Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 37 records · Page 2Linked to original sources

PubMed2004

Diode-end-pumped 4.2-W continuous-wave Yb:Y2O3 ceramic laser.

We report on an efficient diode-end-pumped polycrystalline Yb:Y2O3 ceramic laser. Continuous-wave output power of 4.2 W at 1078 nm was obtained under pump power of 19.5 W. The corresponding slope efficiency was 29%. The beam quality factor (M2) at full pump power was measured to be 1.63. The threshold wavelengths of the laser at various output couplings were also investigated. It was found that the threshold wavelengths shifted approximately 5 nm when the reflectivity of the output coupler changed from 90% to 99.9%, as caused by the strong reabsorption effect in the ceramic sample.

Journal Article↗

PubMed2004

Random-wavelength solid-state laser.

The spectral properties of a diode-pumped Yb:Y2O3 ceramic laser are reported. We show experimentally that the instantaneous emission wavelengths of the laser change randomly with time, whereas its emission has fixed well-defined transverse modes. The central wavelength of the laser emission also shifts prominently with the increase of intracavity light intensity. It is found that the spectral properties of the laser can be explained well based on the strong reabsorption of light in the gain medium.

Journal Article↗

PubMed2004

A new umbilicoplasty for children: creating a longitudinal deep umbilical depression.

When forming a deep umbilical depression for paediatric patients displaying a thin layer of abdominal fat, the V-Y advancement flap method is useful. However, although many plastic surgeons approve of a longitudinal umbilical depression as an ideal, conventional flap methods often result in only a longitudinal scar line with a depression at the end of the scar. The shifted umbilical depression facing upward or downward appears aesthetically unnatural. To resolve these problems, we have devised a new method of umbilicoplasty. Using obliquely opposing flaps, a longitudinal deep umbilical depression facing forward can be created at the correct umbilical position.

Child↗

PubMed2004

Pathology review for paediatric non-Hodgkin's lymphoma patients in Japan; a report from the Japan association of childhood leukaemia study (JACLS).

A central pathology review system with an immunophenotyping laboratory was established in Japan to support the clinical trial, the Japan Association of Childhood Leukaemia Study (JACLS) NHL-98, for patients with paediatric non-Hodgkin's lymphoma (NHL). Pathology samples from 155 clinically-suspected NHL cases were evaluated centrally initially using the Revised European-American Lymphoma (REAL) classification in a rapid review (within 2 weeks after surgery/biopsy) and then later at the consensus review (once a year). The samples were subsequently re-classified according to the new World Health Organisation (WHO) classification. After the pathology review, 96 (62%) patients were eligible for the study, and 58 of them (60%) had extra-nodal primaries. These NHL cases included B-cell lymphomas (precursor B-cell, 11; Burkitt, 18; diffuse large B-cell, 18; not otherwise specified, 3) and T/Natural Killer (NK)-cell lymphomas (precursor T-cell, 23; anaplastic large cell, 20; others, 3). There was excellent concordance in making the diagnoses (95/96, 99%) and typing (93/96, 97%) of NHL between the rapid and consensus reviews. Five cases, initially diagnosed as diffuse large B-cell lymphoma by the review, were re-classified as Burkitt lymphoma according to the immunocytochemical criteria by the WHO classification. A total of 59 (38%) cases were excluded from the study: they were Hodgkin lymphoma (7), leukaemias (11), reactive lymphoid hyperplasia (20), necrotizing lymphadenitis (7), no consensus diagnosis (1), insufficient materials (2), and others (11). This is the first report of the central pathology review from the paediatric NHL group study in Japan. Because various diseases, either neoplastic or reactive, mimicked NHL, clinically and histopathologically, the central pathology review system was critical and essential for patient enrollment and protocol assignment in our clinical trial. Through the two-step review system, highly reliable data were generated to support this study.

Adolescent↗

PubMed2004

Relation between C reactive protein concentrations and coronary microvascular endothelial function.

