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Biosensors Sep 2020Over recent three decades, the electrochemical techniques have become widely used in biological identification and detection, because it presents optimum features for...
Over recent three decades, the electrochemical techniques have become widely used in biological identification and detection, because it presents optimum features for efficient and sensitive molecular detection of organic compounds, being able to trace quantities with a minimum of reagents and sample manipulation. Given these special features, electrochemical techniques are regularly exploited in disease diagnosis and monitoring. Specifically, amperometric electrochemical analysis has proven to be quite suitable for the detection of physiological biomarkers in monitoring health conditions, as well as toward the control of reactive oxygen species released in the course of oxidative burst during inflammatory events. Besides, electrochemical detection techniques involve a simple and swift assessment that provides a low detection-limit for most of the molecules enclosed biological fluids and related to non-transmittable morbidities.
Topics: Biosensing Techniques; Electrochemical Techniques; Humans; Noncommunicable Diseases
PubMed: 32927739
DOI: 10.3390/bios10090121 -
Frontiers in Plant Science 2020Currently, a global analysis of the information available on the relative composition of the floral scents of a very diverse variety of plant species is missing. Such...
Currently, a global analysis of the information available on the relative composition of the floral scents of a very diverse variety of plant species is missing. Such analysis may reveal general patterns on the distribution and dominance of the volatile compounds that form these mixtures, and may also allow measuring the effects of factors such as the phylogeny, pollination vectors, and climatic conditions on the floral scents of the species. To fill this gap, we compiled published data on the relative compositions and emission rates of volatile organic compounds (VOCs) in the floral scents of 305 plant species from 66 families. We also gathered information on the groups of pollinators that visited the flowers and the climatic conditions in the areas of distribution of these species. This information allowed us to characterize the occurrence and relative abundances of individual volatiles in floral scents and the effects of biotic and climatic factors on floral scent. The monoterpenes trans-β-ocimene and linalool and the benzenoid benzaldehyde were the most abundant floral VOCs, in both ubiquity and predominance in the floral blends. Floral VOC richness and relative composition were moderately preserved traits across the phylogeny. The reliance on different pollinator groups and the climate also had important effects on floral VOC richness, composition, and emission rates of the species. Our results support the hypothesis that key compounds or compounds originating from specific biosynthetic pathways mediate the attraction of the main pollinators. Our results also indicate a prevalence of monoterpenes in the floral blends of plants that grow in drier conditions, which could link with the fact that monoterpene emissions protect plants against oxidative stresses throughout drought periods and their emissions are enhanced under moderate drought stress. Sesquiterpenes, in turn, were positively correlated with mean annual temperature, supporting that sesquiterpene emissions are dominated mainly by ambient temperature. This study is the first to quantitatively summarise data on floral-scent emissions and provides new insights into the biotic and climatic factors that influence floral scents.
PubMed: 32849712
DOI: 10.3389/fpls.2020.01154 -
Nuclear Medicine and Biology Jan 2021The prospects for using carbon-11 labelled compounds in molecular imaging has improved with the development of diverse synthesis methods, including C-carbonylations and...
The prospects for using carbon-11 labelled compounds in molecular imaging has improved with the development of diverse synthesis methods, including C-carbonylations and refined techniques to handle [C]carbon monoxide at a nanomole scale. Facilitating biological research and molecular imaging was the driving force when [C]carbon monoxide was used in the first in vivo application with carbon-11 in human (1945) and when [C]carbon monoxide was used for the first time as a chemical reagent in the synthesis of [C]phosgene (1978). This review examines a rich plethora of labelled compounds synthesized from [C]carbon monoxide, their chemistry and use in molecular imaging. While the strong development of the C-carbonylation chemistry has expanded the carbon-11 domain considerably, it could be argued that the number of C-carbonyl compounds entering biological investigations should be higher. The reason for this may partly be the lack of commercially available synthesis instruments designed for C-carbonylations. But as this review shows, novel and greatly simplified methods to handle [C]carbon monoxide have been developed. The next important challenge is to make full use of these technologies and synthesis methods in PET research. When there is a PET-tracer that meets a more general need, the incentive to implement C-carbonylation protocols will increase.
