Purpose Sunburns are an important risk factor for melanoma and those occurring in childhood are often cited as posing the greatest risk. We conducted a meta-analysis to quantify the magnitude of association for melanoma and sunburns during childhood, adolescence, adulthood and over a lifetime. Methods After reviewing over 1300 article titles and evaluating 270 articles in detail, we pooled ORs from 51 independent study populations for “ever” sunburned and risk of cutaneous melanoma. Among these, 26 studies reported results from dose-response analyses. Dose-response analyses were examined using both fixed-effects models and Bayesian random-effects models. Results An increased risk of melanoma was seen with increasing number of sunburns for all time-periods (childhood, adolescence, adulthood and lifetime). In an attempt to understand how risk between life-periods compares, we also report these same linear models on a scale of 5 sunburns per decade for each life-period. The magnitude of risk for 5 sunburns per decade is highest for adult and lifetime sunburns. Conclusions Overall, these results show an increased risk of melanoma with increasing number of sunburns during all life-periods, not just childhood. Prevention efforts should focus on reducing sunburns during all life-periods.

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...

The skin surface represents our interface with the external environment, and as such, is our first line of defense against microbial colonization and infection. Lipids at the skin surface are thought to underlie at least part of an antimicrobial barrier. Some of these lipids are synthesized in the epidermis and are carried to the surface as cells differentiate, whereas others are secreted onto the surface from the sebaceous glands. One such group, free sphingoid bases, are known to have broad antimicrobial activity, and our previous studies demonstrate their presence at the skin surface. Free sphingoid bases may be generated by enzymatic hydrolysis of epidermal ceramides. In addition, our preliminary results demonstrate potent antibacterial activity associated with two specific fatty acids derived from sebaceous triglycerides. Most remarkably, one of these fatty acids (sapienic acid, C16:1#6), in combination with a low concentration of ethanol, is very effective against methicillin-resistant Staphylococcus aureus (MRSA). In fact, this combination was far more effective than mupirocin with or without ethanol. Mupirocin is a "gold standard" for activity against MRSA.

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.

There was limited knowledge of the possible relationships between oral health and pregnancy outcomes in a fairly homogeneous population of women who were of relatively high socioeconomic standing. This study suggests that better education of the importance of dental care before and during pregnancy is needed.