OBJECTIVE: To determine how C reactive protein (CRP), a sensitive marker of inflammation, is related to coronary endothelial function. DESIGN: Changes in quantitative coronary angiographic findings and Doppler flow velocity measurements in response to locally infused acetylcholine were assessed. SETTING: Tertiary cardiology centre. PATIENTS: 46 patients with angiographically normal coronary arteries were divided into groups with normal (< or = 3 mg/l) or increased (> 3 mg/l) CRP concentrations. INTERVENTIONS: Acetylcholine (3 and 30 microg/min) was infused into the left coronary ostium for two minutes. MAIN OUTCOME MEASURES: Percentage change in diameter of epicardial coronary arteries and coronary blood flow (CBF) in response to acetylcholine; and correlations between these parameters and serum CRP concentrations. RESULTS: 15 patients had increased CRP concentrations. The change in coronary artery diameter induced by acetylcholine infusion was similar between the groups but the increase in CBF induced by acetylcholine was smaller in patients with increased CRP concentrations (54.9% v 139.4% with acetylcholine 30 microg/min, p = 0.0030). Multivariate analysis identified increased CRP concentration as independently associated with attenuated CBF response to acetylcholine at 30 microg/min (p = 0.0078, R2 = 0.434). CONCLUSIONS: These findings suggest that inflammation appears to be associated with impaired coronary endothelial function in resistance but not conduit vessels. The data suggest a close relation between chronic vascular inflammation and endothelial dysfunction in atherosclerosis.

Acetylcholine↗

PubMed2004

Long-term efficacy of immunoadsorbent plasmapheresis in a patient with Budd-Chiari syndrome due to antiphospholipid syndrome: case report with nine-year follow-up.

We describe the safety and efficacy of long-term immunoadsorbent plasmapheresis (IAPP) with dextran sulfate-cellulose bead columns in antiphospholipid syndrome (APS). IAPP was administered to a 38-year old male Japanese patient with APS with Budd-Chiari syndrome (BCS), who had presented with refractory lower leg skin ulcers and arterial and venous thromboses including BCS. After hepatic vein transluminal angioplasty was performed, the combination of corticosteroid, aspirin and IAPP was administered because of an underlying bleeding tendency related to liver dysfunction. From February 1994 to February 2003, a total of 228 procedures were performed. No further thrombosis-related symptoms or bleeding have occurred for more than nine years, suggesting that IAPP with dextran sulfate cellulose columns is safe and effective for APS in preventing additional thrombotic events. This IAPP supplements anticoagulation, antiplatelet, corticosteroid and immunosuppressant therapies.

Adult↗

PubMed2004

Using a flat-panel detector in high resolution cone beam CT for dental imaging.

OBJECTIVES: Cone beam CT (CBCT) requires a two-dimensional X-ray detector. In the several CBCT systems developed for dental imaging, detection has been by the combination of an X-ray image intensifier and charge-coupled device (CCD) camera. In this paper, we propose a new CBCT system in which the detector is of the flat-panel type and evaluate its performance in dental imaging. METHODS: We developed a prototype CBCT that has a flat-panel-type detector. The detector consists of a CsI scintillator screen and a photosensor array. First, the flat panel detector and image intensifier detector were compared in terms of the signal-to-noise ratio (SNR) of projected images. We then used these data and a theoretical formula to evaluate noise in reconstructed images. Second, reconstructed images of a bar pattern phantom were obtained as a way of evaluating the spatial resolution. Then, reconstructed images of a skull phantom were obtained. RESULTS: The SNR of the developed system was 1.6 times as high as that of a system with an image intensifier detector of equal detector pitch. The system was capable of resolving a 0.35 mm pattern and its field of view almost completely encompassed that of an image intensifier detector which is used in dentomaxillofacial imaging. The fine spatial resolution of the detector led to images in which the structural details of a skull phantom were clearly visible. CONCLUSIONS: The system's isotropically fine resolution will lead to improved precision in dental diagnosis and surgery. The next stage of our research will be the development of a flat panel detector system with a high frame acquisition rate.

Algorithms↗

PubMed2004

Short communication: Diurnal profiles of conjugated linoleic acids and trans fatty acids in ruminal fluid from cows fed a high concentrate diet supplemented with fish oil, linseed oil, or sunflower oil.

