PubMed Health⌕ Search

Biomedical subjects

K Motoki

Publications and source records attributed to K Motoki.

11 recordsLinked to original sources
PubMed1992

Measurement of sound-pressure distribution in replicas of the oral cavity.

The spatial distributions of sound pressure in artificial oral cavities were measured to examine the characteristics of wave propagation in the vocal tract. The measurement was performed with plaster replicas of the oral cavity, and pure tones were used as the driving signals to obtain both amplitude and phase distributions at varied frequencies. Plane-wave propagation, which has been widely assumed for speech production models, was examined from the measured spatial distributions of sound pressure. Trajectories of media particles and vectorial maps of acoustic intensity, which can be computed from the measured pressure distributions, were also presented to visualize the acoustic field in the oral cavity. The results showed that at certain frequencies there existed points where sound pressure was absolutely zero, with the phase spatially circulating around them. Up to about 4 kHz, except at these certain frequencies, the wave front was almost one-dimensional, though an amplitude gradient was seen in the vertical direction.

Acoustics↗
PubMed1991

Determination of human urinary hyaluronic acid, chondroitin sulphate and dermatan sulphate as their unsaturated disaccharides by high-performance liquid chromatography.

A method for the determination of hyaluronic acid (HA), chondroitin sulphate (CS) and dermatan sulphate (DS) was developed. HA, CS and DS were converted to the corresponding unsaturated disaccharides by digestion with chondroitinase ABC and/or chondroitinase AC-II and determined by high-performance liquid chromatography with fluorimetric detection using 2-cyanoacetamide as a post-column derivatization reagent. The calibration graphs for the unsaturated disaccharides were linear over the range 2 ng - 2 micrograms for each unsaturated disaccharide. This method was applied to the analysis of normal human urine.

Chondroitin Sulfates↗
PubMed1990

[Treatment of adult T-cell leukemia with intravenous administration of IFN-gamma-immunohistochemical studies of infiltrating cells in cutaneous lesions].

Three cases of adult T-cell leukemia (ATL) with cutaneous lesions of disseminated papules or nodules were treated with recombinant human interferon-gamma (IFN-gamma) by intravenous administration. Clinical stage of each case was different, i.e., 1) preleukemic state of ATL (pre-ATL), 2) chronic-type ATL, and 3) crisis-type ATL. We evaluated clinical efficacy of IFN-gamma, and performed immunohistochemical analysis of biopsy specimens derived from cutaneous lesions of the patients both before and during treatment. The case of pre-ATL achieved a complete remission of cutaneous lesions for 18 months. The other cases also obtained clinical responses with a shorter duration, but relapsed while they are still on IFN-gamma therapy. The cutaneous lesions reduced in size during the therapy associated with a decrease in the ratio of Leu3a + 3b (CD4)+ cells in all three cases. After the therapy, Leu7 (HNK-1)+ cells increased in all cases, and LeuM5 (CD11)+ cells did in two. These results suggested that IFN-gamma enhanced tumor immunity although its clinical effect was less clear. Only in the cutaneous lesions of pre-ATL case an increased number of LeuM5+ cells, probably monocyte-macrophage series in host defence, were seen before the therapy. And IFN-gamma was useful for this case after all.

Female↗
PubMed1989

[Long-term follow-up of thallium-201 myocardial scintigraphy in acute myocardial infarction--clinical significance of reverse redistribution during acute period].

To clarify the viability of myocardium in acute myocardial infarction, we examined 18 patients scintigraphically. They underwent rest or stress imaging and delayed imaging of thallium-201 during acute, convalescent and chronic periods. During acute period, a scintigraphic finding of the delayed filling in was observed in 9 cases (50%; Redistribution group). Worsening of the delayed image was observed in 6 cases (33%; Reverse redistribution group). No scintigraphic change of the perfusion defect was observed in 3 cases (17%; No change group). In reverse redistribution group, a remarkable improvement of the delayed image was observed through acute, convalescent and chronic periods. In redistribution group and no change group, no significant improvement was observed. We conclude that the myocardium of the reverse redistribution region during acute period may be viable. In the reverse redistribution region, recanalization of the coronary artery possibly protects myocardial damage from necrosis.

Follow-Up Studies↗
PubMed1977

Hypertensive changes in experimental nephritis combined with experimental hypertension.

The role of hypertension in chronic glomerulonephritis was studied in rats with experimental hypertension and nephrotoxic serum nephritis. Nephrotoxic serum nephritis accelerated the hypertensive course of Godblatt's type of experimental hypertension both in the acute and chronic phases. Malignant hypertension was found to be caused in some rats by the nephrotoxic serum injection in the chronic phase of experimental hypertension. Nephrotoxic serum nephritis was more protracted in SHR than in control rats. These results suggest that hypertensive changes might aggravate glomerulitis, and that nephritic processes also facilitate the hypertensive changes.

Animals↗