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The ISME Journal Jan 2024Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing... (Review)
Review
Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing microbial ecology. Since their first application for aerobic gammaproteobacterial methane oxidizers less than a decade ago, GEMs have substantially increased our understanding of the metabolism of methanotrophs, a microbial guild of high relevance for the natural and biotechnological mitigation of methane efflux to the atmosphere. Particularly, GEMs helped to elucidate critical metabolic and regulatory pathways of several methanotrophic strains, predicted microbial responses to environmental perturbations, and were used to model metabolic interactions in cocultures. Here, we conducted a systematic review of GEMs exploring aerobic methanotrophy, summarizing recent advances, pointing out weaknesses, and drawing out probable future uses of GEMs to improve our understanding of the ecology of methane oxidizers. We also focus on their potential to unravel causes and consequences when studying interactions of methane-oxidizing bacteria with other methanotrophs or members of microbial communities in general. This review aims to bridge the gap between applied sciences and microbial ecology research on methane oxidizers as model organisms and to provide an outlook for future studies.
Topics: Methane; Oxidation-Reduction; Aerobiosis; Metabolic Networks and Pathways; Models, Biological
PubMed: 38861460
DOI: 10.1093/ismejo/wrae102 -
Bioresource Technology Feb 2023Ammonium oxidation coupled to Fe(III) reduction (Feammox) is a newly discovered iron-nitrogen cycle process of microbial catalyzed NH oxidation coupled with iron... (Review)
Review
Ammonium oxidation coupled to Fe(III) reduction (Feammox) is a newly discovered iron-nitrogen cycle process of microbial catalyzed NH oxidation coupled with iron reduction. Fe(III) often exists in the form of insoluble iron minerals resulting in reduced microbial availability and low efficiency of Feammox. Electron shuttles(ESs) can be reversibly oxidized and reduced which has the potential to improve Feammox efficiency. This review summarizes the discovery process, electron transfer mechanism, influencing factors and driven microorganisms of Feammox, ang expounds the possibility and potential mechanism of ESs to enhance Feammox efficiency. Based on an in-depth analysis of the current research situation of Feammox for nitrogen removal, the knowledge gaps and future research directions including how to apply ESs enhanced Feammox to promote nitrogen removal in practical wastewater treatment have been highlighted. This review can provide new ideas for the engineering application research of Feammox and strong theoretical support for its development.
Topics: Ferric Compounds; Electrons; Anaerobiosis; Iron; Nitrogen Cycle; Ammonium Compounds; Oxidation-Reduction; Nitrogen; Denitrification
PubMed: 36526117
DOI: 10.1016/j.biortech.2022.128495 -
Critical Reviews in Food Science and... 2024Carbohydrates (CHO) and caffeine (CAF) are two ergogenic aids commonly used among athletes to enhance performance. However, there is some controversy as to whether the... (Meta-Analysis)
Meta-Analysis
Carbohydrates (CHO) and caffeine (CAF) are two ergogenic aids commonly used among athletes to enhance performance. However, there is some controversy as to whether the concurrent intake of both supplements might result in an additive and synergistic improvement in exercise performance. The aim of this systematic review and meta-analysis was to determine the effect of adding CAF to a protocol of CHO ingestion, compared with the intake of each ergogenic aid alone and with placebo, on exercise performance and metabolic responses in healthy young physically active adults. This study was conducted according to PRISMA 2020 guidelines. The PubMed, Web of Science, Medline Complete, CINAHL, SPORTDiscus and CENTRAL databases were searched including randomized controlled trials (RCT) that were at least single blind. The risk of bias assessment was performed using the Cochrane Risk-of-Bias tool 2. Meta-analysis were performed on performance variables and rating of perceived exertion (RPE) using the random-effects model. Thirteen RCT with 128 participants (117 men and 11 women) were included in this study. The ingestion of CAF and CHO reduced sprint time during repeated sprint protocols in comparison with CHO isolated ingestion (SMD: -0.45; 95% CI: -0.85, -0.05) while there was a tendency for a reduction in the time employed during time trials (SMD: -0.36; 95% CI: -0.77, 0.05). The RPE tended to be lower with CAF and CHO compared with CHO isolated ingestion during steady-state exercise (SMD: -0.43; 95% CI: -0.91, 0.05) with no differences between conditions in performance trials (SMD: -0.05, 95% CI: -0.39, 0.29). Although most of the studies showed higher values of blood glucose when CHO was co-ingested with CAF compared with PLA, only two studies observed higher values with CHO and CAF co-ingestion with respect to the isolated intake of CHO. One study observed greater fat oxidation and lower glycogen use when CAF was added to CHO. In terms of cortisol levels, one study showed an increase in cortisol levels when CAF was co-ingested with CHO compared with PLA. In summary, concurrent CHO and CAF intake may produce an additive ergogenic effect respect of the isolated ingestion of CHO. This additive effect was present when CHO was provided by a 6-9% of CHO solution (maltodextrin/dextrin + fructose) and CAF is administered in a dose of 4-6.5 mg/kg.
