Postoperative Cognitive Dysfunction: Preclinical Highlights and Perspectives on Preventive Strategies

One of the common complications associated with anaesthesia and surgery in geriatric patients is the postoperative cognitive dysfunction (POCD). This cognitive impairment affects the long-term prognosis and has been shown to be associated with long-term disability, higher health care costs, and even increased mortality. On the other hand, clinical research on POCD is in its infancy, the condition has not been clarified, and since no strategy for management is currently available, it is imperative to develop specific methods for prevention and management. Although its pathogenesis involves various factors, accumulating evidence suggests that surgery elicits an inflammatory response in the hippocampus, a brain area closely related to cognitive function, playing a key role in the development of POCD. Several studies suggest that age-related phenotypic change of microglia is associated with pathogenic neuroinflammation, and more importantly it may be modifiable. In this chapter, we discuss the current overview and preclinical highlights regarding POCD. We further discuss some perspectives on preventive strategies for POCD, based on the findings of our preclinical research and the available literature

Big Bang Nucleosynthesis with long-lived strongly interacting relic particles

We study effects of relic long-lived strongly interacting massive particles (X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to have existed during the BBN epoch, but decayed long before detected. The interaction strength between an X and a nucleon is assumed to be similar to that between nucleons. Rates of nuclear reactions and beta decay of X-nuclei are calculated, and the BBN in the presence of neutral charged X^0 particles is calculated taking account of captures of X^0 by nuclei. As a result, the X^0 particles form bound states with normal nuclei during a relatively early epoch of BBN leading to the production of heavy elements. Constraints on the abundance of X^0 are derived from observations of primordial light element abundances. Particle models which predict long-lived colored particles with lifetimes longer than about 200 s are rejected. This scenario prefers the production of 9Be and 10B. There might, therefore, remain a signature of the X particle on primordial abundances of those elements. Possible signatures left on light element abundances expected in four different models are summarized.Comment: 6 pages, 2 figures, to appear in the Proceedings of IAU Symposium 268: Light elements in the Universe (C. Charbonnel, M. Tosi, F. Primas, C. Chiappini, eds.; Cambridge Univ. Press

A Spectrum Sharing Method Based on Users' Behavior and Providers' Profit

In recent years, spectrum sharing has received much attention as a technique for more efficient spectrum use. In the case in which all providers are cooperative, spectrum sensing can easily be realized and can improve user throughput (on average). If that is not the case, providers are not cooperative, i.e., spectrum trading, spectrum bands are rented to promote spectrum sharing. To ensure more profit, however, non-cooperative providers must correctly estimate the fluctuation of the number of connected users to be able to determine the offered channel price. In this paper, we propose a spectrum sharing method to achieve both higher throughput and provider profit via appropriate pricing using a disaggregate behavioral model. Finally, we confirm the effectiveness of the proposed method using simulation experiments

Reduction of Postoperative Pain by Addition of Intravenous Acetaminophen after Total Hip Arthroplasty: A Retrospective Cohort Study

We evaluated the analgesic effects of multimodal pain control in which intravenous acetaminophen (IV APAP) was added to the standard protocol for Japanese patients who had undergone a total hip arthroplasty (THA). We performed a retrospective cohort study of 180 patients aged 66.4±10.5 years (30% male) who had undergone a THA (Oct. 2014 to Feb. 2015) at our hospital. The control patients were administered the standard analgesic protocol: flurbiprofen axetil as a continuous intravenous infusion and oral celecoxib (NAPAP; n=109). The patients in the new analgesic protocol group received IV APAP in addition to the standard analgesic protocol (APAP; n=71). The primary outcome was the maximum value of postoperative pain the patients reported on a numerical rating scale (NRS) during the first 24 h post-surgery. A univariate analysis and multivariate analyses adjusted for age, sex, the stage of hip osteoarthritis, preoperative pain, and surgical time showed that the maximum postoperative pain NRS scores during the first 24 h after surgery was significantly lower when the APAP protocol was used. The addition of IV APAP to the current standard multimodal analgesia protocol for Japanese patients who have undergone a THA may decrease the patients’ postoperative pain

Effects of ketamine on nicorandil induced ATP-sensitive potassium channel activity in cell line derived from rat aortic smooth muscle

Purpose : Nicorandil opens adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system and is being increasingly used for the treatment of angina pectoris. In the present study, we tested whether intravenous anesthetic agent ketamine affected nicorandil-induced native vascular KATP channel activation. Methods : We used excised inside-out patch clamp configurations to investigate the direct effects of ketamine racemate and S-(+)-ketamine on the activities of KATP channels in cultured rat aortic smooth muscle cells. Furthermore, we also investigated whether intracellular MgADP could modulate ketamine inhibition. Results : Nicorandil significantly activated KATP channel activity, whereas this channel activity was completely blocked by glibenclamide, a specific KATP channel blocker. Ketamine racemate inhibited the nicorandil induced KATP channel activity (IC50=34 1M, n=14), but S-(+)-ketamine was less potent than ketamine racemate in blocking nicorandil induced KATP channel activities (IC50=226 7M, n=10). Application of MgADP to the intracellular side of the channel was able to decrease the inhibitory potency of ketamine racemate on nicorandil induced KATP channel activities. Conclusions : Our results indicate that ketamine inhibits nicorandil induced KATP channel activities in a dose dependent and stereoselective manner. Furthermore, increase of intracellularMgADP attenuates the inhibitory potency of ketamine racemate

Homeostatic Mass Control in Gastric Non-Neoplastic Epithelia under Infection of Helicobacter pylori: An Immunohistochemical Analysis of Cell Growth, Stem Cells and Programmed Cell Death

We evaluated homeostatic mass control in non-neoplastic gastric epithelia under Helicobacter pylori (HP) infection in the macroscopically normal-appearing mucosa resected from the stomach with gastric cancer, immunohistochemically analyzing the proliferation, kinetics of stem cells and programmed cell death occurring in them. Ki67 antigen-positive proliferating cells were found dominantly in the elongated neck portion, sparsely in the fundic areas and sporadically in the stroma with chronic infiltrates. CD117 could monitor the kinetics of gastric stem cells and showed its expression in two stages of gastric epithelial differentiation, namely, in transient cells from the gastric epithelial stem cells to the foveolar and glandular cells in the neck portion and in what are apparently progenitor cells from the gastric stem cells in the stroma among the infiltrates. Most of the nuclei were positive for ssDNA in the almost normal mucosa, suggesting DNA damage. Cleaved caspase-3-positive foveolar cells were noted under the surface, suggesting the suppression of apoptosis in the surface foveolar cells. Besides such apoptosis of the foveolar cells, in the severely inflamed mucosa apoptotic cells were found in the neck portion where most of the cells were Ki67 antigen-positive proliferating cells. Beclin-1 was recognized in the cytoplasm and in a few nuclei of the fundic glandular cells, suggesting their autophagic cell death and mutated beclin-1 in the nuclei. Taken together, the direct and indirect effects of HP infection on the gastric epithelial proliferation, differentiation and programmed cell death suggested the in-situ occurrence of gastric cancer under HP infection