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Effect of an enzyme-containing mouthwash on the dental biofilm and salivary microbiome in patients with fixed orthodontic appliances: a randomized placebo-controlled pilot trial.
Hoffstedt, T, Skov Hansen, LB, Twetman, S, Sonesson, M
European journal of orthodontics. 2023;45(1):96-102
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Fixed orthodontic appliances are associated with dysbiosis in the oral cavity which may result in demineralisations of the enamel. Antiseptic mouthwashes have been shown to control the formation of cariogenic biofilm but may have negative effects on the salivary microbiome. The aim of this 8-day double-blind, randomised, placebo-controlled trial, including 35 adolescents with fixed orthodontics, was to evaluate the effect of an enzyme-based mouthwash (EBM), used twice daily, on dental biofilm (plaque) formation and salivary microbiome. At 8 days, a statistically and clinically significant decrease in the orthodontic plaque index was seen in the EBM group, whilst no change was seen in the placebo group. There were no statistically significant changes in microbiome between groups but a trend to increased richness in the placebo group. The authors concluded that the use of an enzyme-based mouthwash alongside regular toothbrushing reduced dental biofilm in adolescents with orthodontics without affecting the salivary microbiome.
Abstract
BACKGROUND Mouthwashes containing oral antiseptics or enzymes are suggested suitable for controlling biofilm accumulation in patients with fixed appliances and thereby limiting unwanted side effects during the orthodontic treatment. OBJECTIVES To evaluate the effect of an enzyme-based mouthwash on the amount of dental biofilm and the composition of the salivary microbiome in patients undergoing treatment with fixed orthodontic appliances. TRIAL DESIGN Randomized double-blind placebo-controlled trial. MATERIAL AND METHODS In total, 35 young adolescents (14-18 years) under treatment with fixed appliances were consecutively enrolled and randomly allocated to an experimental or a placebo group by opening a computer-generated numbered envelope. The subjects were instructed to rinse twice daily during an intervention period of 8 days with experimental mouthwash or placebo without active enzymes. Unstimulated whole saliva samples were collected at baseline and after 8 days. The participants and examiner were blinded for the allocation. The primary outcome was the Orthodontic Plaque Index (OPI) and the secondary was the composition of the salivary microbiome. RESULTS In total, 28 adolescents (21 females and 7 males) completed the trial and there were no differences in age, clinical, or microbial findings between the test (n = 14) and the placebo group (n = 14) at baseline. We found a decreased OPI in the test group after 8 days and the difference was statistically significant compared with the placebo group (P < 0.05). There were no significant treatment effects on the richness and global composition of the salivary microbiome. HARMS In total, one participant in the test group claimed nausea and abandoned the project. In total, two participants did not like the taste of the mouthwash but used it as instructed. No other adverse events or side effects were reported. LIMITATIONS Short-term pilot trials may by nature be sensitive for selection and performance biases and are not designed to unveil persisting effects. CONCLUSION Daily use of enzyme-containing mouthwash reduced the amount of dental biofilm in adolescents under treatment with the fixed orthodontic appliances, without affecting the composition of the salivary microbiota. ETHICAL APPROVAL Approved by the Regional Ethical Board, Lund, Sweden (Dnr 2020-05221). CLINICAL TRIAL REGISTRATION NCT05033015.
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Paroxysmal slow wave events are associated with cognitive impairment in patients with obstructive sleep apnea.
Li, M, Sun, Z, Sun, H, Zhao, G, Leng, B, Shen, T, Xue, S, Hou, H, Li, Z, Zhang, J
Alzheimer's research & therapy. 2022;14(1):200
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Obstructive sleep apnoea (OSA) is a disorder which results in an individual’s breathing being cut off momentarily whilst asleep. OSA has been associated with the development of cognitive impairment, which is characterised by declining memory. The reason for the link is thought to involve a dysfunction in the blood brain barrier, which can be measured by paroxysmal slow wave events (PSWEs). This study of 339 individuals with complaints of snoring aimed to determine the correlation between PSWEs and cognitive impairment. The results showed that cognitive impairment in individuals with OSA due to a lack of oxygen could be due to a dysfunction in the blood brain barrier and that PSWEs are a reliable measure of this. It was concluded that PSWEs can be used as a measure of cognitive impairment in patients with OSA and that brain barrier dysfunction may be involved in its development in this subset of individuals. This study could be used by healthcare professionals to understand that sleep apnoea is more than just snoring, it can be involved in the development of certain chronic diseases.
