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Biomedical subjects

A Kawano

Publications and source records attributed to A Kawano.

At least 37 records · Page 2Linked to original sources
PubMed1996

Does age at cochlear implantation affect the distribution of 2-deoxyglucose label in cat inferior colliculus?

Cochlear implants are one treatment for children who are born deaf or become deaf before acquiring language. The question of optimum age for implantation arises. Using an animal model, we have studied the response of the auditory brainstem to implantation at various ages. Neonatally, pharmacologically deafened cats were implanted with a 4-electrode array in the left cochlea at ages from 100 to over 180 days. Eleven were chronically stimulated (1000 h if possible) with charge-balanced, biphasic current pulses; eight were unstimulated controls. In a terminal experiment, each animal received [14C]2-deoxyglucose i.v. preceding a 45-min stimulation program. The fraction of the right inferior colliculus (IC) with a significant accumulation of label was calculated. If age at implantation were a significant factor in determining the size of the responding region, the fraction would depend on the age; this was not observed. However, there was considerable variation in the IC fraction sizes within both stimulated and unstimulated groups, leading to the conclusion that there are factors other than age which determine the size of the responding region. Thus, for deaf children of corresponding ages, age at implantation may not be of critical importance.

Aging↗
PubMed1996

Computer-aided three-dimensional reconstruction in human cochlear maps: measurement of the lengths of organ of Corti, outer wall, inner wall, and Rosenthal's canal.

This paper describes the application of computer-aided three-dimensional reconstruction to measurements of the length of the organ of Corti (mean +/- SD, 35.58 +/- 1.41 mm), scala tympani outer wall (40.81 +/- 1.97 mm), scala tympani inner wall (18.29 +/- 1.47 mm), and Rosenthal's canal center (15.98 +/- 1.33 mm) in eight adult male cochleas. The Rosenthal's canal center ranged between 1 3/4 and 2 turns, did not appear to be linearly related to the organ of Corti, and lay near the basal end of the latter. The length of the organ of Corti measured with three-dimensional reconstruction differed by 7.6% +/- 3.2% ("cutting angle difference") from that derived from traditional two-dimensional reconstruction on the plane perpendicular to the plane of section, and by 2.6% +/- 1.7% ("geometric difference") from that derived from two-dimensional reconstruction on the axial plane at right angles to the modiolar axis.

Aged↗
PubMed1996

[Comparison of speech perception with cochlear implant and hearing aid--analysis according to speech strategy and hearing level].

This study was carried out to compare the speech perception ability of patients using hearing aids with hearing levels of 81dB or more (55 patients) and those with cochlear implants (67 patients). The patients with hearing aids were divided into group A (hearing levels 81-90dB, 7 patients), group B (91-100dB, 11 patients), group C (101-110dB, 19 patients), group D (111-120dB, 7 patients), and group E (121-130dB, 6 patients). The patients with cochlear implants were using the strategies of F0F1F2 (14 patients), MPEAK (32 patients) and SPEAK (21 patients). Speech perception tests of monosyllables, words, and sentences under conditions of auditory plus vision were administered. The means and standard deviations of percentages giving the correct answer in F0F1F2, MPEAK and SPEAK were 45.2 +/- 14.7%, 45.7 +/- 14.6% and 62.6 +/- 15.9% for monosyllables, 44.8 +/- 18.9%, 56.3 +/- 15.0% and 73.4 +/- 15.5% for words, and 64.0 +/- 26.4%, 60.5 +/- 15.9% and 84.7 +/- 13.8% for sentences. In comparison with the results for patients with hearing aids, and speech perception for F0F1F2 and MPEAK was equivalent to that of group C, and that for SPEAK was better than that of group B but poorer than that of group A. In other words, the speech perception ability in conventional cochlear implant strategies--F0F1F2 and MPEAK--corresponded to that of patients with hearing levels of 101-110dB, but that in the new strategy, SPEAK, gave better results than 91-100dB.

