Development of a robotic endoscope that locomotes in the colon with flexible helical fins

The purpose of this study was to develop a robotic endoscope that is low invasive, easy to operate and capable of locomotion from the rectum to the appendix in the human body. We believe that it would contribute to relieving pain in patients. We therefore developed a robotic endoscope that consists of a front and rear body with clockwise and anticlockwise helical fins, respectively. The front and rear bodies are connected via a DC motor. This robot moves forward in the colon by rotating the front body in the clockwise direction and the rear body in the anticlockwise direction. In addition, the radius of each helical fin can be changed by blowing air into a balloon implemented under each fin using an air compressor. Before experiments with animals, we performed experiments to evaluate the mechanical performance and safety of the robot. We confirmed that the maximum radius of the fins was less than the maximum radius of the colon by blowing air continuously into the balloons. We then confirmed that the robot can locomote in the colon without invasion of scratch and make short hole by performing an in-vivo experiment in live swine.

Reinvestigation on the buildup mechanism of alternate multilayers consisting of poly(L-glutamic acid) and poly(L-, D-, and DL-lysines)

The buildup mechanism of polypeptide multilayers prepared by the layer-by-layer deposition of a polyanion (poly(L-glutamic acid) (PGA)) and polycations (poly(L-lysine) (PLL), poly(D-lysine) (PDL), and copoly(DL-lysine)(PDLL)) was reinvestigated by using in situ ATR-IR spectroscopy. A difference spectral technique applied to analyze the spectra indicated that the deposition of both the PGA and PLL (PDL) layers accompanies the formation of secondary structures consisting mainly of the antiparallel pleated sheet (the beta-sheet) structure, and that the formation of the beta-sheet structure cannot always be explained in terms of polyanion/polycation complex formation or charge compensation between the polyanion and polycations, although it has been considered as a major process in the multilayer buildup process. Instead, the present paper proposes the following mechanism. During the deposition of the polyelectrolyte, a small amount of the beta-sheet structures are produced at the interface as a result of charge compensation between a polyelectrolyte and an oppositely charged polyelectrolyte in the multilayer. The beta-sheets act as nuclei from which further propagation of the structure takes place at the solution/multilayer interfaces. The driving force of the buildup process in the new mechanism is a kinetically favorable insolubilization of each polyelectrolyte in solution at the interfaces.

Magnetic behavior in an ordered Co nanorod array

The magnetization reversal process of an ordered Co nanorod array is shown using the images obtained from successive in-field magnetic force microscope (MFM) measurements. The magnetization reversal model is discussed according to local and whole magnetization reversal properties measured by the polar magneto-optical Kerr effect (PMOKE) and an alternating gradient magnetometer (AGM), respectively. Additionally, the dipolar field was probed using in-field MFM measurements. By removing the effect of the dipolar field, an intrinsic switching field distribution (SFD) is shown in a map with a hexagonal array. A detailed study of the dipolar field in ordered nanorod arrays with various diameters and pitches was carried out by numerical calculations.

Stereospecific oxidation of the (S)-enantiomer of RS-8359, a selective and reversible monoamine oxidase A (MAO-A) inhibitor, by aldehyde oxidase

In a previous paper by the authors on RS-8359, a new selective and reversible monoamine oxidase A (MAO-A) inhibitor, it was reported that the (S)-enantiomer of RS-8359 is rapidly eliminated from rats, monkeys and humans as a result of the formation of a 2-oxidative metabolite. The present study investigates the properties of the enzyme responsible for the 2-oxidation of RS-8359. Subcellular localization, cofactor requirement and the inhibitory effects of typical compounds were studied using rat liver preparations. In addition, the enzyme was purified from rat liver cytosol for further characterization. The enzyme activity was localized in the cytosolic fraction without the need for any cofactor and was extensively inhibited by menadione, chlorpromazine and quinacrine. The purified enzyme was also a homodimer with a monomeric molecular weight of 140 kDa and it had an A280/A450 ratio of 5.1 in the absorption spectrum. The results suggest that the enzyme responsible for the biotransformation of RS-8359 to give the 2-keto derivative is aldehyde oxidase (EC 1.2.3.1). The reaction of aldehyde oxidase is highly stereoselective for the (S)-configuration of RS-8359 and the (9R)-configuration of cinchona alkaloids.

Lack of dimer formation ability in rat strains with low aldehyde oxidase activity

Aldehyde oxidase (AO) is a homodimer with a molecular weight of 300 kDa. To clarify the reasons for the well-known differences in rat strains, we set out to study the relationship between AO activity and the expression levels of its dimer. AO-catalyzed 2-oxidation activity of (S)-RS-8359 was measured in liver cytosols from ten rat strains. The expression levels of AO dimeric protein were evaluated by the native-PAGE/Western blot. Rat strains with low AO activity showed only a monomer, whereas strains with high activity overwhelmingly exhibited a dimer. Exceptionally, one strain in the high AO activity group displayed complex mixed expression patterns of low and high AO activity groups. However, there was a good relationship between AO activity and the expression levels of a dimer, but not of a monomer. The results suggest that rat strains with low AO activity lack the ability to produce a dimer necessary for catalytic activity, and AO differences in rat strains should be discussed in terms of the expression levels of the dimer itself.

