RESUMEN
The greenhouse gases (GHGs) derived from agriculture include carbon dioxide, nitrous oxide, and methane (CH4). Of these GHGs, CH4, in particular, constitutes a major component of the GHG emitted by the agricultural sector. Along with environmental concerns, CH4 emission also leads to losses in gross energy intake with economic implications. While ruminants are considered the main source of CH4 from agriculture, nonruminant animals also contribute substantially, and the CH4 emission intensity of nonruminants remains comparable to that of ruminants. Means of mitigating CH4 emissions from enteric fermentation have therefore been sought. Methane is produced by methanogens-archaeal microorganisms that inhabit the digestive tracts of animals and participate in fermentation processes. As the diversity of methanogen communities is thought to be responsible for the differences in CH4 production among nonruminant animals, it is necessary to investigate the archaeal composition of specific animal species. Methanogens play an important role in energy metabolism and adipose tissue deposition in animals. Higher abundances of methanogens, along with their higher diversity, have been reported to contribute to lean phenotype in pigs. In particular, a greater abundance of Methanosphaera spp. and early dominance of Methanobrevibacter smithii have been reported to correlate with lower body fat formation in pigs. Besides the contribution of methanogens to the metabolic phenotype of their hosts, CH4 release reduces the productivity that could be achieved through other hydrogen (H2) disposal pathways. Enhanced participation of acetogenesis in H2 disposal, leading to acetate formation, could be a more favorable direction for animal production and the environment. Better knowledge and understanding of the archaeal communities of the gastrointestinal tract (GIT), including their metabolism and interactions with other microorganisms, would thus allow the development of new strategies for inhibiting methanogens and shifting toward acetogenesis. There are a variety of approaches to inhibiting methanogens and mitigating methanogenesis in ruminants, which can find an application for nonruminants, such as nutritional changes through supplementation with biologically active compounds and management changes. We summarize the available reports and provide a comprehensive review of methanogens living in the GIT of various nonruminants, such as swine, horses, donkeys, rabbits, and poultry. This review will help in a better understanding of the populations and diversity of methanogens and the implications of their presence in nonruminant animals.
Asunto(s)
Animales Domésticos , Rumen , Animales , Caballos , Metano , Methanobrevibacter , Conejos , Rumiantes , PorcinosRESUMEN
A compendium of all the volatile organic compounds (VOCs) emanating from the human body (the volatolome) is for the first time reported. 1840 VOCs have been assigned from breath (872), saliva (359), blood (154), milk (256), skin secretions (532) urine (279), and faeces (381) in apparently healthy individuals. Compounds were assigned CAS registry numbers and named according to a common convention where possible. The compounds have been grouped into tables according to their chemical class or functionality to permit easy comparison. Some clear differences are observed, for instance, a lack of esters in urine with a high number in faeces. Careful use of the database is needed. The numbers may not be a true reflection of the actual VOCs present from each bodily excretion. The lack of a compound could be due to the techniques used or reflect the intensity of effort e.g. there are few publications on VOCs from blood compared to a large number on VOCs in breath. The large number of volatiles reported from skin is partly due to the methodologies used, e.g. collecting excretions on glass beads and then heating to desorb VOCs. All compounds have been included as reported (unless there was a clear discrepancy between name and chemical structure), but there may be some mistaken assignations arising from the original publications, particularly for isomers. It is the authors' intention that this database will not only be a useful database of VOCs listed in the literature, but will stimulate further study of VOCs from healthy individuals. Establishing a list of volatiles emanating from healthy individuals and increased understanding of VOC metabolic pathways is an important step for differentiating between diseases using VOCs.