Topics: Male; Adult; Female; Humans; Caffeine; Hydrocortisone; Dietary Carbohydrates; Physical Functional Performance; Eating; Polyesters
PubMed: 36178302
DOI: 10.1080/10408398.2022.2128298 -
Scandinavian Journal of Medicine &... Jul 2019Maximal fat oxidation during exercise (MFO) and the exercise intensity eliciting MFO (Fat ) are considered biological markers of metabolic health and performance. A wide...
Maximal fat oxidation during exercise (MFO) and the exercise intensity eliciting MFO (Fat ) are considered biological markers of metabolic health and performance. A wide range of studies have been performed to increase our knowledge about their regulation by exercise and/or nutritional intervention. However, numerous data collection and analysis approaches have been applied, which may have affected the MFO and Fat estimation. We aimed to systematically review the available studies describing and/or comparing different data collection and analysis approach factors that could affect MFO and Fat estimation in healthy individuals and patients. Two independent researchers performed the search. We included all original studies in which MFO and/or Fat were estimated by indirect calorimetry through an incremental graded exercise protocol published from 2002 to 2019. This systematic review provides key information about the factors that could affect MFO and Fat estimation: ergometer type, metabolic cart used, warm-up duration and intensity, stage duration and intensities imposed in the graded exercise protocol, time interval selected for data analysis, stoichiometric equation selected to estimate fat oxidation, data analysis approach, time of the day when the test was performed, fasting time/previous meal before the test, and testing days for MFO/Fat and maximal oxygen uptake assessment. We suggest that researchers measuring MFO and Fat should take into account these key methodological issues that can considerably affect the accuracy, validity, and reliability of the measurement. Likewise, when comparing different studies, it is important to check whether the above-mentioned key methodological issues are similar in such studies to avoid ambiguous and unacceptable comparisons.
Topics: Adipose Tissue; Calorimetry, Indirect; Ergometry; Exercise; Fasting; Humans; Oxidation-Reduction; Oxygen Consumption
PubMed: 30929281
DOI: 10.1111/sms.13424 -
The Canadian Journal of Cardiology Dec 2017Although basic research has suggested that oxidized low-density lipoprotein (ox-LDL) is involved in the pathogenesis of atherosclerosis, population observational studies... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Although basic research has suggested that oxidized low-density lipoprotein (ox-LDL) is involved in the pathogenesis of atherosclerosis, population observational studies have yielded conflicting results about the association between circulating ox-LDL and atherosclerotic cardiovascular disease (ASCVD). Therefore, we performed a systematic review and meta-analysis of currently available observational studies to verify the association between circulating ox-LDL and ASCVD.