Topics: Animals; Carbon Monoxide; Carbon Radioisotopes; Humans; Positron-Emission Tomography; Radiochemistry; Radiopharmaceuticals
PubMed: 32147168
DOI: 10.1016/j.nucmedbio.2020.02.005 -
Medicina (Kaunas, Lithuania) Aug 2019Obstructive sleep apnea syndrome (OSAS) represents an independent risk factor for cardiovascular, metabolic and neurological events. Polysomnography is the...
Obstructive sleep apnea syndrome (OSAS) represents an independent risk factor for cardiovascular, metabolic and neurological events. Polysomnography is the gold-standard for the diagnosis, however is expensive and time-consuming and not suitable for widespread use. Breath analysis is an innovative, non-invasive technique, able to provide clinically relevant information about OSAS. This systematic review was aimed to outline available evidence on the role of exhaled breath analysis in OSAS, taking into account the techniques' level of adherence to the recently proposed technical standards. Articles reporting original data on exhaled breath analysis in OSAS were identified through a computerized and manual literature search and screened. Duplicate publications, case reports, case series, conference papers, expert opinions, comments, reviews and meta-analysis were excluded. : Fractional exhaled Nitric Oxide (FeNO) is higher in OSAS patients than controls, however its absolute value is within reported normal ranges. FeNO association with AHI is controversial, as well as its change after continuous positive airway pressure (C-PAP) therapy. Exhaled breath condensate (EBC) is acid in OSAS, cytokines and oxidative stress markers are elevated, they positively correlate with AHI and normalize after treatment. The analysis of volatile organic compounds (VOCs) by spectrometry or electronic nose is able to discriminate OSAS from healthy controls. The main technical issues regards the dilution of EBC and the lack of external validation in VOCs studies. Exhaled breath analysis has a promising role in the understanding of mechanisms underpinning OSAS and has demonstrated a clinical relevance in identifying individuals affected by the disease, in assessing the response to treatment and, potentially, to monitor patient's adherence to mechanical ventilation. Albeit the majority of the technical standards proposed by the ERS committee have been followed by existing papers, further work is needed to uniform the methodology.
Topics: Breath Tests; Electronic Nose; Gas Chromatography-Mass Spectrometry; Humans; Nitric Oxide; Sleep Apnea, Obstructive; Spectrum Analysis; Volatile Organic Compounds
PubMed: 31461988
DOI: 10.3390/medicina55090538 -
Respiratory Research Jan 2019Exhaled biomarkers may be related to disease processes in idiopathic pulmonary fibrosis (IPF) however their clinical role remains unclear. We performed a systematic...
BACKGROUND
Exhaled biomarkers may be related to disease processes in idiopathic pulmonary fibrosis (IPF) however their clinical role remains unclear. We performed a systematic review to investigate whether breath biomarkers discriminate between patients with IPF and healthy controls. We also assessed correlation with lung function, ability to distinguish diagnostic subgroups and change in response to treatment.
METHODS
MEDLINE, EMBASE and Web of Science databases were searched. Study selection was limited to adults with a diagnosis of IPF as per international guidelines.
RESULTS
Of 1014 studies screened, fourteen fulfilled selection criteria and included 257 IPF patients. Twenty individual biomarkers discriminated between IPF and controls and four showed correlation with lung function. Meta-analysis of three studies indicated mean (± SD) alveolar nitric oxide (CNO) levels were significantly higher in IPF (8.5 ± 5.5 ppb) than controls (4.4 ± 2.2 ppb). Markers of oxidative stress in exhaled breath condensate, such as hydrogen peroxide and 8-isoprostane, were also discriminatory. Two breathomic studies have isolated discriminative compounds using mass spectrometry. There was a lack of studies assessing relevant treatment and none assessed differences in diagnostic subgroups.
CONCLUSIONS
Evidence suggests CNO is higher in IPF, although studies were limited by small sample size. Further breathomic work may identify biomarkers with diagnostic and prognostic potential.
Topics: Biomarkers; Breath Tests; Humans; Idiopathic Pulmonary Fibrosis; Inflammation Mediators; Nitric Oxide; Oxidative Stress; Respiratory Mechanics
PubMed: 30634961
DOI: 10.1186/s12931-019-0971-8 -
Revista Gaucha de Enfermagem Nov 2018To identify the adverse reactions associated with the infusion of hematopoietic stem cells on day zero of hematopoietic stem cell transplantation.