Asunto(s)
Salud , Cuerpo Humano , Compuestos Orgánicos Volátiles/análisis , Líquidos Corporales/química , Pruebas Respiratorias , Heces/química , Humanos , Leche Humana/química , Compuestos Orgánicos Volátiles/sangre , Compuestos Orgánicos Volátiles/orinaRESUMEN
Non-invasive disease monitoring on the basis of volatile breath markers is a very attractive but challenging task. Several hundreds of compounds have been detected in exhaled air using modern analytical techniques (e.g. proton-transfer reaction mass spectrometry, gas chromatography-mass spectrometry) and have even been linked to various diseases. However,the biochemical background for most of compounds detected in breath samples has not been elucidated; therefore, the obtained results should be interpreted with care to avoid false correlations. The major aim of this study was to assess the effects of smoking on the composition of exhaled breath. Additionally, the potential origin of breath volatile organic compounds (VOCs) is discussed focusing on diet, environmental exposure and biological pathways based on other's studies. Profiles of VOCs detected in exhaled breath and inspired air samples of 115 subjects with addition of urine headspace derived from 50 volunteers are presented. Samples were analyzed with GC-MS after preconcentration on multibed sorption tubes in case of breath samples and solid phase micro-extraction (SPME) in the case of urine samples. Altogether 266 compounds were found in exhaled breath of at least 10% of the volunteers. From these, 162 compounds were identified by spectral library match and retention time (based on reference standards). It is shown that the composition of exhaled breath is considerably influenced by exposure to pollution and indoor-air contaminants and particularly by smoking. More than 80 organic compounds were found to be significantly related to smoking, the largest group comprising unsaturated hydrocarbons (29 dienes, 27 alkenes and 3 alkynes). On the basis of the presented results, we suggest that for the future understanding of breath data it will be necessary to carefully investigate the potential biological origin of volatiles, e.g., by means of analysis of tissues, isolated cell lines or other body fluids. In particular, VOCs linked to smoking habit or being the results of human exposure should be considered with care for clinical diagnosis since small changes in their concentration profiles(typically in the ppt(v)ppb(v) range) revealing that the outbreak of certain disease might be hampered by already high background.
Asunto(s)
Contaminantes Atmosféricos , Espiración/fisiología , Fumar/fisiopatología , Compuestos Orgánicos Volátiles/análisis , Adulto , Anciano , Anciano de 80 o más Años , Pruebas Respiratorias , Creatinina/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Compuestos Orgánicos Volátiles/orinaRESUMEN
In this phenomenological study we focus on dynamic measurements of volatile organic compounds (VOCs) in exhaled breath under exercise conditions. An experimental setup efficiently combining breath-by-breath analyses using proton transfer reaction mass spectrometry (PTR-MS) with data reflecting the behaviour of major hemodynamic and respiratory parameters is presented. Furthermore, a methodology for complementing continuous VOC profiles obtained by PTR-MS with simultaneous SPME/GC-MS measurements is outlined. These investigations aim at evaluating the impact of breathing patterns, cardiac output or blood pressure on the observed breath concentration and allow for the detection and identification of several VOCs revealing characteristic rest-to-work transitions in response to variations in ventilation or perfusion. Examples of such compounds include isoprene, methyl acetate, butane, DMS and 2-pentanone. In particular, both isoprene and methyl acetate exhibit a drastic rise in concentration shortly after the onset of exercise, usually by a factor of about 3-5 within approximately 1 min of pedalling. These specific VOCs might also be interpreted as potentially sensitive indicators for fluctuations of blood or respiratory flow and can therefore be viewed as candidate compounds for future assessments of hemodynamics, pulmonary function and gas exchange patterns via observed VOC behaviour.
Asunto(s)
Pruebas Respiratorias/métodos , Espiración , Cromatografía de Gases y Espectrometría de Masas/métodos , Compuestos Orgánicos/análisis , Compuestos Orgánicos/química , Protones , Acetona/análisis , Acetona/química , Acetona/aislamiento & purificación , Adulto , Butadienos/análisis , Butadienos/química , Butadienos/aislamiento & purificación , Femenino , Hemiterpenos/análisis , Hemiterpenos/química , Hemiterpenos/aislamiento & purificación , Humanos , Cinética , Masculino , Gases Nobles/metabolismo , Compuestos Orgánicos/aislamiento & purificación , Pentanos/análisis , Pentanos/química , Pentanos/aislamiento & purificación , Microextracción en Fase Sólida , Relación Ventilacion-Perfusión , Volatilización , Adulto JovenRESUMEN
Breath gas samples from 27 patients with epilepsy (17 male and 10 female patients; mean age: 9.7 years, median age: 8.2 years, SD: ±4.2 years) were screened via proton transfer reaction mass spectrometry. The patients were treated with valproic acid (VPA) therapy, and blood samples for determination of VPA concentrations were surveyed. All patients showed significantly elevated concentrations of 3-heptanone (C(7)H(14)O) in exhaled breath gas (mean: 14.7 ppb, median: 13.8 ppb SD: ±5.7 ppb). In human breath, several hundred different volatile organic compounds can be detected. In breath of patients with valproic acid monotherapy, an increased concentration of 3-heptanone was measured. The objective of this study was to investigate if serum VPA concentrations correlate with 3-heptanone concentrations in exhaled breath. In conclusion, 3-heptanone in breath gas is significantly elevated in patients treated with the valproic acid, but does not correlate significantly with the VPA concentrations in serum or the daily dose of this drug.
