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Biomedical subjects

T Fujii

Publications and source records attributed to T Fujii.

At least 91 records · Page 5Linked to original sources
PubMed2001

Spatiotemporal symmetry in rings of coupled biological oscillators of Physarum plasmodial slime mold.

Spatiotemporal patterns in rings of coupled biological oscillators of the plasmodial slime mold, Physarum polycephalum, were investigated by comparing with results analyzed by the symmetric Hopf bifurcation theory based on group theory. In three-, four-, and five-oscillator systems, all types of oscillation modes predicted by the theory were observed including a novel oscillation mode, a half period oscillation, which has not been reported anywhere in practical systems. Our results support the effectiveness of the symmetric Hopf bifurcation theory in practical systems.

Animals↗
PubMed2001

Quantum mechanical representation of acoustic streaming and acoustic radiation pressure.

We discuss acoustic streaming and acoustic radiation pressure from the viewpoint of energy and momentum of acoustic waves, using a quantum mechanical representation of acoustic waves. We represent the energy epsilon and momentum mu of acoustic waves as epsilon=n(p)homega and mu=n(p)hk; here n(p) is the phonon density, omega is the frequency, k is the wave number, and h is Planck's constant. It is easy to derive the momentum of acoustic waves as mu=epsilon/c (c is the sound velocity). Therefore, we can represent the acoustic streaming and acoustic radiation pressure in terms of the momentum.

Journal Article↗
PubMed2001

Design and synthesis of novel benzofurans as a new class of antifungal agents targeting fungal N-myristoyltransferase. Part 1.

Potent and selective Candida albicans N-myristoyltransferase (CaNmt) inhibitors have been identified through optimization of a lead compound 1 discovered by random screening. The inhibitor design is based on the crystal structure of the CaNmt complex with compound (S)-3 and structure-activity relationships (SARs) have been clarified. Modification of the C-4 side chain of 1 has led to the discovery of a potent and selective CaNmt inhibitor 11 (RO-09-4609), which exhibits antifungal activity against C. albicans in vitro.

Acyltransferases↗
PubMed2001

Mass spectrometry for on-line monitoring of perfluoro compounds using Li+ ion attachment techniques.

Ion attachment mass spectrometry is being developed for continuous measurement of perfluoro compounds (PFCs) found in the atmosphere as a result of semiconductor manufacturing processes. Studies were made on 5 greenhouse gases, CF4, CHF3, C2F6, SF6, and c-C4F8, to develop improved methods for PFC analysis, particularly at levels found in the atmosphere (the parts-per-billion concentration range). The results demonstrate the feasibility of performing real-time measurements of the trace amounts of PFCs encountered in process facilities by generating adduct ions from Li+ ion attachment. The identification and detection of c-C4F8 is described as an example of the utility of this new method.

Journal Article↗
PubMed2001

Localization of a novel susceptibility gene for familial ovarian cancer to chromosome 3p22-p25.

We performed genome-wide linkage analysis in 58 patients and nine unaffected members among 28 families with no mutation in BRCA1 or BRCA2, employing a set of 410 microsatellite markers. We initially screened the whole genome, including the X chromosome, by a non-parametric method using the GENEHUNTER program. As a result, chromosome 3p22-p25 showed a suggestive score for linkage [LOD = 3.49 and non-parametric LOD (NPL) = 2.77 at D3S3611] based on a multipoint analysis. Additionally, based on a two-point analysis using dense markers, this 3p22-p25 region showed a P-value < 0.05 at 10 markers and there is suggestive evidence for linkage at two markers within approximately 19 cM (NPL = 2.60 and 2.49 at D3S1597 and D3S3611, respectively). To explore whether the candidate gene in this 3p22-p25 region contributed to carcinogenesis of familial ovarian cancer in a similar fashion to the tumor suppressor gene, we performed loss of heterozygosity (LOH) analysis. It was observed that the frequency of LOH at four markers in this region was >50% only in tumor tissues from patients with no mutation in BRCA1 or BRCA2, not in those with a BRCA1 mutation.