Transition between internal transport barriers with different temperature-profile curvatures in JT-60U Tokamak plasmas

A spontaneous transition phenomena between two states of a plasma with an internal transport barrier (ITB) is observed in the steady-state phase of the magnetic shear in the negative magnetic shear plasma in the JT-60U tokamak. These two ITB states are characterized by different profiles of the second radial derivative of the ion temperature inside the ITB region (one has a weak concave shape and the other has a strong convex shape) and by different degrees of sharpness of the interfaces between the L mode and the ITB region, which is determined by the turbulence penetration into the ITB region.

All-polarization-maintaining Er-doped ultrashort-pulse fiber laser using carbon nanotube saturable absorber

We present an all-polarization-maintaining Er-doped ultrashort-pulse fiber laser using a single-wall carbon nanotube polyimide nanocomposite saturable absorber. The maximum average power for single-pulse operation is 4.8 mW, and the repetition frequency is 41.3 MHz. Self-start and stable mode-locking operation is achieved. The RF amplitude noise is also examined and it is confirmed that the noise figure is as low as that of a solid-state laser. Using a polarization-maintaining anomalous dispersive fiber, a 314 fs output pulse is compressed to 107 fs via higher-order soliton compression. The peak power of the compressed pulse is up to 1.1 kW.

Insulin-like growth factor I regulates apoptosis in condylar cartilage

Endogenous insulin-like growth factor-I (IGF-I) is known to affect the growth and development of condylar cartilage. However, the critical effect of IGF-I on cell survival is still unknown. We hypothesized that endogenous IGF-I could regulate the survival of cells of the mandibular condylar cartilage. Mandibular condyles dissected from 12-day-old rats were cultured for 1, 3, and 5 days in medium containing antisense oligodeoxynucleotide (AS-ODN) for IGF-I. Real-time RT-PCR analysis showed that the levels of IGF-I and IGF binding protein (IGFBP)3 mRNAs in the AS-ODN group were significantly decreased. After 3 days' culture, the number of necrotic cells was observed in the undifferentiated mesenchymal cell layer. These cells were TUNEL-positive and confirmed to be apoptotic by electron microscopic observation. Immunoblotting revealed that expression of cleaved caspase3 was increased with AS-ODN. These results may suggest that the cells in the undifferentiated mesenchymal cell layer of the mandibular condyle require IGF-I for survival.

Effect of pectin enhancement on plasma quercetin and fecal flora in rutin-supplemented mice

Few reports have considered the effects of dietary fiber on plasma quercetin and the intestinal flora. We investigated the effects of pectin on the plasma and fecal flora of mice fed a diet supplemented with the quercetin glycoside rutin. Male mice were randomly divided into 2 groups, which were fed a pectin-rutin (PR) or cellulose-rutin (CR) diet for 14 d. Plasma quercetin and isorhamnetin metabolites were measured by high-performance liquid chromatography. Feces were immediately processed with bacteriological procedures. The fecal flora was investigated. Plasma quercetin and isorhamnetin concentrations were significantly higher in the PR diet group, as was the plasma isorhamnetin/quercetin ratio. The composition of the intestinal flora differed between the 2 dietary groups. The total number of fecal bacteria was significantly larger in the PR group, in which most types of bacteria were more abundant, with the exceptions of bifidobacteria, fusiform-shaped bacteria, and staphylococci. The lower gut seemed to be the major absorption site for rutin. Pectin might thus enhance the bioavailability of quercetin from rutin by altering the metabolic activity of the intestinal flora and/or gut physiological function.

Bifurcation phenomena of a magnetic island at a rational surface in a magnetic-shear control experiment

Three states of a magnetic island are observed when the magnetic shear at the rational surface is modified using inductive current associated with the neutral beam current drive in the Large Helical Device. One state is the healed magnetic island with a zero island width. The second state is the saturated magnetic island with partial flattening of the T(e) profile. The third state is characterized by the global flattening of the T(e) profile in the core region. As the plasma assumes each of the three states consecutively through a bifurcation process a clear hysteresis in the relation between the size of the magnetic island and the magnetic shear is observed.

