Biomedical subjects

Paulo H N Saldiva

Publications and source records attributed to Paulo H N Saldiva.

At least 19 recordsLinked to original sources

PubMed2006

Increased levels of air pollution and a decrease in the human and mouse male-to-female ratio in São Paulo, Brazil.

A significant negative association (R(2) = 0.7642; P=.013) between particulate matter and secondary sex ratio was found when evaluating people in the city of São Paulo, Brazil. An animal model with male mice raised in nonfiltered open-top chambers showed a significant reduction in the secondary sex ratio (P=.041), suggesting that ambient air pollution may interfere with sex distribution by altering the X:Y sperm proportion in pollution-exposed males.

Air Pollution↗

PubMed2006

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.

Aged↗

PubMed2006

Evaluation of mutagenic potential of contaminated atmosphere at Ibirapuera Park, São Paulo - SP, Brazil, using the Tradescantia stamen-hair assay.

Trad-SHM assay was used to check mutagenic potential of atmospheric contamination at Ibirapuera Park, located in São Paulo city, Brazil, and variation of risk along the year, besides determining which Tradescantia clone, BNL 4430 or KU-20, better indicates risk. Thirty pots of both clones were exposed during one-year period (September, 2002-August, 2003). Twenty inflorescences were taken from each clone twice a month in the morning, in order to estimate the frequency of mutations in stamen hairs. Results were compared to air pollution and climatic data measured next to the exposure site. KU-20 showed stamen-hair mutations greater than BNL 4430. Greatest mutation rates in KU-20 were observed in condition of high monthly mean of NO(2) and average peak concentrations of NO during the day, indicating that mutagenic effects originated from vehicular pollution. Clone KU-20 revealed to be more appropriate for biomonitoring purposes at the Park.

Air Pollutants↗

PubMed2006

Short-term effects of nCPAP on nasal mucociliary clearance and mucus transportability in healthy subjects.

Nasal mucociliary clearance is a primary defense mechanism of the upper airways and may be acutely affected by nasal continuous positive airway pressure (nCPAP). nCPAP treatment is effective and safe. However, it can cause nasal side effects and contribute to a low compliance to the treatment. The aim of this study was to investigate the short-term effects of nCPAP on nasal mucociliary clearance and on mucus transportability of healthy subjects. Eleven healthy subjects were submitted to 20 min of nCPAP (10 cm H2O). Five subjects were also evaluated before and after 20 min of rest on the consecutive study day. Nasal mucociliary clearance was measured by the saccharin nasal transit time test and nasal mucus was collected for the in vitro study of mucus transportability by the frog palate model, both before and after the nCPAP challenge. Saccharin nasal transit time decreased significantly after nCPAP (9.29+/-6.06 min and 4.83+/-5.57 min; P=0.002 before and after nCPAP respectively). No significant changes were observed on the control day (11.66+/-7.57 min and 12.40+/-5.62 min; P=0.70). Mucus transportability was not significantly affected by nCPAP. Our results suggest that nCPAP can acutely increase nasal mucociliary clearance but does not affect in vitro mucus transportability in healthy subjects.

Adult↗

PubMed2006

Comparison between clinical diagnoses and autopsy findings in a pediatric intensive care unit in São Paulo, Brazil.

OBJECTIVE: To verify the frequency of discrepancies between clinical diagnoses and autopsy findings in patients from a pediatric intensive care unit and to look for predictive factors of the discrepancies. DESIGN: Prospective evaluation performed between September 1996 and December 1998. SETTING: Eight-bed pediatric intensive care unit of a university hospital. PATIENTS: One hundred and two autopsies. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Disagreements between autopsy and antemortem diagnoses were classified as proposed by Goldman. Patient age, presence of underlying disease, and length of stay were studied as possible predictive factors for diagnosis discrepancies. During the 28 months of study there were 779 admissions to the pediatric intensive care unit; the death rate was 26% and the autopsy rate was 55%. One hundred and two of 114 (89.5%) autopsies were evaluated. The median age of the patients was 21 months, and 85% of them had a previous underlying disease. One third of patients died before 24 hrs of admission to the pediatric intensive care unit. The autopsy revealed unexpected findings in 73 study patients (72%), 33 of which were related to "major diagnoses" (Goldman's classes I or II), either causes of death or main underlying disease. In 12 patients (12%), the correct diagnosis, if known before death, might have led to a change in the patient's therapy or outcome (class I). Unexpected findings in this group included viral or fungal infection and pulmonary embolism. None of the possible predictive factors that we studied showed significant statistical association between clinical and autopsy discrepant diagnoses in the univariate analysis. CONCLUSIONS: Although diagnoses of both cause of death and underlying disease were accurate in most cases before death, some autopsies revealed findings that would have changed intensive care unit therapy. Nonbacterial infections and pulmonary thromboembolism should always be considered when managing critically ill patients with underlying disease. Autopsy examinations continue to provide important information, especially in the pediatric intensive care unit setting, despite the advances in diagnostic technology.