Abstract
BACKGROUND Increasing evidence has supported a link between obstructive sleep apnea (OSA) and cognition, and blood-brain barrier (BBB) dysfunction which can be reflected by paroxysmal slow wave events (PSWEs) may be a potential mechanism. The purpose of our study was to investigate the correlation between the PSWEs and cognitive impairment in patients with OSA, with a focus on the possible mechanism. METHODS In total, 339 subjects with subjective snoring complaints from the Sleep Medicine Center underwent magnetic resonance imaging and whole-night polysomnography. OSA was defined as apnea-hypopnea index (AHI) ≥ 5 events/h. MCI was defined as the MoCA < 26 and met the criteria: (1) subjective cognitive impairment; (2) objective impairment in one or more cognitive domains; (3) slightly impaired complex instrumental daily abilities, but independent daily living abilities; and (4) no dementia. The PSWEs calculated by self-developed Python scripts were defined for EEG recordings as a median power frequency of < 6 Hz for more than five consecutive seconds. Serum cyclophilin A (CyPA) and matrix metalloproteinase-9 (MMP-9) levels and amyloid-β 42 levels in neuron-derived exosomes were determined. The participants who received continuous positive airway pressure (CPAP) were followed up and their PSWEs were recalculated after 1 year of treatment. RESULTS A total of 339 participants were divided into the OSA+MCI group (n = 157), OSA-MCI group (n = 118), and controls (normal cognitive state without OSA) (n = 64). The total PSWEs and the occurrence per minute of PSWEs at stage REM in the OSA+MCI group were higher than those in the OSA-MCI and control groups. The duration ratio of PSWEs at stage REM in the OSA+MCI group significantly increased. The total PSWEs and PSWEs at the F4-M1, O1-M2, and O2-M1 channels in stage REM were independently associated with cognitive impairment in OSA patients. There were positive correlations between the PSWEs and serum CyPA and MMP-9 levels in patients with OSA. The mediation analysis showed that the relationship between mean SaO2 and percentage of sleep time spent with oxygen saturation <90% with MoCA scores was mediated by the total PSWEs (proportion of mediation 77.89% and 82.89%). The PSWEs were negatively correlated with global cognitive performance and cognitive subdomains. After 1 year of CPAP treatment, the total PSWEs, PSWEs in stage REM, and serum CyPA and MMP-9 levels decreased significantly, and MoCA scores were improved compared with baseline. CONCLUSIONS The PSWEs were implicated in cognitive impairment in patients with OSA, and the mechanisms of cognitive impairment due to hypoxia in OSA patients could be BBB dysfunction. The PSWEs can be used as a marker of cognitive impairment in patients with OSA. TRIAL REGISTRATION This trial is registered on the Chinese Clinical Trial Registry, number ChiCTR1900021544. The trial was registered on February 27, 2019.
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Nicotinamide Riboside Enhances In Vitro Beta-adrenergic Brown Adipose Tissue Activity in Humans.
Nascimento, EBM, Moonen, MPB, Remie, CME, Gariani, K, Jörgensen, JA, Schaart, G, Hoeks, J, Auwerx, J, van Marken Lichtenbelt, WD, Schrauwen, P
The Journal of clinical endocrinology and metabolism. 2021;106(5):1437-1447
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Brown fat is a type of fat that burns energy to regulate the body’s temperature in cold conditions. A high level of activity in the brown fat has been associated with healthy whole-body metabolism. Several supplements have been investigated for their potential to activate brown fat, however many of these have limiting side effects. Nicotinamide riboside (NR), also known as vitamin B3, is a supplement which can boost energy burning pathways within the body. This randomised control trial was part of a larger trial including a study on human brown fat cells and aimed to determine whether NR supplementation in overweight and obese individuals may act on the activity of brown tissue. The results showed that 6 weeks of NR supplementation had no effect on brown tissue activity or energy expenditure. It was concluded that NR supplementation for 6 weeks in individuals with obesity had no effect on brown fat tissue for reasons unknown, as the cellular study showed an increase in activity. This study could be used by healthcare professionals to better understand the role of brown fat in metabolism.
