Biomedical subjects

A Kodama

Publications and source records attributed to A Kodama.

At least 37 records · Page 2Linked to original sources

PubMed1997

[Development and clinical application of MR simulation system for radiotherapy planning: with reference to intracranial and head and neck regions].

To obtain the optimal radiation field, an MR simulation system (MRSS) has been developed. It basically depends upon the higher soft tissue contrast resolution of MRI than of CT. The system consists of an MR unit, an image processing work-station and a laser marking system. In brief, the procedures are as follows: [1] marking the reference point on the patient's skin out of the MR gantry, and automatic table shift to set the reference point at the center of the magnetic field (CMF); [2] MR imaging (T1W1: SE, TR:500 msec, TE: 20 msec); [3] transfer of MR data to a work-station through floppy disc; [4] postprocessing of MR data using a work-station to perform radiotherapy planning; delineation of ROI for irradiation, calculation of the contour of radiation field along with iso-center; [5] corresponding the reference point correspond with the base point of the laser marking system on the CT table; [6] reproducing the calculated iso-center on the patient's skin using the laser marking system. A phantom study of geographic distortion and the total accuracy of MRSS revealed that the former was less than 1 mm within a 90 mm distance between MR slices and CMF, while the latter showed maximal errors of 2 mm in field size and 3 mm in iso-center. This system was applied to 15 patients with intracranial or head and neck lesions, and all procedures were smoothly performed. In order to evaluate the usefulness of MRSS, 6 experienced radiation oncologists compared the difference between MRSS and a CT simulation system in setting the radiation field. The results were satisfactory in all cases, especially in cases in which the tumor extent was unclear on CT images. In spite of some limitations of MRI such as distortion of image and impossibility of iso-dose curve calculation, it was considered that this system could support radiotherapy planning for intracranial or head and neck regions.

Adult↗

PubMed1997

Correlation between antifungal activity and hydrophobicity of imidazole antifungal agents.

To examine the effects of the affinity of antifungal imidazole agents to cell membranes on the in vitro antifungal activity, the correlation between antifungal activity and hydrophobicity of these drugs was investigated. The capacity factor (k') in HPLC was used as a parameter of hydrophobicity, and the minimum inhibitory concentration (MIC) as a parameter of antifungal activity. Consequently, a significant portion correlation was noted in the case of Candida albicans. However, no obvious correlation was noted for Trichophyton mentagrophytes and Trichophyton rubrum. Therefore, the mechanism of action of imidazole derivatives for Candida albicans was considered to mainly consist in the membrane action.

Antifungal Agents↗

PubMed1996

Trisomy 10 in acute myeloid leukemia.

We observed two patients with acute myeloid leukemia (AML) exhibiting trisomy 10 as the sole chromosome abnormality at the time of diagnosis. One patient was diagnosed with AML-MO, and the other with AML-M2. Both cases were CD7-antigen positive. However, we could not find any distinct clinico-hematologic characteristics of AML with trisomy 10 in these two patients. Trisomy 10 might be a rare recurring numerical chromosome abnormality and the incidence may be about 0.5% in de novo AML.

Aged↗

PubMed1996

Near-hexaploid Ph-positive acute myeloid leukemia with major-BCR/ABL transcript.

We describe the first case of acute myeloid leukemia (AML) with a Philadelphia (Ph) translocation and a near-hexaploid range chromosome number, whose leukemic cells had the major-BCR/ABL transcript. The genesis of near-hexaploid leukemic cells might be due to endoreduplication of triploid leukemic cells with the Ph, since the relapsed leukemic cells had triploid range chromosomes with double Ph chromosomes.

Aneuploidy↗

PubMed1996

Severe acute pancreatitis as a first symptom of primary hyperparathyroid adenoma: a case report.

We present a case of severe acute pancreatitis in a 14-year-old boy that may have been caused by hyperparathyroidism. The clue to finding the parathyroid adenoma was the hypercalcaemia. Although the patient did have acute pancreatitis, no therapy had been effective until the discovery of the parathyroid adenoma. After the excision of the parathyroid adenoma, the function of the pancreas and serum calcium returned to normal. This result suggests a certain cause and effect relationship between hyperparathyroidism and acute pancreatitis.