Adolescent↗

PubMed2006

The impact of sugar cane-burning emissions on the respiratory system of children and the elderly.

We analyzed the influence of emissions from burning sugar cane on the respiratory system during almost 1 year in the city of Piracicaba in southeast Brazil. From April 1997 through March 1998, samples of inhalable particles were collected, separated into fine and coarse particulate mode, and analyzed for black carbon and tracer elements. At the same time, we examined daily records of children (<13 years of age) and elderly people (>64 years of age) admitted to the hospital because of respiratory diseases. Generalized linear models were adopted with natural cubic splines to control for season and linear terms to control for weather. Analyses were carried out for the entire period, as well as for burning and nonburning periods. Additional models were built using three factors obtained from factor analysis instead of particles or tracer elements. Increases of 10.2 microg/m3 in particles<or=2.5 microm/m3 aerodynamic diameter (PM2.5) and 42.9 microg/m3 in PM10 were associated with increases of 21.4% [95% confidence interval (CI), 4.3-38.5] and 31.03% (95% CI, 1.25-60.21) in child and elderly respiratory hospital admissions, respectively. When we compared periods, the effects during the burning period were much higher than the effects during nonburning period. Elements generated from sugar cane burning (factor 1) were those most associated with both child and elderly respiratory admissions. Our results show the adverse impact of sugar cane burning emissions on the health of the population, reinforcing the need for public efforts to reduce and eventually eliminate this source of air pollution.

Aged↗

PubMed2006

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 microg/m(3)) and SO2 (10.73 microg/m(3)) 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. CONCLUSIONS: The results show that cardiovascular diseases in São Paulo are strongly affected by air pollution.

Aged↗

PubMed2005

Effects of exercise training on papain-induced pulmonary emphysema in Wistar rats.

The purpose of the present study was to evaluate the role of exercise training on the development of papain-induced emphysema in rats. Our hypothesis was that the increase in pulmonary tissue stretching associated with exercise could increase the severity of a protease-induced emphysema. Wistar rats were randomly assigned to four groups (n = 10 for each group) that received, respectively, intratracheal infusion of papain (6 mg in 1 ml of 0.9% NaCl) or vehicle and were submitted or not to a protocol of exercise on a treadmill. Rats exercised at 13.3 m/min, 6 days/wk, for 9 wk (increasing exercise time, from 10 to 35 min). We measured respiratory system elastance and resistance, the size and weight of the heart, and pulmonary mean linear intercept (Lm). After 9 wk of exercise training, there were no differences in respiratory system resistance and elastance values among the four experimental groups. Volume of the heart was significantly greater in rats submitted to exercise training (P = 0.007) compared with sedentary rats due to increases in volumes of both right and left cardiac chambers. Lm was significantly greater in rats that received papain compared with saline-infused rats (P = 0.025). Surprisingly, this was true, even though there was no significant decrease in elastance, possibly due to connective tissue remodeling. However, Lm was significantly greater in papain + exercise rats compared with rats that received papain and were not submitted to exercise. We conclude that exercise training can increase alveolar damage induced by papain infusion.

Airway Resistance↗

PubMed2005

Nitric acid-induced bronchiolitis in rats mimics childhood Bronchiolitis obliterans.

BACKGROUND: Childhood bronchiolitis obliterans (CBO) is an infrequent but severe disease, characterized by persistent obstructive respiratory symptoms after an acute episode of bronchiolitis. Its etiology is mostly postviral, especially in developing countries. Pathologically, CBO is characterized as constrictive-type BO. The pathogenesis of this disease is poorly understood and there is no specific treatment. Animal models could help to better understand the sequence of events culminating in bronchiolar obliteration and serve as basis for experimental therapeutic research. OBJECTIVES: In this study, we adapted the nitric acid (NA) technique to develop a suitable model to study CBO in rats. METHODS: We have intratracheally instilled 0.5% NA or saline and studied the histological lesions on days 2, 7, 14 and 30. NA-instilled animals developed a sequence of bronchiolar lesions that included necrotizing bronchiolitis, proliferative (PROL) bronchiolar lesions and constrictive (CONS) bronchiolar lesions with bronchiectasis, mucostasis and macrophagic accumulation. RESULTS: The frequency of PROL lesions decreased and that of the CONS lesions increased, with a statistically significant difference at the sacrifice days, except for day 7 (PROL vs. CONS lesions day 2: p = 0.001; PROL vs. CONS lesions day 7: p = 0.38; PROL vs. CONS lesions day 14: p < 0.001; PROL vs. CONS lesions day 30: p < 0.001). CONCLUSIONS: We conclude that this model presents histological similarities with the histological picture of CBO, being suitable for further developmental and therapeutic experimental research in this field.

