A validated method for rapid analysis of ethane in breath and its application in kinetic studies in human volunteers

Frequent sampling allows detection of short and rapid surges of exhaled ethane during cardiac surgery

During cardiopulmonary bypass (CPB), hypoperfusion and reperfusion may cause oxidative stress and lipid peroxidation that generates ethane. The aim of this pilot study was to assess the feasibility of frequent sampling of exhaled ethane during cardiac surgery. After approval of the Research Ethics Committee, 10 patients undergoing combined aortic valve and coronary artery bypass surgery were enrolled. Breath samples were drawn in the perioperative period and analyzed by a rapid, sensitive and validated gas-chromatographic method. Increased exhaled ethane was regularly seen following sternotomy, after the start of CPB and after aortic clamp removal, whereas no change was seen after termination of bypass. In one patient, the maximum increase in exhaled ethane was 30-fold. Peak durations lasted only 2–4 min. This study demonstrates that frequent sampling of breath ethane is feasible in a clinical setting, allowing detection of rapid ethane surges of short duration.

Infrared spectroscopy study of the influence of inhaled vapors/smoke produced by cigarettes of active smokers

While much is known about the effect of smoke and vapors on the composition of blood, little is known about their impact on the composition of breath. When tobacco from traditional cigarettes (T) is burned, it produces harmful smoke compared with the vapor produced when using electronic cigarettes (E). Using a noninvasive, safe, and rapid CO2 laser-photoacoustic method, this study aimed to examine the ethylene changes at different time intervals in the exhaled breath composition of E-cigarette smokers and T-cigarette smokers, before and after the consecutive exposures to cigarettes. Oxidative stress from exposure to tobacco smoke has a role in the pathogenic process, leading to chronic obstructive pulmonary disease. The evidence on the mechanisms by which T-smoking causes damage indicates that there is no risk-free level of exposure to tobacco smoke. The study revealed that the ethylene level (in the E-cigarette smoker's case) was found to be in smaller concentrations (compared with T-cigarette smoker's case) and that E-cigarettes may provide an alternative to T-cigarette smoking.

Reactive oxygen species in periodontitis

Recent epidemiological studies reveal that more than two-third of the world's population suffers from one of the chronic forms of periodontal disease. The primary etiological agent of this inflammatory disease is a polymicrobial complex, predominantly Gram negative anaerobic or facultative bacteria within the sub-gingival biofilm. These bacterial species initiate the production of various cytokines such as interleukin-8 and TNF-α, further causing an increase in number and activity of polymorphonucleocytes (PMN) along with these cytokines, PMNs also produce reactive oxygen species (ROS) superoxide via the respiratory burst mechanism as the part of the defence response to infection. ROS just like the interleukins have deleterious effects on tissue cells when produced in excess. To counter the harmful effects of ROS, human body has its own defence mechanisms to eliminate them as soon as they are formed. The aim of this review is to focus on the role of different free radicals, ROS, and antioxidants in the pathophysiology of periodontal tissue destruction.

Inflammatory markers in blood and exhaled air after short-term exposure to cooking fumes

Objectives:

Cooking fumes contain aldehydes, alkanoic acids, polycyclic aromatic hydrocarbons, and heterocyclic compounds. The inhalation of cooking fumes entails a risk of deleterious health effects. The aim of this study was to see if the inhalation of cooking fumes alters the expression of inflammatory reactions in the bronchial mucosa and its subsequent systemic inflammatory response in blood biomarkers.

Methods:

Twenty-four healthy volunteers stayed in a model kitchen on two different occasions for 2 or 4h. On the first occasion, there was only exposure to normal air, and on the second, there was exposure to controlled levels of cooking fumes. On each occasion, samples of blood, exhaled air, and exhaled breath condensate (EBC) were taken three times in 24h and inflammatory markers were measured from all samples.

Results:

There was an increase in the concentration of the d-dimer in blood from 0.27 to 0.28mg ml^–1 on the morning after exposure to cooking fumes compared with the levels the morning before (P-value = 0.004). There was also a trend of an increase in interleukin (IL)-6 in blood, ethane in exhaled air, and IL-1β in EBC after exposure to cooking fumes. In a sub-analysis of 12 subjects, there was also an increase in the levels of ethane—from 2.83 parts per billion (ppb) on the morning before exposure to cooking fumes to 3.53 ppb on the morning after exposure (P = 0.013)—and IL-1β—from 1.04 on the morning before exposure to cooking fumes to 1.39 pg ml^–1 immediately after (P = 0.024).

Conclusion:

In our experimental setting, we were able to unveil only small changes in the levels of inflammatory markers in exhaled air and in blood after short-term exposure to moderate concentrations of cooking fumes.

Measuring reactive species and oxidative damage in vivo and in cell culture: how should you do it and what do the results mean?

Free radicals and other reactive species (RS) are thought to play an important role in many human diseases. Establishing their precise role requires the ability to measure them and the oxidative damage that they cause. This article first reviews what is meant by the terms free radical, RS, antioxidant, oxidative damage and oxidative stress. It then critically examines methods used to trap RS, including spin trapping and aromatic hydroxylation, with a particular emphasis on those methods applicable to human studies. Methods used to measure oxidative damage to DNA, lipids and proteins and methods used to detect RS in cell culture, especially the various fluorescent "probes" of RS, are also critically reviewed. The emphasis throughout is on the caution that is needed in applying these methods in view of possible errors and artifacts in interpreting the results.