Adolescent↗
PubMed1996

[Effects of chronic electrical stimulation on cochlear nuclear neuron size in deaf kittens].

It is now well recognized that normal afferent innervation is necessary for development of the auditory pathway. This study investigated the effect of chronic electrical stimulation of the auditory nerve on the size of cochlear nucleus somata of neonatally deafened kittens. Four kittens were deafened by using kanamycin and ethacrynic acid at 10 days of age and implanted at various ages with an active intracochlear implant in the left side and a dummy implant in the right side, and chronically electrically stimulated from ages 98-142 days for approximately 1000 hours at twice the EABR threshold. After chronic stimulation or after an equivalent period in the controls, the animals were injected with 2-deoxyglucose (2DG) and stimulated electrically for 45 minutes, then processed for autoradiography. Then the sections were stained for Nissle substance, and the cross-sectional areas (CSSA) of approximately 33,000 neuron somata in the cochlear nuclei were measured with an image-analysis system. Soma sizes in regions with 2DG uptake were compared with those without the uptake. The CSSA of 2DG-labeled regions was usually significantly larger than that of the unlabeled regions, but there were no significant right-left differences. Thus, chronic electrical stimulation of a restricted sector of the cochlea is correlated with a larger soma size in the corresponding region of the cochlear nucleus.

Animals↗
PubMed1994

Enzyme immunoassay of motilin in human plasma.

A sensitive and specific double-antibody enzyme-linked immunoassay (EIA) for detecting a motilin-like immunoreactive substance (M-IS) in human plasma has been developed. In competitive reactions, the motilin antibody was incubated with a plasma sample (or motilin standard) and beta-D-galactosidase-linked synthetic motilin. Free and antibody-bound enzymes were separated using an anti-rabbit IgG-coated immunoplate. Enzyme activity on the plate was determined by fluorophotometric analysis. This immunoassay allows the detection of 20 to 200 fmol/ml (54 to 540 pg/ml) of motilin. The mean level of M-IS detected in human plasma was 53.9 +/- 25.6 pg/ml.

Adult↗
PubMed1993

[Practical hearing compensation and an assessment of hearing effect in patients with profound hearing loss using hearing aids].

This investigation was carried out to study practical hearing compensation with hearing aids and the correlation between subjective evaluation (questionnaire survey) and objective evaluation (speech perception test) as an assessment of hearing aid effect in patients with profound hearing loss. 1. Forty-nine patients with hearing levels of 90dB or more (23 men and 26 women) were examined. Their mean and median hearing levels were 105.9dB (standard deviation: 10.4dB) and 106.3dB, respectively. The patients ranged in age from 18 to 74, with a mean age of 47.4. 2. Subjective evaluation was carried out by a questionnaire survey in which the patients chose one of 4 or 5 graded categories in 10 different hearing conditions, and three items of "satisfactory", "uneasiness" and "effectiveness". Speech sound discrimination ability for vowels and monosyllables, and speech intelligibility of words and sentences, were evaluated in audition only (A), vision only (V) and a combination of both (A + V), totaling 12 conditions with hearing aids as the objective evaluation using video tapes materials. 3. The subjective evaluation revealed that 60% of patients with hearing loss of 90-110dB understood "one to one conversation in a quiet place". Speech perception was poorer in "conversation in a noisy place" than in "conversation in a quiet place". Speech perception became poorer in the order of "one to one", "to a few people", and "to many people". For subjective feeling, 56.4% answered "satisfactory", and for hearing aid effectiveness, 78.7% answered "effective". 4. In the objective evaluation, the rates of correct answers were 19.6% in A and 46.3% in A + V for monosyllables, 19.8% in A and 43.4% in A + V for words, and 29.5% in A and 60.0% in A+V for sentences. 5. There were significant correlations (p < 0.001) between subjective evaluation of "in a quiet place and one to one conversation" (among other conditions) and objective evaluations of monosyllables, and word and sentence recognition, mostly in A and A + V. These results suggest that hearing compensation by hearing aids can be evaluated objectively in patients with profound hearing loss when word and sentence recognition tests are performed in addition to the monosyllable recognition test, and it is more practical if vision is examined in addition to hearing for speech perception in patients with profound hearing loss.

