山口 匡

The cirrhotic liver has many fibrotic tissue structures known as nodule structures. Understanding this characteristic in diseased tissue is important for quantitative diagnosis. In this paper, we present a technique to extract quantitative three-dimensional information from a cirrhotic liver. Consecutive two-dimensional images acquired by fan like scanning were processed using constant false alarm rate (CFAR). The 2D professed images are accumulated to obtain 3D information. The nodular structure is clear in the constructed images.

The prevalence of chlamydia antibodies in Japan was investigated in 215 cat sera, consisting of 88 sera of stray cats and 127 sera of pet cats, and 2,184 human sera, taken from 2,003 general persons and 181 small animal clinic veterinarians, by microimmunofluorescence (MIF) testing with Chlamydia psittaci Fe/Pn1 of feline origin and Prk/6BC of avian origin as antigens, The prevalence rates of anti-Fe/Pn1 antibodies were 45.5% in stray cats, 17.3% in pet cats, 1.7% in general persons and 8.8% in small animal clinic veterinarians, The prevalence rates of anti-Prk/6BC antibodies were 51.1% in stray cats, 15.0% in pet cats, 3.1% in general persons and 5.0% in small animal clinic veterinarians. These results suggested that feline chlamydia infection is widely spread in cats especially in stray cats in Japan, and suggested that feline chlamydiosis could be transmitted to people who are in close contact with infected cats.

HIV-1 enters cells through interacting with cell surface molecules such as CD4 and chemokine receptors, We generated recombinant soluble gp120s derived from T-cell line-tropic (T-tropic) and macrophage-tropic (M-tropic) HIV-1 strains using a baculovirus expression system and investigated the association of CD4-gp120 complex with the chemokine receptor and/or other surface molecule(s). For monitoring the co-down-modulations of the CD4-gp120 complex, a cytoplasmic domain deletion mutant (tailless CD4), which is not capable of undergoing down-modulation by itself in response to phorbol ester PMA, was used. Our studies revealed both cell-type and HIV-1 strain-specific differences. We found that T-tropic gp120s were capable of priming co-down-modulation with tailless CD4 by interacting with CXCR4, whereas M-tropic SF162 gp120 could not after PMA treatment even in the presence of CCR5, Among the T-tropic HIV-1 envelopes, IIIB gp120 was the most potent. Furthermore, the ability of gp120 to prime the PMA induced co-down-modulation of tailless CD4 appeared to be dependent on the concentration of the principal coreceptor CXCR4. Nevertheless, the observation that IIIB gp120 strongly primed tailless CD4 co-down-modulation on human osteosarcoma HOS cells that express undetectable levels of surface CXCR4 raised the possibility that membrane component(s) other than those recently identified can be involved in down-modulation of the CD4/gp120 complexes.

The effect of chelating agents on the electron beam exposure characteristics as well as environmental stability of the spin-coatable Al2O3 gel films is discussed. It was found that the Al2O3 gel films prepared by reacting aluminium tri-sec-butoxide, Al(OBu5)(3), with acetylacetone (AcAc), AcAc/Al2O3, gave better environmental stability and patterning characteristic than the gel films prepared by reacting the Al(OBu5)(3) with ethylacetoacetate (EAcAc), EAcAc/Al2O3. The latter suffered from a faster moisture attack in the laboratory atmosphere. Both EAcAc/Al2O3 and AcAc/Al2O3 films are similar to 10(6) times more electron beam sensitive than sputtered AlOx films, thus bringing the formers' sensitivity very close to some of the organic electron beam resists. It was seen that the baking temperature up to 70 degreesC has almost no effect on either the sensitivity or the contrast in both the films; but it has a significant effect on the developing characteristics. Electron beam nanolithography gave 20 nm linewidth with a rectangular cross-section in both EAcAc/Al2O3 and AcAc/Al2O3 films. It was observed that the etching characteristics of Al2O3 films in the electron cyclotron resonance (ECR) plasma are dependent upon the final baking temperature of the developed pattern. Preliminary plasma etching studies show that 15 nm lines on polysilicon can be etched.