Acute Disease↗

PubMed1996

Mild form of beta-ketothiolase deficiency (mitochondrial acetoacetyl-CoA thiolase deficiency) in two Japanese siblings: identification of detectable residual activity and cross-reactive material in EB-transformed lymphocytes.

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inherited metabolic disorder of isoleucine and ketone body catabolism. We report the cases of two siblings who showed clinically mild forms of this disorder. They did not excrete tiglylglycine in urine. Their EB-transformed lymphocytes contained residual T2 activity, which was confirmed by immunotitration analysis. In immunoblot analysis, the bands corresponding to T2 in the samples of the cell lines from two patients were the most intensely detected among those from 19 T2-deficient cell lines tested.

Acetyl-CoA C-Acyltransferase↗

PubMed1996

[Long-term results of Feldmann's osteoplastic approach for chronic middle ear disease].

Between 1978 and 1981, Feldmann's osteopathic approach was often used to manage chronic middle ear disease. In this procedure, the superior and posterior segment of the ear canal wall was cut after complete mastoidectomy, removed temporarily and re-positioned in the previous position after handling the diseased focus in the tympanic isthmus area. Forty-one cases (24 cases of non-cholesteatomatous chronic otitis media and 17 cases of cholesteatoma) were followed and long-term results of this procedure were studied with regard to re-operative findings following this procedure. Among the 41 patients, 13 (31.7%) required revision surgery because of cholesteatoma formation, infection etc. Seven of these 13 patients (53.8%) required revision surgery because of cholesteatoma formation after this procedure. None of these 7 cases appeared to involve residual cholesteatoma. The most important problem is that 3 of the 7 patients showing cholesteatoma formation had non-cholesteatomatous chronic otitis media before this procedure. In other words, the Feldmann's osteoplastic approach may iatrogenically induce cholesteatoma formation in non-cholesteatomatous chronic otitis media. The re-operative findings indicated that the re-positioned canal wall in this procedure may have small bony defects or bony erosion, inducing pocket formation through these defects to create a new cholesteatoma. Although recent literature concerning tympanoplasty recommends posterior canal wall reconstruction using cartilage, bone, ceramic material or bone-pate rather than the canal wall down method, careful follow-up should be continued with regard to pocket formation and/or cholesteatoma formation.

Cholesteatoma, Middle Ear↗

PubMed1995

A preadipocyte clonal line from bovine intramuscular adipose tissue: nonexpression of GLUT-4 protein during adipocyte differentiation.

A clonal bovine intramuscular preadipocyte (BIP) line has been established from the intramuscular white adipose tissue of the M. longissimus thoracis in each of three Japanese Black cattle. Exponentially growing BIP cells exhibited a fibroblastic appearance. Adipocyte differentiation was initiated by treating confluent BIP cells with differentiation medium containing insulin and dexamethasone. Small lipid droplets appeared 5-6 days after stimulation and occupied a large fraction of the cell volume at 10 days and beyond. During the adipose conversion, the incorporation of acetate to the cells gradually increased by 10-fold and reached a maximum at day 5. However, incorporation of glucose increased only 3-folds prior to this conversion, even though GLUT-1 level increased by 13-fold at day 7. GLUT-4, on the other hand, was not detected during the course of differentiation. These results suggested that adipose tissue metabolisms in ruminants were different from that of non-ruminants.

Acetates↗

PubMed1995

Clinical findings in Menière's disease with bilateral fluctuant hearing loss.

Our department conducted an examination of the clinical characteristics of Menière's disease with bilateral fluctuant hearing loss, using data obtained in a survey involving sixteen institutes associated with the Vestibular Disorder Research Committee, Japan. A total of 480 cases were surveyed, of which 204 showed normal hearing in the second ear, and were thus classified as unilateral Menière's disease, or Menière's disease with unilateral involvement; 135 cases showed fluctuating cochlear symptoms in the second ear, and were therefore classified as Menière's disease with bilateral fluctuant hearing loss or bilateral involvement. Our results show that patients with bilateral involvement experience increased disruption of daily life activities, and respond poorly to therapy with diuretics or steroids. Hospitalization is often considered for these patients. For these reasons it is especially important that bilaterality be diagnosed as early as possible, and that intensive treatment be carried out. ENT specialists must recognize the seriousness of bilateral involvement, and take particular precautions against its occurrence.

