Archaeal Phospholipid Biosynthetic Pathway Reconstructed in Escherichia coli

A part of the biosynthetic pathway of archaeal membrane lipids, comprised of 4 archaeal enzymes, was reconstructed in the cells of Escherichia coli. The genes of the enzymes were cloned from a mesophilic methanogen, Methanosarcina acetivorans, and the activity of each enzyme was confirmed using recombinant proteins. In vitro radioassay showed that the 4 enzymes are sufficient to synthesize an intermediate of archaeal membrane lipid biosynthesis, that is, 2,3-di-O-geranylgeranyl-sn-glycerol-1-phosphate, from precursors that can be produced endogenously in E. coli. Introduction of the 4 genes into E. coli resulted in the production of archaeal-type lipids. Detailed liquid chromatography/electron spray ionization-mass spectrometry analyses showed that they are metabolites from the expected intermediate, that is, 2,3-di-O-geranylgeranyl-sn-glycerol and 2,3-di-O-geranylgeranyl-sn-glycerol-1-phosphoglycerol. The metabolic processes, that is, dephosphorylation and glycerol modification, are likely catalyzed by endogenous enzymes of E. coli

Estimation of Dietary Intake of Radionuclides and Effectiveness of Regulation after the Fukushima Accident and in Virtual Nuclear Power Plant Accident Scenarios

Evaluation of radiation exposure from diet is necessary under the assumption of a virtual accident as a part of emergency preparedness. Here, we developed a model with complete consideration of the regional food trade using deposition data simulated by a transport model, and estimated the dietary intake of radionuclides and the effectiveness of regulation (e.g., restrictions on the distribution of foods) after the Fukushima accident and in virtual accident scenarios. We also evaluated the dilution factors (i.e., ratios of contaminated foods to consumed foods) and cost-effectiveness of regulation as basic information for setting regulatory values. The doses estimated under actual emission conditions were generally consistent with those observed in food-duplicate and market-basket surveys within a factor of three. Regulation of restricted food distribution resulted in reductions in the doses of 54–65% in the nearest large city to the nuclear power plant. The dilution factors under actual emission conditions were 4.4% for radioiodine and 2.7% for radiocesium, which are ~20 times lower than those used in the Japanese provisional regulation values after the Fukushima accident. Strict regulation worsened the cost-effectiveness for both radionuclides. This study highlights the significance and utility of the developed model for a risk analysis of emergency preparedness and regulation

Fast-Ion-Diagnostics for CHS Experiment

Fast-ion-diagnostics have played an important role in investigating issues related to fast ion orbits and fast-ion-driven MHD instabilities in CHS experiments. The fast-ion diagnostics employed in CHS are reviewed and experimentally obtained knowledge is summarized

Elevated Levels of VE-Cadherin-Positive Endothelial Microparticles in Patients With Type 2 Diabetes Mellitus and Coronary Artery Disease

ObjectivesThe purpose of this study was to examine whether CD144-EMP (endothelium-derived microparticles) is useful as a specific marker of endothelial cell (EC) dysfunction and to determine whether plasma levels of circulating CD144-EMP predicted coronary artery disease (CAD) in patients with type 2 diabetes mellitus (DM).BackgroundEndothelial cell dysfunction is involved in atherogenesis; however, the quantitative assessment of EC dysfunction has yet to be established clinically. Endothelium-derived microparticles are small, membrane-shed vesicles that are generated from the EC surface in response to cellular dysfunction and/or injury. Diabetes mellitus is known to be associated with EC dysfunction and accelerated atherosclerosis.MethodsWe characterized EMP using anti-CD144 (VE-Cadherin) antibody in various atherosclerosis-related cells and investigated the association between the levels of CD144-positive microparticles and hydrogen-peroxide-induced EC injury and acetylcholine-induced coronary vasomotion. Furthermore, we evaluated plasma CD144-EMP levels in patients with and without DM.ResultsWe demonstrated that CD144-positive microparticles were derived selectively from human EC. The levels of CD144-EMP reflected the degree of in vitro hydrogen-peroxide-induced EC injury and impairment of in vivo endothelium-dependent coronary vasodilation (p < 0.01). Plasma CD144-EMP levels were increased significantly in DM patients compared with patients without DM (p < 0.001). In DM patients, the elevated levels of CD144-EMP were the most significant risk factor for CAD relative to all other traditional risk factors (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.8 to 6.9, p < 0.001). Notably, plasma CD144-EMP identified a subpopulation of established CAD patients in DM subjects without typical anginal symptoms (OR 10.6, 95% CI 3.9 to 29.5, p < 0.001).ConclusionsThe CD144-positive EMP exist in human plasma, and plasma CD144-EMP levels can be a clinically specific and quantitative marker of EC dysfunction and/or injury. Measurement of CD144-EMP, by providing a quantitative assessment of EC dysfunction, may be useful for identifying DM patients with increased risk of CAD

Exertional evaluation for BT

Bronchial thermoplasty (BT) had been reported to improve the symptoms of severe asthma. However, the exertional responses of BT based on the mechanisms have not been elucidated. A 57-year-old man and a 60-year-old woman underwent BT due to intractable severe asthma. We evaluated the therapeutic effects of BT using cardiopulmonary exercise testing (CPET). After BT, the exercise time during CPET substantially prolonged reducing exertional dyspnea in the former (good), but not in the latter (poor). In the good responder, the high air remaining in the lung after expiration (i.e., inspiratory tidal volume minus expiratory tidal volume) during CPET decreased after BT. In contrast, in the poor responder, the high air remaining after expiration during exercise was not obtained before BT. Further investigations are necessary to confirm that the presence or absence of the exertional wasted ventilation on CPET may be informative to evaluate the therapeutic effects of BT

pH-resistant Inhibitor of Mitochondrial ADP/ATP Carrier

Bongkrekic acid (BKA), isolated from Burkholderia cocovenenans, is known to specifically inhibit the mitochondrial ADP/ATP carrier. However, the manner of its interaction with the carrier remains elusive. In the present study, we tested the inhibitory effects of 17 bongkrekic acid analogues, derived from the intermediates obtained during its total synthesis, on the mitochondrial ATP/ATP carrier. Rough screening of these chemicals, done by measuring their inhibitory effects on the mitochondrial ATP synthesis, revealed that 4 of them, KH-1, 7, 16, and 17, had moderate inhibitory effects. Further characterization of the actions of these 4 analogues on mitochondrial function showed that KH-16 had moderate; KH-1 and KH-17, weak; and KH-7, negligible side effects of both permeabilization of the mitochondrial inner membrane and inhibition of the electron transport, indicating that only KH-7 had a specific inhibitory effect on the mitochondrial ADP/ATP carrier. Although the parental bongkrekic acid showed a strong pH dependency of its action, the inhibitory effect of KH-7 was almost insensitive to the pH of the reaction medium, indicating the importance of the 3 carboxyl groups of BKA for its pH- dependent action. A direct inhibitory effect of KH-7 on the mitochondrial ADP/ATP carrier was also clearly demonstrated