Heredity mode of genetic polymorphism in aldehyde oxidase activity in Donryu strain rats

Donryu strain rats show genetic polymorphisms in the aldehyde oxidase gene, resulting in the phenotypic expression of ultrarapid metabolizers with homozygous nucleotide sequences (337G, 2604C), extensive metabolizers with heterozygous nucleotide sequences (377G/A, 2604C/T), and poor metabolizers with homozygous nucleotide sequences (377A, 2604T). In the mating experiments the ratio of the number of ultrarapid metabolizers, extensive metabolizers, and poor metabolizers rats in the F1 generation from the heterozygous F0 extensive metabolizers male and female rats was roughly 0.6 : 1.5 : 1, and the ratio converged to approximately 1 : 2 : 1 in the F2 generation from the heterozygous F1 extensive metabolizers male and female rats. On the contrary, all the F2 generation from homozygous F1 ultrarapid metabolizers male and female rats or from homozygous F1 poor metabolizers male and female rats had the ultrarapid metabolizers or the poor metabolizers genotypes and phenotypes. The genotypes completely agreed with the phenotypes in all individuals of F0, F1, and F2 generations. The results indicate that the genetic polymorphism of aldehyde oxidase in Donryu strain rats obeys Mendelian heredity. The reason for a low ratio of the ultrarapid metabolizers rats in the commercially available Donryu strain rats - not more than several per cent - compared with the ratio expected from the Mendelian rule is unknown.

Expression of BAFF and BAFF-R in the synovial tissue of patients with rheumatoid arthritis

OBJECTIVE

The elevated expression of B-cell-activating factor belonging to the TNF family (BAFF) is associated with systemic autoimmune disease, including rheumatoid arthritis (RA). The present study was undertaken to determine the distribution of BAFF and its receptor BAFF-R in the cells residing in the rheumatoid synovium.

METHODS

The expression of BAFF and BAFF-R in synovial tissues obtained from 12 RA patients was examined by immunohistochemistry and flow cytometry. The mRNA expression of these molecules was determined by reverse transcriptase polymerase chain reaction (RT-PCR). Soluble BAFF levels were measured with an enzyme-linked immunosorbent assay (ELISA). Fibroblast-like synoviocytes (FLS) purified from the RA (RA-FLS) were co-cultured with peripheral B cells. The degree of apoptosis in the B cells was measured to assess the effects on the viability of the B cells.

RESULTS

The RA synovium showed focal or diffuse infiltration of mononuclear cells (MNCs), and one specimen showed germinal centre (GC)-like structures. Synovial sublining cells, but not lining cells, expressed BAFF. These sublining cells were negative for BAFF-R. BAFF and BAFF-R were expressed in B and T cells extracted from the RA synovium. Notably, RA-FLS spontaneously expressed cytoplasmic BAFF after 4-6 passages; however, they did not express BAFF or BAFF-R on their cell surface. RA-FLS could support the survival of B cells by preventing their apoptosis, but its effect on B cells might not be BAFF dependent.

CONCLUSIONS

BAFF and BAFF-R are widely expressed in the RA synovium. The cells residing in the RA synovium might affect each other through BAFF.

Fine positioning of a poloidal probe array

Multipoint detection is an essential requirement for investigating plasma turbulence which is a highly nonlinear phenomenon in space and time. We have fabricated an array of 64-channel poloidal probes surrounding the linear cylindrical plasma named LMD-U in order to study turbulence properties, particularly the nonlinear mode couplings, in the domain of poloidal wave number and frequency. However, misalignments of probe tips produce spurious modes, which do not exist in the real plasma, to distort the precise wave number measurements. The paper presents the description of the 64-channel poloidal probe array with means to adjust the probe positions, with discussion on the effects of the misalignments on the wave number measurements.

Identification of Lck-derived peptides applicable to anti-cancer vaccine for patients with human leukocyte antigen-A3 supertype alleles

The identification of peptide vaccine candidates to date has been focused on human leukocyte antigen (HLA)-A2 and -A24 alleles. In this study, we attempted to identify cytotoxic T lymphocyte (CTL)-directed Lck-derived peptides applicable to HLA-A11⁺, -A31⁺, or -A33⁺ cancer patients, because these HLA-A alleles share binding motifs, designated HLA-A3 supertype alleles, and because the Lck is preferentially expressed in metastatic cancer. Twenty-one Lck-derived peptides were prepared based on the binding motif to the HLA-A3 supertype alleles. They were first screened for their recognisability by immunoglobulin G (IgG) in the plasma of prostate cancer patients, and the selected candidates were subsequently tested for their potential to induce peptide-specific CTLs from peripheral blood mononuclear cells of HLA-A3 supertype⁺ cancer patients. As a result, four Lck peptides were frequently recognised by IgGs, and three of them – Lck₉₀₋₉₉, Lck_449−458, and Lck_450−458 – efficiently induced peptide-specific and cancer-reactive CTLs. Their cytotoxicity towards cancer cells was mainly ascribed to HLA class I-restricted and peptide-specific CD8⁺ T cells. These results indicate that these three Lck peptides are applicable to HLA-A3 supertype⁺ cancer patients, especially those with metastasis. This information could facilitate the development of peptide-based anti-cancer vaccine for patients with alleles other than HLA-A2 and -A24.