Short-term use of an exposed polypropylene barrier in the preservation of alveolar bone after extraction: randomized clinical trial.

This study was performed to evaluate the short-term preservation of alveolar bone volume with or without a polypropylene barrier and exposure of the area after extractions. Thirty posterior tooth extraction sockets were distributed randomly to a control group (n=15; extraction and suture) and a barrier group (n=15; extraction, barrier, and suture). All sutures and barriers were removed 10 days postoperatively. Cone beam computed tomography scans taken with the aid of a tomographic guide were obtained preoperatively, immediately postoperative, and at 120 days postoperative. A visual analysis of the coronal sections of the alveolus was performed, and vertical loss in the mesial, distal, buccal, and lingual bone ridges and horizontal thickness were evaluated. The mean vertical loss after extraction did not differ significantly between the control and barrier groups (Student t-test: mesial P= 0.989, buccal P= 0.997, lingual/palatal P= 0.070, distal P= 0.107). The mean vertical loss at 120 days postoperative did not differ significantly between the control (0.65 mm) and barrier (0.52 mm) groups (P> 0.05), with an effect size of 0.13 mm. At 120 days, the barrier group presented a mean resorption in thickness (0.45 mm) that was significantly lower than that in the control group (0.76 mm) (P= 0.021), with an effect size of 0.31 mm. The polypropylene barrier reduced the horizontal resorption in sockets of posterior teeth after extraction.

Synthesis, characterization and applications of maghemite beads functionalized with rabbit antibodies.

Magnetic nanoparticles (NPs) have attracted great attention owing to their applications in the biomedical field. In the present work, maghemite (γFe2O3) NPs of 6.5 nm were prepared using a sonochemical method and used to prepare magnetic beads through silanization with 3-aminopropyltrimethoxysilane (APTS). Subsequently, amino groups in the resulting APTS-γFe2O3 beads were converted to carboxylic acid (CARB-γFe2O3) through the succinic anhydride reaction, as confirmed by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy and dynamic light scattering (DLS) measurements. The size of these beads was measured as 12 nm and their hydrodynamic diameter as 490 nm, using TEM analysis and DLS, respectively. The CARB-γFe2O3 beads were further functionalized by immobilizing rabbit antibodies on their surfaces; the immobilization was confirmed by flow cytometry and ionic strength. The samples were further characterized by Mössbauer spectroscopy and DC magnetization measurements. Studies on magnetic relaxivities showed that magnetic beads present great potential for application in MR imaging.

Evidence for multiple sylvatic transmission cycles during the 2016-2017 yellow fever virus outbreak, Brazil.

OBJECTIVES: Since December 2016, Brazil has experienced an unusually large outbreak of yellow fever (YF). Whether urban transmission may contribute to the extent of the outbreak is unclear. The objective of this study was to characterize YF virus (YFV) genomes and to identify spatial patterns to determine the distribution and origin of YF cases in Minas Gerais, Espírito Santo and Rio de Janeiro, the most affected Brazilian states during the current YFV outbreak. METHODS: We characterized near-complete YFV genomes from 14 human cases and two nonhuman primates (NHP), sampled from February to April 2017, retrieved epidemiologic data of cases and used a geographic information system to investigate the geospatial spread of YFV. RESULTS: All YFV strains were closely related. On the basis of signature mutations, we identified two cocirculating YFV clusters. One was restricted to the hinterland of Espírito Santo state, and another formed a coastal cluster encompassing several hundred kilometers. Both clusters comprised strains from humans living in rural areas and NHP. Another NHP lineage clustered in a basal relationship. No signs of adaptation of YFV strains to human hosts were detected. CONCLUSIONS: Our data suggest sylvatic transmission during the current outbreak. Additionally, cocirculation of two distinct YFV clades occurring in humans and NHP suggests the existence of multiple sylvatic transmission cycles. Increased detection of YFV might be facilitated by raised awareness for arbovirus-mediated disease after Zika and chikungunya virus outbreaks. Further surveillance is required, as reemergence of YFV from NHPs might continue and facilitate the appearance of urban transmission cycles.