[en] This study was conducted with the aim of testing the hypothesis that raspberry and strawberry fruits from nonorganic farming release more ethylene gas compounds compared to organic ones. At the same time, the experiments focused on evaluation of the potential and capabilities of the laser photoacoustic spectroscopy (LPAS) method in the assessment of fruit quality related to the effects of nitrogen. Ethylene gas can be harmful and carcinogenic, because it can accelerate the natural ripening process of physiologically mature fruits and makes the fruits more consistent in size. With the advantages of LPAS, we demonstrate that the concentration of ethylene from nonorganic raspberry and strawberry fruits is greater than from organic ones. (paper)

[en] In recent years there has been a large increase in the areas related to developments in the prevention of diseases, especially in explaining the role of oxidative stress. Lipid peroxidation and oxidative stress contributes to morbidity in hemodialysis (HD) patients. It is therefore relevant to analyze the impact of oxidative stress and its related species (ethylene) immediately after dialysis treatment in order to prevent trauma in the renal failure of elderly patients. In this paper we describe recent progress in laser photoacoustic spectroscopy detection of ethylene in renal failure patients. We have found that HD treatment increases ethylene concentration in the exhaled breath of elderly patients and may intensify oxidative stress. (paper)

[en] Full text: Concerning the complications associated with type 2 diabetes, the emission of ethylene from the human breath as a consequence of oxidative stress determination by lipid peroxidation was monitored using laser photoacoustic spectroscopy (LPAS). Lipid peroxidation (LP) is the oxidative degradation of polyunsaturated fatty acids (PUFA) induced by free radicals (reactive molecules that posses an unpaired electron. The cell damage started by free radicals action on biomolecules plays a very important role in the pathogenesis of some diseases, such as cancer, cardiopulmonary bypass, Alzheimer, atherosclerosis and inflammation. Under stress conditions (e.g. ionising radiation, toxic chemical substances, chronic or acute diseases, etc), the free radical production is significantly increased. Breath analysis has long been recognized as a potentially powerful tool for the diagnosis and study of medical diseases. The molecular profile of breath will be the product of the composition of the inspiratory air and the volatile molecules that are present in the blood. The bulk matrix of breath is a mixture of nitrogen, oxygen, carbon dioxide, water vapors and the inert gases. Over 1,000 compounds have been identified to be present in exhaled human breath with concentrations range from ppb to ppt levels. Approximately, 35 of the identified compounds in the exhaled breath have been established as biomarkers for particular diseases and metabolic disorders. Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from effects of insulin action, insulin secretion or both. Diabetes has taken place as one of the most important diseases worldwide, reaching epidemic proportions. Diabetes is a major source of morbidity, mortality, and economic cost to the society. In addition to this, diabetics are also at risk of experiencing chronic complications such as coronary heart diseases, retinopathy, nephropathy and neuropathy, and foot ulceration. Oxidative stress plays an important role in the pathogenesis and the complications of diabetes. Hyperglycemia results in overproduction of oxygen free radicals, which contributes to the progression of diabetes. Ethylene as biomarkers for lipid peroxidation in humans can be detected in the exhaled breath by means of very sensitive gas sensors based on high resolution molecular spectroscopy. To this purpose, a CO₂ laser photoacoustic spectroscopy system (CO₂LPAS) for online ethylene monitoring in subjects with type 2 diabetes. The high resolution laser spectroscopy is able to detect trace gases in human breath with high sensitivity and can help medicine and science in understanding the life processes and designing sensors useful for non-invasive clinical diagnostic procedures. The method was applied in a study of the correlation between the exhaled ethylene and the complication related with type 2 diabetes. The results seems to indicate an increase in ethylene concentrations at subjects with different complications due to diabetes. Additional work is needed to confirm the reported results and to take same advantage from them, and in general from the possibility offered by the LPAS facility. (author)

[en] Full text: The quest for non-invasive and real-time monitoring tools is a characteristic of the modern medicine. The technique that is developed in this research complies with this requirement, ensuring the advantages of health state assessment by monitoring the evolution of gaseous biomarkers in human body. We chose to characterize by breath air the assessment of ammonia and ethylene in mental disorders, but the techniques can be easily extended to other pathological issues. The first objective of the present study was to analyze the oxidative stress marker in breath samples of patients with mental disorder before and after the treatment. The second objective was to analyze the deficiency of amino acids marker in breath samples of patients with mental disorder before and after the treatment; subsequently, laser spectroscopy was used to assess the exhaled breath compounds of the study peoples. The breath gases in the exhalation of patients exhibited significant differences from the breath gases in the exhalation of healthy controls. In conclusion, the data from this study support the hypothesis of the oxidant/antioxidant balance as a key component that may contribute to mental disorder pathology. Based on a non-invasive sampling method, stable in biological materials, and easy to measure, we conclude that laser spectroscopy analyses of breath ethylene/ammonia in alveolar air appeared to distinguish patients with mental disorder from healthy controls. Although laser spectroscopy is a sensitive, non-invasive and real time method to accurately analyze breathing gas concentrations, finding a sensitive, specific and non invasive biomarker of mental disorder, which could be measured in alveolar air, still remains an important task. (author)