RESUMEN
Proton-transfer-reaction mass spectrometry (PTR-MS) is a convenient technique for fast analysis of exhaled breath without prior sample preparation. Since compounds are not separated prior to analysis as in gas chromatography mass spectrometry (GC-MS), and since protonated molecules may fragment, relatively complex spectra may arise, which are not easily interpreted in a quantitative way. We calibrated 21 different compounds of importance for exhaled breath analysis, based on the respective pure standards diluted with nitrogen. These calibration measurements included determination of the fragmentation pattern of each compound under dry conditions and in the absence of CO(2). Even though the fragmentation pattern may be predicted in a qualitative manner, the quantitative details may depend on water and CO(2) content. This is exemplarily shown for isoprene. Out of the selected 21 compounds, 11 compounds showed substantial fragmentation (fragments proportion > 10%). Fragmentation of several volatile organic compounds (VOCs) in the drift tube of PTR-MS has been previously observed (Buhr et al 2002 Int. J. Mass Spectrom. 221 1-7; Taipale et al 2008 Atmos. Chem. Phys. Discuss. 8 9435-75; Hewitt et al 2003 J. Environ. Monit. 51-7; Warneke et al 2003 Environ. Sci. Technol. 37 2494-501; de Gouw and Warneke 2007 Mass Spectrom. Rev. 26 223-57; Pozo-Bayon et al 2008 J. Agric. Food Chem. 56 5278-84) and calibration factors for several compounds at corresponding mass-to-charge ratios have been calculated. In this paper, besides the calibration factors, the proportions of substantial fragments are also taken into account for a correct quantification in the case of overlapping signals. The spectrum of a mixture of the considered 21 compounds may be simulated. Conversely, the determination of concentrations from the spectrum of such a mixture is a linear optimization problem, whose solution is determined here using the simplex algorithm.
RESUMEN
The present study was performed to determine the variations of breath acetone concentrations with age, gender and body-mass index (BMI). Previous investigations were based on a relatively small cohort of subjects (see Turner et al 2006 Physiol. Meas. 27 321-37). Since exhaled breath analysis is affected by considerable variation, larger studies are needed to get reliable information about the correlation of concentrations of volatiles in breath when compared with age, gender and BMI. Mixed expiratory exhaled breath was sampled using Tedlar bags. The concentrations of a mass-to-charge ratio (m/z) of 59, attributed to acetone, were then determined using proton transfer reaction-mass spectrometry. Our cohort, consisting of 243 adult volunteers not suffering from diabetes, was divided into two groups: one that fasted overnight prior to sampling (215 volunteers) and the other without a dietary control (28 volunteers). In addition, we considered a group of 44 healthy children (5-11 years old).The fasted subjects' concentrations of acetone ranged from 177 ppb to 2441 ppb, with an overall geometric mean (GM) of 628 ppb; in the group without a dietary control, the subjects' concentrations ranged from 281 ppb to 1246 ppb with an overall GM of 544 ppb. We found no statistically significant shift between the distributions of acetone levels in the breath of males and females in the fasted group (the Wilcoxon-Mann-Whitney test yielded p = 0.0923, the medians being 652 ppb and 587 ppb). Similarly, there did not seem to be a difference between the acetone levels of males and females in the group without a dietary control. Aging was associated with a slight increase of acetone in the fasted females; in males the increase was not statistically significant. Compared with the adults (a merged group), our group of children (5-11 years old) showed lower concentrations of acetone (p < 0.001), with a median of 263 ppb. No correlation was found between the acetone levels and BMI in adults. Our results extend those of Turner et al's (2006 Physiol. Meas. 27 321-37), who analyzed the breath of 30 volunteers (without a dietary control) by selected ion flow tube-mass spectrometry. They reported a positive correlation with age (but without statistical significance in their cohort, with p = 0.82 for males and p = 0.45 for females), and, unlike us, arrived at a p-value of 0.02 for the separation of males and females with respect to acetone concentrations. Our median acetone concentration for children (5-11 years) coincides with the median acetone concentration of young adults (17-19 years) reported by Spanel et al (2007 J. Breath Res. 1 026001).
RESUMEN
One hundred and ninety five wild pigs from two different regions of Poland were investigated for transferrin, amylase and ceruloplasmin polymorphism. A new tranferrin phenotype Tf PB was detected. This phenotype differed from Tf AB in the electrophoretic mobility of the more anodal transferrin. Tf P is assumed to be the product of a new allele Tf P at the Tf locus. Two amylase phenotypes Am 1-2 and Am 2 were observed. The Am 1 allele was absent from the pigs in the Poznan region. Only one ceruloplasmin phenotype, Cp B, was found.