PubMed Health⌕ Search

Biomedical subjects

Hiroshi Ono

Publications and source records attributed to Hiroshi Ono.

18 recordsLinked to original sources
PubMed2003

Caffeic acid derivatives in the roots of yacon (Smallanthus sonchifolius).

Five caffeic acid derivatives were found in the roots of yacon, Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson, Asteraceae, as the major water-soluble phenolic compounds. The structures of these compounds were determined by analysis of spectroscopic data. Two of these were chlorogenic acid (3-caffeoylquinic acid) and 3,5-dicaffeoylquinic acid, common phenolic compounds in plants of the family Asteraceae. Three were esters of caffeic acid with the hydroxy groups of aldaric acid, derived from hexose. The structure of the aldaric moiety was determined by hydrolysis and comparison of NMR spectra with those of standard aldaric acids. The compounds were novel caffeic acid esters of altraric acid: 2,4- or 3,5-dicaffeoylaltraric acid, 2,5-dicaffeoylaltraric acid, and 2,3,5- or 2,4,5-tricaffeoylaltraric acid.

Asteraceae↗
PubMed2003

Leonardo's constraint: two opaque objects cannot be seen in the same direction.

Given Leonardo's constraint that 2 opaque objects cannot be seen in the same direction, how are the regions of objects occluded to 1 eye included in perception? To answer this question, the authors presented 3-dimensional stimuli, similar to the ones that concerned Leonardo, and measured the visual directions of their monocular and binocular regions. When the distance between near and far objects was large, the nonfixated object was seen as double and blurry. Leonardo's constraint was met by seeing the near object as double and transparent or the distant object as double and superimposed. When the distance between near and far objects was small, the constraint was met by a perceptual displacement and compression of parts of the nonfixated object.

Depth Perception↗
PubMed2003

What does the dominant eye dominate? A brief and somewhat contentious review.

We examine a set of implicit and explicit claims about the concept of eye dominance that have been made over the years and note that the new literature on eye dominance does not reflect the old literature from the first half of the last century. We argue that the visual and oculomotor function of the dominant eye--defined by such criteria as asymmetry in acuity, rivalry, or sighting--remains unknown and that the usefulness of the concept for understanding its function is yet to be determined. We suggest that the sighting-dominant eye is the eye used for monocular tasks and has no unique functional role in vision.

Dominance, Cerebral↗
PubMed2003

[Superselective endovascular treatment of renal artery aneurysms with detachable microcoils].

Selective transcatheter embolization using an interlocking detachable coil was performed in two cases with renal artery aneurysms. Case 1, a 73-year-old male, was referred to our department complaining of macrohematuria persisting for three days. Case 2, a 52-year-old female, visited our department because calcifications in both renal pedicle areas were found in a health check up. Drip infusion pyelography (DIP) and computerized tomography (CT) revealed in case 1 an aneurysm which was 11 x 10 cm in diameter with nearly circumferential calcification in the right renal pedicle area and in case 2 two aneurysms, one 12 x 10 cm in the right and one 22 x 20 cm in the left with imperfect calcification. Enhanced CT confirmed blood flow in the aneurysms. Because abdominal surgery, was considered to be a highrisks in both cases 1 and 2 the coil embolization was performed. The patients have been followed up after the embolization without any particular complications or changes in the coil location.

Aged↗
PubMed2002

Antimutagenicity of some edible Thai plants, and a bioactive carbazole alkaloid, mahanine, isolated from Micromelum minutum.

The antimutagenic activity against Trp-P-1 of methanolic extracts of 118 samples (108 species) of edible Thai plants was examined by the Ames Test. The activity was evaluated by the amount of plant extracts which suppressed 90% of the mutagenesis (ED90). Five plants, Micromelum minutum, Oroxylum indicum, Cuscuta chinensis, Azadirachta indica, and Litsea petiolata, exhibited significant activity with antimutagenic ED90 values lower than 5 microL/plate (0.1 mg of dry plant material equivalent). The activity-guided fractionation of the extract of M. minutum, which exhibited the highest antimutagenic activity in the screening, resulted in the isolation of an active principle, (+)-mahanine (1) as confirmed by its physicochemical properties. Compound 1 showed a wide variety of biological activity, including antimutagenicity against heterocyclic amines such as Trp-P-1 with an IC50 of 5.2 microM, cytotoxicity against a tumor cell line HL60 with a MIC100 of 4.0 microg/mL, and antimicrobial activity against Bacillus cereus and Staphylococcus aureus with MIC100 values of 6.25 and 12.5 microg/mL, respectively.

Anti-Bacterial Agents↗
PubMed2002

Oxygenation of bisphenol A to quinones by polyphenol oxidase in vegetables.