Animals↗

PubMed2005

Sputum induction as a research tool for the study of human respiratory mucus.

The study objectives were to compare in vitro transportability and physical properties of respiratory mucus, obtained invasively by direct collection (DC) right after endotracheal intubation and non-invasively by sputum induction with 3% hypertonic saline solution inhalation (SI) 24 h before the anesthesia. Twenty-two patients with no pulmonary disease scheduled for elective abdominal surgical procedures were studied. The parameters analyzed and the main results are as follows. (1) Transportability by cilia (MCT), SI was higher than DC (0.94+/-0.25 and 0.62+/-0.25; P<0.001). There was a significant correlation between the two methods and DC could be estimated by: DC=0.21+(0.44 SI) (r=0.44; P<0.001). (2) Transportability by cough (CC), SI was higher than DC (68.23+/-32.1 and 33.58+/-19.04 mm; P=0.002). (3) Contact angle (CA), SI was lower than DC (10+/-3 degrees and 22+/-14 degrees ; P=0.025). (4) Rheological properties (no significant difference obtained between SI and DC). These results indicated that SI changes mucus physical properties and transportability in non-expectorators.

Adolescent↗

PubMed2004

Anti-oxidants reduce the acute adverse effects of residual oil fly ash on the frog palate mucociliary epithelium.

There is evidence indicating that oxidants play a pivotal role in determining air pollution-dependent lung injury. In the present study we explored the role of oxidants present in ambient particles in causing damage to the mucociliary epithelium. We explored the protective effects of pretreatment with three substances (n-propyl gallate, DL-alpha-tocopherol acetate, and EDTA) on the frog palate exposed to residual oil fly ash (ROFA). The parameters analyzed were mucociliary transport (MCT) and ciliary beating frequency (CBF) after 0, 10, 20, 30, 60, and 120 min of exposure. MCT was decreased significantly by ROFA (P < 0.001), with a significant interaction effect (P = 0.02) between the duration of exposure and treatment with antioxidants. The inhibitory effects on MCT of the substances tested were significantly different (P = 0.002); vitamin E was similar to control (Ringer) and different from all other groups. CBF showed no significant effect of duration of exposure (P = 0.465), but a significant interaction between duration of exposure and treatments was observed (P = 0.011). Significant differences were detected among treatments (P < 0.001), with ROFA and n-propyl gallate at concentrations of 50 microM presenting a short-lived increase in CBF, which was not observed in the remaining groups. The results showed that both MCT and CBF were affected within a short period (100 min) of exposure to ROFA and that the presence of antioxidant substances, such as vitamin E (4 mg/mL) and n-propyl gallate (300 microM), protected against the mucociliary impairment induced by ROFA on the frog palate.

Acute Disease↗

PubMed2004

[Hospital admissions and mortality: association with air pollution in São Paulo, Brazil, 1993 to 1997].

OBJECTIVE: To investigate short-term effects of air pollution on respiratory morbidity of children under 15 and elderly mortality. METHODS: The study was carried out in the city of São Paulo, Brazil. Daily hospital admissions due to respiratory conditions in children under 15 and mortality of adults over 64 years of age were obtained for the period ranging from 1993 to 1997. Daily levels of PM10, CO and O3 were collected for the same period. Poisson regression analysis was used in generalized additive models, which were adjusted for temporal trends, seasonality, day of the week, temperature and relative humidity as well as serial autocorrelation. RESULTS: A 10th to 90th percentile variation of pollutants was significantly associated with respiratory admissions of children and PM10 (%RR=10.0), CO (%RR=6.1), and O3 (%RR=2.5). Similar results were observed for mortality in elderly people and PM10 (%RR=8.1) and CO (%RR=7.9). CONCLUSIONS: The study results are consistent with other studies showing an association of short-term variations of air pollution and increase of morbidity and mortality in large urban centers.

Adolescent↗

PubMed2004

Abnormal alveolar attachments with decreased elastic fiber content in distal lung in fatal asthma.

