Unique Reactivity of the 1,4-Bis(silyloxy)-1,3-cyclopentadiene Moiety: Application to the Synthesis of 7-Norbornanone Derivatives.

We describe a method for the synthesis of various 2-silyloxy-2-norbornen-7-ones by exploiting the specific reactivity of the 1,4-bis(silyloxy)-1,3-cyclopentadiene framework, which is generated by the silylation of a 2,2-disubstituted-1,3-cyclopentanedione bearing a picolinoyloxy group at the 2' position of its C-2 side chain. The release of the acyloxy group during the reaction generates carbocations that are then attacked by silyloxy-substituted carbons in the 1,4-bis(silyloxy)-1,3-cyclopentadiene moiety skeleton, forming a 4,5-cis-fused ring skeleton. Skeletal rearrangement of the bicyclic core results in the formation of the corresponding 2-silyloxy-2-norbornen-7-one. This novel transformation of 1,3-cyclopentanedione moieties can be used to synthesise other cyclopentenone-fused bicyclic frameworks.

Population pharmacokinetics and pharmacogenomics of apixaban in Japanese adult patients with atrial fibrillation.

AIMS: This study aimed to analyse the effects of genetic polymorphisms in drug transporters and metabolizing enzymes, and clinical laboratory data on the pharmacokinetic parameters of apixaban. METHODS: Data were collected from 81 Japanese patients with atrial fibrillation. Pharmacogenomic data were stratified by ABCB1, ABCG2 and CYP3A5 polymorphisms. The pharmacokinetic profile of apixaban was described by a one-compartment model with first-order absorption. Population pharmacokinetic analysis was conducted using a nonlinear mixed effect modelling (NONMEM™) program. RESULTS: The nonlinear relationship between oral clearance (CL/F) of apixaban and creatinine clearance (Ccr) was observed. The population mean of CL/F for a typical patient (Ccr value of 70 ml min-1 ) with the CYP3A5*1/*1 and ABCG2 421C/C or C/A genotypes was estimated to be 3.06 l h-1 . When Ccr values were set to the typical value, the population mean of CL/F was 1.52 times higher in patients with the CYP3A5*1/*1 genotype compared with patients with the CYP3A5*1/*3 or *3/*3 genotype, while the population mean of CL/F was 1.49 times higher in patients with the ABCG2 421C/C or C/A genotype compared with patients with the ABCG2 421A/A genotype. However, no covariates affected the population mean of the apparent volume of distribution (Vd/F) of apixaban. The population mean of Vd/F was estimated to be 24.7 l. CONCLUSION: The present study suggests that the ABCG2 421A/A and CYP3A5*3 genotypes and renal function are intrinsic factors affecting apixaban pharmacokinetics. These findings may provide useful information for precision medicine using apixaban, to avoid the risk of adverse reactions.

Impact of ABCB1, ABCG2, and CYP3A5 polymorphisms on plasma trough concentrations of apixaban in Japanese patients with atrial fibrillation.

OBJECTIVES: During anticoagulant therapy, major bleeding is one of the most severe adverse effects. This study aimed to evaluate the relationships between ABCB1, ABCG2, and CYP3A5 polymorphisms and plasma trough concentrations of apixaban, a direct inhibitor of coagulation factor X. PATIENTS AND METHODS: A total of 70 plasma concentrations of apixaban from 44 Japanese patients with atrial fibrillation were analyzed. In these analyses, the plasma trough concentration/dose (C/D) ratio of apixaban was used as a pharmacokinetic index and all data were stratified according to the presence of ABCB1 (ABCB1 1236C>T, 2677G>T/A, and 3435C>T), ABCG2 (ABCG2 421C>A), and CYP3A5 (CYP3A5*3) polymorphisms. Influences of various clinical laboratory parameters (age, serum creatinine, estimated glomerular filtration rate, aspartate amino transferase, and alanine amino transferase) on the plasma trough C/D ratio of apixaban were included in analyses. RESULTS: Although no ABCB1 polymorphisms affected the plasma trough C/D ratio of apixaban, the plasma trough C/D ratio of apixaban was significantly higher in patients with the ABCG2 421A/A genotype than in patients with the ABCG2 421C/C genotype (P<0.01). The plasma trough C/D ratio of apixaban in patients with CYP3A5*1/*3 or *3/*3 genotypes was also significantly higher than that in patients with the CYP3A5*1/*1 genotype (P<0.05). Furthermore, the plasma trough C/D ratio of apixaban decreased with increased estimated glomerular filtration rate. CONCLUSION: These results indicate that ABCG2 421A/A and CYP3A5*3 genotypes and renal function are considered potential factors affecting trough concentrations of apixaban.