To understand conversion of bisphenol A and its related compounds under some chemical and biological environments, oxidation of these compounds was performed. Bisphenol A was oxidized to monoquinone and bisquinone derivatives by Fremy's salt, a radical oxidant; but salcomine and alkali did not catalyze the oxidation by molecular oxygen. Bisphenol A, bisphenol B, and 3,4'-(1-methylethylidene)bisphenol were converted to their monoquinone derivatives in the presence of oxygen and polyphenol oxidase from mushroom at 25 degrees C at pH 6.5. Among crude enzyme solutions of fruits and vegetables, potato, mushroom, eggplant, edible burdock, and yacon showed remarkable oxidative activity on bisphenol A. The highest activity was observed in potato, and the main product obtained by the enzymatic oxygenation was the monoquinone derivative of bisphenol A, accompanied by a small amount of the bisquinone derivative. The oxidation reactions found here will be useful for developing techniques for elimination of phenolic endocrine disrupters from the environment.

Agaricales↗
PubMed2002

Fluorescent labeling of pectic oligosaccharides with 2-aminobenzamide and enzyme assay for pectin.

Oligogalacturonides [oligomers composed of (1-->4)-linked alpha-D-galactosyluronic acid residues] with degrees of polymerization (DP) from 1 to 10, and a tri-, penta-, and heptasaccharide generated from the backbone of rhamnogalacturonan I (RG-I) were labeled at their reducing ends using aqueous 2-aminobenzamide (2AB) in the presence of sodium cyanoborohydride in over 90% yield. These derivatives were analyzed by high-performance anion-exchange chromatography (HPAEC) and structurally characterized by electrospray-ionization mass spectrometry (ESIMS) and by 1H and 13C NMR spectroscopy. The 2AB-labeled oligogalacturonides and RG-I oligomers are fragmented by endo- and exo-polygalacturonase and by Driselase, respectively. 2AB-labeled oligogalacturonide is an exogenous acceptor for galacturonosyltransferase of transferring galacturonic acid from UDP-GalA. Thus, the 2AB-labeled oligogalacturonides and RG-I oligomers are useful for studying enzymes involved in pectin degradation and biosynthesis and may be of value in determining the biological functions of pectic fragments in plants.

Carbohydrate Sequence↗
PubMed2002

Relevance of chemical structure and cytotoxicity to the induction of chromosome aberrations based on the testing results of 98 high production volume industrial chemicals.

Over a 6-year period (1991-1996), the chromosomal aberration testing of high production volume (HPV) industrial chemicals had been conducted using Chinese hamster lung (CHL/IU) cells according to OECD HPV testing program and the national program in Japan. A total of 98 chemicals were tested for the induction of chromosome aberration (CA), consisting of structural CA and polyploidy. Of the 98 chemicals, structural CA and/or polyploidy were induced by 39 chemicals (40%). Anilines and phenols tended to induce only structural CA. p-tert-Butylphenol had a peculiar feature in inducing not only structural CA but also polyploidy at considerably high frequency (93.2%) after continuous treatment for 48 h, posing an aneugenic potential. Not all, but six of 11 carboxylic acids or esters also showed the simultaneous induction of structural CA and polyploidy. The majority of organic phosphates, alcohols or ethers, alkyl benzenes and non-cyclic alkanes had no CA induction activity. For chemicals which were negative in the bacterial reverse mutation assay (Ames test), the proportion of the chemicals that induced CA at a severely cytotoxic dose (doses manifesting more than 50% cytotoxicity) was similar to that of the CA-negative chemicals manifesting severe cytotoxicity, suggesting that severely cytotoxic chemicals do not always induce CA.

Alcohols↗
PubMed2002

Acylated and non-acylated flavonol monoglycosides from the Indian minor spice Nagkesar (Mammea longifolia).

A methanol extract of nagkesar (buds of Mammea longifolia), which showed strong radical scavenging activity, yielded 13 compounds by separations using column chromatography and HPLC. Structure elucidation of these compounds was achieved by (1)H and (13)C NMR, including DQF-COSY, TOCSY, DEPT, HMQC, HSQC, and HMBC. They include two new compounds, quercetin 3-O-(2' ',4' 'di-E-p-coumaroyl)-alpha-L-rhamno-pyranoside and quercetin 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, along with known compounds kaempferol, quercetin, the isopropylidenedioxy derivative of shikimic acid, kaempferol 3-O-(2' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, shikimic acid, kaempferol 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranoside, and beta-sitosterol 3-O-beta-D-glucopyranoside.

Acylation↗
PubMed2002

The cyclopean eye in vision: the new and old data continue to hit you right between the eyes.

We argue against recent claims by Erkelens and van Ee (Vision Res., in press) and by Erkelens (Vision Res. 40 (2000) 2411) that "the concept of the cyclopean eye is em leader always irrelevant as far as vision is concerned" (p. 1157) [corrected] and that "perceived direction during monocular viewing is based on the signals of the viewing eye only" (p. 2411), respectively. In Experiment 1, we presented a pair of small lights on a visual axis and measured the absolute visual direction of the near light with reference to different parts of the face. The near light appeared in front of the bridge of the nose or very near it, contrary to what was expected from Erkelens and van Ee's claim that monocular stimuli are seen in their correct locations. In Experiment 2, we replicated Erkelens' experiments with measurements of phoria and analyses of eye movements. The results confirmed his finding that the cyclopean illusion occurred rarely in the monocular condition, but our phoria and eye movement data provided the basis for a very different interpretation. Our data show that the oculomotor signal in his particular monocular condition was considerably weaker than in his binocular condition; therefore, the rarity of the monocular cyclopean illusion is not surprising. Moreover, since both claims above are based on an over-generalization of the results of Erkelens' study, neither claim is persuasive.

