There is growing evidence that the role of lipids in innate immunity is more important than previously realized. How lipids interact with bacteria to achieve a level of protection, however, is still poorly understood. To begin to address the mechanisms of antibacterial activity, we determined MICs and minimum bactericidal concentrations (MBCs) of lipids common to the skin and oral cavity-the sphingoid bases D-sphingosine, phytosphingosine, and dihydrosphingosine and the fatty acids sapienic acid and lauric acid-against four Gram-negative bacteria and seven Gram-positive bacteria. Exact Kruskal-Wallis tests of these values showed differences among lipid treatments (P < 0.0001) for each bacterial species except Serratia marcescens and Pseudomonas aeruginosa. D-Sphingosine (MBC range, 0.3 to 19.6 g/ml), dihydrosphingosine (MBC range, 0.6 to 39.1 g/ml), and phytosphingosine (MBC range, 3.3 to 62.5 g/ml) were active against all bacteria except S. marcescens and P. aeruginosa (MBC > 500 g/ml). Sapienic acid (MBC range, 31.3 to 375.0 g/ml) was active against Streptococcus sanguinis, Streptococcus mitis, and Fusobacterium nucleatum but not active against Escherichia coli, Staphylococcus aureus, S. marcescens, P. aeruginosa, Corynebacterium bovis, Corynebacterium striatum, and Corynebacterium jeikeium (MBC > 500 g/ml). Lauric acid (MBC range, 6.8 to 375.0 g/ml) was active against all bacteria except E. coli, S. marcescens, and P. aeruginosa (MBC > 500 g/ml). Complete killing was achieved as early as 0.5 h for some lipids but took as long as 24 h for others. Hence, sphingoid bases and fatty acids have different antibacterial activities and may have potential for prophylactic or therapeutic intervention in infection.C ommon sphingolipids and fatty acids are involved in the physical barrier, permeability barrier, and immunologic barrier functions of the skin and oral mucosa (8,14). Epithelial layers contain ceramides, free fatty acids, and cholesterol; sebaceous lipids at the skin surface include a complex mixture of triglycerides, fatty acids, wax esters, squalene, cholesterol, and cholesterol esters; and saliva contains the same sebaceous lipids (6,14,19). These sebaceous secretions contribute to (i) the transport of fatsoluble antioxidants to the skin and mucosal surfaces, (ii) the proand anti-inflammatory properties of the skin and mucosal surfaces, and (iii) the innate antimicrobial activity of the skin and mucosal surfaces (20,26,27).Although the composition, biosynthesis, secretion, and function of cutaneous lipids are well characterized from extensive and elegant work done in the 1970s, little is known about their role in controlling microbial infection and colonization. Certain fatty acids and sphingoid bases found at the skin and mucosal surfaces are known to have antibacterial activity and are thought to play a more direct role than previously thought in innate immune defense against epidermal and mucosal bacterial infections (10). They include free sphingosines, dihydrosphingosines, lauric acid, and sapienic aci...
Alveolar ridge preservation strategies are indicated to minimize the loss of ridge volume that typically follows tooth extraction. The aim of this systematic review was to determine the effect that socket filling with a bone grafting material has on the prevention of postextraction alveolar ridge volume loss as compared with tooth extraction alone in nonmolar teeth. Five electronic databases were searched to identify randomized clinical trials that fulfilled the eligibility criteria. Literature screening and article selection were conducted by 3 independent reviewers, while data extraction was performed by 2 independent reviewers. Outcome measures were mean horizontal ridge changes (buccolingual) and vertical ridge changes (midbuccal, midlingual, mesial, and distal). The influence of several variables of interest (i.e., flap elevation, membrane usage, and type of bone substitute employed) on the outcomes of ridge preservation therapy was explored via subgroup analyses. We found that alveolar ridge preservation is effective in limiting physiologic ridge reduction as compared with tooth extraction alone. The clinical magnitude of the effect was 1.89 mm (95% confidence interval [CI]: 1.41, 2.36; p < .001) in terms of buccolingual width, 2.07 mm (95% CI: 1.03, 3.12; p < .001) for midbuccal height, 1.18 mm (95% CI: 0.17, 2.19; p = .022) for midlingual height, 0.48 mm (95% CI: 0.18, 0.79; p = .002) for mesial height, and 0.24 mm (95% CI: -0.05, 0.53; p = .102) for distal height changes. Subgroup analyses revealed that flap elevation, the usage of a membrane, and the application of a xenograft or an allograft are associated with superior outcomes, particularly on midbuccal and midlingual height preservation.
Objectives: To (1) investigate effects of aerobic walking on motor function, cognition, and quality of life in Parkinson disease (PD), and (2) compare safety, tolerability, and fitness benefits of different forms of exercise intervention: continuous/moderate intensity vs interval/alternating between low and vigorous intensity, and individual/neighborhood vs group/facility setting. Methods:Initial design was a 6-month, 2 3 2 randomized trial of different exercise regimens in independently ambulatory patients with PD. All arms were required to exercise 3 times per week, 45 minutes per session.Results: Randomization to group/facility setting was not feasible because of logistical factors.Over the first 2 years, we randomized 43 participants to continuous or interval training. Because preliminary analyses suggested higher musculoskeletal adverse events in the interval group and lack of difference between training methods in improving fitness, the next 17 participants were allocated only to continuous training. Eighty-one percent of 60 participants completed the study with a mean attendance of 83.3% (95% confidence interval: 77.5%-89.0%), exercising at 46.8% (44.0%-49.7%) of their heart rate reserve. There were no serious adverse events. Across all completers, we observed improvements in maximum oxygen consumption, gait speed, Unified Parkinson's Disease Rating Scale sections I and III scores (particularly axial functions and rigidity), fatigue, depression, quality of life (e.g., psychological outlook), and flanker task scores (p , 0.05 to p , 0.001). Increase in maximum oxygen consumption correlated with improvements on the flanker task and quality of life (p , 0.05). Conclusions:Our preliminary study suggests that aerobic walking in a community setting is safe, well tolerated, and improves aerobic fitness, motor function, fatigue, mood, executive control, and quality of life in mild to moderate PD. Classification of evidence:This study provides Class IV evidence that in patients with PD, an aerobic exercise program improves aerobic fitness, motor function, fatigue, mood, and cognition. Figure Test; FSS 5 Fatigue Severity Scale; HR max 5 maximal heart rate; HRR 5 heart rate reserve; PD 5 Parkinson disease; PDQUALIF 5 Parkinson's Disease Quality of Life Scale; PIS 5 percent increase score; RT 5 reaction time; UPDRS 5 Unified Parkinson's Disease Rating Scale; Vȯ 2 5 maximum oxygen uptake.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.