Trans-18:1 and 18:2 isomer composition in ruminal fluid during the daily feeding cycle was examined in 3 cows fed a high concentrate diet (35:65) with 5% (DM basis) sunflower oil (SO), 5% linseed oil (LO), or 2.5% fish oil (FO) in a 3 x 3 Latin square with 3 4-wk periods. Grass hay and concentrate mixtures were fed at 0900, 1300, and 1700 h daily. Ruminal fluid was collected at 0900, 1100, 1300, 1500, 1700, 2000, and 0000 h. Feeding SO resulted in the greatest mean concentrations (% of total fatty acids) of trans10,cis12-18:2 and cis9,trans11-18:2. In particular, trans10,cis12-18:2 with SO was greater at 1500 (0.29%), 2000 (0.34%), and 0000 h (0.25%) relative to 0900 h (0.07%). Cis9,trans11-18:2 concentration increased from 0.47% at 0900 h to a peak of 2.06% at 1100 h; it remained greater than the percentage determined at 0900 h at 1300 (1.4%) through 0000 h (1.1%). Concentration of trans11,cis15-18:2 was greatest with LO, ranging from 3.3% (0900 h) to a peak of 11.4% at 2000 h. Mean trans10-18:1 concentration ranked by diet was SO > FO > LO. Peak trans10-18:1 with SO was observed at 1700 h (14.9%) compared with 0900 h (5.1%). Trans11-18:1 did not differ with diet or time. Stearic acid decreased over time with all diets reaching minimum concentrations at 1700 to 2000 h relative to 0900 h. Feeding FO, however, decreased mean 18:0 concentration 4-fold compared with LO or SO. The moderate effect on concentration of trans-18:1 coupled with accumulation of 18:2 intermediates and the decrease of 18:0 over time suggest that oils reduced the biohydrogenation of 18:2 isomers to trans-18:1.

Animals↗

PubMed2004

Biohydrogenation, duodenal flow, and intestinal digestibility of trans fatty acids and conjugated linoleic acids in response to dietary forage:concentrate ratio and linseed oil in dairy cows.

Duodenal flows of hydrogenation intermediates in response to changes in dietary forage:concentrate ratio (F:C) and linseed oil were evaluated using 4 lactating Holstein cows fed a low (65:35 forage to concentrate) or high (35:65) concentrate diet without (LC, HC) added oil or with linseed oil (LCO, HCO) at 3% of DM. A 4 x 4 Latin square design was implemented for 5 wk. Lower hydrogenation of 18:2n-6 and 18:3n-3 was observed with HC, but it increased with LCO or HCO. Duodenal flow of total conjugated linoleic acids (CLA) increased by 1.40 (LCO) to 3.01 (HCO) g/d with linseed oil. This response was associated with greater flows of cis9,trans11- (+0.21 to +0.55 g/d), trans11,cis13- (+0.33 to +0.36), trans11,trans13- (+1.01 to +1.15 g/d), and trans,trans-CLA (+0.12 to +0.72 g/d). Trans10,cis12-CLA flow averaged 0.08 g/d and was not affected by F:C or oil. trans11,cis15-18:2 flow increased by 8.5 (LCO) to 62 (HCO) g/d in response to linseed oil. Total trans-18:1 flow was 37 g/d in cows fed LC and increased to 81 g/d with HC. Feeding oil increased total trans-18:1 to the greatest extent with HCO. Flow of trans10-18:1 was lower with LC than with HC (1.46 vs. 20 g/d). Linseed oil increased trans11-18:1 flow by 40 (LCO) to 113 g/d (HCO). Feeding LCO and HCO also increased flows of trans6+7+8-, trans13+14-, trans15-, and trans16-18:1. Apparent intestinal digestibility of trans-18:1 isomers was largely unaffected by concentrate level and ranged between 67 and 95%. Linseed oil increased digestibility of nearly all isomers by 3 to 16 percentage units. Digestibility of cis9,trans11-CLA was greater in cows fed HC (55%) compared with cows fed LC (32%) and was not affected by linseed oil. Data suggest that high concentrate diets enhanced ruminal outflow of trans10-18:1. We provide initial in vivo evidence that supplemental 18:3n-3 is hydrogenated to trans11,cis15-18:2, trans11-18:1, trans13+14-18:1, trans15-18:1, trans6+7+8-18:1, and trans16-18:1 primarily.

Animals↗

PubMed2004

[Negative pleural cytology after intrapleural perfusion hyperthermo-chemotherapy for malignant pleural effusion].