Adult↗
PubMed2002

Content and context of monocular regions determine perceived depth in random dot, unpaired background and phantom stereograms.

Perceived depth was measured for three-types of stereograms with the colour/texture of half-occluded (monocular) regions either similar to or dissimilar to that of binocular regions or background. In a two-panel random dot stereogram the monocular region was filled with texture either similar or different to the far panel or left blank. In unpaired background stereograms the monocular region either matched the background or was different in colour or texture and in phantom stereograms the monocular region matched the partially occluded object or was a different colour or texture. In all three cases depth was considerably impaired when the monocular texture did not match either the background or the more distant surface. The content and context of monocular regions as well as their position are important in determining their role as occlusion cues and thus in three-dimensional layout. We compare coincidence and accidental view accounts of these effects.

Depth Perception↗
PubMed2002

Bilateral bipartite lunate: a case report.

A rare case of bilateral bipartite lunate is reported. Radiographs showed that the lunate was divided into palmar and dorsal parts. Computed tomography and magnetic resonance imaging were used to differentiate this variant from lunate fracture.

Diagnosis, Differential↗
PubMed2002

The pursuit of Leonardo's constraint.

Leonardo da Vinci (1452-1519) identified two stimulus situations that cannot be painted faithfully on a canvas: (a) when two objects are located in the same direction with respect to the painter's head, and (b) when parts of a surface are visible to one eye, but occluded from the other eye. He analysed these situations in terms of rays being emitted from the two eyes and, aside from the origin of the rays, the projective geometry he used was correct. His analyses showed that what can be seen from two vantage points cannot be represented on a canvas, because a 'correct' painting must be created from a single 'station point'. He was struck by the consequence of this fact that the depth seen on a canvas cannot match that of viewing the scene with two eyes. Subsequent visual scientists focused on Leonardo's observation about the lack of vivid depth in a picture. We argue that a complete understanding of what we see in the two stimulus situations requires consideration of visual direction in addition to visual depth. More specifically, we argue that the visual directions of the two objects, (a) above, and the visual direction of the monocular areas, (b) above, are dependent upon the constraint that two opaque objects cannot be represented in the same direction. Demonstrations that readers can perform, and that support this argument, are provided on the Perception website at http://www.perceptionweb.com/perc0102/ono.html.

Depth Perception↗
PubMed2002

Total synthesis of (+/-)-syn-copalol.

The labdane diterpene derivative, syn-copalol [(+)-5] is the alcohol part of syn-copalyl diphosphate [(+)-4]. In this paper, racemic (+/-)-5 was synthesized from a known racemic lactone in 8 steps. The current and our previous syntheses provide all four copalol derivatives [(+)-3, (-)-3 and (+/-)-5] which are required for the biosynthetic study of polycyclic diterpenes.

Catalysis↗
PubMed2002

Adaptation to relative and uniform motion.

We compared the discriminability of motion direction with a relative motion stimulus after prolonged exposure to relative or uniform motion. Experiment 1 showed that the velocity threshold for the relative motion test after relative motion exposure was higher than that after uniform motion exposure, whereas no such difference was found when we tested with a uniform motion stimulus. Experiment 2 showed that prolonged exposure to relative motion decreased the discriminability of speed differences more than exposure to uniform motion. These results suggest that the visual system's pathway for relative motion signals is different from that for uniform motion signals.

Adaptation, Physiological↗
PubMedDate not supplied

Low-dose bisphenol A does not affect reproductive organs in estrogen-sensitive C57BL/6N mice exposed at the sexually mature, juvenile, or embryonic stage.

Bisphenol A (BPA) is used on a large scale in the manufacture of polycarbonate plastics. BPA has been shown to bind weakly to both estrogen receptor (ER) alpha and ER beta. The objective of this study was to evaluate the effects of low-dose BPA on male sexual development after exposure at various stages of development. Mice of the estrogen-sensitive strain C57BL/6N were exposed to BPA orally at doses of 2, 20, or 200 microg/kg at various stages, i.e. adulthood, the immature stage just after weaning, or the embryonic/fetal stage, to evaluate the effects of low-dose BPA on male reproductive organs. Body weight changes, weights of reproductive organs (testes, epididymides, seminal vesicles), cauda epididymal sperm density, and histology of reproductive organs including the ventral prostate were not affected by exposure to BPA at any dose examined. The results of this study indicate that exposure of estrogen-sensitive C57BL/6N mice to low-dose BPA did not reduce sperm density or disrupt development of the male reproductive organs.

Air Pollutants, Occupational↗