Adolescent↗
PubMed1992

Enzyme immunoassay of angiotensin II in human plasma.

We established a highly sensitive double-antibody enzyme immunoassay (EIA) for angiotensin (ANG) II. For competitive reactions, the ANG II-antibody was incubated with ANG II standard (or sample) and beta-D-galactosidase-labeled ANG III (delayed addition). Free and antibody-bound labeled antigen were separated using an anti-rabbit immunoglobulin G (IgG) coated immunoplate. The enzyme activity on the plate was fluorometrically determined. The present immunoassay allows detection of 0.4 to 72 fmol/well of ANG II. Using the present EIA, ANG II-like immunoreactivity (-LI) in human plasma was determined. The level of ANG II-LI in human plasma from 10 healthy volunteers was 33.3 +/- 10.4 pmol/l.

Amino Acid Sequence↗
PubMed1989

[Direct observation of the tympanic cavity by the superfine fiberscope].

As a clinical test, direct observation of the middle ear should be ideally performed without any surgical intervention such as myringotomy. This paper reports a newly invented superfine fiberscope which makes it possible to insert through the eustachian tube, and direct views of the middle ear structures on normal subjects and patients. The patients were of a small cholesteatoma and traumatic dislocation of the ossicular chain. All of them were tested with local anesthesia in outpatient clinic. This superfine fiberscope was of great value in observing of middle ear structures as a diagnostic instruments, as that no surgical intervention was necessary in the procedure.

Adult↗
PubMed1985

[Liposarcoma arising from the renal capsule].

Liposarcoma is one of the most common soft tissue sarcomas, but liposarcoma arising from the renal capsule is rare. We report a case of liposarcoma arising from the renal capsule. Preoperative diagnosis was achieved by computerized tomography and and selective renal angiography. The tumor resected with he left kidney which weighed 4,370 g. Postoperative adjuvant chemotherapy with cyclophosphamide, bleomycin, actinomycin D, adriamycin and vinblastine was carried out. Although the patient's general conditions was fine, local recurrence occurred after 24 months postoperatively. Five cases of liposarcoma arising from the renal capsule including our case have been reported in Japan.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Immunohistochemical detection of carcinoembryonic antigen in benign hyperplasia and adenocarcinoma of the prostate with monoclonal antibody.

Immunoperoxidase localization of carcinoembryonic antigen was done on tissue sections of benign hyperplasia and adenocarcinoma of the prostate using murine monoclonal antibody against carcinoembryonic antigen. The study was done to determine whether carcinoembryonic antigen would be a tissue marker of prostatic malignancy. Of 30 benign lesions 25 (83 per cent) were negative and 5 had focally weak staining, while of 36 adenocarcinomas 31 (86 per cent) had diffusely positive staining and 5 were negative. Diffusely moderate or strong staining was noted in 5 of 10 grade I (50 per cent), 11 of 12 (92 per cent) grade II and 13 of 14 (93 per cent) grade III tumors, as well as 14 of 15 (93 per cent) tumors from patients with bone metastasis. These findings suggested that extensive immunostaining for carcinoembryonic antigen in prostatic glandular lesions might be a potentially important prognostic marker of malignancy. Further studies are warranted to extend and confirm these results.

Adenocarcinoma↗
PubMed1984

[Clinical study of squamous cell carcinoma of the bladder].

Clinical and statistical observations were made on 15 cases of squamous cell carcinoma of the bladder experienced at our department during the past 19 years. The patients were 10 men and 5 women ranging in age from 41 to 80 years (median: 65.1 years). Forty percent of the chief complaints was bladder irritability without macrohematuria. The prognosis was very poor. Three-year and five-year survival rates were 32.3% and 26.1% respectively.

Adult↗