METHODS
We systematically searched PubMed and the Cochrane Library from their inception to March 27, 2017, for nested case-control studies, case-cohort studies, and prospective cohort studies on the relationship between ox-LDL and ASCVD. Studies that did not assess the hazard ratio, relative risk, or odds ratio of ox-LDL or did not adjust for other risk factors, or those without examination of ox-LDL before collection of ASCVD occurrences were excluded. The summarized effect size was combined using fixed effect models. Subgroup analyses were performed on the basis of study quality, study design, definition of ASCVD events, effect size types, types of ox-LDL assay, ox-LDL contrast level, and whether low-density lipoprotein cholesterol was adjusted in a multivariate model.
RESULTS
A total of 12 included studies consisted of 3 nested case-control studies, 1 case-cohort study, 5 hospital-based cohort studies, and 3 community-based cohort studies. The summary effect size of increased circulating ox-LDL was 1.79 (95% confidence interval, 1.56-2.05) for ASCVD. Similar associations were shown in all subgroups.
CONCLUSIONS
Our findings indicate that increased levels of circulating ox-LDL are associated with clinical ASCVD events. Further well designed community-based cohort studies or intervention studies are needed to confirm our findings.
Topics: Atherosclerosis; Biomarkers; Case-Control Studies; Disease Progression; Humans; Lipoproteins, LDL; Observational Studies as Topic; Oxidation-Reduction
PubMed: 29173602
DOI: 10.1016/j.cjca.2017.07.015 -
Obstetrical & Gynecological Survey Nov 2009Preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity; however, there is no consensus as to the extent of these conditions. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity; however, there is no consensus as to the extent of these conditions.
OBJECTIVE
To assess the association of lipid peroxidation and antioxidant status with preeclampsia quantitatively using meta-analysis.
DESIGN
Systematic review and meta-analysis.
SEARCH STRATEGY
Studies were identified by performing an extensive search using BIOSIS (1986-2007), EMBASE (1986-2007), Medline (1986-2007), and the Cochrane database.
DATA ANALYSIS
Standardized mean differences (SMD) with 95% confidence intervals (CI) were used in the meta-analysis and sources of heterogeneity were examined.
MAIN RESULTS
In the included studies, the overall SMD was a 1.21 nmol/mL increase in serum malondialdehyde in preeclampsia cases compared to controls (95% CI: 0.76, 1.66). Overall, total serum thiobarbituric acid-reactive substances SMD were 1.62 nmol/mL greater in cases than in controls (95% CI: 0.27, 2.96). The overall estimate SMD for serum vitamin E was 1.12 nmol/mL less in cases than controls (95% CI: -1.77, -0.48) and vitamin C SMD overall estimate was -0.53 (95%CI: -1.03, -0.02), significantly lower in cases compared with controls. The overall SMD for erythrocyte superoxide dismutase was -2.37 (95% CI: -4.76, 0.03), a marginally significant decrease in cases versus controls.
CONCLUSIONS
Established preeclampsia is associated with increased concentrations of oxidative stress markers including lipid peroxidation products, and a reduction in antioxidant concentrations.
TARGET AUDIENCE
Obstetricians & Gynecologists, Family Physicians.
LEARNING OBJECTIVES
After completion of this educational activity, the participant should be better able to describe the pattern of oxidative stress markers associated with preeclampsia, and interpret the available literature as it relates to oxidative stress and preeclampsia.
