Effect of Nanosecond Pulsed Currents on Directions of Cell Elongation and Migration through Time-Lapse Analysis.

It is generally known that cells elongate perpendicularly to an electric field and move in the direction of the field when an electric field is applied. We have shown that irradiation of plasma-simulated nanosecond pulsed currents elongates cells, but the direction of cell elongation and migration has not been elucidated. In this study, a new time-lapse observation device that can apply nanosecond pulsed currents to cells was constructed, and software to analyze cell migration was created to develop a device that can sequentially observe cell behavior. The results showed nanosecond pulsed currents elongate cells but do not affect the direction of elongation and migration. It was also found the behavior of cells changes depending on the conditions of the current application.

Theoretical study of the transpore velocity control of single-stranded DNA.

The electrokinetic transport dynamics of deoxyribonucleic acid (DNA) molecules have recently attracted significant attention in various fields of research. Our group is interested in the detailed examination of the behavior of DNA when confined in micro/nanofluidic channels. In the present study, the translocation mechanism of a DNA-like polymer chain in a nanofluidic channel was investigated using Langevin dynamics simulations. A coarse-grained bead-spring model was developed to simulate the dynamics of a long polymer chain passing through a rectangular cross-section nanopore embedded in a nanochannel, under the influence of a nonuniform electric field. Varying the cross-sectional area of the nanopore was found to allow optimization of the translocation process through modification of the electric field in the flow channel, since a drastic drop in the electric potential at the nanopore was induced by changing the cross-section. Furthermore, the configuration of the polymer chain in the nanopore was observed to determine its translocation velocity. The competition between the strength of the electric field and confinement in the small pore produces various transport mechanisms and the results of this study thus represent a means of optimizing the design of nanofluidic devices for single molecule detection.

[A case of isolated CNS sarcoidosis with diffuse confluent high intensity lesions at bilateral deep white matter].

We reported a 60-year-old woman who suffered from isolated neurosarcodosis. She was presenting comprehensive dysfunction and intermittent high fever. In several months she gradually developed dysorientation, amnesia, dementia. However, no focal sign such as paralysis or sensory disturbance was demonstrated. Her blood chemistry showed normal including ACE (angiotensin converting enzyme) and lysozyme. Cerebrospinal fluid revealed elevated mononuclear cells, protein, and decreased glucose level. At first we treated with antibiotics including antiviral drugs in suspect of the infectious encephalomeningitis. But no improvement was observed. The elevation of ACE in spinal fluid made us suspect of neurosarcoidosis. So intravenous predonizoron (1,000 mg) was given, improving. Her high fever and mental disturbance improved. Second spinal fluid showed improvement. During the course her brain MRI revealed new bilateral diffuse confluent high intensity lesions at the deep white matters. Brain biopsy of deep matter at the right anterior lobe showed noncaseating granuloma. Since systemic work-up to detect sarcoidosis did not reveal lesions other than CNS, we considered this patient as having isolated CNS sarcoidosis.

Synthesis and characterization of polyester dendrimers from acetoacetate and acrylate.

New aliphatic polyester-type dendrimers were synthesized using a new AB2-type building block 3, prepared from benzyl acetoacetate and 2 equiv of tert-butyl acrylate by acetoacetic acid ester synthesis. The reiterative [deprotection by HCO2H, then EDCI/DMAP coupling] sequence using divergent growth method gave [G1]-4tBu-[G5]-64tBu dendrimers. 13C NMR relaxation time (T1) measurements on the carboxy carbons show that the extended chain conformations are predominant in CDCl3. [structure: see text]