Cigarette smoke and bleomycin-induced pulmonary oxidative stress in rats.

Bleomycin causes pulmonary fibrosis by increasing free oxygen radicals. Cigarette smoke is a strong oxidant which adversely affects pulmonary tissue. We evaluated the effects of cigarette smoke administered with intratracheal bleomycin on pulmonary tissue. We studied 3 groups of rats (n=10): one group received intratracheal saline and served as a control; one received intratracheal bleomycin (IT) (0.5 U/100 g body weight, single dose on the first day), and one group received intratracheal bleomycin (single dose on first day) and tobacco smoke (two times per day) (IT-S). After 4 weeks, the levels of malondialdehyde (MDA) and nitric oxide (NO) and the activities of superoxide dismutase (SOD) and xanthine oxidase (XO) were assayed in the homogenate of the lung tissue samples. The severity of interstitial fibrosis was assessed using the grading system described by Ashcroft. There was more intensive fibrosis in the IT and IT-S than in the control samples (P<0.001). The levels of MDA, NO and activity of XO were significantly increased (P<0.001, <0.002 and <0.002, respectively), and SOD activity (P<0.001) was significantly decreased in the IT group when compared to these values in the control group. The concentration of NO was significantly decreased (P<0.002), and SOD activity was significantly increased (P<0.05) in the lung tissue samples of the IT-S group. Theoretically, the combination of cigarette smoke and bleomycin may have a synergistic effect on oxidative lung injury. In conclusion, we showed that inhalation of cigarette smoke provides protection against oxidative stress in the lung tissue of rats with bleomycin-induced pulmonary fibrosis.

[Diagnostic efficiency of pseudocholinesterase level in discrimination of transudates-exudates]. / Transüda-eksüda ayriminda plevral sivi psödokolinesteraz düzeyinin tanisal degeri.

In this study, 80 cases with pleural effusion hospitalized at the departments of Chest Diseases and Internal Medicine in the Medical School of Selcuk University, and 30 healthy people as control group were studied. Regarding to the diagnosis, pleural fluids were classified into two groups as follows; transudates and exudates. Difference between the mean pleural pseudocholinesterase levels of transudates and exudates was statistically significant (p< 0.001). Similar significance was also obtained in the mean pleural fluid/serum pseudocholinesterase ratios of the groups (p< 0.001). In determination of exudative fluids both sensitivity and specificity of the pleural fluid pseudocholinesterase level was 100%. Sensitivity and specificity of the pleural fluid/serum pseudocholinesterase ratio were 90 and 87%, respectively. We have concluded that pleural pseudocholinesterase level and pleural fluid/serum pseudocholinesterase ratio can be used as a parameter with high diagnostic efficiency in discrimination of pleural effusions as exudates and transudates.

[Diagnostic efficiency of serum lipid-bound sialic acid level in malignant pleural effusions]. / Malignite kaynakli plevra sivilarinda lipide bagli sialik asit düzeyi tayininin tanisal degeri.

In this study, pleural fluid and serum lipid-bound sialic acid (LBSA) levels of 68 cases with pleural effusion hospitalised at the department of Chest Diseases in the Medical School of Selçuk University, and serum LBSA levels of 30 healthy individuals as control group were studied. Pleural effusions of 32 cases were due to malignancy of which considerably lung cancer. In the other 36 cases the causes were nonmalignant in origin. Levels of mean serum LBSA in malignant and benign groups were significantly higher than control group (p< 0.001). However, difference of the mean serum LBSA levels of malignant and benign groups was not statistically significant. We found the mean pleural fluid LBSA level of 23.34 mg/dL in malignant group and it was significantly higher than benign group (17.97 mg/dL) (p< 0.05). It was observed that there was no significant statistical difference between the pleural fluid to serum LBSA ratios of malignant and benign groups. In differential diagnosis of malignant pleural effusions, sensitivity and specificity of pleural fluid LBSA were 91%, and 51%, respectively. In conclusion, for the differentiation of malignant pleural effusions LBSA is not believed to be a reliable tumor marker since it may also increase in various chronic and inflammatory diseases. Despite of that, in cases with a suspicion of malignancy, the increased level of pleural fluid LBSA may be useful as a supportive parameter.