We propose a cross-linking technique as a new approach to reducing the line-edge roughness (LER) of resist patterns. In addition, we also develop a cross-linked positive-tone resist called the suppressed aggregate extraction development (SAGEX) resist, based on this technique. Our key approach to reducing the LER is the suppression of the aggregate extraction development, which causes LER We demonstrate successful suppression of the aggregate extraction development by cross-linking polymers in the surrounding regions and by reducing the difference between dissolution rates inside and outside the aggregates, and clarify that the LER of the resist patterns in the SAGEX resist is reduced.

We used an atomic force microscope (AFM) to study the surface morphology of butterfly-like crystals of BaTiO3, Observations were made while varying the temperature from room temperature to 150 degrees C and the annihilation process of the surface structure due to 90 degrees domain boundaries was detected. The relationship between the surface gradient change at the domain boundaries and the tetragonal distortion was discussed.

The human liver is composed of small hexagonal structures known as the liver lobules. In this paper, we propose a modeling technique for the change of the scatterer distribution on liver tissue considering the liver lobule structure to obtain cirrhotic liver images of the continuous stage. We calculate the squared difference between the Rayleigh distribution and the probability density of the echo amplitude of each cirrhosis image. The difference increases with the progression of cirrhosis, These results agree well with the results obtained from clinical liver cirrhosis images. It is found that the proposed modeling technique is valid for analyzing the relationship between the change of characteristics of biological tissue and change of B-modo image on the progression of liver cirrhosis.

A highly conserved 40-nucleotide sequence was identified. Two completely conserved sequences, TAGATT and TAAACT, separated by 17 nucleotides resemble the consensus sequence recognized by the Escherichia coli major sigma factor and sequence found in other chlamydial promoters. In addition, the adenine-rich sequence present in many chlamydial promoters was also conserved upstream of the putative -35 element. These findings suggest that the conserved sequence may play a role in the regulatory function at the transcriptional level, Multiple ATG codons were found at the 5'-terminal region of the chlamydial sigA ORFs except for Chlamydia pneumoniae, although the putative Shine-Dargarno sequence was absent.

Vpr, one of the accessory molecules of HIV-1, has been demonstrated to arrest the cell cycle at the G(2) phase. This Vpr-mediated cell cycle arrest is implicated to have an important role in the viral life cycle. In the present study, we quantitate the extent of Vpr-mediated cell cycle arrest with the use of a bicistronic vector consisting of a vpr gene and a green fluorescence protein sequence. Using this system, we examined the effect of several Vprs on cell cycle progression and growth of cells from different species quantitatively, We found that Vpr from the T-cell line-adapted HIV-1(SF2) strain (Vpr2) could not significantly induce G(2) arrest in HeLa cells but was able to induce it in 293T cells, However, strong inhibition of cell proliferation in HeLa cells as well as in 293T cells was observed by Vpr2, This ability of Vpr2 to inhibit cell proliferation without G(2) arrest was also observed when expressed in monkey cell line. Analyses of chimeric Vprs revealed that this species-non-specific growth inhibitory activity of Vpr was not mediated solely by the C-terminal region of Vpr, These results indicated that the growth inhibitory activity of Vpr is independent of its G(2) arresting activity. In addition, the species-non-specific nature of this activity suggests that Vpr has a novel mechanism to retard cell proliferation by influencing basic cellular functions.

The Coxiella burnetii sucB gene encoding the dihydrolipoamide succinyltransferase (E2o) enzyme was cloned by immunological screening of a lambda EMBL3 genomic library prepared from strain Nine Mile DNA and sequenced. The homology of the cloned gene product to the counterpart in Escherichia coli was 54.3 %, but the homology of the N-terminal region was only 42 %. The gene was expressed in E. coli as an independent unit from its own promoter, producing an immunoreactive protein of about 50 kDa on SDS-PAGE which reacted with antisera from laboratory animals and sera from human patients with acute Q fever. The study results suggest that the C, burnetii E2o enzyme may serve as a potential target antigen for diagnostic assays for Q fever.

