Periodontal herpesvirus morbidity and treatment

Four billion individuals worldwide have a history of periodontitis, with the poorest people in society most affected. Periodontitis can lead to unsightly drifting of teeth and tooth loss that may interfere with the wellbeing of daily living and has also been linked to at least 57 medical diseases and disabilities. The etiology of severe periodontitis includes active herpesviruses, specific bacterial pathogens, and destructive immune responses, but herpesviruses seem to be the major pathogenic determinant. Periodontal herpesviruses that disseminate via the systemic circulation to nonoral sites may represent a major link between periodontitis and systemic diseases. Current treatment of periodontitis focuses almost exclusively on bacterial biofilm and will require revision. Periodontal therapy that targets both herpesviruses and bacterial pathogens can provide long‐term clinical improvement and potentially reduces the risk of systemic diseases. Molecular diagnostic tests for periodontal pathogens may enable early microbial identification and preemptive therapy. This review details an efficient and reliable anti‐infective treatment of severe periodontitis that can be carried out in minimal time with minimal cost.     

Accurate determination of blood–brain barrier permeability using dynamic contrast-enhanced T1-weighted MRI: a simulation and in vivo study on healthy subjects and multiple sclerosis patients

Dynamic contrast-enhanced magnetic resonance imaging (DCE–MRI) is increasingly used to estimate permeability in situations with subtle blood–brain barrier (BBB) leakage. However, the method''s ability to differentiate such low values from zero is unknown, and no consensus exists on optimal selection of total measurement duration, temporal resolution, and modeling approach under varying physiologic circumstances. To estimate accuracy and precision of the DCE–MRI method we generated simulated data using a two-compartment model and progressively down-sampled and truncated the data to mimic low temporal resolution and short total measurement duration. Model fit was performed with the Patlak, the extended Tofts, and the Tikhonov two-compartment (Tik-2CM) models. Overall, 17 healthy controls were scanned to obtain in vivo data. Long total measurement duration (15 minutes) and high temporal resolution (1.25 seconds) greatly improved accuracy and precision for all three models, enabling us to differentiate values of permeability as low as 0.1 ml/100 g/min from zero. The Patlak model yielded highest accuracy and precision for permeability values <0.3 ml/100 g/min, but for higher values the Tik-2CM performed best. Our results emphasize the importance of optimal parameter setup and model selection when characterizing low BBB permeability.