Serial Changes of Serum Growth Factor Levels and Liver Regeneration after Partial Hepatectomy in Healthy Humans

This study aimed to investigate the associations of the serial changes of serum levels of various growth factors with liver regeneration after hepatectomy in healthy liver donors. Sixteen healthy liver donors who underwent conventional liver resection were included. Serum levels of various growth factors before hepatectomy and on postoperative day (POD) 1, 3, 5 and 7 were measured. Liver volume data calculated by multi-detector computed tomography using workstation. The ratio of remnant liver volume on POD 0 to liver volume before the operation was 51% ± 20%. The ratio of liver volume on POD 14 to liver volume on POD 0 were inversely correlated with remnant liver volume on POD 0 (r = −0.91). The ratio of liver volume on POD 14 to liver volume on POD 0 were significantly correlated with serum hepatocyte growth factor (HGF) levels on POD 1 (r = 0.54), serum leptin levels on POD 1 (r = 0.54), and serum macrophage colony-stimulating factor (M-CSF) levels on POD 5 (r = 0.76) and POD 7 (r = 0.80). These results suggest that early-phase elevation of serum levels of HGF, leptin and M-CSF may be associated with the acceleration of liver regeneration after hepatectomy in humans.     

Micromachining of electroformed nickel mold using thick photoresist microstructure for imprint technology

In order to fabricate polymer-based microstructures with feature sizes on the order of micrometers, we have been developing a microimprint technology with a fine nickel (Ni) mold instead of a conventional photolithography technique. The Ni mold was successfully fabricated by electroforming using a positive thick photoresist microstructure patterned on a silicon substrate as a replication master. The photoresist microstructure with excellent edge quality can be obtained under irradiation with single wavelength (g line) selected from a high-pressure mercury lamp. In addition, its sidewall angle in the range of 65° to 84° can be controlled precisely by varying the distance between a photomask and a photoresist surface. On the structured photoresist master, Ni was electroplated up to a thickness of about 110 μm, and then removed from the master. In this process, two-step electroplating at different current densities was carried out in order to prevent deformation of the photoresist master due to stress generated in a Ni electrodeposit. With the Ni mold, fine patterns with a width of 10 or 30 μm and a depth of 24 μm were almost completely transferred to polymetric materials (PMMA). The geometrical dimensions of the fabricated PMMA microstructures were found to be only about 10% reduction against the Ni mold.     

Successfully operated case of posterior fossa tuberculoma in childhood (author's transl)

A case of intracerebellar tuberculoma is described in which a tuberculoma was removed successfully through the administration of antituberculous agents, and a full recovery was obtained. The patient was a 3-year-old boy who had been receiving antituberculous agents for about 4 months because of acute inflammation followed by osteomyelitis of his right big toe, which was suspected to be tuberculous, and because of pulmonary tuberculosis diagnosed in a chest roentgenogram taken about 1 month after osteomyelitis was cured. While his osteomyelitis was being treated, disturbance in his gait, due to progressive spastic paraparesis, was not iced, and thereafter left cerebellar symptoms with impairment of equilibrium appeared additionally. Then, he was reffered to our clinic for further neurosurgical examination, and was admitted on November 1, 1974 after right carotid and vertebral angiography was performed via the right axillar artery, in which findings suggesting left cerebellar tumor and internal hydrocephalus were obtained. After he was admitted to our clinic, a diagnosis of tumor of the left cerebellum and internal hydrocephalus was more precisely confirmed by pneumoventriculography. Suboccipital craniectomy was then carried out and the tumor, weighing 60 gm, was completely removed from the left cerbellar hemisphere. The tumor was confirmed as tuberculoma not only by histological findings but also by the vertification of tuberculous bacilli in it. Though, moderate fever lasted for about 2 weeks postoperatively, no obvious meningitic signs or new neurological deficits were noted. The patient showed marked improvement especially in his gait disturbance, and was discharged ambulatory 40 days after the operation, and has since been asymptomatic except for slight ataxic gait. The antituberculous agents have been continuously administered postoperatively.     

Vapor pressure measurement of zn-fe intermetallic compounds

Most galvanized steel sheets are produced by a continuous galvanizing line. Some of the operations include a subsequent heat treatment termed galvannealing to form intermetallic phases on the surface. These galvanizing reactions are essentially regarded as “making intermetallic compounds” in the Fe-Zn-M system. This makes it important to know the thermodynamic properties of the system for any detailed discussion on the formation of these intermetallics; however, experimental difficulties have limited the number of studies. In the present study, two-phase regions of these intermetallics were examined, and the following two-phase mixtures were prepared at 723 K: Fe(α)+Γ, Γ,+Γ₁, Γ₁+δ ₁+ζ. The double cell-type Knudsen mass spectrometer system was developed and employed, in which two sets of Knudsen cells were installed in the same cell holder. The reference material (pure zinc) was placed in one cell and a sample in the other. The cell holder was rotated to the reference and sample positions to measure zinc vapor effused from two cells by a quadrupole mass spectrometer. Material containing the two phases was placed in a Knudsen-type effusion cell and the mass spectrum studied to evaluate the vapor pressure of zinc. The activity of zinc in the intermetallics was determined by comparing the intensity from pure zinc and that from intermetallics. Results for Fe(α)+Γ were 0.46 to 0.48; for Γ+Γ₁, 0.51 to 0.54; for Γ₁+δ ₁, 0.62 to 0.66; and for δ ₁+ζ, 0.80 to 0.83, between the temperatures of 623 and 698 K.     

