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Cancer Metastasis Reviews Jun 2019
Topics: Aerobiosis; Glycolysis; Humans; Hydrogen-Ion Concentration; Neoplasms
PubMed: 31069573
DOI: 10.1007/s10555-019-09798-1 -
Nutrients Aug 2020Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition... (Meta-Analysis)
Meta-Analysis
Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition zones is scarce and the results controversial. The aim of this systematic review and meta-analysis is to analyze the effects of BA supplementation on physical performance in aerobic-anaerobic transition zones. At the same time, the effect of different dosages and durations of BA supplementation were identified. The search was designed in accordance with the PRISMA guidelines for systematic reviews and meta-analyses and performed in Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2010 and 2020. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the Time Trial Test (TTT) and Time to Exhaustion (TTE) tests, the latter separated into the Limited Time Test (LTT) and Limited Distance Test (LDT). The analysis was carried out with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Nineteen studies were included in the systematic review and meta-analysis, revealing a small effect for time in the TTT (SMD, -0.36; 95% CI, -0.87-0.16; I = 59%; = 0.010), a small effect for LTT (SMD, 0.25; 95% CI, -0.01-0.51; I = 0%; = 0.53), and a large effect for LDT (SMD, 4.27; 95% CI, -0.25-8.79; I = 94%; = 0.00001). BA supplementation showed small effects on physical performance in aerobic-anaerobic transition zones. Evidence on acute supplementation is scarce (one study); therefore, exploration of acute supplementation with different dosages and formats on physical performance in aerobic-anaerobic transition zones is needed.
Topics: Aerobiosis; Anaerobiosis; Dietary Supplements; Humans; Physical Functional Performance; Sports Nutritional Physiological Phenomena; beta-Alanine
PubMed: 32824885
DOI: 10.3390/nu12092490 -
Journal of Molecular Evolution Sep 2002The huge variation in the genomic guanine plus cytosine content (GC%) among prokaryotes has been explained by two mutually exclusive hypotheses, namely, selectionist and...
The huge variation in the genomic guanine plus cytosine content (GC%) among prokaryotes has been explained by two mutually exclusive hypotheses, namely, selectionist and neutralist. The former proposals have in common the assumption that this feature is a form of adaptation to some ecological or physiological condition. On the other hand, the neutralist interpretation states that the variations are due only to different mutational biases. Since all of the traits that have been proposed by the selectionists either appeared to be limited to certain genera or were invalidated by the availability of more data, they cannot be considered as a selective force influencing the genomic GC% across all prokaryotes. In this report we show that aerobic prokaryotes display a significant increment in genomic GC% in relation to anaerobic ones. This is the first time that a link between a metabolic character and GC% has been found, independently of phylogenetic relationships and with a statistically significant amount of data.
Topics: Aerobiosis; Archaea; Bacterial Physiological Phenomena; Base Composition; Cytosine; DNA; DNA Damage; DNA Glycosylases; DNA Repair; DNA-Formamidopyrimidine Glycosylase; Evolution, Molecular; Guanine; Models, Biological; Mutation; N-Glycosyl Hydrolases; Prokaryotic Cells; Selection, Genetic; Thermodynamics
PubMed: 12187379
DOI: 10.1007/s00239-002-2323-3 -
Minerva Anestesiologica Apr 2003The detection of tissue hypoxia and its correction is one of the aim of the hemodynamic monitoring. Classical hemodynamic variable often fail to achieve this goal.... (Review)
Review
The detection of tissue hypoxia and its correction is one of the aim of the hemodynamic monitoring. Classical hemodynamic variable often fail to achieve this goal. Lactate measurements may be a good indicator of tissue hypoxia. Selected review of the articles on lactate in critically ill patients. Tissue hypoxia is associated with an increase in blood lactate levels. However lactate can also be produced in aerobic conditions, in inflammated tissues, and lactate clearance is often decreased in critically ill patients. Whatever its origin, blood lactate levels have a strong predictive value. The interpretation of blood lactate levels is difficult. Nevertheless, monitoring blood lactate levels can be useful to detect tissue hypoxia and to monitor the effects of therapy.
Topics: Acidosis, Lactic; Aerobiosis; Anaerobiosis; Humans; Lactates; Prognosis; Sepsis
PubMed: 12766720
DOI: No ID Found -
Current Opinion in Biotechnology Jun 2001Novel dehalogenases have been identified recently in various bacteria that utilise halogenated substrates. X-ray studies and sequence analysis have revealed insight into... (Review)
Review
Novel dehalogenases have been identified recently in various bacteria that utilise halogenated substrates. X-ray studies and sequence analysis have revealed insight into the molecular mechanisms of hydrolytic dehalogenases. Furthermore, genetic and biochemical studies have indicated that reductive dehalogenases are extra-cytoplasmic corrinoid-containing iron-sulphur proteins. Sequence analysis and mutagenesis studies indicate that several dehalogenases are homologous to enzymes that carry out transformations on non-halogenated substrates.
Topics: Aerobiosis; Anaerobiosis; Bacteria; Bacterial Physiological Phenomena; Biodegradation, Environmental; Catalysis; Hydrocarbons, Halogenated; Hydrolases
PubMed: 11404103
DOI: 10.1016/s0958-1669(00)00208-1 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Oct 2021Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to... (Review)
Review
Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.