Small airway disease is thought to contribute significantly to functional impairment caused by asthma. Functional evidence of airway-parenchyma uncoupling in asthma, such as loss of deep breath bronchodilator effect in bronchoconstrictive episodes and enhanced airway closure, has been previously demonstrated. Elastic fibers are essential to maintain adequate elastic recoil of the lungs. In this study, we hypothesized that alveolar attachments could be abnormal and that elastic fibers could be damaged in the distal lungs of patients with fatal asthma. For this purpose, we measured the number of abnormal alveolar attachments and quantified the content of elastic fibers in the adventitial layer of small airways and in the peribronchial and distal alveolar septa of 15 patients who died of asthma (FA) and 9 control subjects (CTRL). Our data (geometric mean [range]) showed an increased proportion of abnormal alveolar attachments per centimeter of basement membrane perimeter in fatal asthma (FA, 0.18 [0.03-4.00]; CTRL, 0.00 [0.00-0.12]; p < 0.001) and decreased elastic fiber content in the small airway adventitial layer (FA, 4.08 [2.22-11.46] microm; CTRL, 6.79 [5.62-10.0] microm; p = 0.01) and in the peribronchial alveoli (FA, 1.08 [0.46-1.91] microm; CTRL, 1.81 [1.22-1.74] microm; p = 0.003), but not in the distal alveoli. We propose that structural alterations at the peribronchiolar level might contribute to the pathogenesis of some functional abnormalities observed in patients with severe asthma.

Adult↗

PubMed2004

Evaluation of the mutagenic potential of urban air pollution in São Paulo, Southeastern Brazil, using the Tradescantia stamen-hair assay.

We used a short-term bioassay--the Tradescantia stamen-hair assay (TSH)--to evaluate the toxicity of ambient particles with an aerodynamic diameter less than 10 microm sampled in the metropolitan region of São Paulo, Brazil. Two exposure locations were selected: downtown São Paulo and Caucaia do Alto (mean PM10 levels of 64 and 14 microg/m3, respectively). The experiment was conducted July 11-August 15, 2002, and toxicity was assessed with the Tradescantia stamen-hair assay (TSH) employing clone KU-20 of Tradescantia. Four experimental groups were defined: inflorescences collected from plants cultivated in Caucaia, inflorescences collected from plants cultivated in São Paulo (to establish the baseline level of mutations in stamen hairs at both sites), inflorescences collected from plants cultivated in Caucaia and brought to São Paulo and maintained in chambers that received ambient air, and inflorescences collected from plants cultivated in Caucaia and brought to São Paulo and maintained in chambers that received air passed through a particle filter. The frequency of mutations observed in Caucaia was significantly lower than that in the remaining groups. Flower cuttings brought from Caucaia and receiving ambient air of São Paulo showed a rate of mutations similar to that of plants cultivated in São Paulo. Filtering particles from the air reduced the rate of mutation but not sufficiently to reach the level of that in Caucaia. The frequency of mutations observed in São Paulo was significantly associated with PM10 levels on the fifth day before the opening of the flowers (r = 0.47, p = 0.025). Our results indicate that urban particles play a significant role in the development of pollution-dependent mutations.

Air Movements↗

PubMed2004

Histologic patterns of lung infiltration of B-cell, T-cell, and Hodgkin lymphomas.

Secondary lung infiltration by lymphomas occurs frequently. To our knowledge, however, no recent studies have attempted to discriminate histologic patterns of lung infiltration in the lymphoma subtypes. We retrospectively evaluated the frequency of lung infiltration and the respective infiltration patterns by lymphomas at autopsy, during an 11-year period. Lymphomas were classified according to the 2001 World Health Organization Classification of hematologic malignancies in B-cell, T-cell, and Hodgkin lymphomas (HLs). In 21,157 autopsies, 414 reports with lymphoma diagnosis were reviewed histologically, and 85 showed lung infiltration (20.5%). We studied 14 HLs, 43 B-cell lymphomas, and 20 T-cell lymphomas. Five infiltration patterns were identified: peribronchial-perivascular, nodular alveolar, interstitial, and pleural. Approximately half of the lymphomas had more than 1 infiltration pattern (mean, 1.7); peribronchial-perivascular and pleural were the most frequent. The frequency of nodular infiltration was larger in HL than in B-cell lymphomas. T-cell lymphomas had a larger frequency of the interstitial infiltration pattern compared with B-cell lymphomas. Recognizing the frequency and patterns of lung infiltration in the light of a more recent classification is certainly useful for physicians dealing with lymphoma diagnostic procedures, such as radiologists and pathologists.

Adolescent↗

PubMed2003

Vascular remodeling process in reversibility of pulmonary arterial hypertension secondary to congenital heart disease.