Rapid expansion of a left atrial myxoma caused by acute multiple internal hemorrhages: a case report and literature review.

BACKGROUND: Left atrial myxoma is the most common benign tumor, with the growth rate remaining unknown because specific symptoms do not present until the tumor grows to a certain size. Early surgical management is performed in most cases once it is detected by physicians. Despite cardiac myxomas commonly being perceived as slow-growing tumors, rapid enlargement of myxomas has been reported. CASE PRESENTATION: A 64-year-old woman was referred to our hospital with a diagnosis of a left atrial tumor. The pointed tumor changed morphologically in a few hours, and her respiratory condition, which had been normal at admission, suddenly deteriorated. Emergent surgery was performed, and the diagnosis was myxoma with multiple intratumor massive hematomas. The patient recovered uneventfully and was discharged on postoperative day 12 without any complications. CONCLUSIONS: We report an extremely rare case of left atrial myxoma rapidly expanded due to acute multiple hemorrhages within itself. Massive internal hemorrhage alters the size, shape, and fragility of the tumor. We should recognize the potential risk of internal hemorrhage that may lead to acute deterioration of the so-called "slow-growing benign" tumors, such as myxomas.

Total Synthesis of (+)-Coriamyrtin via a Desymmetrizing Strategy Involving a 1,3-Cyclopentanedione Moiety.

We describe the total synthesis of (+)-coriamyrtin, which bears a highly functionalized cis-hydrindane skeleton and is a widely known neurotoxin of the Coriariaceae family. Our synthetic strategy involves the highly stereoselective construction of the cis-hydrindane skeleton via a desymmetrizing strategy involving a 1,3-cyclopentanedione moiety using an intramolecular aldol reaction and the formation of the 1,3-diepoxide moiety of coriamyrtin through the elaborate functionalization of the cyclopentane ring in the bicyclic structure.

Apelin-transgenic mice exhibit a resistance against diet-induced obesity by increasing vascular mass and mitochondrial biogenesis in skeletal muscle.

BACKGROUND: Apelin is an endogenous ligand for the G-protein-coupled 7-transmembrane receptor, APJ. The administration of apelin-13, a truncated 13-amino acid apelin peptide, in diet-induced obese mice is reported to result in a decrease in adiposity due to the increase of energy expenditure with an increase in the expression of uncoupling proteins. METHODS: We systematically compared the phenotype of human apelin-transgenic (apelin-Tg) mice fed standard or high-fat diets (HFD) with that of non-Tg control mice to clarify the effect of apelin on obesity. The beneficial effects of apelin were evaluated by multiple assay methods including indirect calorimetrical measurements, gene expression analysis, and immunohistochemical staining. RESULTS: Apelin-Tg mice inhibited HFD-induced obesity without altering food intake and exhibited increased oxygen consumption and body temperature compared to non-Tg controls. Interestingly, the mRNA expressions of angiopoietin-1 (Ang1), a key molecule for vascular maturation, and its receptor, endothelium-specific receptor tyrosine kinase 2 (Tie2), were significantly upregulated in the skeletal muscle of HFD-fed apelin-Tg mice, and the areas of anti-CD31 antibody-positive endothelial cells also increased. Furthermore, both the aerobic type-I muscle fibre ratio and the DNA copy number of mitochondrial NADH dehydrogenase subunit 1 increased 2.0- and 1.4-fold in skeletal muscle, respectively. CONCLUSIONS: These findings suggest that apelin stimulates energy expenditure via increase vascular mass and mitochondrial biogenesis in skeletal muscle. GENERAL SIGNIFICANCE: Apelin is a prerequisite factor for anti-obesity by stimulating energy expenditure via regulating homeostatic energy balance.

Spatial and temporal role of the apelin/APJ system in the caliber size regulation of blood vessels during angiogenesis.

Blood vessels change their caliber to adapt to the demands of tissues or organs for oxygen and nutrients. This event is mainly organized at the capillary level and requires a size-sensing mechanism. However, the molecular regulatory mechanism involved in caliber size modification in blood vessels is not clear. Here we show that apelin, a protein secreted from endothelial cells under the activation of Tie2 receptor tyrosine kinase on endothelial cells, plays a role in the regulation of caliber size of blood vessel through its cognate receptor APJ, which is expressed on endothelial cells. During early embryogenesis, APJ is expressed on endothelial cells of the new blood vessels sprouted from the dorsal aorta, but not on pre-existing endothelial cells of the dorsal aorta. Apelin-deficient mice showed narrow blood vessels in intersomitic vessels during embryogenesis. Apelin enhanced endothelial cell proliferation in the presence of vascular endothelial growth factor and promoted cell-to-cell aggregation. These results indicated that the apelin/APJ system is involved in the regulation of blood vessel diameter during angiogenesis.

