The minimum sum of absolute errors regression: a robust alternative to the least squares regression.

This paper concerns the minimum sum of absolute errors regression. It is a more robust alternative to the popular least squares regression whenever there are outliers in the values of the response variable, or the errors follow a long tailed distribution, or the loss function is proportional to the absolute errors rather than their squared values. We use data from a study of interstitial lung disease to illustrate the method, interpret the findings, and contrast with least squares regression.

Exploring the clastogenic effects of air pollutants in São Paulo (Brazil) using the Tradescantia micronuclei assay.

This study was designed to determine the clastogenicity of particulate matter (aerodynamic diameter smaller than 10 microm) in the urban polluted air in the city of São Paulo. The Tradescantia-micronucleus (Trad-MCN) assay was used throughout this study to evaluate the clastogenicity of the extracts of the particulate matter. Tradescantia pallida (Rose) Hunt.

Airspace configuration at different transpulmonary pressures in normal and paraquat-induced lung injury in rats.

The aim of this study is to evaluate histoarchitecture of airspaces at different positive transpulmonary pressures, both during inflation and deflation of excised normal and paraquat-damaged rat lungs. Freshly excised lungs were placed in a plethysmograph connected to a graded pipette. Immediately after the achievement of the desired pressure level (5, 15, 25 cm H2O during inflation, and 15 and 5 cm H2O during deflation), the tracheal cannula was occluded and lungs were quick-frozen by immersion in liquid nitrogen, and fixed using Carnoy's solution.

Paraquat poisoning: an experimental model of dose-dependent acute lung injury due to surfactant dysfunction.

Since the most characteristic feature of paraquat poisoning is lung damage, a prospective controlled study was performed on excised rat lungs in order to estimate the intensity of lesion after different doses. Twenty-five male, 2-3-month-old non-SPF Wistar rats, divided into 5 groups, received paraquat dichloride in a single intraperitoneal injection (0, 1, 5, 25, or 50 mg/kg body weight) 24 h before the experiment. Static pressure-volume (PV) curves were performed in air- and saline-filled lungs; an estimator of surface tension and tissue works was computed by integrating the area of both curves and reported as work/ml of volume displacement.

Association between air pollution and intrauterine mortality in São Paulo, Brazil.

The associations among daily counts of intrauterine mortality and pollutant concentrations (NO2, SO2, CO, O3, and particulate matter (3/4)10 microm) were investigated for the period ranging from January 1991 to December 1992 in the city of São Paulo, Brazil. We used Poisson regression techniques, adjusted for season and weather. The association between intrauterine mortality and air pollution was strong for NO2 (coefficient = 0.

Respiratory changes due to long-term exposure to urban levels of air pollution: a histopathologic study in humans.

Study Objectives: To evaluate the potential associations between long-term exposure to air pollution and histopathologic evidence of damage to the lungs in humans.

Design: Lung tissue samples were collected during necropsies of individuals who died due to violent causes, selected on the basis of their exposure background.

Patients: The exposed group was composed of individuals who lived in Guarulhos, an area with high mean levels of inhalable particles.

[Effect of glucidic and fat total parenteral nutrition on macrophage phagocytosis in rats].

Fat lipid emulsions in Total Parenteral Nutrition (TPN) have been associated to Mononuclear Phagocytary System (MPS) changes. Intravenous lipid emulsions may alter macrophage membrane composition but there are controversies about their effects on MPS function. The aim of the present investigation was to assess the influence of fat free TPN and fat emulsions TPN on the macrophage phagocytosis.

The use of the frog palate preparation to assess the effects of oxidants on ciliated epithelium.

This work was designed to develop a simple method based on the frog palate preparation to study the effects of hydrogen peroxide (H2O2) on ciliated epithelium. For this purpose, five sets (n = 10 per set) of frog palate preparations (Rana catesbeiana) were studied during 35 min after immersion in increasing concentrations of H2O2: 1, 8, 16, 32, and 64 microM. The effects of H2O2 on ciliated epithelium were assessed by measuring transepithelial potential difference (PD) and mucociliary transport (MT).

Pulmonary emphysema induced by passive smoking: an experimental study in rats.

We describe a short time model for inducing experimental emphysema in rats by chronic tobacco smoke inhalation. Three groups of male Wistar rats (6 months old) were studied: controls (N = 8), rats intoxicated for 45 days (s-45, N = 7) or for 90 days (s-90, N = 8). The exposed animals were intoxicated 3 times a day (10 cigarettes per exposure period), 5 days a week.

Lung tissue mechanics in the early stages of induced paracoccidioidomycosis in rats.

Pulmonary dysfunction represents the most important cause of death in patients with paracoccidioidomycosis (PBM). In order to investigate the functional changes of the lungs in the early stages of PBM, a model of benign disease was developed by intratracheal challenge of 12-week old isogenic Wistar rats with 1 x 10(6) yeast forms of Paracoccidioides brasiliensis. Animals were studied 30 and 60 days after infection, when fully developed granulomas were demonstrable in the lungs.

Quantitation in inflammatory pleural disease to distinguish tuberculous and paramalignant from chronic non-specific pleuritis.

Aim: To determine by morphometry if pleural biopsies with the histopathological diagnosis of "non-specific pleuritis", malignant, and tuberculous disease could be distinguished morphologically from those with truly non-specific disease.

Methods: Each pleural biopsy was reviewed taking into account three compartments of reference: the visceral/parietal mesothelial compartment, the submesothelial screen compartment, and the submesothelial adipose tissue compartment. Normal connective tissue, granulation tissue, fibrocellular proliferation, fibrin, polymorphonuclear cells, mononuclear cells, and mesothelial cells were measured using conventional point counting procedures in terms of the fractional area occupied by each parameter within each compartment of reference.

