Enzymatic activity and expression of cytochrome P450 LA omega within intrasplenically transplanted fetal hepatocytes in spontaneously hypertensive rats

We examined the expression and enzymatic activity of cytochrome P450 LA omega within transplanted hepatocytes. Fetal hepatocytes were harvested at day 20 of gestation from spontaneously hypertensive rats (SHRs) and transplanted into recipient adult SHR spleens. Microscopic examination of the recipient spleens at 4 and 10 wk after transplantation revealed masses of hepatocytes with cord-like structures in the red pulp. Immunochemical studies detected cytochrome (cyto) P450 LA omega in the fetal hepatocytes before transplantation without prior induction. Although the cyto P450 LA omega was not detected by the second week after transplantation, by the 6th and 10th wk after transplantation, it was. Cyto P450-arachidonic acid omega/omega-1 hydroxylase activity (formation of 20- and 19-hydroxyeicosatetraenoic acid) was detected at 10 wk after transplantation, but not 2 or 6 wk after transplantation. These results demonstrated that fetal hepatocytes can be transplanted successfully into recipient spleens and then grow in the spleens, as in the case of the adult hepatocyte response.     

In vitro antioxidant activity of Vietnamese ginseng saponin and its components

To elucidate the antioxidant action of Vietnamese ginseng saponin against free radial-mediated cellular damage, we examined the effect of Vietnamese ginseng saponin on lipid peroxidation in the mouse brain, liver, and liver microsomes by using two in vitro free radical generating systems (iron ferrous+ascorbic acid and iron ferrous+hydrogen peroxide). Free radical-mediated lipid peroxidation was determined by measuring the endogenous and stimulated accumulation of thiobarbituric acid reactive substance (TBA-RS). Vietnamese ginseng saponin (0.05-0.5 mg/ml), as well as vitamin E, significantly inhibited the formation of TBA-RS in tissue homogenates. Panax ginseng saponin, at the same concentration range as Vietnamese ginseng saponin, also had inhibitory action on free radical-mediated lipid peroxidation. However, majonoside-R2, ginsenoside-Rg1 and ginsenoside-Rb1, the main saponin components of Vietnamese ginseng saponin fraction, had no effect on lipid peroxidation. These results suggest that Vietnamese ginseng exerts a protective action against free radical-induced tissue injury and that this effect is attributable to minor components rather than the main saponin components tested.     

A real-time motion estimation and compensation LSI with wide searchrange for MPEG2 video encoding

This paper presents a motion estimation and compensation large scale integration (LSI) for the MPEG2 standard. An embedded RISC processor and special hardware modules enable the LSI to achieve a sufficient ability to perform real-time operation and provide the availability to realize many kinds of block matching algorithms. Using a three-step hierarchical telescopic search algorithm, a single chip accomplishes real-time motion estimation with search ranges of ±32.5×±32.5 pixels for motion vectors. The chip was fabricated using 0.5-μm CMOS technology and has an area of 16.5×16.5 mm² and 2.0 M transistors     

Survival for 145 days with a total artificial heart

A calf into which a biolized, total artificial heart (TAH) had been implanted survived for 145 days. All measured physiological parameters except central venous pressure (CVP) were back to normal one month after implantation, and thereafter the animal's physiological development was similar to that of a normal calf. The intimal weight, which was 96 kilograms at implantation, reached 190 kilogram at the end of experiment, with a daily gain rate of 0.9 kilogram per day. After the nineteenth postoperative week, signs of congestive heart failure appeared, such as high venous pressure, ascites, and enlarged liver although the calf outwardly appeared well. On postoperative day 146, the animal started foaming at the mouth, and a convulsion occurred; then, the experiment was terminated after 3,494 hours of pumping. At autopsy, there were acute bilateral bronchopneumonia involving mostly both upper lobes, pulmonary edema, slight chronic pneumonitis, and hepatomegaly. There were no serious thrombotic deposits inside the cardiac prosthesis.     

Optical phase-locked loop with fibre lasers for low phase noise millimetre-wave signal generation

An optical phase-locked loop (OPLL) using two continuous-wave commercial fibre lasers was implemented by means of pump power modulation. Although the 3 dB bandwidth of the frequency modulation transfer function of a fibre laser was measured to be approximately 6 kHz, the control bandwidth of the loop was extended by a factor of 10 using electronic phase-lead compensation. The operation of our OPLL was stable with a residual RMS phase fluctuation of 57 mrad. By using this technique, the photonic generation of millimetre-wave signals up to 64 GHz was successfully demonstrated.     