Adult↗
PubMed2001

Effects of water activity and aqueous solvent ordering on thermal stability of lysozyme, alpha-chymotrypsinogen A, and alcohol dehydrogenase.

Effects of water activity (aW) and solvent ordering were separately analyzed on the thermal unfolding of lysozyme and alpha-chymotrypsinogen A, and also on the thermal deactivation of yeast alcohol dehydrogenase (YADH) in aqueous solutions with various additives. With the coexistence of additives, water activity was the determinant of the extent of the change in the thermal stability of proteins while solvent ordering was the determinant of the direction of the change. The parameter alpha, determined from the activity coefficient of water, representing the deviation of aW from that of the ideal solution, was useful as a quantitative index of the solvent ordering showing good correlations with the unfolding temperature and enthalpy of lysozyme and alpha-chymotrypsinogen A and also with the thermal deactivation rate constant of YADH at a constant aW. Solvent ordering seemed to affect the thermal stability of proteins mainly through its effect on the intramolecular hydrophobic interaction among amino acid residues in a protein molecule but the contribution of the electrostatic interaction including hydrogen bonding through the change in permittivity of solution was also suggested.

Alcohol Dehydrogenase↗
PubMed2001

The use of the L-plastin promoter for adenoviral-mediated, tumor-specific gene expression in ovarian and bladder cancer cell lines.

A 2.4-kb truncated L-plastin promoter was inserted either 5' to the LacZ gene (Ad-Lp-LacZ) or 5' to the cytosine deaminase (CD) gene (Ad-Lp-CD) in a replication-incompetent adenoviral vector backbone. Infectivity and cytotoxicity experiments with the LacZ and CD vectors suggested that the L-plastin promoter-driven transcriptional units were expressed at much higher levels in explants of ovarian cancer cells from patients and in established ovarian or bladder cancer cell lines than they were in normal peritoneal mesothelial cells from surgical specimens, in organ cultures of normal ovarian cells, or in the established CCD minimal deviation fibroblast cell line. Control experiments showed that this difference was not attributable to the lack of infectivity of the normal peritoneal cells, the normal ovarian cells, or the minimal deviation CCD fibroblast cell line, because these cells showed expression of the LacZ reporter gene when exposed to the replication-incompetent adenoviral vector carrying the cytomegalovirus (CMV)-driven LacZ gene (Ad-CMV-LacZ). The Ovcar-5 and Skov-3 ovarian cancer cell lines exposed to the Ad-Lp-CD adenoviral vector were much more sensitive to the prodrug 5-fluorocytosine (5FC), which is converted from the 5FC prodrug into the toxic chemical 5-fluorouracil, than was the CCD minimal deviation fibroblast cell line after exposure to the same vector. A mouse xenograft model was used to show that the Ad-Lp-CD vector/5FC system could prevent engraftment of ovarian cancer cells in nude mice. Finally, injection of the Ad-Lp-CD vector into s.c. tumor nodules generated a greater reduction of the size of the tumor nodules than did injection of the Ad-CMV-LacZ vectors into tumor nodules. The Ad-Lp-CD vectors were as suppressive to tumor growth as the Ad-CMV-CD vectors. These results suggest that an adenoviral vector carrying the CD gene controlled by the L-plastin promoter (Ad-Lp-CD) may be of potential value for the i.p. therapy of ovarian cancer.

Adenoviridae↗
PubMed2001

Glufosinate ammonium induces convulsion through N-methyl-D-aspartate receptors in mice.

Glufosinate ammonium, a broad-spectrum herbicide, causes convulsion in rodents and humans. Because of the structural similarities between glufosinate and glutamate, the convulsion induced by glufosinate ammonium may be ascribed to glutamate receptor activation. Three N-methyl-D-asparate (NMDA) receptor antagonists, dizocilpine, LY235959, and Compound 40, and an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate receptor antagonist, NBQX, were coadministrated with glufosinate ammonium (80 mg/kg, intraperitoneally) in mice. Statistical analyses showed that the NMDA receptor antagonists markedly inhibited the convulsions, while the AMPA/kainate receptor antagonist had no effect on the convulsion. These results suggest that the convulsion caused by glufosinate ammonium is mediated through NMDA receptors.

