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ARONJ/MRONJ has characteristic CT image findings which could be useful for its assessment.

BackgroundSince pancreatic steatosis is reported as a possible risk factor for pancreatic cancer, the development of a non-invasive method to quantify pancreatic steatosis is needed. Proton density fat fraction (PDFF) measurement is a magnetic resonance imaging (MRI) based method for quantitatively assessing the steatosis of a region of interest (ROI). Although it is commonly used for quantification of hepatic steatosis, pancreatic PDFF can greatly vary depending on the ROI’s location because of the patchy nature of pancreatic fat accumulation. In this study, we attempted to quantify pancreatic steatosis by fat-water MRI with improved reproducibility.MethodsUsing the MRI images of 159 patients with nonalcoholic fatty liver disease, we attempted to calculate the average PDFF of whole pancreas. We set ROIs covering the entire area of the pancreas appearing in every slice and calculated the average PDFF from all the voxels included in the pancreas. We named this average value as whole-pancreatic PDFF and evaluated the reproducibility of the measured values. In addition to whole-pancreatic PDFF, we measured the average PDFF of the pancreatic head (head-PDFF) and that of the pancreatic body plus tail separately and analyzed their correlation with the clinical characteristics of the patients.ResultsThe mean inter-examiner coefficient of variation of the whole-pancreatic PDFF was 11.39%. The whole-pancreatic PDFF was correlated with age (p = 0.039), body mass index (p = 0.0093) and presence/absence of diabetes (p = 0.0055). The serum level of low-density lipoprotein cholesterol was inversely correlated with the head-PDFF.ConclusionWe developed a new measurement method of the pancreatic PDFF with greater reproducibility. Using this method, we characterized pancreatic steatosis in detail. This novel measurement method allows accurate estimation of the severity of pancreatic steatosis and is therefore useful for the detailed characterization of pancreatic steatosis.

Background and study aims: Neoadjuvant chemotherapy (NAC) may lead to a successful margin-negative resection in patients with initially unresectable locally advanced Klatskin tumor (IULAKT). Use of removable plastic stents is preferable for the safe implementation of NAC in patients with IULAKT to reduce the risk of recurrent cholangitis. Our aim was to evaluate the efficacy associated with the use of plastic stents placed across the stenosis and above the papilla (above stent) during NAC. Patients and methods: In this study, we stratified the patients into two groups chronologically with respect to the period of stent placement: above stent group (n = 17) and across stent group (n = 23) (plastic stent across the sphincter of Oddi). Results: The median stent patency period was 99 days in the above stent group and 31 days in the across stent group (P < 0.0001). The number of stents (P = 0.017) and the rate of emerging undrained cholangitis areas (P = 0.025) were significantly reduced in the above stent group than the counterpart. Regarding time to recurrent biliary obstruction, the above stent group had a longer duration than the across stent group (log rank test, P = 0.004). Length of hospital stay was significantly shorter for the above stent group than the across stent group (P = 0.0475). Multivariate analysis revealed that above stent placement (odds ratio = 33.638, P = 0.0048) was significantly associated with stent patency over a period of 90 days. Conclusions: Above stent placement should be considered for the relief of biliary obstruction and potentially reduces the cost for patients with IULAKT scheduled to receive NAC.

Memory is fixed solidly by repetition. However, the cellular mechanism underlying this repetition-dependent memory consolidation/reconsolidation remains unclear. In our previous study using stable slice cultures of the rodent hippocampus, we found long-lasting synaptic enhancement/suppression coupled with synapse formation/elimination after repeated inductions of chemical LTP/LTD, respectively. We proposed these phenomena as useful model systems for analyzing repetition-dependent memory consolidation. Recently, we analyzed the dynamics of dendritic spines during development of the enhancement, and found that the spines increased in number following characteristic stochastic processes. The current study investigates spine dynamics during the development of the suppression. We found that the rate of spine retraction increased immediately leaving that of spine generation unaltered. Spine elimination occurred independent of the pre-existing spine density on the dendritic segment. In terms of elimination, mushroom-type spines were not necessarily more stable than stubby-type and thin-type spines.