Activities of Daily Living↗

PubMed1995

Late appearance of a Philadelphia translocation with minor-BCR/ABL transcript in a t(7;11)(p15;p15) acute myeloid leukemia.

We describe a patient with a t(7;11)(p15;p15) acute myeloid leukemia who was subsequently found to harbor the Philadelphia (Ph) translocation, in addition to the t(7;11), at the second relapse. A BCR/ABL transcript was detected at the second relapse by reverse transcription-polymerase chain reaction assay; the leukemic cells had a BCR/ABL fusion gene involving the minor breakpoint cluster region (minor-BCR; situated in intron 1 of the BCR gene). Although the Ph translocation is commonly detected in de novo acute leukemia and chronic myeloid leukemia as the primary leukemia-specific chromosomal translocation, our case suggests that this cytogenetic change might occur as an additional chromosomal change in neoplastic cells. Moreover, minor-BCR/ABL rearrangements may also occur as a late appearance of Ph translocation.

Base Sequence↗

PubMed1994

Tinnitus evaluation using the tinnitus grading system.

We developed a system to help evaluate the likelihood of a particular patient requiring intensive tinnitus treatment. The system is based on Vernon's tinnitus grading system, in which patients assign values from 1 to 5 to each of the three subjective complaints of loudness, annoyance, and interference with life activities. In our study, we collected data from 346 of our tinnitus patients and analyzed the relationship between the three values. On the basis of these results the patients were divided into five tinnitus-type groups. Scores on a tinnitus severity scale were also determined by adding the three values together. We similarly evaluated 87 patients whose tinnitus was severe enough to require hospitalization. It was found that patients who had high values for annoyance and life interference and who showed tinnitus severity scores of 9 or more tended to require careful observation and intensive treatment. These patients also tended to have physical and psychological problems in addition to their tinnitus.

Activities of Daily Living↗

PubMed1994

A soundproof pressure chamber.

For neurotological research we designed a soundproof pressure chamber in which pressure can be adjusted +/- 1000 mmH2O at the rate of less than 100 mmH2O per second. Noise in the chamber can be maintained under 30-35 dB while pressure is kept at a given level.

Atmosphere Exposure Chambers↗

PubMed1994

Effect of atmospheric pressure on hearing in normal subjects.

Hearing is assumed to be altered during or immediately after a change in atmospheric pressure, although this has not been tested experimentally. We used a soundproof pressure chamber to examine the effect of alterations in atmospheric pressure on hearing in 26 normal healthy subjects. The subjects were placed in the soundproof pressure chamber in a supine position and instructed to actively equilibrate middle ear pressure or to abstain from doing so. When the pressure was changed to +/- 500 mmH2O at 33 mmH2O/s the results were as follows: When subjects did not equilibrate middle ear pressure, air conduction at low frequency tones increased more than bone conduction. The degree of deterioration in hearing was greater when the chamber pressure was increased (descent) than where pressure was decreased (ascent). When the subjects equilibrated middle ear pressure, little change in the levels of air or bone conduction was observed. Most of the deterioration in bone conduction was considered to reflect functional loss due to increased stiffness and damping of the sound transmission mechanism.

Adult↗

PubMed1994

Mechanism of hearing disturbance due to alteration in atmospheric pressure.

We used a soundproof pressure chamber to examine how the changes in atmospheric pressure as experienced in daily life reduces bone conduction in a total of 48 normal adults. The subjects were given special ear plugs that connected external auditory canal to the pressure gauge and a small pump located outside the chamber, and were instructed not to swallow, to avoid active opening of the Eustachian tube. The chamber pressure was increased (or decreased) to +/- 500 mmH2O at a rate of 33 mmH2O/s. Then pressure in the external auditory canal was increased (or decreased) gradually after the chamber pressure had reached +/- 500 mmH2O, to equilibrate the pressure across the ear drum. Bone conduction did not recover the level before increase (or decrease) in the chamber pressure. We conclude that at least a minor part of the deterioration in bone conduction after changes in the chamber pressure was caused by displacement of the round window membrane.