Aminobutyrates↗
PubMed2001

Successful emergency endometrial ablation for intractable uterine bleeding in a postmenopausal woman complicated with liver cirrhosis and morbid obesity.

Life-threatening intractable uterine bleeding is difficult to treat when concurrent medical complications contraindicate invasive surgery. We present a case of heavy uterine bleeding in a postmenopausal woman that was complicated by liver cirrhosis and morbid obesity. The bleeding was successfully halted through emergency endometrial ablation after failure of uterine artery embolization.

Electrocoagulation↗
PubMed2001

Rational design, synthesis, and biological evaluation of rigid pyrrolidone analogues as potential inhibitors of prostate cancer cell growth.

In view of its role in tumor promotion and signal transduction, protein kinase C (PKC) has proven to be an exciting target for cancer therapy. With the aid of molecular modeling, we rationally designed and stereoselectively synthesized a new class of rigidified pyrrolidone-based PKC activators. Pyrrolidone 15 was found to exhibit reasonable affinity for PKCdelta, with lower affinity for the other isozymes tested. Pyrrolidone 2 causes the dose-dependent induction of apoptosis in LNCaP prostate cancer cells. This apoptotic effect could be markedly potentiated by the use of LNCaP cells overexpressing the PKCalpha or delta isozymes.

Antineoplastic Agents↗
PubMed2001

Regional characteristics of sulfur and lead isotope ratios in the atmosphere at several Chinese urban sites.

Sulfur and lead isotope ratios in the atmosphere were measured at several selected sites (Harbin, Changchun, Dalian, Waliguan, Shanghai, Nanjing, Guiyang) in China and Tsukuba (Japan), to reveal regional sources characteristics over Eastern Asia. Average S isotope ratios for SO2 and sulfate in the atmosphere in China were close to those of the coals used in each region, indicating a considerable contribution of coal combustion to the sulfur compounds in the atmosphere. Most northern cities had around 5% sulfur isotope ratio, while Guiyang, a southwestern city in China, showed a considerably lower sulfur isotope ratio (about -3%) because of the unusually light sulfur isotope ratio of coals in this region. These were considerably different from the value (-1.4%) for Tsukuba (Japan). Lead isotope ratios also suggested that coal combustion considerably contributed to atmospheric lead in some cases in China. At the same time, influences by the emission of Chinese lead ores were also observed in northern cities. Seasonal variations of both sulfur and lead isotope ratios indicated the existence of a certain amount of industrial sources other than coal combustion. In addition, fractionation effect between SO2 and sulfate showed a seasonal tendency (high in winter (0-6%) and low in summer (-1-3%)), suggesting the oxidation pathway of SO2 changed seasonally.

Air Pollution↗
PubMed2001

Molecular cloning of Na(+)-ATPase cDNA from a marine alga, Heterosigma akashiwo.

We cloned novel Na(+)-ATPase (HANA) cDNA from marine alga Heterosigma akashiwo. The full-length HANA cDNA was 4467 bp long and coded for a 1330 amino acid protein with a molecular weight of 146,306. The deduced product exhibited around 40% identity in amino acids with Na(+)/K(+)-ATPase alpha-subunits. A hydrophilic sequence of 285 amino acid residues that showed no homology with any sequence listed in databases existed in the M7--M8 junction of HANA. This is the first report on the primary structure of putative Na(+)-transporting ATPase from plant cells.

Adenosine Triphosphatases↗
PubMed2001

Detection of fibrous cap in atherosclerotic plaque by intravascular ultrasound by use of color mapping of angle-dependent echo-intensity variation.

