Chitosan is a naturally derived polymer with antimicrobial and anti-inflammatory properties. However, studies evaluating the role of chitosan in the control of periodontal pathogens and the responses of fibroblasts to inflammatory stimuli are lacking. In the present study, we analyzed whether chitosan particles may inhibit the growth of periodontal pathogens and modulate the inflammatory response in human gingival fibroblasts. Chitosan particles were generated through ionic gelation. They inhibited the growth of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans at 5 mg/mL. Conversely, IL-1β strongly stimulated PGE2 protein levels in gingival fibroblasts, and chitosan inhibited this response at 50 µg/mL. IL-1β-stimulated PGE2 production was dependent on the JNK pathway, and chitosan strongly inhibited this response. IL-1β stimulated NF-κB activation, another signaling pathway involved in PGE2 production. However, chitosan particles were unable to modify NF-κB signaling. The present study shows that chitosan exerts a predominantly anti-inflammatory activity by modulating PGE2 levels through the JNK pathway, which may be useful in the prevention or treatment of periodontal inflammation.

Background The objective of this study was to determine the effect of antibiotic prophylaxis in preventing postoperative infections after extraction of impacted mandibular third molars. Material and Methods A Parallel-group, randomized, blind, placebo-controlled trial was performed. 154 patients were randomly allocated to 2 groups; experimental (n=77) receiving 2g amoxicillin 1 hour prior to surgery and control (n=77) receiving placebo. Primary outcome was postoperative infections and secondary outcome was the need for rescue analgesia. Results 4.5% of patients developed postoperative infections, five patients of the control group (4 alveolar osteitis, 1 surgical site infection) and two of the experimental group (1 alveolar osteitis, 1 surgical site infection). Difference between groups was not statistically significant, RR=0.4 (95%CI 0.08-1.99, 𝘱=0.41) NNTB=26. Rescue analgesia intake was significantly higher in the control group (41 vs 18 patients of experimental group) RR=0.49 (95%CI 0.32-0.75, 𝘱<0.05) NNTB=3. Conclusions The use of 2g amoxicillin 1 hour before surgery was not effective in significantly reducing the risk of postoperative infections from impacted mandibular third molars extraction, when compared to placebo. Nevertheless, antibiotic prophylaxis was associated with a reduced need for rescue analgesia. Key words: Antibiotic prophylaxis, third molar, tooth extraction, impacted tooth, dry socket, surgical wound infection, oral surgery.

Background Esophageal and gastric cancers are a significant public health problem worldwide, with most patients presenting with advanced-stage disease and, consequently, poor prognosis. Systemic oncological treatments (SOT) have been widely used over more conservative approaches, such as supportive care. Nevertheless, its effectiveness in this scenario is not sufficiently clear. This paper provides an overview of systematic reviews that assessed the effectiveness of SOT compared with the best supportive care (BSC) or placebo in patients with advanced esophageal or gastric cancers in an end-of-life context. Methods We searched MEDLINE, EMBASE, The Cochrane Library, Epistemonikos, and PROSPERO for eligible systematic reviews (SRs) published from 2008 onwards. The primary outcomes were overall survival (OS), progression-free survival (PFS), functional status, and toxicity. Two authors assessed eligibility and extracted data independently. We evaluated the methodological quality of included SRs using the AMSTAR-2 tool and the overlap of primary studies (corrected covered area, CCA). Also, we performed a de novo meta-analysis with data reported for each primary study when it was possible. We assessed the certainty of evidence using the GRADE approach. Results We identified 16 SRs (19 included trials) for inclusion within this overview. Most reviews had a critically low methodological quality, and there was a very high overlap of primary studies. It is uncertain whether SOT improves OS and PFS over more conservative approaches due to the very low certainty of evidence. Conclusions The evidence is very uncertain about the effectiveness of SOT for advanced esophageal or gastric cancers. High-quality SRs and further randomized clinical trials that include a thorough assessment of patient-centered outcomes are needed. Trial registration Open Science Framework, 10.17605/OSF.IO/7CHX6.

Limited number of studies have focused on the impact of pollen exposure on asthma. As a part of the EAACI Guidelines on Environment Science, this first systematic review on the relationship of pollen exposure to asthma exacerbations aimed to bridge this knowledge gap in view of implementing recommendations of prevention. We searched electronic iPubMed, Embase, and Web of Science databases using a set of MeSH terms and related synonyms and identified 73 eligible studies that were included for systemic review. When possible, meta‐analyses were conducted. Overall meta‐analysis suggests that outdoor pollen exposure may have an effect on asthma exacerbation, but caution is needed due to the low number of studies and their heterogeneity. The strongest associations were found between asthma attacks, asthma‐related ED admissions or hospitalizations, and an increase in grass pollen concentration in the previous 2‐day overall in children aged less than 18 years of age. Tree pollen may increase asthma‐related ED visits or admissions lagged up to 7‐day overall in individuals younger than 18 years. Rare data show that among subjects under 18 years of age, an exposure to grass pollen lagged up to 3 days may lower lung function. Further research considering effect modifiers of pollen sensitization, hay fever, asthma, air pollution, green spaces, and pre‐existing medications is urgently warranted to better evaluate the impacts of pollen on asthma exacerbation. Preventive measures in relation to pollen exposure should be integrated in asthma control as pollen increase continues due to climate change.