Topics: Aerobiosis; Denitrification; Nitrification; Nitrogen; Wastewater
PubMed: 34708607
DOI: 10.13345/j.cjb.210407 -
Free Radical Biology & Medicine Aug 2019For well over a hundred years, members of the bacterial phylum Cyanobacteria have been considered strictly photosynthetic microorganisms, reflected in their... (Review)
Review
For well over a hundred years, members of the bacterial phylum Cyanobacteria have been considered strictly photosynthetic microorganisms, reflected in their classification as "blue-green algae" in the botanical code. Recently, genomes recovered from environmental sequencing surveys representing two major uncultured basal lineages (classes) of Cyanobacteria have been found to completely lack photosynthetic and CO fixation genes. The most likely explanation for this finding is that oxygenic photosynthesis was not an ancestral feature of the Cyanobacteria, and rather originated following divergence of the primary lines of descent. Here we describe recent findings on the evolution of aerobic respiration in the non-photosynthetic cyanobacterial classes, and how this has been interpreted by researchers interested in the evolution of oxygenic photosynthesis.
Topics: Aerobiosis; Biological Evolution; Cell Respiration; Cyanobacteria; Oxygen; Photosynthesis
PubMed: 30930297
DOI: 10.1016/j.freeradbiomed.2019.03.029 -
Current Issues in Molecular Biology 2019This review is focused on recent studies of carbon metabolism in aerobic methanotrophs that specifically addressed the properties, distribution and phylogeny of some of... (Review)
Review
This review is focused on recent studies of carbon metabolism in aerobic methanotrophs that specifically addressed the properties, distribution and phylogeny of some of the key enzymes involved in assimilation of carbon from methane. These include enzymes involved in sugar sythesis and cleavage, conversion of intermediates of the tricarboxylic acid cycle, as well as in osmoadaptation in halotolerant methanotrophs.
Topics: Adaptation, Biological; Aerobiosis; Biodiversity; Carbon; Citric Acid Cycle; Methane; Osmotic Pressure; Phylogeny; Soil Microbiology
PubMed: 31166186
DOI: 10.21775/cimb.033.085 -
Current Opinion in Clinical Nutrition... Jul 2010Cancer cells alter their metabolism in order to support their rapid proliferation and expansion across the body. In particular, tumor cells, rather than fueling glucose... (Review)
Review
PURPOSE OF REVIEW
Cancer cells alter their metabolism in order to support their rapid proliferation and expansion across the body. In particular, tumor cells, rather than fueling glucose in the oxidative phosphorylation pathway, generally use glucose for aerobic glycolysis. In this review, we discuss some of the mechanisms thought to be responsible for the acquisition of a glycolytic phenotype in cancer cells and how the switch towards glycolysis represents a selective growth advantage.
RECENT FINDINGS
Glucose deprivation can activate oncogenes and these can upregulate proteins involved in aerobic glycolysis. In turn, proteins implicated in increased glycolysis can render tumor cells more resistant to apoptosis. Aerobic glycolysis induces acidification of the tumor environment, favoring the development of a more aggressive and invasive phenotype. Altering the pH around tumors might represent a way to hamper tumor development as suggested by a recent work demonstrating that bicarbonate, which increases the pH of tumors, prevented spontaneous metastatization.
SUMMARY
The acquisition of a glycolytic phenotype by transformed cells confers a selective growth advantage to these cells. Interfering with aerobic glycolysis, therefore, represents a potentially effective strategy to selectively target cancer cells.
Topics: Aerobiosis; Animals; Apoptosis; Bicarbonates; Cell Proliferation; Glucose; Glycolysis; Humans; Hydrogen-Ion Concentration; Neoplasms; Oncogenes; Oxidative Phosphorylation; Phenotype
PubMed: 20473153
DOI: 10.1097/MCO.0b013e32833a5577 -
FEMS Yeast Research Jun 2003Yeast species can grow on various sugars. However, in many cases the growth on certain sugars (especially oligosaccharides) occurs only under aerobic conditions, and not... (Review)
Review
Yeast species can grow on various sugars. However, in many cases the growth on certain sugars (especially oligosaccharides) occurs only under aerobic conditions, and not in anaerobiosis or in the absence of respiration. Fermentation is blocked under these conditions. This apparent dependence of sugar utilization on the respiration has been called Kluyver effect, and such 'respiration-dependent' species are called Kluyver effect positive. A yeast may be Kluyver effect positive for some sugars and not for others. The physiological meaning and the molecular basis of the phenomenon are not clear. It has recently been reported that Kluyveromyces lactis, which is Kluyver effect positive for galactose and a few other sugars, could be converted into a Kluyver effect-negative form by introduction of relevant sugar transporter genes. Such results offer for the first time a direct support to the hypothesis that the immediate cause of the Kluyver effect may be the low level of sugar transporter activities which is not sufficient to sustain the high substrate flow necessary for fermentative growth, whereas the energy-efficient respiratory growth does not require a high rate of sugar uptake. We examined to what extent this sugar transporter theory of the Kluyver effect can be generalized.
Topics: Aerobiosis; Anaerobiosis; Carbohydrate Metabolism; Cell Respiration; Fermentation; Membrane Transport Proteins; Oxygen Consumption; Yeasts
PubMed: 12748045
DOI: 10.1016/S1567-1356(03)00112-0