cys plasma concentrations were assessed when the animals were 3 months old. In our study, both the tHcy and Cys concentrations were decreased in groups that spent their final stage of life in polluted chambers, suggesting recent alterations in tHcy and Cys concentrations due to air pollution exposure. The possible relationship of these data with cardiovascular dysfunction is still a matter of controversy in animals; nevertheless, epigenetic mechanisms emerge as a possible issue to consider in the investigation of the link between air pollution and Hcy measurement.

Spatial analysis of urban violence based on emergency room data

OBJECTIVE

To estimate the spatial intensity of urban violence events using wavelet-based methods and emergency room data.

METHODS

Information on victims attended at the emergency room of a public hospital in the city of São Paulo, Southeastern Brazil, from January 1, 2002 to January 11, 2003 were obtained from hospital records. The spatial distribution of 3,540 events was recorded and a uniform random procedure was used to allocate records with incomplete addresses. Point processes and wavelet analysis technique were used to estimate the spatial intensity, defined as the expected number of events by unit area.

RESULTS

Of all georeferenced points, 59% were accidents and 40% were assaults. There is a non-homogeneous spatial distribution of the events with high concentration in two districts and three large avenues in the southern area of the city of São Paulo.

CONCLUSIONS

Hospital records combined with methodological tools to estimate intensity of events are useful to study urban violence. The wavelet analysis is useful in the computation of the expected number of events and their respective confidence bands for any sub-region and, consequently, in the specification of risk estimates that could be used in decision-making processes for public policies.

Ambient levels of air pollution induce goblet-cell hyperplasia in human conjunctival epithelium

BACKGROUND

Ocular mucosa is exposed constantly to the external environment, and chronic exposure to air pollution may affect the ocular surface.

OBJECTIVE

We assessed the effect of air pollution on the ocular surface by combining determinations of individual exposure and conjunctival impression cytology.

METHODS

A panel study was conducted with 29 volunteers recruited in two locations with different pollution levels: São Paulo (n = 13) and Divinolândia (n = 16). We assessed mean individual levels of nitrogen dioxide (NO2) exposure for 7 days, using a passive sampler. Impression cytology samples were obtained from inferior tarsal conjunctiva. Comparisons between the two groups in terms of NO2 exposure and goblet-cell counts were performed using the Student t-test. Correlations between goblet-cells counts and corresponding individual NO2 exposure levels were determined using Spearman's correlation.

RESULTS

Individuals living in São Paulo received a significantly (p = 0.005) higher dose of NO2 (mean 32.47; SD 9.83) than those living in Divinolândia (mean 19.33; SD 5.24). There was a steady increase in goblet-cell counts, proportional to NO2 exposure (Spearman's correlation = 0.566, p = 0.001), with a dose-response pattern.

CONCLUSIONS

A positive and significant association between exposure to air pollution and goblet-cell hyperplasia in human conjunctiva was detected. The combination of simple measurements of exposure and impression cytology was an effective and noninvasive approach for characterizing human response to ambient levels of air pollution.

Associação entre poluição atmosférica e doenças respiratórias e cardiovasculares na cidade de Itabira, Minas Gerais, Brasil

A cidade de Itabira, Minas Gerais, Brasil, está localizada na Serra do Espinhaço, onde existem grandes jazidas de minério de ferro que são extraídas em lavra mecanizada a céu aberto. Este estudo foi realizado para avaliar os efeitos agudos do material particulado inalável (PM10) sobre os atendimentos em pronto-socorro por doenças respiratórias e cardiovasculares no Município de Itabira. Modelos aditivos generalizados de regressão de Poisson foram utilizados, controlando-se para temperatura, umidade e sazonalidades de longa e curta duração. Aumentos de 10µg/m³ no PM10 foram associados com aumentos nos atendimentos de pronto-socorro por doenças respiratórias de 4% (IC95%: 2,2-5,8), no dia e no dia seguinte, para crianças menores de 13 anos, e de 12% (IC95%: 8,5-15,5), nos três dias subseqüentes para os adolescentes entre 13 e 19 anos. Dentre os atendimentos por doenças cardiovasculares, o efeito foi agudo (4%; IC95%: 0,8-8,5), principalmente para os indivíduos com idade entre 45 e 64 anos. Esses resultados mostram que o PM10 gerado principalmente através de mineração a céu aberto pode acarretar prejuízos à saúde da população exposta.

Effects of air pollution on blood pressure and heart rate variability: a panel study of vehicular traffic controllers in the city of São Paulo, Brazil

AIMS

Evaluating the effects of air pollution on Sao Paulo city's vehicular traffic controllers by means of risk indicators for cardiovascular diseases.