Stereological estimates of the nuclear/cytoplasmic ratio and star volume on fibreoptic biopsies are of prognostic value for survival in a preliminary study of advanced squamous cell carcinoma of the lung.

Aims: This study evaluated the role of morphometric and clinical parameters in establishing the prognosis of patients submitted to radiotherapy for advanced squamous cell carcinoma of the lung.

Methods And Results: Morphometric studies were performed by point counting techniques. Forty patients were included in this study.

Differential distribution of elastic system fibers in control and bronchoconstricted intraparenchymatous airways in the guinea-pig lung.

The elastic system fibers were studied at the light microscopic level by using Weigert's resorcin-fuchsin method after oxidation. This study was designed to describe the distribution of these fibers in intrapulmonary guinea-pig airways and to characterize their conformational changes during bronchoconstriction induced by methacholine aerosol. Airways present a palisade of elastic system fibers just beneath the epithelial basement membrane; these fibers are also present in the adventitial connective tissue.

Prognostic significance of argyrophilic nucleolar organizer region (AgNOR) in resected non-small cell lung cancer (NSCLC).

The expression of the nucleolar organizer regions (NORs) was quantified in paraffin sections of tumors and lymph node metastasis, by means of digital image analysis, in 75 patients with resected non-small cell lung cancer (NSCLC). Patients were divided in two groups: early stage (stages I and II) and advanced stage (stages IIIa, IIIb and IV). The prognostic significance of AgNOR expression was tested by Cox regression analysis in models controlled for age, sex, vital status, stage and histological type.

Upregulation of collagen messenger RNA expression occurs immediately after lung damage.

Background: Mortality of ARDS still exceeds 50%. Though pulmonary fibrosis is a marker of severe prognosis in the evolution of ARDS, its onset is not yet established. Cardiopulmonary bypass (CPB), usually utilized in patients with a previously normal lung, can cause ARDS and often causes alveolar damage, the earliest lesion observed in ARDS, thus providing a unique opportunity to study the molecular mechanisms of fibrogenesis.

A prognostic model of survival in surgically resected squamous cell carcinoma of the lung using clinical, pathologic, and biologic markers.

The biologic behavior of tumoral cells plays a significant role in the progression of the neoplasia, because 30 to 35% of patients with Stage I squamous cell carcinoma relapse. The present study was designed to determine whether age, pathologic parameters, DNA ploidy, and a cell proliferation index (the area of nucleolar organizer regions, AgNOR), could be used to predict survival in patients who undergo resection for limited squamous cell carcinoma of the lung. For histopathologic analysis, the parameters of histologic grading, pleural involvement, vascular invasion, and residual disease were considered.

Organization of collagen and elastic fibers studied in stretch preparations of whole mounts of human visceral pleura.

Fibers of the collagenous and elastic systems are most relevant in the double mechanical action of visceral pleura (VP), i.e. volume limitation and the generation of elastic recoil pressure.

Effects of neurokinin depletion on airway inflammation induced by chronic antigen exposure.

We assessed the effects of neurokinin (tachykinin) depletion by capsaicin (CAP) treatment on airway inflammation induced by repeated ovalbumin (OA) aerosol exposures (twice a week for 4 wk) in guinea pigs. The animals were then anesthetized, tracheostomized, mechanically ventilated and challenged with ovalbumin aerosol. Maximal values of respiratory system resistance and elastance after antigen challenge were significantly lower in capsaicin-treated guinea pigs than in intact animals (p < 0.

Morphological determinants of peripheral lung mechanical changes induced by capsaicin.

We studied the morphological elements associated with airway and pulmonary tissue responses to capsaicin in mechanically ventilated guinea pigs. Lungs were excised and frozen in liquid nitrogen 3 and 20 min after capsaicin infusion (1 or 100 micrograms/kg i.v.

Work organization is significantly associated with upper extremities musculoskeletal disorders among employees engaged in interactive computer-telephone tasks of an international bank subsidiary in São Paulo, Brazil.

This study was designed to verify the risk factors for developing upper extremities musculoskeletal disorders (UEMD) among workers engaged in customer service tasks performed by telephone at a private banking corporation in São Paulo, Brazil. The monthly incidence of UEMD in hands and/or wrists in this group was studied retrospectively from January 1993 to June 1995. The statistical analysis was done by using multiple linear regression with the monthly incidence of UEMD considered as dependent variable in models controlled for age, seniority, mean daily regular worktime and overtime per operator, time pressure at work, rest/work schedule, management status, personnel training on postural and muscle stretching, and ergonomic hazards.

Dating of fibrotic lesions by the Picrosirius-polarization method. An application using the lesions of Lechiguana (bovine focal proliferative fibrogranulomatous panniculitis).

This work was designed to verify if a simple quantitative procedure to estimate the state of collagen aggregation is useful in describing the natural history of a fibrous process. For this purpose sixteen cases of Lechiguana lesion were used. Histochemical evaluation of the collagen content and its state of aggregation was done by the Picrosirius-polarization method.

Case report: massive cardiopulmonary cysticercosis in a leukemic patient.

A 53-year-old woman who had acute leukemia and massive cardiopulmonary cysticercosis is reported. Pulmonary cysticercosis is rare and in this case may have been promoted by the immunosuppression caused by acute leukemia.

Urban air pollution enhances the formation of urethane-induced lung tumors in mice.

This paper investigates the association between air pollution and lung neoplasia in an animal model. The experimental exposures were done in two locations with different air pollution profiles: a polluted area (downtown São Paulo) and a "clean" environment (Atibaia). Swiss mice were employed and urethane (3 g/kg) was used as carcinogenic substance.