A photoinduced growth system of peptide nanofibres addressed by DNA hybridization

Spatiotemporal control of peptide nanofibre growth was achieved by photocleavage of a DNA-conjugated β-sheet forming peptide that is linked through a photoresponsive amino acid residue. Peptide nanofibres were selectively formed by photocleaving the conjugate on complementary DNA-immobilised glass substrate

Loss of Tumor Necrosis Factor Production by Human Monocytes in Falciparum Malaria after Their Maturation in Vitro

In Plasmodium-infected mammals, phagocytosis and production of tumor necrosis factor (TNF) by monocytes and macrophages are prominent features. The present work aimed at clarifying the relationship between the maturation of human monocytes to macrophages and their TNF productivity and phagocytic ability in the presence of Plasmodium falciparum-infected erythrocytes. Fresh monocytes produced a significantly higher quantity of TNF in the presence of schizont-infected erythrocytes than macrophages obtained by in vitro monocyte maturation on autologous serum, whereas phagocytic activity of macrophages was much higher than that of fresh monocytes. This indicated that the TNF-inducing factors from P. falciparum-infected erythrocytes could stimulate fresh monocytes, but not macrophages, to release TNF, regardless of their development of phagocytosis. Activation of macrophages by interferon-{gamma} could not recover their TNF productivity in the presence of P. falciparum-infected erythrocytes, but it enhanced their TNF productivity in the presence of lipopolysaccharide(s). The TNF-inducing factors were contained mainly in erythrocytes infected with mature schizonts but not in erythrocytes infected with the younger stages of the parasites. Fractionation of infected erythrocytes revealed that both soluble and insoluble components almost equally contained those factors

Light-induced propulsion of a giant liposome driven by peptide nanofibre growth

Light-driven nano/micromotors are attracting much attention, not only as molecular devices but also as components of bioinspired robots. In nature, several pathogens such as Listeria use actin polymerisation machinery for their propulsion. Despite the development of various motors, it remains challenging to mimic natural systems to create artificial motors propelled by fibre formation. Herein, we report the propulsion of giant liposomes driven by light-induced peptide nanofibre growth on their surface. Peptide-DNA conjugates connected by a photocleavage unit were asymmetrically introduced onto phase-separated giant liposomes. Ultraviolet (UV) light irradiation cleaved the conjugates and released peptide units, which self-assembled into nanofibres, driving the translational movement of the liposomes. The velocity of the liposomes reflected the rates of the photocleavage reaction and subsequent fibre formation of the peptide-DNA conjugates. These results showed that chemical design of the light-induced peptide nanofibre formation is a useful approach to fabricating bioinspired motors with controllable motility

電波干渉計の新たなイメージング法について

Open House, ISM in Tachikawa, 2015.6.19統計数理研究所オープンハウス（立川）、H27.6.19ポスター発

Computer-controlled closed-loop norepinephrine infusion system for automated control of mean arterial pressure in dogs under isoflurane-induced hypotension: a feasibility study

Introduction: Intra-operative hypotension is a common complication of surgery under general anesthesia in dogs and humans. Computer-controlled closed-loop infusion systems of norepinephrine (NE) have been developed and clinically applied for automated optimization of arterial pressure (AP) and prevention of intra-operative hypotension in humans. This study aimed to develop a simple computer-controlled closed-loop infusion system of NE for the automated control of the mean arterial pressure (MAP) in dogs with isoflurane-induced hypotension and to validate the control of MAP by the developed system. Methods: NE was administered via the cephalic vein, whereas MAP was measured invasively by placing a catheter in the dorsal pedal artery. The proportional-integral-derivative (PID) controller in the negative feedback loop of the developed system titrated the infusion rate of NE to maintain the MAP at the target value of 60 mmHg. The titration was updated every 2 s. The performance of the developed system was evaluated in six laboratory Beagle dogs under general anesthesia with isoflurane. Results: In the six dogs, when the concentration [median (interquartile range)] of inhaled isoflurane was increased from 1.5 (1.5-1.5)% to 4 (4-4)% without activating the system, the MAP was lowered from 95 (91-99) to 41 (37-42) mmHg. In contrast, when the concentration was increased from 1.5 (1.0-1.5)% to 4 (4-4.8)% for a 30-min period and the system was simultaneously activated, the MAP was temporarily lowered from 92 (89-95) to 47 (43-49) mmHg but recovered to 58 (57-58) mmHg owing to the system-controlled infusion of NE. If the acceptable target range for MAP was defined as target MAP ±5 mmHg (55 ≤ MAP ≤65 mmHg), the percentage of time wherein the MAP was maintained within the acceptable range was 96 (89-100)% in the six dogs during the second half of the 30-min period (from 15 to 30 min after system activation). The median performance error, median absolute performance error, wobble, and divergence were - 2.9 (-4.7 to 1.9)%, 2.9 (2.0-4.7)%, 1.3 (0.8-1.8)%, and - 0.24 (-0.34 to -0.11)%·min-1, respectively. No adverse events were observed during the study period, and all dogs were extubated uneventfully. Conclusion: This system was able to titrate the NE infusion rates in an accurate and stable manner to maintain the MAP within the predetermined target range in dogs with isoflurane-induced hypotension. This system can be a potential tool in daily clinical practice for the care of companion dogs