OBJECTIVE
To identify the adverse reactions associated with the infusion of hematopoietic stem cells on day zero of hematopoietic stem cell transplantation.
METHODOLOGY
Integrative literature review, without temporal cut, with search in the following databases: PubMed, CINAHL, SCOPUS, BVS, SciELO, Web of Science and CAPES; the final sample consisted of 18 scientific articles, published between 1998 and 2017, based on the inclusion and exclusion criteria.
RESULTS
Mild and moderate adverse reactions were the most frequent in studies that used the classification by severity, and nausea and emesis had the highest incidence; the most affected organ systems were the cardiovascular, respiratory and gastrointestinal.
CONCLUSION
The main adverse reactions identified in the studies were nausea and emesis. Those classified as mild and moderate were the most frequent in the studies that used the severity classification; and the cardiovascular, respiratory and gastrointestinal systems were the most affected in those that used the classification by organic systems.
Topics: Cardiovascular Diseases; Cryopreservation; Cryoprotective Agents; Epoxy Compounds; Gastrointestinal Diseases; Hematopoietic Stem Cell Transplantation; Humans; Nausea; Postoperative Complications; Respiration Disorders; Time Factors; Vomiting
PubMed: 30517435
DOI: 10.1590/1983-1447.2018.20180095 -
Respiratory Research Oct 2015Metabolic profiling through targeted quantification of a predefined subset of metabolites, performed by mass spectrometric analytical techniques, allows detailed... (Review)
Review
Metabolic profiling through targeted quantification of a predefined subset of metabolites, performed by mass spectrometric analytical techniques, allows detailed investigation of biological pathways and thus may provide information about the interaction of different organic systems, ultimately improving understanding of disease risk and prognosis in a variety of diseases. Early risk assessment, in turn, may improve patient management in regard to cite-of-care decisions and treatment modalities. Within this review, we focus on the potential of metabolic profiling to improve our pathophysiological understanding of disease and management of patients. We focus thereby on lower respiratory tract infections (LRTI) including community-acquired pneumonia (CAP) and chronic obstructive pulmonary disease (COPD), an important disease responsible for high mortality, morbidity and costs worldwide. Observational data from numerous clinical and experimental studies have provided convincing data linking metabolic blood biomarkers such as lactate, glucose or cortisol to patient outcomes. Also, identified through metabolomic studies, novel innovative metabolic markers such as steroid hormones, biogenic amines, members of the oxidative status, sphingo- and glycerophospholipids, and trimethylamine-N-oxide (TMAO) have shown promising results. Since many uncertainties remain in predicting mortality in these patients, further prospective and retrospective observational studies are needed to uncover metabolic pathways responsible for mortality associated with LRTI. Improved understanding of outcome-specific metabolite signatures in LRTIs may optimize patient management strategies, provide potential new targets for future individual therapy, and thereby improve patients' chances for survival.
Topics: Animals; Biomarkers; Energy Metabolism; Humans; Lipid Metabolism; Lung; Metabolomics; Oxidative Stress; Predictive Value of Tests; Prognosis; Respiratory Tract Infections; Risk Assessment; Risk Factors
PubMed: 26471192
DOI: 10.1186/s12931-015-0283-6 -
Preventive Medicine Dec 2014To provide a systematic review of the existing literature on health consequences of vaporing of electronic cigarettes (ECs). (Review)
Review
OBJECTIVE
To provide a systematic review of the existing literature on health consequences of vaporing of electronic cigarettes (ECs).
METHODS
Search in: PubMed, EMBASE and CINAHL.
INCLUSION CRITERIA
Original publications describing a health-related topic, published before 14 August 2014. PRISMA recommendations were followed. We identified 1101 studies; 271 relevant after screening; 94 eligible.
RESULTS
We included 76 studies investigating content of fluid/vapor of ECs, reports on adverse events and human and animal experimental studies. Serious methodological problems were identified. In 34% of the articles the authors had a conflict of interest. Studies found fine/ultrafine particles, harmful metals, carcinogenic tobacco-specific nitrosamines, volatile organic compounds, carcinogenic carbonyls (some in high but most in low/trace concentrations), cytotoxicity and changed gene expression. Of special concern are compounds not found in conventional cigarettes, e.g. propylene glycol. Experimental studies found increased airway resistance after short-term exposure. Reports on short-term adverse events were often flawed by selection bias.
