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Osteoarthritis is a leading cause of disability in the world. The scientific literature highlights the critical importance of epigenetic regulatory effects, intertwined with biomechanical and biochemical peculiar conditions within each musculoskeletal district. While the contribution of genetic and epigenetic factors to knee OA is well-recognized, their precise role in disease management remains an area of active research. Such a field is particularly heterogeneous, calling for regular analysis and summarizing of the data that constantly emerge in the scientific literature, often sparse and scant of integration. The aim of this study was to systematically identify and synthesize all new evidence that emerged in human and animal model studies published between 2020 and 2023. This was necessary because, to the best of our knowledge, articles published before 2019 (and partly 2020) had already been included in systematic reviews that allowed to identify the ones concerning the knee joint. The review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only peer-reviewed articles were considered for inclusion. A total of 40 studies were identified, showing promising results in terms either of biomarker identification, new insight in mechanism of action or potential therapeutic targets for knee OA. DNA methylation, histone modification and ncRNA were all mechanisms involved in epigenetic regulation of the knee. Most recent evidence suggests that epigenetics is a most promising field with the long-term goal of improving understanding and management of knee OA, but a variety of research approaches need greater consolidation.

Background: Clinical remission and endoscopic mucosal healing are the main treatment targets in patients with ulcerative colitis (UC). Recently, the concept of disease clearance has been proposed as a potential target in UC., Objective: We aimed to evaluate the impact of disease clearance on long-term outcomes in UC patients., Methods: A multicenter retrospective cohort study was conducted at the Humanitas Research Hospital-IRCCS (Italy) and at the Nancy University Hospital (France) between 2014 and 2021. Disease clearance in UC was defined as simultaneous clinical (partial-Mayo score ≤2), endoscopic (endoscopic-Mayo score = 0), and histological (Nancy index = 0) remission, and patients were monitored over a long-time follow-up (≥12 months), to compare the occurrence of negative outcomes., Results: A total of 494 patients with UC was included in the study (269, 54.4% males). Disease clearance was present in 109 patients (22.1%) at baseline. Median follow up was 24 months. Patients with disease clearance were associated to a significantly lower risk of UC-related hospitalization compared with the control group (5.5% vs. 23.1%; p < 0.001) at last observation. Similarly, a lower rate of surgeries was detected in patients with disease clearance at baseline compared with those without (1.8% vs. 10.9%; p = 0.003). The Kaplan Meier curves confirmed that patients with disease clearance at baseline had a lower risk of hospitalization (log-rank p < 0.0001) and surgery (log-rank p < 0.00095)., Conclusion: In UC patients with early disease clearance are at significant lower risk for hospitalization and surgery. Disease clearance should be considered as a new composite outcome., (© 2022 The Authors. United European Gastroenterology Journal published by Wiley Periodicals LLC. on behalf of United European Gastroenterology.)

Objectives: Δ(9)-Tetrahydrocannabinol (THC) can be measured in exhaled breath by using an aerosol particle collection device. The sampling procedure is simple, non-invasive and takes only 2-3min. In the present study we measured the amount of THC in exhaled breath of cannabis users at specific time intervals up to 3h after smoking one cannabis cigarette., Design and Methods: The breath concentration-effect relationship was studied by measuring the pulse rate and the pupil diameter to assess physiological changes. THC and the main metabolite 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol were analyzed in exhaled breath by a liquid chromatography-tandem mass spectrometry method. Thirteen subjects (9 males and 4 females, aged 23-24years) participated. Five of those were using cannabis more frequently than monthly., Results: THC was detected in most subjects already at baseline, concentrations increased following smoking and remained detectable for over 3h (mean THC concentration in breath at 3h: 1479pg/sample). Pulse rate (p=0.015) and pupil diameter (p=0.044) were significantly altered up to 30min after smoking. The detection window of cannabis in breath after smoking one cannabis cigarette in occasional and chronic smokers was at least 3h. Only THC was detected, and not the metabolite. The THC concentration in exhaled breath was related to the physiological changes that occur over time., Conclusions: Exhaled breath can be used to detect recent cannabis exposure., (Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

A comparative study of the citrate synthases purified from the facultatively photosynthetic bacterium Rhodospirillum rubrum (Gram negative) and the thermophile Bacillus stearothermophilus (Gram positive) was made. The citrate synthase from R. rubrum was activated by KCl (6-fold at 0.1 M KCl) and, less effectively, by NaCl and NH4Cl. Its molecular weight was about 300,000. The enzyme was strongly inhibited by NADH, and this inhibition was counteracted by AMP. The citrate synthase from B. stearothermophilus was little affected by KCl, NaCl and NH4Cl, all of which activated by about 25% at 0.1 M. Its molecular weight was ca 100,000. The enzyme was not affected by NADH or AMP. Both citrate synthases were insensitive to alpah-oxoglutarate concentrations up to 5 mM, and were inhibited by ATP; the B. stearothermophilus enzyme was more strongly inhibited than the R. rubrum enzyme. In both cases the ATP inhibition was strictly competitive towards acetyl-CoA and non-competitive towards oxaloacetate. Both enzymes, in spite of the peculiar physiological properties of their bacterial sources, followed the close correlation between the properties of the citrate synthase and the taxonomical position of the microorganism, proposed by Weitzman and his co-workers.

Citrate synthase (citrate-oxaloacetate lyase (CoA acetylating), EC 4.1.3.7) has been purified to electrophoretic homogeneity from a marine Pseudomonas. The enzyme was made up of identical subunits, with a molecular wieght of about 53 000, as determined by sodium dodecyl sulphate - polyacrylamide gel electrophoresis. The native enzyme (citrate synthase II, CS II) could be dissociated by dialysis against 20 mM phosphate (Pi), pH 7; the enzyme thus obtained (citrate synthase I, CS I) was still active, but presented different molecular weight and kinetic and regulatory properties. CS II was activated by adenosine monophosphate (AMP), Pi, and KCl, and inhibited by reduced nicotinamide adenine dinucleotide (NADH), being apparently insensitive to adenosine triphosphate (ATP) and adenosine diphosphate (ADP). The inhibition by NADH was completely counteracted by 0.1 mM AMP, but not by 50 mM Pi or 0.1 M KCl. The activation by KCl and Pi, or by KCl and AMP was nearly additive, whereas that by AMP and Pi was not. The activators acted essentially by increasing Vmax, although they also caused a decrease in the Km values. CS I was inhibited by ATP, ADP, AMP, and KCl, and was insensitive to NADH. CS I could be reassociated after elimination of Pi by dialysis, regaining the higher molecular weight and the activation by AMP characteristic of CS II.