Topics: Antioxidants; Ascorbic Acid; Biomarkers; Female; Free Radical Scavengers; Humans; Lipid Peroxidation; Oxidative Stress; Pre-Eclampsia; Pregnancy; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Vitamin E
PubMed: 19849867
DOI: 10.1097/OGX.0b013e3181bea0ac -
Critical Reviews in Food Science and... 2014F2-isoprostanes are a biomarker of lipid peroxidation, and their measurement has emerged as a reliable approach to assess oxidative stress. However, dietary intervention... (Review)
Review
F2-isoprostanes are a biomarker of lipid peroxidation, and their measurement has emerged as a reliable approach to assess oxidative stress. However, dietary intervention studies in humans have provided contrasting results following supplementation with antioxidant-rich foods or supplements. In this paper, we have systematically reviewed the evidence about the effect of supplementation with antioxidant-rich foods and galenic antioxidants on isoprostanes levels in humans. Moreover, the association with nonenzymatic antioxidant capacity (NEAC), a biomarker of endogenous antioxidant status, has also been investigated. MEDLINE database was searched using the terms "(isoprostane* OR isoP OR iso-PGF OR epi-PGF) AND (intervention* OR consumption* OR administration* OR supplementation*)," with limits activated "humans" and "English." Abstracts and full texts were screened, from which were selected human intervention studies reporting isoprostanes measurement in biological fluids. The total of the studies carried out with antioxidant-rich foods and antioxidant galenic supplements was 113, reporting 154 interventions. Results suggest that dietary antioxidants modulate successfully the levels of isoprostanes in less than 45% of the interventions. A correspondence between the effect on isoprostane and NEAC has been evidenced, and this correspondence suggests the importance of measuring different biomarkers to obtain a better outline of the redox events following supplementation.
Topics: Antioxidants; Biomarkers; Cacao; Diet; Dietary Supplements; F2-Isoprostanes; Fruit; Humans; Lipid Peroxidation; MEDLINE; Plant Extracts; Tea; Vitamins; Wine
PubMed: 24499151
DOI: 10.1080/10408398.2011.630153 -
Journal of Human Nutrition and... Oct 2014Although the regular consumption of green tea or green tea extract has been considered to improve insulin sensitivity, the reported results are inconsistent. Therefore,... (Comparative Study)
Comparative Study Meta-Analysis Review
Effects of green tea or green tea extract on insulin sensitivity and glycaemic control in populations at risk of type 2 diabetes mellitus: a systematic review and meta-analysis of randomised controlled trials.
BACKGROUND
Although the regular consumption of green tea or green tea extract has been considered to improve insulin sensitivity, the reported results are inconsistent. Therefore, we conducted a meta-analysis to evaluate the effect of green tea or green tea extract on insulin sensitivity and glycaemic control in populations at risk of type 2 diabetes mellitus (T2DM).
METHODS
Electronic databases, including PUBMED, The Cochrane Library, EMBASE, ISI Web of Knowledge, Chinese Biomedical Literature Database and Chinese Scientific Journals Fulltext Database, were systematically searched to identify randomised controlled trials (RCTs) up to December 2011, supplemented by the Clinicaltrials.gov websites and the reference lists of identified studies. Two reviewers independently selected trials, extracted data, and evaluated the methodological qualities and evidence levels.
RESULTS
Seven RCTs involving 510 participants were identified. There was no statistically significant difference between green tea or green tea extract group and placebo group with regard to fasting plasma glucose [standardised mean difference (SMD) 0.04; 95% confidence interval (CI) -0.15 to 0.24], fasting serum insulin (SMD -0.09; 95% CI -0.30 to 0.11), 2-h plasma glucose in the oral glucose tolerance test (OGTT-2 h) (SMD -0.14; 95% CI -0.63 to 0.34), haemoglobin A₁c (SMD 0.10; 95% CI -0.13 to 0.33) and homeostasis model of insulin resistance (HOMA(IR)) index (SMD -0.06; 95% CI -0.35 to 0.23) in participants at risk of T2DM.
CONCLUSIONS
The consumption of green tea did not decrease the levels of fasting plasma glucose, fasting serum insulin, OGTT-2 h glucose, haemoglobin A₁c and HOMA(IR) in populations at risk of T2DM. Larger, longer-term and high-quality RCTs are needed to further definitely determine the effect of green tea or green tea extract on insulin sensitivity and glycaemic control in populations at risk of T2DM.