CONCLUSIONS
Due to many methodological problems, severe conflicts of interest, the relatively few and often small studies, the inconsistencies and contradictions in results, and the lack of long-term follow-up no firm conclusions can be drawn on the safety of ECs. However, they can hardly be considered harmless.
Topics: Animals; Conflict of Interest; Cytotoxins; Electronic Nicotine Delivery Systems; Glycols; Humans; Metals, Heavy; Mice; Particulate Matter; Steam; Volatilization
PubMed: 25456810
DOI: 10.1016/j.ypmed.2014.10.009 -
Indian Journal of Dental Research :... 2014Antioxidant properties and Vitamin C. (Review)
Review
CONTEXT
Antioxidant properties and Vitamin C.
BACKGROUND
Vitamin C is a naturally occurring organic compound and a potent antioxidant preventing oxidative damage to lipids and other macromolecules. It can also exhibit bimodal activity as a pro-oxidant at a higher concentration. Vitamin C has a switch over role from being an antioxidant in physiologic conditions to a pro-oxidant under pathologic conditions. A systematic review of this role would help to elucidate whether it is an antioxidant or a pro-oxidant in the oral environment.
OBJECTIVE
To review studies reported in the literature elucidating the activity of Vitamin C and determine whether it is an antioxidant or a pro-oxidant.
MATERIALS AND METHODS
Articles were searched in PubMed, MEDLINE using appropriate key words like "Vitamin C," "antioxidant activity," "pro-oxidant activity," "oral health" "oral disease." Hand search of journals was also performed. Articles were reviewed and analyzed.
RESULTS
Search strategy reviewed 10 relevant articles which studied the dual role of Vitamin C. 65% of authors analyzed antioxidant action of ascorbic acid compared to 35% of the pro-oxidant potential. Vitamin C acts as an antioxidant and a pro-oxidant by a plethora of mechanisms. Factors determining its bimodal activity were studied, and the frequencies of their occurrence in the literature were depicted in percentage.
CONCLUSION
The data validates the role of Vitamin C as an antioxidant under physiologic conditions exhibiting a cross over role as a pro-oxidant in pathological conditions. Further studies are required to substantiate its pro-oxidant activity to draw concrete conclusions.
Topics: Antioxidants; Ascorbic Acid; Humans; Mouth; Reactive Oxygen Species
PubMed: 25307916
DOI: 10.4103/0970-9290.142547 -
BMC Anesthesiology 2014In critically ill patients, glucose control with insulin mandates time- and blood-consuming glucose monitoring. Blood glucose level fluctuations are accompanied by... (Review)
Review
BACKGROUND
In critically ill patients, glucose control with insulin mandates time- and blood-consuming glucose monitoring. Blood glucose level fluctuations are accompanied by metabolomic changes that alter the composition of volatile organic compounds (VOC), which are detectable in exhaled breath. This review systematically summarizes the available data on the ability of changes in VOC composition to predict blood glucose levels and changes in blood glucose levels.
METHODS
A systematic search was performed in PubMed. Studies were included when an association between blood glucose levels and VOCs in exhaled air was investigated, using a technique that allows for separation, quantification and identification of individual VOCs. Only studies on humans were included.
RESULTS
Nine studies were included out of 1041 identified in the search. Authors of seven studies observed a significant correlation between blood glucose levels and selected VOCs in exhaled air. Authors of two studies did not observe a strong correlation. Blood glucose levels were associated with the following VOCs: ketone bodies (e.g., acetone), VOCs produced by gut flora (e.g., ethanol, methanol, and propane), exogenous compounds (e.g., ethyl benzene, o-xylene, and m/p-xylene) and markers of oxidative stress (e.g., methyl nitrate, 2-pentyl nitrate, and CO).
CONCLUSION
There is a relation between blood glucose levels and VOC composition in exhaled air. These results warrant clinical validation of exhaled breath analysis to monitor blood glucose levels.
Topics: Blood Glucose; Breath Tests; Exhalation; Humans; Oxidative Stress; Volatile Organic Compounds
PubMed: 24963286
DOI: 10.1186/1471-2253-14-46