Abstract
CONTEXT Elevating nicotinamide adenine dinucleotide (NAD+) levels systemically improves metabolic health, which can be accomplished via nicotinamide riboside (NR). Previously, it was demonstrated that NR supplementation in high-fat-diet (HFD)-fed mice decreased weight gain, normalized glucose metabolism, and enhanced cold tolerance. OBJECTIVE Because brown adipose tissue (BAT) is a major source of thermogenesis, we hypothesize that NR stimulates BAT in mice and humans. DESIGN AND INTERVENTION HFD-fed C56BL/6J mice were supplemented with 400 mg/kg/day NR for 4 weeks and subsequently exposed to cold. In vitro primary adipocytes derived from human BAT biopsies were pretreated with 50 µM or 500 µM NR before measuring mitochondrial uncoupling. Human volunteers (45-65 years; body mass index, 27-35 kg/m2) were supplemented with 1000 mg/day NR for 6 weeks to determine whether BAT activity increased, as measured by [18F]FDG uptake via positron emission tomography-computed tomography (randomized, double blinded, placebo-controlled, crossover study with NR supplementation). RESULTS NR supplementation in HFD-fed mice decreased adipocyte cell size in BAT. Cold exposure further decreased adipocyte cell size on top of that achieved by NR alone independent of ex vivo lipolysis. In adipocytes derived from human BAT, NR enhanced in vitro norepinephrine-stimulated mitochondrial uncoupling. However, NR supplementation in human volunteers did not alter BAT activity or cold-induced thermogenesis. CONCLUSIONS NR stimulates in vitro human BAT but not in vivo BAT in humans. Our research demonstrates the need for further translational research to better understand the differences in NAD+ metabolism in mouse and human.
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Brown Adipose Crosstalk in Tissue Plasticity and Human Metabolism.
Scheele, C, Wolfrum, C
Endocrine reviews. 2020;41(1)
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Brown adipose tissue (BAT) is an important contributor to the regulation of metabolism via cellular communication with organs such as liver, muscle, gut and central nervous system. BAT is important for heat generation and is at high levels in human infants. Levels of activation of BAT decline as we age and it has been shown that the amount of BAT is smaller and its activity reduced in those with obesity and type 2 diabetes. To date, there is no answer to efficiently restore functional BAT in aging and obese subjects. This review looks at experiments done on the factors secreted from active BAT (batokines). The review aims to provide a structure for the processes and cell types involved in BAT and the recent findings of BAT whole-body communication are discussed. Altogether, these findings demonstrate that BAT has an adaptive capacity. Studying batokines, offers an alternative approach to identify novel drug targets for metabolic regulation.
Abstract
Infants rely on brown adipose tissue (BAT) as a primary source of thermogenesis. In some adult humans, residuals of brown adipose tissue are adjacent to the central nervous system and acute activation increases metabolic rate. Brown adipose tissue (BAT) recruitment occurs during cold acclimation and includes secretion of factors, known as batokines, which target several different cell types within BAT, and promote adipogenesis, angiogenesis, immune cell interactions, and neurite outgrowth. All these processes seem to act in concert to promote an adapted BAT. Recent studies have also provided exciting data on whole body metabolic regulation with a broad spectrum of mechanisms involving BAT crosstalk with liver, skeletal muscle, and gut as well as the central nervous system. These widespread interactions might reflect the property of BAT of switching between an active thermogenic state where energy is highly consumed and drained from the circulation, and the passive thermoneutral state, where energy consumption is turned off. (Endocrine Reviews 41: XXX - XXX, 2020).