Pulmonary vascular remodeling process was analyzed using morphometry in lung biopsy specimens taken from 26 children, aged 6 to 160 months, who had congenital heart disease and significant pulmonary arterial hypertension. Reparative surgery was performed in 22 patients and palliative surgery was performed in four patients. One patient expired postoperatively and four others after hospital discharge. Vascular remodeling examination revealed a characteristic pathological picture: pronounced medial thickening with increased collagen content (fibrosis), without significant arterial intimal proliferation. At a mean follow-up of 44 months, 72% of the survivors were asymptomatic with no medication. Diagnosed by echocardiogram, 22% of these patients were shown to have pulmonary arterial hypertension. The characteristic pathological features described above occurred in 38% of the patients who either expired or had pulmonary hypertension postoperatively. These findings were an aid to identifying a high risk group in which the outcome does not meet expectations for the classical grade I and II changes. We concluded that the presence of isolated medial thickening does not ensure either survival or a normal postoperative pulmonary arterial pressure at late follow-up and that the collagen content can be a better reference for good outcome. Early intracardiac repair is recommended before the development of significant medial fibrosis.

Adolescent↗

PubMed2003

Comparison of three methods for differential cell count in induced sputum.

BACKGROUND: Induced sputum (IS) using the cytospin technique has been extensively employed to characterize inflammatory airway diseases; however, procedures of cell enrichment based on cytospin increase the analytical costs and require slide processing within a short period of time after sampling. STUDY OBJECTIVES: To compare three different techniques for cytologic analysis of IS, and to determine the time required by each method and the costs involved. DESIGN: Cross-sectional study. SETTING: Tertiary-care university hospital. PATIENTS AND MEASUREMENTS: Eighty-nine patients with asthma and 11 subjects without asthma were submitted to increasing hypertonic saline solution concentrations of 2, 3, 4, and 5% for 7 min for sputum induction. Samples were smeared without treatment with 0.1% dithiothreitol (DTT) [technique A], after treatment with DTT (technique B), and after treatment with DTT and cytospin (technique C). All slides were air-dried and stained with Leishman stain. Two independent observers counted at least 200 inflammatory cells on each slide. RESULTS: Eighty percent of the slides processed by techniques A and B and 65% of the slides processed by technique C represented sputum samples of acceptable quality. The eosinophil percentages in sputum obtained by techniques A and C were closely correlated, as also were those obtained by techniques B and C (r = 0.64 and r = 0.63, respectively; p < 0.01). There was a positive correlation for eosinophils when we compared techniques A and B (r = 0.57, p < 0.01). The neutrophil correlation was significant when the three techniques were compared (technique A vs technique B, r = 0.66; technique A vs technique C, r = 0.51; and technique B vs technique C, r = 0.57; p < 0.01). Bland-Altman analysis showed a good agreement for eosinophil and neutrophil counts when techniques A and B were compared to technique C. CONCLUSIONS: The three techniques are good indicators of lung inflammation. Techniques A and B are less time consuming and are of lower cost.

Adolescent↗

PubMed2002

Lung inflammation induced by concentrated ambient air particles is related to particle composition.

The objectives of this study were (1) to determine whether short-term exposures to concentrated air particles (CAPs) cause pulmonary inflammation in normal rats and rats with chronic bronchitis (CB); (2) to identify the site within the lung parenchyma where CAPs-induced inflammation occurs; and (3) to characterize the component(s) of CAPs that is significantly associated with the development of the inflammatory reaction. Four groups of animals were studied: (1) air treated, filtered air exposed (air-sham); (2) sulfur dioxide treated (CB), filtered air exposed (CB-sham); (3) air treated, CAPs exposed (air-CAPs); and (4) sulfur dioxide treated, CAPs exposed (CB-CAPs). CB and normal rats were exposed by inhalation either to filtered air or CAPs during 3 consecutive days (5 hours/day). Pulmonary inflammation was assessed by bronchoalveolar lavage (BAL) and by measuring the numerical density of neutrophils (Nn) in the alveolar walls at the bronchoalveolar junction and in more peripheral alveoli. CAPs (as a binary exposure term) and CAPs mass (in regression correlations) induced a significant increase in BAL neutrophils and in normal and CB animals. Nn in the lung tissue significantly increased with CAPs in normal animals only. Greater Nn was observed in the central compared with peripheral regions of the lung. A significant dose-dependent association was found between many CAPs components and BAL neutrophils or lymphocytes, but only vanadium and bromine concentrations had significant associations with both BAL neutrophils and Nn in CAPs-exposed groups analyzed together. Results demonstrate that short-term exposures to CAPs from Boston induce a significant inflammatory reaction in rat lungs, with this reaction influenced by particle composition.

Air Pollutants↗