Time to culture conversion in smokers with pulmonary tuberculosis

Background and objective. It has been reported that tobacco smoking slows the sterilisation of sputum culture in pulmonary tuberculosis, but the factors that could delay culture conversion in patients who smoke are not known. Our aim is to identify the factors influencing sputum culture conversion in smokers with pulmonary tuberculosis. Methods. Ninety-nine patients with a smoking history and diagnosed with pulmonary tuberculosis were analysed retrospectively. The relationship between sputum culture status at the second month and the following variables: age, gender, pack-years index, comorbid diseases, number acid-fast bacilli (AFB) in sputum smear examination, radiological findings (cavitary, extensive or limited disease), drug susceptibility pattern and initial treatment, was analysed. The Student t-test, chi-square test and logistic regression model with forward stepwise conditional methods were used for statistical analysis. A p value of <0.05 was considered to be statistically significant. Results. Twenty six patients (26.2%): 18 males (22.2%) and 8 females (44%) were sputum culture positive at the end of the second month of treatment. In univariate analysis, culture conversion time was significantly associated with female gender and extensive disease, but in a logistic regression analysis was only correlated with female gender (OR=5.63 95% CI 1.21-20.64-p=0.02). Conclusion. In current smokers with pulmonary tuberculosis, the ‘time to culture’ conversion relates only to the female gender

Comparison between emissions from the pyrolysis and combustion of different wastes

A comparison between different emission rates of various pollutants obtained from various wastes is presented. The studied wastes were the following: polyethylene (PE), tyres, sewage sludges, polyvinyl chloride (PVC), cotton textiles, polyester textiles, meat and bone meals (MBMs), varnish wastes, olive oil solid waste (pomace), waste lube oils and paper waste. The decomposition of these wastes was studied in a horizontal laboratory scale reactor under fuel-rich conditions, and the analysis of the pollutants evolved comprised several compounds such as light hydrocarbons, polyaromatic hydrocarbons (PAHs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). From the studied wastes, a general behaviour was deduced regarding the evolution of semi-volatile compounds with the increase of temperature, both in pyrolysis and combustion. The results showed that the emissions of some compounds decreased with increasing oxygen ratio. Compounds with this behaviour were mainly volatile hydrocarbons, which were consumed in presence of oxygen. In addition, compounds with oxidized structure were present a maximum with oxygen ratio. Intermediate compounds with very high resistance to the oxygen under the working conditions increased continuously in concentration when the oxygen ratio increased. With reference to behaviour versus temperature there were compounds whose yields decreased with increasing temperature, such as volatile hydrocarbons and semi-volatile compounds. Also some pollutants are promoted at intermediate temperatures, e.g. light hydrocarbons, semi-volatile compounds, many monoaromatic compounds and many polyaromatic hydrocarbons.Financial support from Generalitat Valenciana (Spain) project GV06/069, and the Spanish MCT research project CTQ2005-05262/PPQ