The Fluorescence and Electroluminescence Properties of the Carbazole–Phenylazomethine Double Layer-Type Dendrimer

The fluorescence properties of double layer-type dendrimers with carbazole as the outer layer and phenylazomethine as the inner layer of the dendron with a zinc porphyrin core were studied. Based on the fluorescence quantum yield (solution), the effect of the bulky dendron to inhibit the interaction of the chromophores was confirmed. Additionally, the efficient light-harvesting property of the double layer-type dendron was revealed by the fluorescence measurement at several excitation wavelengths. These dendrimers were used as an emitting-layer in an OLED device. The electroluminescence of the core porphyrin was observed and it was shown that the double layer-type dendrimer with a luminescent core has the potential to be a hole-transporting/emitting material.     

Formation of hexachlorobenzene from dusts of an electric arc furnace used in steelmaking: effect of temperature and dust composition

A certain amount of hexachlorobenzene (HCB), designated a persistent organic pollutant (POP) by the Stockholm Convention, is emitted from an electric arc furnace (EAF) used in the steelmaking process. To understand the formation and decomposition behaviors of HCB during the treatment of waste gases from an EAF, characterization of dust samples from EAFs in different plants was conducted. Dusts 1 and 2 were bag filter dusts collected from a common steel plant and a special steel plant, respectively. The initial concentrations of HCB in dusts 1 and 2 were 62 and < 0.1 ng/g of dust, respectively. Then a series of heating experiments was carried out with these dust samples under various conditions. The formation of HCB from both dusts was not significant under an Ar atmosphere, although the amount of formation from dust 1 slightly increased with an increase in the holding temperature. Under an Ar--20% O2 atmosphere, however, a remarkable amount of HCB formed from dust 1 above 573 K. A certain amount of HCB was also formed from dust 2, even though the initial concentration of HCB was very low. Moreover, the coexistence of metallic compounds such as CuCl2 had a significant accelerating effect on the formation of HCB.     

Investigation on the Interactions between Self-Assembled β-Sheet Peptide Nanofibers and Model Cell Membranes

Self-assembled peptide nanofibers (NFs) obtained from β-sheet peptides conjugated with drugs, including antigenic peptides, have recently attracted significant attention. However, extensive studies on the interactions of β-sheet peptide NFs with model cell membranes have not been reported. In this study, we investigated the interactions between three types of NFs, composed of PEG-peptide conjugates with different ethylene glycol (EG) lengths (6-, 12- and 24-mer), and dipalmitoylphosphatidylcholine (DPPC) Langmuir membranes. When increasing the EG chain length, those interactions significantly decreased considering measurements in the presence of the NFs of: (i) changes in surface pressure of the DPPC Langmuir monolayers and (ii) surface pressure–area (π–A) compression isotherms of DPPC. Because the observed trend was similar to the EG length dependency with regard to cellular association and cytotoxicity of the NFs that was reported previously, the interaction of NFs with phospholipid membranes represented a crucial factor to determine the cellular association and toxicity of the NFs. In contrast to NFs, no changes were observed with varying EG chain length on the interaction of the building block peptide with the DPPC membrane. The results obtained herein can provide a design guideline on the formulation of β-sheet peptide NFs, which may broaden its potential.     

Vaporization behavior of lead from the FeO-CaO-SiO_2-Al_2O_3 slag system

Vaporization behavior (1163-1463 K) of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaCl2 was examined.A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapor species from the sample of the FeO-CaO-SiO2-AI203 system+PbO+CaCl2 were metallic Pb,PbC1,PbCl2,and FeC12,at the experimental temperature range.The experimental results show that the mole ratio of vaporized CI in lead chlorides to vaporized Pb,simply expressed as CI/Pb,decreases with increasing temperature.The larger CUPb means a larger ratio of gaseous PbCl2,since metallic Pb and PbCI vapors are formed in a similar reduction atmosphere.The evaporation is initially rapid and becomes steady after holding for 10 rain.Gaseous PbCI2 is mainly formed during the heating period,and at the holding stage,it reacts with FeO to produce gaseous FeCI2.With regard to slag composition,FeO content and basicity significantly affect the evaporation of lead.High FeO content and high basicity promotes the formation of metallic Pb and PbCI,whereas,it prohibits PbCl2 evaporation.