Blast Injuries by an Improvised Explosive Device in Japan: A Case Report.

Blast injuries caused by an improvised explosive device (IED) are becoming more common in civilian settings. However, physicians may not be familiar with the treatment and management of blast-injured victims. To the best of our knowledge, this is the first case report of a blast injury caused by an IED in Japan. A 64-year-old man was admitted to our hospital's emergency department after sustaining a blast injury. His vital signs were stable, but he had multiple small wounds with embedded foreign bodies that were consistent with injuries sustained by IED victims. The patient was treated for his injuries and was moved to another hospital on day 37. Knowledge about blast injuries caused by IEDs and management strategies for mass casualties are both necessary.

Characterization and reduction of non-endocrine cells accompanying islet-like endocrine cells differentiated from human iPSC.

The differentiation of pancreatic endocrine cells from human pluripotent stem cells has been thoroughly investigated for their application in cell therapy against diabetes. Although non-endocrine cells are inevitable contaminating by-products of the differentiation process, a comprehensive profile of such cells is lacking. Therefore, we characterized non-endocrine cells in iPSC-derived pancreatic islet cells (iPIC) using single-cell transcriptomic analysis. We found that non-endocrine cells consist of (1) heterogeneous proliferating cells, and (2) cells with not only pancreatic traits but also liver or intestinal traits marked by FGB or AGR2. Non-endocrine cells specifically expressed FGFR2, PLK1, and LDHB. We demonstrated that inhibition of pathways involving these genes selectively reduced the number of non-endocrine cells in the differentiation process. These findings provide useful insights into cell purification approaches and contribute to the improvement of the mass production of endocrine cells for stem cell-derived cell therapy for diabetes.

Non-Flammable and Highly Concentrated Carbonate Ester-Free Electrolyte Solutions for 5 V-Class Positive Electrodes in Lithium-Ion Batteries.

Non-flammable and highly concentrated electrolyte solutions were designed using tris(2,2,2-trifluoroethyl) phosphate (TFEP) as a main solvent toward a radical improvement in the safety and energy density of lithium-ion batteries. Unlike conventional carbonate ester-based solutions, simple TFEP-based electrolyte solutions were not intrinsically compatible with 5 V-class LiNi0.5 Mn1.5 O4 positive electrodes, even at high concentrations. Based on the degradation mechanism that was analyzed by Raman spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, a fluorinated diluent of methyl 3,3,3-trifluoropropionate (FMP) was introduced to suppress the decomposition of LiBF4 and TFEP at high potentials. A nearly saturated LiBF4 /TFEP+FMP electrolyte solution with a specific composition improved the charge and discharge performance of a LiNi0.5 Mn1.5 O4 electrode, and the solution structure was studied by pulsed-field-gradient NMR spectroscopy.

Potentiality of multiple modalities for single-cell analyses to evaluate the tumor microenvironment in clinical specimens.

Single-cell level analysis is powerful tool to assess the heterogeneity of cellular components in tumor microenvironments (TME). In this study, we investigated immune-profiles using the single-cell analyses of endoscopically- or surgically-resected tumors, and peripheral blood mononuclear cells from gastric cancer patients. Furthermore, we technically characterized two distinct platforms of the single-cell analysis; RNA-seq-based analysis (scRNA-seq), and mass cytometry-based analysis (CyTOF), both of which are broadly embraced technologies. Our study revealed that the scRNA-seq analysis could cover a broader range of immune cells of TME in the biopsy-resected small samples of tumors, detecting even small subgroups of B cells or Treg cells in the tumors, although CyTOF could distinguish the specific populations in more depth. These findings demonstrate that scRNA-seq analysis is a highly-feasible platform for elucidating the complexity of TME in small biopsy tumors, which would provide a novel strategies to overcome a therapeutic difficulties against cancer heterogeneity in TME.

Comparison of 18FBPA uptake with 18FDG uptake in cancer patients.

For the patients who underwent 18fluorinated para-boronophenylalanine (18FBPA) positron emission tomography (PET) and 18fluorodeoxyglucose (18FDG) PET within a period of 2 weeks, maximum standardized uptake value (SUVmax), tumor-to-normal tissue ratio (TNR), and tumor-to-blood ratio (TBR) for 18FBPA were compared with SUVmax for 18FDG. A total of 30 patients were selected for comparison. SUVmax for 18FBPA was correlated the best with SUVmax for 18FDG. Subsequently, the SUVmax correlation between 18FBPA and 18FDG were verified among 82 patients. The correlation factor was 0.4825.

