Prostanoids [prostaglandins (PGs) and thromboxanes (TXs)] are a series of bioactive lipid metabolites that function in an autacoid manner via activation of cognate G protein-coupled receptors (GPCRs). The nine subtypes of prostanoid receptors (DP1, DP2, EP1, EP2, EP3, EP4, FP, IP, TP) are involved in a wide range of functions, including inflammation, immune response, reproduction, and homeostasis of the intestinal mucosa and cardiovascular system. Among the prostanoid receptors, the structure of antagonist-bound DP2, which belongs to the chemoattractant receptor family, was previously determined. However, the mechanisms of prostanoid recognition and receptor activation remained elusive. To address this issue, we determined the crystal structures of antagonist-bound EP4 and PGE2-bound EP3. The EP3-PGE2 complex exhibits an active-like conformation, including outward movement of the cytoplasmic end of transmembrane (TM) 6 relative to the cytoplasmic end of TM6 of the EP4 complex. The carboxyl moiety of PGE2 is recognized through three hydrogen bonds formed by highly conserved residues Y1142.65, T206Extracelluar loop 2 (ECL2), and R3337.40 (superscripts denote Ballesteros-Weinstein numbering). In addition, the ω-chain of PGE2 orients toward TM6, which appears to contribute to receptor activation. The structure reveals important insights into the activation mechanism of prostanoid receptors and provides a molecular basis for the binding modes of endogenous ligands. These findings should facilitate the development of subtype-selective and non-PG-like ligands.We have been conducting research with the aim of generating evidence for the safety of perinatal drugs. As a result of reviewing the records of inquiries to the Drug Information Office of our hospital, we found a large discrepancy between the description of perinatal drugs in package inserts in Japan and the description of the Pregnancy Risk Category according to the U.S. Food and Drug Administration. In the Japan Environment and Children's Study (JECS), we determined the proportion of drug and supplement use among 97464 pregnant women. We clarified that prescriptions of antihypertensive drugs for pregnant women increased during the second half of pregnancy, while prescriptions of anti-epileptic and anti-anxiety drugs decreased after pregnancy using a claims database. A survey of pharmacists and pharmacy students revealed a lack of awareness of effective folic acid intake to reduce the risk of neural tube defects in infants. The percentage of pre-pregnancy folic acid supplementation among pregnant women participating in the Babies and their Parents' Longitudinal Observation in Suzuki Memorial Hospital on Intrauterine Period (BOSHI) study, the JECS, and the Tohoku Medical Megabank (TMM) Birth and Three-Generation (BirThree) cohort study was 6.3-18.0%. As a result of close examination of the records of inquiries to the Drug Information Office of our hospital, and of cases in which our lactation plan sheet was applied, it was found that there were discrepancies between the information on the drug package insert and the information on Medications & Mother's Milk, etc. in Japan. The results obtained have been clinically applied in daily practice and we are continuing our research while taking measures.The blood-brain barrier (BBB) consists of brain capillary endothelial cells linked by tight junctions and serves to regulate the transfer of endogenous compounds and xenobiotics between the circulating blood and brain interstitial fluid. We have developed a methodology to characterize brain-to-blood efflux transport in vivo, using the Brain Efflux Index and an in vitro culture model of the BBB, i.e., a conditionally immortalized cell line of the neurovascular unit. Employing these methods, we showed that the BBB plays an important role in protecting the brain by transporting neurotransmitters, neuromodulators, metabolites, uremic toxins, and xenobiotics together with atrial natriuretic peptide from the brain interstitial fluid to the circulating blood. We also developed a highly selective, sensitive LC-MS/MS method for simultaneous protein quantification. We found significant species differences in the expression amounts of various BBB transporter proteins among mice, rats, marmosets, cynomolgus monkeys, and humans. Among transporter proteins at the BBB, multidrug resistance protein 1 (Mdr1/Abcb1) is known to generate a concentration gradient of unbound substrate drugs between the blood and brain. Based on measurements of the intrinsic efflux transport rate of Mdr1 and the protein expression amounts of Mdr1 in mouse brain capillaries and Mdr1-expressing cell lines, we predicted the unbound drug concentration gradients of 7 drugs in the mouse brain in vivo. This was the first successful prediction of in vivo drug transport activity from in vitro experimental data and transporter protein concentration in tissues. This methodology and findings should greatly advance central nervous system barrier research.Nausea is a typical adverse event associated with opioids. In this study, we performed logistic regression analysis with the aim of clarifying the risk factors for nausea induced by extended-release oxycodone (ER-OXY).  https://www.selleckchem.com/products/Oridonin(Isodonol).html  Furthermore, we constructed a decision tree (DT) model, a typical data mining method, to estimate the risk of oxycodone-induced nausea by combining multiple factors. A retrospective study was conducted on patients who newly received ER-OXY for cancer pain during hospitalization at Hokkaido University Hospital in Japan from April 2015 to March 2018. In logistic regression and DT analyses, the dependent variable was the presence or absence of nausea. Independent variables were the potential risk factors. First, univariate analyses were performed to screen potential factors associated with oxycodone-induced nausea. Then, multivariate and DT analyses were performed using factors with p-values less then 0.1 in the univariate analysis. Of 267 cases included in this study, nausea was observed in 30.3% (81/267). In multivariate logistic regression analysis, only female sex was extracted as an independent factor affecting nausea (odds ratio, 1.98). In the DT analysis, we additionally revealed that an age less then 50 years was a risk factor for nausea in female patients. Thus, our DT model indicated that the risk of ER-OXY-induced nausea was highest in the subgroup comprising females less then 50 years of age (66.7%) and lowest in male patients (25.1%). The DT model suggested that the factor of young women may be an increased risk of ER-OXY-induced nausea.