METHODS AND RESULTS

Twenty-four hour blood pressure recordings and an electrocardiogram were obtained in 48 healthy, non-smoking vehicular traffic controllers, aged 31-55 years, during three periods: winter 2000, summer 2001, and winter 2001. Effects of air pollutants on the outcomes were estimated using linear regression based on generalized estimated equations, controlling for age, body mass index, humidity, and temperature. An interquartile range (IQR) increase in CO (1.1 p.p.m.) was associated with increases of 2.6 mmHg (95% CI 1.0, 4.2), 1.8 mmHg (95% CI 0.8, 2.8), and 2.4 mmHg (95% CI 1.1, 3.6) in systolic, diastolic, and mean 24 h ambulatory blood pressures. SO(2) also had relevant effects on blood pressure. On heart rate variability, an IQR increase of SO2 (9.6 microg/m3) was negatively associated with the standard deviation (SD) of normal RR intervals (SDNN) -7.93 ms (95% CI -15.3, -0.6).

CONCLUSION

This study supplies biological plausibility for observational studies on air pollution-related cardiovascular morbidity and mortality.

Queima de biomassa e efeitos sobre a saúde

A primeira idéia que se forma na mente das pessoas e do pesquisador é associar a poluição do ar aos grandes centros urbanos, com a imagem de poluentes sendo eliminados por veículos automotores ou pela chaminé de suas fábricas. Entretanto, uma parcela considerável da população do planeta convive com uma outra fonte de poluição, que atinge preferencialmente os países em desenvolvimento: a queima de biomassa. Este artigo tem como objetivo chamar a atenção do pneumologista, da comunidade e das autoridades para os riscos à saúde da população exposta a essa fonte geradora de poluentes, seja em ambientes internos, seja em ambientes abertos. O presente trabalho caracteriza as principais condições que levam à combustão de biomassa, como a literatura tem registrado os seus efeitos sobre a saúde humana, discutindo os mecanismos fisiopatológicos envolvidos, e finaliza com a apresentação de dois estudos recentes que enfatizam a importância da queima de um tipo específico de biomassa, a palha da cana-de-açúcar, prática comum no interior do Brasil, e sua interferência no perfil de morbidade respiratória da população exposta.

Centrilobular fibrosis: a novel histological pattern of idiopathic interstitial pneumonia

The classification of idiopathic interstitial pneumonias (IIP) is still under debate. In this context, we observed in some of our patients with a clinical and radiological diagnosis of IIP a different histological picture with an aggressive centrilobular scarring centered in the bronchiolar epithelia, but involving the surrounding parenchyma, which underwent extensive remodeling. We hypothesized that this pattern is a form of IIP that could be separated out histologically from the previously described patterns, in particular from usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP). Forty-nine patients with clinical and radiological diagnosis of IIP and open-lung biopsies were retrospectively selected from 1982 to 1998. The biopsies were reviewed according to the following criteria: derangement of lobular architecture, temporal homogeneity and subpleural or bronchocentric distribution of the lesions, fibroblast foci, bronchial epithelium necrosis and regeneration, exposure of the basal membrane, squamous metaplasia, basophilic intraluminal contents, and foreign bodies within the remodeling airspaces. Three groups were found: UIP (24 patients), NSIP (13), and a third that we named centrilobular fibrosis (CLF) (12). All histological parameters were significantly different among the three groups (p < 0.001). CLF is a specific, homogeneous, and recognizable histological pattern of IIP, and can be isolated from UIP and NSIP.

Air pollution and emergency room visits due to chronic lower respiratory diseases in the elderly: an ecological time-series study in São Paulo, Brazil

The objective of this study was to investigate the effect of daily air pollution levels (carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide, and particulate matter with an aerodynamic profile < or = 10 microns) on morbidity by using the daily number of emergency room visits due to chronic lower respiratory disease (CLRD) in people older than 64 years of age in the city of São Paulo, Brazil, from 1996 to 1998. Generalized additive Poisson regression models adjusted for long-time trend and weather (nonparametric functions), weekdays (dummy variable), and daily number of nonrespiratory admissions were adopted. Ozone and sulfur dioxide were the pollutants statistically associated with CLRD visits. Interquartile range increases in the 6-day moving average of sulfur dioxide (11.82 micrograms/m3) and in the 4-day moving average of ozone(35.87 micrograms/m3) increased CLRD emergency room visits in 18% and 14%, respectively. These results reinforce the idea that air pollution may promote adverse health effects in the elderly.