[Business administration of PET facilities: a cost analysis of three facilities utilizing delivery FDG].

BACKGROUND: PET (positron emission tomography) has been proved to be a powerful imaging tool in clinical oncology. The number of PET facilities in Japan has remarkably increased over the last decade. Furthermore, the approval of delivery FDG in 2005 resulted in a tremendous expansion of the PET institutions without a cyclotron facility. The aim of this study was to conduct a cost analysis of PET institutions that utilized delivery FDG. METHODS: Three PET facilities using delivery FDG were investigated about the costs for PET service. Fixed costs included depreciation costs for construction and medical equipments such as positron camera. Variable costs consisted of costs for medical materials including delivery FDG. The break-even point was analyzed in each of three institutions. RESULTS: In the three hospitals (A, B and C), the annual number of PET scan was 1,591, 1,637 and 914, while cost per scan was accounted as yen 110,262, yen 111,091, and yen 134,192, respectively. The break-even point was calculated to be 2,583, 2,679 and 2,081, respectively. CONCLUSIONS: PET facilities utilizing delivery FDG seemed to have difficulty in business administration. Such a situation suggests the possibility that the current supply of PET facilities might exceed actual demand for the service. The efficiency of resource allocation should be taken into consideration in the future health service researches on PET.

[Business administration of PET facilities: a nationwide survey for prices of PET screening and a cost analysis of three facilities].

The purpose of this study is to analyze the business administration of PET facilities based on the survey of the price of PET cancer screening and cost analysis of PET examination. The questionnaire survey of the price of PET cancer screening was implemented for all PET facilities in Japan. Cost data of PET examination, including fixed costs and variable costs, were obtained from three different medical institutions. The marked price of the PET cancer screening was 111,499 yen in average, and the most popular range of prices was between 80,000 yen and 90,000 yen. Costs of PET per examination were accounted for 110,675 yen, 79,158 yen and Y11,644 yen in facility A, B and C, respectively. The results suggested that facilities with two or more PET/CT per a cyclotron could only secure profits. In Japan, the boom in PET facility construction could not continue in accordance with increasing number of PET facilities. It would become more essential to analyze the appropriate distribution of PET facilities and the adequate amount of PET procedures from the perspective of efficient utilization of the PET equipments and supply of PET-related healthcare.

Real-time monitoring of superoxide anion radical generation in response to wounding: electrochemical study.

BACKGROUND: The growth and development of plants is deleteriously affected by various biotic and abiotic stress factors. Wounding in plants is caused by exposure to environmental stress, mechanical stress, and via herbivory. Typically, oxidative burst in response to wounding is associated with the formation of reactive oxygen species, such as the superoxide anion radical (O2•-), hydrogen peroxide (H2O2) and singlet oxygen; however, few experimental studies have provided direct evidence of their detection in plants. Detection of O2•- formation in plant tissues have been performed using various techniques including electron paramagnetic resonance spin-trap spectroscopy, epinephrine-adrenochrome acceptor methods, staining with dyes such as tetrazolium dye and nitro blue tetrazolium (NBT); however, kinetic measurements have not been performed. In the current study, we provide evidence of O2•- generation and its kinetics in the leaves of spinach (Spinacia oleracea) subjected to wounding. METHODS: Real-time monitoring of O2•- generation was performed using catalytic amperometry. Changes in oxidation current for O2•- was monitored using polymeric iron-porphyrin-based modified carbon electrodes (φ = 1 mm) as working electrode with Ag/AgCl as the reference electrode. RESULT: The results obtained show continuous generation of O2•- for minutes after wounding, followed by a decline. The exogenous addition of superoxide dismutase, which is known to dismutate O2•- to H2O2, significantly suppressed the oxidation current. CONCLUSION: Catalytic amperometric measurements were performed using polymeric iron-porphyrin based modified carbon electrode. We claim it to be a useful tool and a direct method for real-time monitoring and precise detection of O2•- in biological samples, with the potential for wide application in plant research for specific and sensitive detection of O2•-.

Recent advances in mammalian RFamide peptides: the discovery and functional analyses of PrRP, RFRPs and QRFP.