我々はこれまでに, 硬変肝画像中の散乱体分布情報に着目し, 病変の進行に対応した定量的情報を抽出することを試みてきた。本報告では正常及び硬変肝画像に対して, 異なる2つの評価法を用いて散乱体分布特性を解析し, 病変進行に伴う肝組織構造の変化と画像変化との関係について検討した。また, 画像全体から病変部位の情報を抽出し, その特性についての解析を行った。その結果, 病変の進行した画像では病変組織の散乱体分布に基づく画像情報が存在し, ランダムに分布している散乱体による正常肝画像から段階的に変化していくことが分かった。

Thermal stress and strain were measured during heating from 30 degrees C to 100 degrees C for drawn polyethylene films of various draw temperatures and ratios. Behavior of thermal strain was classified into three types, and discussed in terms of structural change in polymer chains during the drawing process. The Arrhenius plot was constructed for the temperature dependence of thermal strain, and an inflection point was observed in the plot over the temperature range studied. Temperature dependence of thermal stress showed the maximum value, which increased with draw ratio. An empirical equation for the behavior of thermal stress is derived using Boltzmann's superposition principle. Good agreement was found between calculated and measured values of thermal stress.

A large optical band gap chromium aluminum oxide (Cr1-xAlx)(2)O-3 for deep-ultraviolet photomask applications has been studied using DV-X alpha cluster method and RF sputtering. Theoretical analyses indicate that the electronic structure and energy gap depend not only on the substituted elements but also un the structural relaxation after substitution. The energy gap (E-gu) between the highest occupied molecular orbital (HOMO) of O2p and the lowest unoccupied molecular orbital (LUMO) of Cr3d increases almost linearly from 4.28: to 5.21 eV with the increase of Al concentration is) in the range of 0-0.75. It is expected that a significant increase of such E-gu could happen when x is in the region between 0.8 and 1.0. The evaluation of RF sputtered AI-Cr oxide thin films shows that the material exhibiting variable optical band gap up to 5.6 eV has been obtained which is larger than that of Cr2O3 (E-g approximate to 4.25 eV). The deep-UV region transmittance of 5-20% at reasonable film thickness of about 122 nm reveals the feasibility of such films to be used in single-layer halftone phase-shifting mask (SLHTPSM) photolithographic applications in the exposure wavelength region between 170-200 nm.

In the B-mode image of the liver obtained by an ultrasonic imaging system, the speckled pattern changes with the progression of the disease such as liver cirrhosis. In this paper we present the statistical characteristics of the echo envelope of the liver, and the technique to extract information of the scatterer distribution from the normal and cirrhotic liver images using constant false alarm rate (CFAR) processing. We analyze the relationship between the extracted scatterer distribution and the stage of liver cirrhosis. The ratio of the area in which the amplitude of the processing signal is more than the threshold to the entire processed image area is related quantitatively to the stage of liver cirrhosis. It is found that the proposed technique is valid for the quantitative diagnosis of liver cirrhosis.

A persistent-photoconductivity (PPC) effect and the related deep metastable centers have been investigated for a p-type ZnMgSSe quaternary system grown by molecular beam epitaxy. A low temperature photo-excitation revealed a marked PPC effect in nitrogen doped p-type Zn1-xMgxSySe1-y (0.05 < x < 0.18, 0.08 < y < 0.2) with an exponential temperature dependence of the carrier decay time constant: tau(T) = tau(0) exp(-490 +/- 50 meV/kT). It is also confirmed that the low-temperature photo-excitation has caused a new deep metastable hole trap center with thermal hole activation energy of 650 meV. This metastable deep center is evidenced to be responsible for the observed PPC effect.