Adult↗

PubMed1994

Test for pressure control capacity of the Eustachian tube.

Because of Eustachian tube controls middle ear pressure to maintain the best hearing level, we tested the equilibration capacity of the Eustachian tube by measuring hearing levels in a soundproof pressure chamber. The number of swallows to recover normal hearing after the chamber pressure reached -200 mm H2O (an index of equilibration capacity for the static pressure differences across the eardrum) was less than 9 in normal subjects. The worst level of hearing and the time required to recover normal hearing from the beginning of alteration in the chamber pressure to -700 mm H2O (indexes of equilibration capacity for dynamic pressure differences across the eardrum) were 0-17 dB and within 120s in normal subjects. It was difficult to determine definitive normal ranges of the equilibrium capacity of the Eustachian tube when positive pressure was applied.

Adult↗

PubMed1994

A ventilation capacity test for the Eustachian tube using a soundproof pressure chamber.

Using a soundproof pressure chamber, we performed Békésy air conduction audiometry at 1000 Hz under the following pressure conditions: 1) from atmospheric pressure (AP) to 200 mmH2O below AP, 2) AP to 200 mmH2O above AP, 3) AP to 700 mmH2O below AP, and 4) AP to 700 mmH2O above AP. In conditions 1) and 2), the patient was instructed not to swallow until the pressure change was complete, then to swallow once every 15 seconds. The number of swallows required for hearing to return to the baseline level was counted. In conditions 3) and 4), the patient was told to swallow as many times as possible both before and after completion of the pressure change; maximum hearing level and the time needed for return to the baseline level were measured. Although all except one of the seven patients with suspected tubal dysfunction showed normal results with catheter insufflation and tympanometry, six of the seven showed abnormality and one reported the disappearance of ear stuffiness after the ventilation capacity test. We concluded that this test is useful not only for the diagnosis of tubal dysfunction but also as a possible therapy for aiding adaptation to changing environmental pressure.

Acoustic Impedance Tests↗

PubMed1994

Pressure test in normal subjects.

The application of pressure to the middle ear changes the normal inner ear pressure in animal experiments. In this study we tested the effect of exposure to under- or overpressure on hearing in a total of 78 normal ears (40 subjects) in a soundproof pressure chamber. [After exposure to underpressure, a 10 dB or more gain in 3 ears and loss in 2 ears for at least one of the test frequencies was observed in 38 ears. After exposure to overpressure, a 10 dB or more gain in 5 ears and loss in 1 ear for at least one of the test frequencies was observed in 40 ears.] The characteristics of transferred inner ear pressure during a series of exposures to underpressure seemed to be similar to those during exposures to overpressure.

Acoustic Impedance Tests↗

PubMed1994

Pressure test for the diagnosis of Menière's disease.

In the last 15 years, a pressure chamber able to generate negative air pressure has been used to treat patients with Menière's disease. In this study we sought to clarify whether the underpressure chamber can be used to diagnose Menière's disease. We studied 45 ears from patients with neurotological diseases. The subjects were placed supine in a soundproof pressure chamber. The pressure was first decreased to -500 mmH2O, and after 5 min to -700 mmH2O. The pressure was kept at this level for another 5 min and then increased to 0 mmH2O. This procedure was done three times in succession. While the chamber pressure was below 0 mmH2O, the subjects were instructed to abstain from actively equilibrating middle ear pressure. When the chamber pressure was raised to 0 mmH2O, they were instructed to equilibrate middle ear pressure, and if necessary Politzerization or catheterization of the Eustachian tube was done. As a result, hearing was improved after this procedure only in patients with Menière's disease (50%) and/or cochlear Menière's disease (32%) in which endolymphatic hydrops was suspected.

Acoustic Impedance Tests↗