We gave intrapleural perfusion hyperthermo-chemotherapy to a 72-year-old woman in whom malignant pleural effusion developed after surgery for primary cancer. This procedure involved irrigating the pleural space for 2 hours with a water solution at 42-43 degrees containing 240 mg cisplatin using specially devised extracorporeal circuits. Thoracoscopy was used to examine the intrapleural cavity and to place the catheters for perfusion. The patient had an uneventful postoperative course and was discharged for hospital on the second postoperative day. Thereafter, she experienced good quality of life with negative pleural cytology. Unfortunately, the patient died 3 months after the therapy, but the cause of death was unknown and there was no cancer recurrence. This technique may be safe and feasible for controlling malignant effusion to preserve quality of life, although the survival benefit has not yet been clarified.

Aged↗

PubMed2004

[Mechanism of the brain's adaptation to stress].

To clarify the mechanism of adaptation to stress in the brain, we performed neuroimaging studies by functional magnetic resonance imaging and magnetoencephalography. First, to investigate which areas of the brain play an important role in the perception of stressful events, we performed fMRI for recognition of unpleasant words concerning interpersonal relationships. Secondly, we evaluated the effect of various stresses on the sensory gating system by MEG to show whether stress could affect the brain mechanism. Finally, we studied the neural activity associated with the expectancy of emotional stimuli using fMRI and MEG, because of the importance of expectancy in adaptation to stress. Our results suggested that stressful events might be recognized in the same brain regions, that acute stress might affect one brain mechanism, and that expectancy might suppress incoming stressful stimuli.

Adaptation, Physiological↗

PubMed2004

[Thoracoscopic lung biopsy in the diagnosis of diffuse lung disease].

The diagnosis of diffuse lung disease can only be made accurately by performing a thoracoscopic lung biopsy. We evaluated the safety and efficacy of thoracoscopic lung biopsy in diffuse lung disease. Between May 1999 and April 2003, 34 patients were referred to us for thoracoscopic lung biopsy. We compared the clinical characteristics, number of biopsies, operation times, postoperative course, complications, and mortality in 19 patients with dyspnea and 15 patients who were asymptomatic. Although the number of biopsies, operation times, duration of chest drainage, and postoperative stay did not differ significantly between the 2 groups, postoperative oxygen support was needed for significantly longer in the dyspnea group (p =0.038). A pathological diagnosis was established in all patients. Postoperative complications developed in 4 patients. A prolonged air leak in 1 patient and a wound infection in another resolved conservatively, but 2 patients died of acute exacerbation. Thus, we conclude that the indications for surgery must be carefully considered in dyspneic patients with diffuse lung to prevent acute exacerbation.

Biopsy↗

PubMed2003

Effective extracellular trehalose production by Cellulosimicrobium cellulans.

A bacterium isolated from a petal of Casa Blanca Lily (ST26 strain) produced a marked amount of extracellular trehalose (alpha- d-glucopyranosyl-[1,1]-alpha- d-glucopyranose) in culture medium containing glucose. 16S rDNA-based phylogeny showed that ST26 belongs to, or is related to, Cellulosimicrobium cellulans, a close relative of Cellulomonas spp. Various Cellulomonas strains obtained from culture collections also showed extracellular trehalose productivity, suggesting that trehalose production is a common property of this bacterial genus. ST26 accumulated trehalose in medium supplied with glucose but not with sucrose, glycerol or maltose. Effective extracellular trehalose production by ST26 was achieved by supplying 0.5-1% ammonium sulfate and 0.5-1% CaCO(3). The addition of CaCO(3) adjusted the pH of the culture to around 5.0. The optimized culture conditions yielded trehalose from glucose at a conversion rate of 61%. The addition of ammonium sulfate greatly reduced the dry cell weight of ST26 and intracellular content of trehalose, which suggests that the addition of ammonium sulfate makes ST26 cells leak trehalose into the medium. ST26 effectively propagated in minimal medium containing trehalose as a sole carbon source, which suggests that trehalose serves as a carbohydrate reserve of this organism.

Ammonium Sulfate↗

PubMed2003

Doppler effect in resonant photoemission from SF6: correlation between Doppler profile and Auger emission anisotropy.

Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.

Journal Article↗

PubMed2003

Anisotropic ultrafast dissociation probed by the Doppler effect in resonant photoemission from CF4.