The possibility of simultaneous monitoring of the temperature and the thickness of the surface layer of a crystalline silicon (c-Si) substrate by in situ spectroscopic ellipsometry (SE) is demonstrated using a surface adsorption layer (SAL) as an example. The model dielectric function (MDF) developed by Adachi and the tabular data of the dielectric function of fused silica were applied to a Si wafer and SAL, respectively. The best-fit curve has been obtained by fitting the measured Psi and Delta spectra simultaneously by adjusting the 12 MDF parameters and the thickness of SAL over the temperature range of 293-803 K. The best-fit MDF parameters indicate that the SAL thickness has almost no influence on the best-fit values of the MDF parameters. This fact can be used to monitor the temperature of a c-Si wafer independent of the thickness of surface layer by checking the shift of MDF parameters (e.g., E-2) using the SE and the MDF. The measurement errors in thickness and temperature are roughly estimated to be 0.1 nm and less than 10 K, respectively.

Silicon rich nitride (SiRN) film prepared by plasma enhanced chemical vapor deposition (PECVD) for use as the phase-shifting mask for Deep-ultraviolet (UV) lithography has been developed. Optical properties and compositional characterizations of the SiRN films using Anger electron spectroscopy (AES) and spectroscopic ellipsometry (SE) combined with an empirical dielectric function (EDF), as well as phase-shifting mask simulation show that the SiRN is feasible for use in the application of single layer halftone phase-shifting mask (SLHTPSM) in the Deep-UV range. Optical constants of n approximate to 2.5 and k < 0.6 at 193 nm were realized by approaching the N/Si composition to the stoichiometric ratio of Si3N4. The deposition conditions for the films having the transmittance of 5 - 10% with a 180 degrees phase shift at 193 nm (ArF) have been determined. Short wavelength extrapolation by EDF best-fit parameters based on a proper film stack model provides a potential method to characterize the optical properties of amorphous SiRN down to about 190 nm, which is outside the range of most commercial SE's.

The influence of sulphidation treatment on the performance of room temperature InAsPSb/InAs photodetectors was investigated. Measurements of photoresponsivity, external quantum efficiency and detectivity of the detectors with and without the sulphidation treatment showed that after the sulphidation treatment the sensitivity of the detectors improved 1.5 times. A study of the chemical state of sulphur on an (NH4)(2)S-x-treated InAs(001) surface was performed by high-resolution X-ray photoelectron spectroscopy (XPS). The chemical state of sulphur bonded to indium (In) and arsenic (As) atoms for the as-treated surface was observed showing the termination of the dangling bonds at the surface by the sulphidation treatment. This gives rise to a remarkable decrease of surface recombination center density and results in the increase of photodetector sensitivity.

Eighteen Coxiella burnetii strains from a variety of clinical and geographical sources were screened for antigenic variation of polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with Coomassie brilliant blue (CBB) staining or immunoblotting. These polypeptide profiles showed the greatest variability in the region from 33 to 8.1 kDa, Such differences in the antigenicity of the polypeptides were also recognized by immunoblotting with 15 various mouse anti-C., burnetii antisera, In addition, we detected a polypeptide at about 28 kDa which was immunodominant in strains from human cases of acute Q fever, milk and ticks but not immunogenic in strains from human cases of chronic Q fever, These findings suggest that this polypeptide is a marker to distinguish between acute and chronic strains.

The 27-kDa outer membrane protein from eight strains of Coxiella burnetii was expressed in the pET-21c protein expression system. Two fusion proteins with molecular masses of 30 and 32 kDa were evident in all eight of the recombinants by SDS-PAGE and immunoblotting, A protein having an approximate size of 30 kDa was purified from the Escherichia coli lysates by one-step affinity purification. The utility of the purified recombinant protein in ELISA was also evaluated by testing its reactivity with human sera and comparing this reactivity with that of Nine Mile phase II antigen. All of the 40 IF-positive serum samples were ELISA-positive for both the Nine Mile phase II and recombinant antigens, and negative serum controls were negative for both antigens, These results suggest that ELISA with the 27-kDa recombinant antigen is a sensitive and specific method for detecting anti-C, burnetii antibodies in human sera.

