Oxidative stress plays an important role in the pathogenesis of some diseases such as lung cancer, chronic obstructive pulmonary disease, and atheroscleorosis. Smoking may enhance oxidative stress not only through the production of reactive oxygen radicals in smoke but also through weakening of the antioxidant defense systems. In this study, we investigated the effects of smoking on lipid peroxidation and paraoxonase activity in a healthy population. The study consisted of (n = 30) smokers and (n = 30) nonsmokers. The age of the population which is studied was 44.74 +/- 10.59 yr. The levels of serum malondialdehyde (MDA) and paraoxonase (PON1) activities were measured by the modified Buege method and the Eckerson method, respectively. Student's t-test was used to analyze the data. The serum MDA levels were significantly higher (p < .05) and serum PON1 activities were significantly lower (p < .001) in smokers than in nonsmokers. Thus, increased levels of serum MDA and decreased PON1 activities may be important in determining the oxidant/antioxidant imbalance in smokers.

Background: Inhabitants of the southeast of Turkey (ST) have been exposed since childhood to inhalation of asbestos, from a material containing tremolite, used for whitewashing. This has resulted in an increased incidence of malignant pleural mesothelioma (MPM). Objectives: To review the epidemiological features of MPM cases in ST; to calculate and compare the incidence with the previously reported ones. Subjects and Methods: The study included 176 MPM cases from different places in ST. The incidence of MPM was calculated for those places according to the distribution of the cases. Results: In the previously identified regions of asbestos (region 1) where the population had been informed of the danger with the soil some decades ago, the MPM incidence was decreased, as compared to the previous reports. The annual incidence of MPM in these places was found to be 42.9 per million in this study while it had been reported to be 105.5 per million in the previous studies. In contrast, the incidence that was reported previously to be 2.75 per million in the regions where asbestos exposure had not been identified before (region 2) was found to be 8.6 per million in this study. In region 2 the incidence of MPM increased even in the second half of the last decade (5.9 versus 11.9 per million). Conclusions: Use of asbestos-containing soil continues in different places in ST. Even if the use of this soil is abandoned today, MPM will be an important health problem in this region till the third or fourth decades of this century. Informing the villagers of the danger and preventing the use of this soil may result in a considerable decrease in the incidence of MPM.

The aim of this study is to investigate immunoreactivity for p53, p21 and metallothionein in diffuse malignant pleural mesothelioma (DMPM) and to determine the relationships between the age, sex, asbestos exposure time, survival of DMPM patients with environmental asbestos exposure and immunoreactivity to p53, p21 and metallothionein. Sixty-seven histopathologically-confirmed DMPMs, 38 of whom had environmental and 29 had occupational asbestos exposure, were included. The tumour tissue samples were immunostained with antibodies against p53, p21 and metallothionein. Epidemiological data and the survival times for the DMPM patients with environmental asbestos exposures were obtained from hospital records. Thirty-three per cent of the DMPMs were positive for p53, 35% for p21 and 52% for metallothionein. There was no statistical difference between the histological subtypes of DMPM in terms of immunoreactivity for p53, p21 and metallothionein. For p21 and metallothionein there was a statistically significant difference between the exposure characteristics: patients with environmental asbestos exposure had shown more immunopositivity. There were statistically significant differences between age groups and between asbestos exposure times for metallothionein, and between asbestos exposure times and p21. The patients with positive immunostaining had longer exposure times and were older than those having negative immunostaining. The differences between survival of the patients were not statistically significant in terms of the immunohistochemical results for p53, p21 and metallothionein.

Background and Objectives: Although all parts of the lung can be affected as a consequence of asbestos exposure, most CT protocols tend to scan only the middle and lower parts of the thorax. The aim of this study was to investigate parenchymal and pleural lesions of persons exposed to environmental asbestos, using a high-resolution computed tomography (HRCT) protocol scanning the whole thorax. Methods: We analyzed the chest radiographs and HRCT scans of 26 patients who presented bilaterally with multiple pleural plaques related to environmental asbestos exposure. Results: Twenty-four cases (92%) had an abnormal HRCT suggestive of asbestosis. Apart from common HRCT changes related to asbestosis, we detected apical pleural thickening (APT) in 9 cases as well as a coarse honeycomb pattern adjacent to APT in 7 of these cases. Cavitary lesions due to pulmonary tuberculosis were observed on HRCT scans from 4 patients in total. Neither apical pulmonary fibrosis nor cavitary lesions were visible on chest radiographs. Conclusions: We suggest that the HRCT protocol for examining asbestos-exposed individuals with pleural plaques on chest X-rays should include the whole thorax, since the asbestos-related pathologies may involve all parts of the lung.

No abstract