Since the first discovery of a peptide with RFamide structure at its C-terminus (i.e., an RFamide peptide) from an invertebrate in 1977, numerous studies on RFamide peptides have been conducted, and a variety have been identified in various phyla throughout the animal kingdom. The first reported mammalian RFamide peptides were neuropeptide FF (NPFF) and neuropeptide AF (NPAF) in 1985. However, for many years after this, no new novel RFamide peptides were identified in mammals. A breakthrough in discovering mammalian RFamide peptides was made possible by reverse pharmacology on the basis of orphan G protein-coupled receptor (GPCR) research. The first report of an RFamide peptide identified from orphan GPCR research was prolactin (PRL)-releasing peptide (PrRP) in 1998. To date, a total of five RFamide peptide genes have been discovered in mammals. Orphan GPCR research has contributed considerably to the identification of these peptides and their receptor genes. This paper examines these mammalian RFamide peptides focusing especially on PrRP, RFamide-related peptides (RFRPs) and, the most recently identified, pyroglutamylated RFamide peptide (QRFP), the discovery of all of which the authors were at least partly involved in. We review here the strategies employed for the identification of these peptides and examine their characteristics, tissue distribution, receptors and functions.

Myocardial 11C-diacylglycerol accumulation and left ventricular remodeling in patients after myocardial infarction.

UNLABELLED: Left ventricular (LV) remodeling after myocardial infarction (MI) is a maladaptive process that increases the risk of heart failure and death. The myocardial phosphoinositide cycle, which is located downstream from several neurohumoral factors, plays a crucial role in LV remodeling. Our animal studies demonstrated that 1-[1-11C]butyryl-2-palmitoyl-rac-glycerol (11C-DAG) can be used to visualize regions with an activated phosphoinositide cycle. Therefore, we examined whether myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement and systolic dysfunction in post-MI patients. METHODS: We performed PET with 11C-DAG in 13 post-anteroseptal MI patients and 4 healthy volunteers. We placed regions of interest on the noninfarcted myocardium and calculated the myocardium-to-left atrial (LA) chamber ratio of 11C-DAG accumulation. RESULTS: The myocardium-to-LA chamber ratio of 11C-DAG was significantly higher in the post-MI patients (mean +/- SD, 1.73 +/- 0.35) compared with that of the healthy volunteers (mean +/- SD, 1.25 +/- 0.13; P < 0.05). In the post-MI patients, the myocardium-to-LA chamber ratio of (11)C-DAG was significantly correlated with the LV end-diastolic volume index (r = 0.79, P < 0.01) and the plasma concentration of brain natriuretic peptide (r = 0.85, P < 0.001) and negatively correlated with the LV ejection fraction (r = -0.69, P < 0.01). CONCLUSION: These findings suggest that the myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement, LV systolic dysfunction, and humoral activation in post-MI patients. This new imaging strategy based on intracellular signaling may contribute to the assessment and treatment of post-MI patients.

Development of target system for intense neutron source of p-Li reaction.

A target cooling system was developed for an intense neutron source of p-Li reaction. The system consists of target cooling devices and protection devices for lithium evaporation. A pin-structure cooling device was developed to enhance cooling power. Functional graded material was utilized for the evaporation of lithium. Test experiments were performed by using the neutron exposure accelerator system for biological effect experiments (NASBEE) at the National Institute of Radiological Sciences (NIRS) in Japan. The target system was confirmed to be applicable for accelerator-based boron neutron capture therapy.

The Japanese national health screening and intervention program aimed at preventing worsening of the metabolic syndrome.

Similar to the healthcare systems in other industrialized countries, the Japanese healthcare system is facing the problem of increasing medical expenditure. In Japan, this situation may be primarily attributed to advanced technological developments, an aging population, and increasing patient demand. Japan also faces the problem of a declining youth population due to a low birth rate. Taken together, these problems present the healthcare system with a very difficult financial situation. Several reforms have been undertaken to contain medical expenditure, such as increasing employee copayment for health insurance from 10% to 20% in 1997 and from 20% to 30% in 2003 in order to curb unnecessary visits to medical institutions. Since the aging of the Japanese population is inevitable, a suitable method to contain medical expenditure may be to screen individuals who are likely to develop lifestyle-related diseases and conduct early intervention programs for them to prevent the development of diseases such as myocardial infarction or stroke that are costly to treat. If this goal is attained, it may contribute to the containment of medical expenditure as well as to improving the quality of life of the elderly. Therefore, the Japanese Ministry of Health, Labor and Welfare has decided to introduce a nationwide health screening and intervention program specifically targeting the metabolic syndrome commencing April 2008. Here, we discuss (1) the background of the Japanese healthcare system and the problems facing it, (2) the underlying objective and details of the new screening program, and (3) the expected impact of the program.