METHODS: Dissolution kinetics of CHX-HMP were firstly explored using spectroscopy and a colorimetric phosphate assay. Elastomeric ligatures were categorized into 3 groups-acetone-conditioned, ethanol-conditioned, and as received-and were then immersed in 5 mM CHX-HMP suspension or 5 mM chlorhexidine digluconate solution and rinsed. CHX release was measured over 8 weeks, and the effects of conditioning and immersion on elastomeric force and extension at rupture and surface topography were investigated.
RESULTS: CHX-HMP exhibited a gradual equilibration that had not reached equilibrium within 8 weeks, releasing soluble CHX and a mixture of polyphosphate and orthophosphate. CHX digluconate-treated ligatures showed no CHX release, whereas CHX-HMP-treated ligatures showed varying degrees of release. As received, CHX-HMP-treated ligatures showed a modest release of CHX up to 7 days. Acetone conditioning did not enhance CHX-HMP uptake or subsequent CHX release and caused a deterioration in mechanical properties. Ethanol conditioning enhanced CHX-HMP uptake (6×) and led to a sustained CHX release over 8 weeks without affecting mechanical properties.
CONCLUSIONS: Within the inherent limitations of this in-vitro study, CHX-HMP led to a sustained release of CHX from orthodontic elastomeric ligatures after ethanol conditioning. Conditioned and coated elastomeric ligatures may ultimately find application in the prevention of white spot lesions in orthodontic patients.
METHODS: A total of 93 blood samples from Macaca fascicularis, Macaca leonina and Macaca arctoides were collected from four locations in Thailand: 32 were captive M. fascicularis from Chachoengsao Province (CHA), 4 were wild M. fascicularis from Ranong Province (RAN), 32 were wild M. arctoides from Prachuap Kiri Khan Province (PRA), and 25 were wild M. leonina from Nakornratchasima Province (NAK). DNA was extracted from these samples and analysed by nested PCR assays to detect Plasmodium, and subsequently to detect P. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldi.
RESULTS: Twenty-seven of the 93 (29%) samples were Plasmodium-positive by nested PCR assays. Among wild macaques, all 4 M. fascicularis at RAN were infected with malaria parasites followed by 50% of 32 M. arctoides at PRA and 20% of 25 M. leonina at NAK. Only 2 (6.3%) of the 32 captive M. fascicularis at CHA were malaria-positive. All 5 species of Plasmodium were detected and 16 (59.3%) of the 27 macaques had single infections, 9 had double and 2 had triple infections. The composition of Plasmodium species in macaques at each sampling site was different. Macaca arctoides from PRA were infected with P. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldi.
CONCLUSIONS: The prevalence and species of Plasmodium varied among the wild and captive macaques, and between macaques at 4 sampling sites in Thailand. Macaca arctoides is a new natural host for P. knowlesi, P. inui, P. coatneyi and P. fieldi.
METHODS: 28 experts from 11 countries reviewed the evidence and modified the statements using the Delphi method, with consensus level predefined as ≥80% of agreement on each statement. The Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach was followed.
RESULTS: Consensus was reached in 26 statements. At an individual level, eradication of H. pylori reduces the risk of GC in asymptomatic subjects and is recommended unless there are competing considerations. In cohorts of vulnerable subjects (eg, first-degree relatives of patients with GC), a screen-and-treat strategy is also beneficial. H. pylori eradication in patients with early GC after curative endoscopic resection reduces the risk of metachronous cancer and calls for a re-examination on the hypothesis of 'the point of no return'. At the general population level, the strategy of screen-and-treat for H. pylori infection is most cost-effective in young adults in regions with a high incidence of GC and is recommended preferably before the development of atrophic gastritis and intestinal metaplasia. However, such a strategy may still be effective in people aged over 50, and may be integrated or included into national healthcare priorities, such as colorectal cancer screening programmes, to optimise the resources. Reliable locally effective regimens based on the principles of antibiotic stewardship are recommended. Subjects at higher risk of GC, such as those with advanced gastric atrophy or intestinal metaplasia, should receive surveillance endoscopy after eradication of H. pylori.
CONCLUSION: Evidence supports the proposal that eradication therapy should be offered to all individuals infected with H. pylori. Vulnerable subjects should be tested, and treated if the test is positive. Mass screening and eradication of H. pylori should be considered in populations at higher risk of GC.