Formation and Microstructure of Carbon-Containing Oxide Scales by Oxidation of Single Crystals of Zirconium Carbide

The isothermal oxidation of ZrC single crystals with (100) orientation was carried out at temperatures of 500°, 550°, and 600°C at an oxygen pressure of 2.6 kPa for times up to 240 h. A polished cross section of the oxidized crystal was observed by backscattered electron imaging in a scanning electron microscope. Quantitative chemical analysis for Zr, O, and C and their elemental profiles by the linescan method in the ZrC and oxide scale were performed by wavelength dispersive X-ray microanalysis. A thin foil of a crystal oxidized at 600°C was examined by transmission electron microscopy. It was found that the oxide scale was divided into two regions, zones 1 and 2, which contained 14 to 23 and 7 to 10 at. % carbon, respectively. Zone 1 exhibited an almost compact, pore-free matrix of c -ZrO₂. In zone 2, some growth and aggregation of the c -ZrO₂ occurred, producing 5- to 20-nm-sized particles between which carbon should have been present. The thickness of zone 1 increased parabolically up to 240 h at 500°C and probably in an early period at 550° and 600°C, reaching a constant (about 2 (μm), in contrast to the thickness of zone 2, which increased linearly with time.     

Sliding Mode Control For Invertible Systems Based On A Direct Design Of Interactors

The sliding mode tracking control is reviewed and extended so that it can be applicable to general invertible systems. The main advantage of this paper is a direct and numerical stable design of interactors for general invertible systems which is performed by calculating infinite eigenbasis of system matrices.     

Inhibitory guanine-nucleotide-binding-regulatory protein alpha subunits in medaka (Oryzias latipes) oocytes--cDNA cloning and decreased expression of proteins during oocyte maturation

We have previously shown that pertussis-toxin-sensitive inhibitory guanine-nucleotide-binding-regulatory proteins (G proteins) are involved in the signal transduction of steroidal maturation-inducing hormone (MIH) of rainbow trout (Oncorhynchus mykiss) oocytes, 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-DP) [Yoshikuni, M. & Nagahama, Y. (1994) Dev. Biol. 166, 615-622]. In this study, we obtained five different cDNA fragments of G protein alpha subunits from medaka (Oryzias latipes) intact ovarian follicles (three subtypes of G(i alpha), G(i alpha a), G(i alpha b) and G(i alpha c); two subtypes of G(s alpha), G(s alpha d), and G(s alpha e)). Using a newly developed extraction method for medaka oocyte RNA, we demonstrated that oocytes expressed both G(i alpha a) and G(i alpha c), but not G(i alpha b). Full-length cDNA clones for G(i alpha a) and G(i alpha c) were then isolated from a medaka ovarian follicle cDNA library. The predicted amino acid sequences of G(i alpha a) and G(i alpha c) exhibited significant similarity with G(i alpha1) and G(i alpha2) of other species, respectively. Both G(i alpha a) and G(i alpha c) possessed a specific Cys residue in the C-terminal region that was the site for ADP-ribosylation by pertussis toxin. G(o alpha), another G protein that is ADP-ribosylated by pertussis toxin, was not detected in oocytes, although it was expressed in brain tissue. Western blot analyses using a specific antibody against G(i alpha1) and G(i alpha2) subunit proteins revealed that in both medaka and rainbow trout G(i alpha) subunit protein (40 kDa) contents were abundant in plasma membranes of postvitellogenic immature oocytes, decreased in mature oocytes, and were absent in ovulated eggs. Furthermore, specific 17alpha,20beta-DP binding to plasma membranes was higher in postvitellogenic immature oocytes than in ovulated eggs. Taken together, these results suggest that G(i alpha a) and/or G(i alpha c) may be involved in the transduction of the signal from 17alpha,20beta-DP receptors during oocyte maturation of fish oocytes.     

Association study of a functional catechol-O-methyltransferase gene polymorphism in Japanese schizophrenics

Catechol-O-methyltransferase (COMT) is an enzyme which inactivates catecholamine neurotransmitters by methylation, and is considered a candidate for involvement in schizophrenia. A functional COMT gene polymorphism influencing the enzyme activities, the high activity (val-108) and the low activity allele (met-108), was recently confirmed. We investigated a genetic association between schizophrenia and the COMT gene polymorphism in 150 Japanese schizophrenics and controls. We detected the low activity met-108 allele more frequently in schizophrenics than in the controls, and found that subjects sharing the met-108 allele (val/met and met/met) are significantly more common in the patients than in the controls. The results suggest that the low activity met-108 allele may be involved in susceptibility for schizophrenia.     

Filter with variable transmission characteristics for determination of three-dimensional roughness

In this study, we propose a low-pass filter whose transmission characteristics are determined to be more than 99.99% identical to the designed transmission characteristics at wavelengths greater than the cut-off wavelength. This low-pass filter is realized using a frequency-domain method which uses down-sampling, a frequency filter, and a cubic B-spline. When the frequency characteristics of a Gaussian filter (GF) were used as the designed transmission characteristics, this low-pass filter perfectly replaced the GF. In addition, no end effects and directional characteristics developed, and high-speed computation was possible. Furthermore, we can easily realize a low-pass filter having transmission characteristics that rise sharply at a right angle like a step edge.