The resonant Auger spectrum from the decay of F 1s-excited CF4 is measured. Several lines exhibit a nondispersive kinetic energy as the exciting photon energy is tuned through the resonance region. The F 1s(-1) atomiclike Auger line is split into two components due to the emission of Auger electrons by a fragment in motion, when electron emission is observed along the polarization vector of the light. This Doppler splitting is direct evidence that the core excitation leads to T(d)-->C(3v) symmetry lowering, by elongation of a specific C-F bond preferentially aligned along the polarization vector of the incident photon.

Journal Article↗

PubMed2003

Doppler-free resonant Raman auger spectroscopy of Ne+ 2s2p(5)3p excited states.

Using very high resolution achieved by the Doppler-free resonant Raman Auger technique, we have resolved the lowest terms of the series of inner-valence excitations 2s2p(5)((1,3)P)np 2S, 2P, and 2D in Ne+. The measured Auger anisotropic parameters and branching ratios help to establish the assignments of these levels. The measured lifetime widths are in reasonable agreements with ab initio calculations available in the literature.

Journal Article↗

PubMed2003

Development and disintegration of phragmoplasts in living cultured cells of a GFP::TUA6 transgenic Arabidopsis thaliana plant.

Cultured suspension cells of Arabidopsis thaliana that stably express a green-fluorescent protein-alpha-tubulin 6 fusion protein were used to follow the development and disintegration of phragmoplasts. The development and disintegration of phragmoplasts in the living cultured cells could be successively observed by detecting the green-fluorescent protein fluorescence of the microtubules. In the early telophase spindle, where two kinetochore groups and two daughter chromosome groups had completely separated from one another, fluorescence appeared in the interzone between the two chromosome groups. The fluorescent region was gradually condensed at the previous equator and increased in fluorescence intensity, and finally it formed the initial phragmoplast. The initial phragmoplast moved from the cell center towards the cell periphery, and it lost fluorescence at its center and became double rings in shape. The expansion orientation of the phragmoplast was not always the same as that of the future new cell wall before it came in contact with the cell wall. The phragmoplast did not usually come in contact with the cell wall simultaneously with its entire length. A portion of the phragmoplast which was earlier in contact with the cell wall disappeared earlier than other portions of the phragmoplast. The duration of contact between any portions of the phragmoplast and the plasma membrane of the cell wall was 15-30 min. The fluorescence intensity of the cytoplasm did not seem to be elevated by the disintegration of the strongly fluorescent phragmoplast.

Arabidopsis↗

PubMed2003

Effect of linseed oil supplementation on ruminal digestion in dairy cows fed diets with different forage:concentrate ratios.

The effect of linseed oil (LSO) supplementation on total-tract and ruminal nutrient digestibility, N metabolism, and ruminal fluid characteristics was investigated in dairy cows fed diets containing different forage to concentrate ratios (F:C). The experimental design was a 4 x 4 Latin square with 2 x 2 factorial arrangement of treatments. Four lactating Holstein cows were fed a forage-rich diet without LSO (F; F:C = 65:35, dry matter basis), a forage-rich diet with LSO (FO; F:C = 65:32, 3% LSO), a concentrate-rich diet without LSO (C; F:C = 35:65), or a concentrate-rich diet with LSO (CO; F:C = 35:62, 3% LSO). Total-tract digestibility of DM and OM was greater with supplemental LSO. A tendency for greater total-tract digestibility of NDF and ADF also was observed in cows fed LSO. Ruminal digestibility of NDF or ADF decreased when CO was fed compared with C. In contrast, feeding FO increased NDF or ADF digestibility compared with F. Although ruminal starch digestion was nearly complete with all diets, digestibility was greater when cows were fed C or CO compared with F or FO. Bacterial N flow to the duodenum decreased when FO was fed compared with F. In contrast, feeding CO increased bacterial-N flow compared with C. Neither F:C nor LSO supplementation affected ruminal pH or total VFA concentration in ruminal fluid. However, molar proportion of propionate was greater with C or CO compared with F or FO and increased with LSO supplementation regardless of F:C. Molar proportion of n-butyrate decreased with LSO supplementation. Total protozoal numbers in ruminal fluid decreased markedly only when CO was fed. Overall, data show that feeding LSO had no negative effects on total-tract digestion in dairy cows but may decrease ruminal fiber digestibility when fed with high-concentrate diets. The widely spread idea that LSO decreases digestibility, arising from studies with sheep, did not seem to apply to lactating cows fed 3% LSO.

Animals↗