A total of 19 Escherichia coli O157 isolates were obtained in Nagasaki Prefecture, in the southwestern part of Japan, between 1990 and 1996, Pulsed-field gel electrophoresis (PFGE) and computer-assisted analysis were applied to determine genetic relationships among these strains. Fragment patterns of the isolates in Nagasaki, as determined by PFGE, were compared with those of isolates in other areas where large outbreaks and sporadic cases of E. coli O157 infection occurred. Similarity values of all the strains isolated in Nagasaki Prefecture were over 0.65 except for E, coli O26, Some strains were identical to the strains isolated from the areas where large outbreaks occurred. All strains were susceptible to ampicillin, fosfomycin, minocycline, amikacin, ofloxacin and sulfamethoxazole-trimethoprim.

Epitaxial silicon on sapphire (SOS) grown using a commercial process was characterized by means of spectroscopic ellipsometry (SE). The SE data of a thin Si layer of SOS were analyzed based on the air/SiO2/Si/Al2O3 structure, in which the Si layer was analyzed using the established optical properties of bulk-Si and model dielectric functions (MDFs) of Si, and also with two layers, the bottom layer with MDFs and the top layer with bulk-Si. The best fit of the SE data with two layers shows that the optical properties of the Si layer in the early stage of growth are different from those of bulk-Si due to the effect of lattice mismatch between Al2O3 and Si. The thickness of the interface layer estimated from SE data analysis is around 20 nm, in reasonable agreement with the previous reports.

A novel proximity effect, which includes the effect due to secondary electron scattering to a range of less than a micron and the pattern dependence of resist development, has been found and investigated to develop a precise dose control method in electron beam nanolithography. Experiments and simulations including secondary electron scattering were performed for precise evaluation of the proximity effect. This result revealed that the proximity effect caused by secondary electron scattering to the range between 30nm and a micron is not negligible for nano-patterns. In addition, from experimental estimation of the rate of development of patterns of various sizes, a significant decrease of the rate was found for patterns less than 30-nm wide. The difference of the rate is also modified by the background deposited energy due to surrounding patterns. Therefore, we have to be very careful about how we determine the proper dose for a given nano-pattern.

我々はこれまでに, 硬変肝画像中の散乱体分布情報に着目し, 病変の進行に対応した定量的情報を抽出することを試みてきた. 本報告では, 正常及び硬変肝画像を用いて, 画像中の様々な領域での散乱体分布情報を解析し, 組織構造を反映した硬変肝画像の構成要素について検討した. その結果, ランダムな散乱体からの情報からなる正常肝の画像は, 病変の進行とともに病変組織特有の散乱体分布情報が混在した画像に変化していくことがわかった. この結果から, 最適な処理パラメータを決定し, 種々の硬変肝画像に適用した. 処理の結果, 病変の進行に対応した情報が抽出され, 病変の定量的評価に有効であることが示された.

Spectroscopic ellipsometry has been used to characterize SIMOX (separation by implanted oxygen) wafers. High-dose SIMOX wafers with 450 nm thick buried SiO2 were measured using a four-zone null spectroscopic ellipsometer in a 230-840 nm range. The measured spectra of Psi and Delta were analyzed based on a multilayer structure of air/surface-SiO2/top-Si/buried-SiO2/Si in which the optical constants of the top-Si layer were analyzed using the optical constants of bulk-Si and also using model dielectric functions proposed for Si. In the fitting of Psi and Delta spectra, a thickness fluctuation of buried-SiO2 was considered with an arbitrary thickness distribution function. Measured Psi and Delta spectra could be well fitted under the assumption of thickness distribution in the buried-SiO2. To examine the thickness dependence of the optical properties of the top-Si layer, the thickness of this layer was systematically reduced by repeating oxidation and etching with HF. It was found that the optical constants of the top-Si layer were equal to those of Si for a thickness above 5 nm.