BACKGROUND: The thickness of the fibrous cap is a major determinant in the vulnerability of atherosclerotic plaque to rupture. It has been demonstrated that intravascular ultrasound (IVUS) backscatter from fibrous tissue is strongly dependent on the ultrasound beam angle of incidence. This study investigated the feasibility of using a new IVUS color mapping technique representing the angle-dependent echo-intensity variation to determine the thickness of the fibrous cap in atherosclerotic plaque. METHODS AND RESULTS: Nineteen formalin-fixed noncalcified human atherosclerotic plaques from necropsy were imaged in vitro with a 30-MHz IVUS catheter. The IVUS catheter was moved coaxially relative to the plaque. The images showing maximum and minimum echo intensity of the plaque surface were selected to calculate the angle-dependent echo-intensity variation. A colorized representation of the echo-intensity variation in the plaque was obtained from the 2 IVUS images. A clearly bordered area with large variation in echo intensity was revealed for each plaque surface in the colorized IVUS image. The thickness (x, mm) of this area correlated significantly with that of fibrous cap (y, mm) measured from histologically prepared sections as y=1.05x-0.01 (r=0.81, P:<0.0001). Bland-Altman analysis also supported the reliability of this method (mean difference, 0.00+/-0.10 mm). CONCLUSIONS: This novel technique for color mapping the echo-intensity variation in IVUS provided an accurate representation of the thickness of the fibrous cap in atherosclerotic plaque. This method may be useful in assessing plaque vulnerability to rupture in atherosclerosis.

Arteriosclerosis↗
PubMed2001

Judging semantic and episodic incongruity: a magnetoencephalographic study.

Evoked magnetic fields over the entire head were measured during a semantic judgment task, in which conditions of the pre-test learning session were manipulated. Subjects learnt related and unrelated category-noun pairs, and were then asked to judge the relationship between category and noun. Unrelated pairs evoked activation around 400 ms in the left temporal area. In addition, newly presented related pairs, of which the categories were used to learn unrelated pairs, also evoked similar activities. Our findings suggest that these activities are not only related to the semantic incongruity between a pair of words as in previous studies, but also to the episodic incongruity between the learning and measurement sessions.

Adult↗
PubMed2001

cDNA cloning and expression of a novel cytochrome p450 (cyp4f12) from human small intestine.

A cDNA encoding a novel human CYP4F enzyme (designated CYP4F12) was cloned by PCR from a human small intestine cDNA library. RT-PCR analysis demonstrated that CYP4F12 is expressed in human small intestine and liver. This cDNA contains an entire coding region of a 524-amino-acid protein that is 81.7, 78.3, and 78.2% identical to CYP4F2, CYP4F3, and CYP4F8, respectively. When expressed in Saccharomyces cerevisiae, the P450 catalyzes leukotriene B(4) omega-hydroxylation and arachidonic acid omega-hydroxylation, typical reactions of CYP4F isoforms. Their activity levels are, however, much lower than those of CYP4F2. Interestingly, CYP4F12 catalyzes the hydroxylation of the antihistamine ebastine with significantly higher catalytic activity relative to CYP4F2 (385 vs 5 pmol/min/nmol P450). These results indicate that CYP4F12 has a different profile of substrate specificity from other CYP4F isoforms, enzymes responsible for metabolizing endogenous autacoids, therefore suggesting that it may play an important role in xenobiotic biotransformation in the human small intestine.

Amino Acid Sequence↗
PubMed2001

High and low levels of cottontail rabbit papillomavirus E2 protein generate opposite effects on gene expression.

The papillomavirus E2 protein plays an important role in viral transcriptional regulation and replication. We chose to study the cottontail rabbit papillomavirus (CRPV) E2 protein as a transcriptional regulator because of the availability of an animal model for papilloma formation, which may be relevant for human papillomavirus (HPV) infection and replication. We studied the effect of expression levels of E2 on the long control region, which contains transcriptional promoter and enhancer elements, and synthetic E2-dependent artificial promoters in which the E2 was the dominant factor in the transcriptional activation. These experiments indicated that high levels of E2 were inhibitory and low levels were stimulatory for transactivation. In addition, we showed that the complex formed between CRPV E2 and the cognate binding site was less stable than the complex formed between HPV E2 and the same cognate binding site. Furthermore, we showed that CRPV E2 binding to its transcriptional regulatory sequence was stabilized by other proteins such as E1, which produced increments in transcriptional activation of E2-dependent genes. The data may be used to define conditions in which the rabbit model can be used for the screening of drugs which are inhibitory to the HPV and CRPV replication and gene expression.

Animals↗