Topics: Diabetes Mellitus, Type 2; Dietary Supplements; Evidence-Based Medicine; Food Handling; Humans; Hyperglycemia; Hyperinsulinism; Insulin Resistance; Oxidation-Reduction; Plant Extracts; Plant Leaves; Randomized Controlled Trials as Topic; Risk Factors; Tea
PubMed: 24206044
DOI: 10.1111/jhn.12181 -
Colombia Medica (Cali, Colombia) Sep 2015Our objective was to systematically review the published observational research related to the role of oxidative-nitrosative stress in pathogenesis of dengue. (Review)
Review
OBJECTIVE
Our objective was to systematically review the published observational research related to the role of oxidative-nitrosative stress in pathogenesis of dengue.
METHODS
We searched electronic databases (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) using the term: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide, and nitric oxide synthase. Articles were selected for review by title and abstract excluding letter, review, in vivo and in vitro studies, and duplicates studies. Selected articles were reviewed for study design, original purposes, sample size, main outcomes, methods, and oxidative-nitrosative stress markers values.
RESULTS
In total, 4,331 non-duplicates articles were identified from electronic databases searches, of which 16 were eligible for full text searching. Data from the observational studies originate from Asian countries (50%; 8/16), South American countries (31.2%; 5/16), and Central America and the Caribbean countries (18.8%; 3/16). Case-control study was the type of design most common in researches reviewed. The 1997 World Health Organization (WHO) dengue case classification criteria were used in all studies included in this review.
CONCLUSIONS
Based on published data found in peer-reviewed literature, oxidative and nitrosative stress are demonstrated by changes in plasma levels of nitric oxide, antioxidants, lipid peroxidation and protein oxidation markers in patients with dengue infection. Additionally, elevated serum protein carbonyls and malondialdehyde levels appear to be associated with dengue disease severity.
Topics: Animals; Antioxidants; Dengue; Humans; Lipid Peroxidation; Nitric Oxide; Oxidative Stress; Proteins; Severity of Illness Index
PubMed: 26600629
DOI: No ID Found -
The Journal of Nutrition Dec 2023The indicator amino acid oxidation (IAAO) method has been accepted as an approach to evaluate habitual protein requirements under free-living conditions.
BACKGROUND
The indicator amino acid oxidation (IAAO) method has been accepted as an approach to evaluate habitual protein requirements under free-living conditions.
OBJECTIVES
This scoping review reports on literature that evaluated protein requirements in humans using the IAAO methods.
METHODS
Three databases (PubMed/Medline, Web of Science, and ProQuest) were systematically searched to identify studies that evaluated protein requirements using the IAAO method published in English until 5 June, 2023. We evaluated the study quality using previously developed criteria. We extracted the characteristics of the study design and the results of protein requirements. Two reviewers conducted both reviews and quality assessments independently; any differences among them were resolved by consensus or agreement of all team members.
RESULTS
We extracted 16 articles targeting children, young adults (including pregnant women, resistance training athletes, endurance-training athletes, and team sports), and older adults. In quality assessment, 14 studies were evaluated "strong," but the remaining 2 were "moderate." These studies were conducted in only 3 countries and did not include all sexes or life stages. The range of the estimated average protein requirements of each life stage was 1.30 g/kg body weight/d for children, 0.87 to 2.10 (0.87-0.93 for general young adults, 1.22-1.52 for pregnant women, 1.49-2.00 for resistance-trained athletes, 1.65-2.10 for endurance athletes, and 1.20-1.41 for team sports athletes) g/kg body weight/d for young adults, and 0.85 to 0.96 g/kg body weight/d for older adults.
CONCLUSIONS
Protein requirements in 14 studies were higher than the current reference for each sex, life stage, and physical activity that are related to protein requirements. In the future, protein requirements of various populations including sex and life stage could be assessed using the IAAO methods worldwide.
Topics: Young Adult; Child; Humans; Female; Pregnancy; Aged; Amino Acids; Nutritional Requirements; Dietary Proteins; Oxidation-Reduction; Body Weight
PubMed: 37573015
DOI: 10.1016/j.tjnut.2023.07.015