Fas/APO-1 mediates apoptosis via Fas and Fas ligand transduction, Recently, a soluble form of Fas (sFas) was described which seems to be functionally implicated in the Fas signal system, suggesting a relationship between some disorders and sFas function, We measured sFas-levels in sera from normal controls and patients with disorders linked to human retroviral infection of human immunodeficiency virus (HIV) and human T-cell leukemia virus type-1 (HTLV-1), The sFas level of normal controls, HTLV-1 carriers seronegative for HIV, and patients with HTLV-1 associated myelopathy/tropical paraparesis (HAM/TSP), adult T-cell leukemia (ATL), and AIDS was 1.62+/-0.49, 1.90+/-0.49, 2.00+/-0.59, 3.32+/-2.05, and 3.06+/-0.92 ng/ml, respectively, Although the level of sFas in patient groups with HAM/TSP, ATL, and AIDS was significantly high in comparison to that of normal controls (p<0.01), the individual values were highly variable within the groups, The sFas level was statistically correlated to the soluble interleukin-2 receptor (sIL-2R) level, as well as to cells expressing membrane Fas (mFas), indicating the same cellular origin, In some ATL cases, however, serum sFas levels and mFas expression density on leukemic T-cells were discrepant, with especially high levels of the soluble form and a lack of expression of the membrane form observed in 2 cases, sFas detection could serve as a putative marker for active diseases in patients with ATL and AIDS.

The gene (com1) encoding a 27-kDa outer membrane protein in 21 strains of Coxiella burnetii from a variety of clinical and geographical sources was sequenced for strain differentiation. The com1 gene was highly conserved among all the strains tested but there were several differences in nucleotide and deduced amino acid sequences, Based on the com1 gene-specific nucleotides and deduced amino acids, the 21 strains were divided into four groups, Group 1 contained 14 strains originating from ticks, cattle and human cases of acute Q fever, Groups 2 and 3 included 2 and 3 strains, respectively, originating from human cases of chronic Q fever, Group 4 contained 2 strains originating from a human case of acute Q fever and a goat with abortion, The results indicated that the strains originating from ticks, cattle and human cases of acute Q fever differed at the molecular level from those of human chronic Q fever, This study suggests that a sequence analysis of the com1 gene can be used for strain differentiation of C. burnetii.

A new method for preparation of ordered vacancy chalcopyrite (OVC) thin films by rf sputtering is presented. From X-ray diffraction analyses, all thin films prepared from a CuInSe<SUB>2</SUB> and Na<SUB>2</SUB>Se mixture target with [Na]/[CuInSe<SUB>2</SUB>] ratio above 1% show an OVC structure, and the lattice parameters of the thin films are slightly smaller than that of CuInSe<SUB>2</SUB>, suggestive of the OVC model. The optical absorption coefficients above the fundamental band edge exceed 3× 10<SUP>4</SUP> cm<SUP>-1</SUP> and the optical band gap increases from 1.02 eV to 1.33 eV with increasing [Na]/[CuInSe<SUB>2</SUB>] ratio from 0% to 10% in the target.

医用超音波診断装置は安全、安価、小型などの利点から、医療分野の臨床診断に広く利用されているが、定性的な診断の段階にとどまっている。そこで、本研究では、硬変肝を対象に、肝臓内の散乱仕分布と画像の関係を定量的に明らかにするため、計算機シミュレーションモデルを提案した。計算機上でBモード映像系モデルをシミュレートし、散乱体パラメータと画像の関係を検討した。次に、硬変肝画像を作成し、散乱体の状況の変化が画像の性質にどのような影響を及ぼすか検討した。この結果、病変肝の散乱体分布変化と画像の間の関係について、基礎的資料を得ることができた。