Biomedical subjects

K Yukawa

Publications and source records attributed to K Yukawa.

At least 37 records · Page 2Linked to original sources

PubMed1994

Classification of body shape of male athletes by factor analysis.

The purpose of this study was to evaluate the body shape of athletes in comparison with adult non-athletes by factor analysis. The subjects were 210 male adult non-athletes and 485 male high school age and adult athletes participating in 13 different sporting events. Physique, skinfold thickness and body composition of each subject were measured. Measured values from adult non-athletes were analyzed by factor analysis, and body shape of the athletes was then analyzed according to these factors. The results are summarized as follows: 1. Four main factors, that is, body fat, mass, leg length to height ratio and length, which could explain 88.5 percent of total variance, were extracted from the measured values from adult non-athletes. 2. Similarity of body shape between sporting events was analyzed by cluster analysis. Body shape of the athletes could be classified into 3 categories: muscular and well-balanced type; rich muscular and large-built type; and rich muscular and long-torso type. Compared with adult non-athletes, male athletes had less body fat and greater mass except for long-distance runners. The present results suggested that the athletes had body shapes suitable to their sporting events.

Adult↗

PubMed1994

[Testing of synthetic vowels in patients with 22 channel cochlear implant].

In the 22 multi-channel cochlear implant system, F0 information determines the frequency of electrical stimulation, and F1 and F2 information determine the number of stimulating electrodes. We performed tests using synthetic vowels on 16 patients who had undergone 22 channel cochlear implant surgery and 6 months' speech rehabilitation. Information transmission rates were calculated to analyze the response pattern. As a result, 1) the vowel recognition ability of patients with cochlear implant surgery correlated with the number of electrodes being used. 2) The value of vowel confusion decreased so as to be separated by a pair of stimulating electrodes, and the confusion in F1 information was regarded to be less than that for F2 information.

Adolescent↗

PubMed1993

Epoc-1: a POU-domain gene expressed in murine epidermal basal cells and thymic stromal cells.

POU-domain transcription factors are known as developmental regulators which control organ development and cell phenotypes. In order to clarify the roles of POU-domain transcription factors in cell differentiation, we cloned a novel POU family gene, Epoc-1, from a murine thymus cDNA library. The amino acid (aa) sequence of the POU-specific domain of Epoc-1 is almost identical to those of Oct-1 and Oct-2. However, within the POU-homeodomain, 13 out of 60 aa differ between Epoc-1 and Oct-2. Recombinant Epoc-1 products were found to bind specifically to the octamer sequence. Epoc-1 was found to be expressed in skin, thymus, stomach and testis. In situ hybridization experiments and RNase protection assays indicated that Epoc-1 is expressed in the epidermal basal cells of the skin, which contain stem cells unipotent for keratinocyte differentiation and in thymic stromal elements. These results suggest that Epoc-1 might be one of the developmental regulators which controls epidermal development and thymic organogenesis.

Amino Acid Sequence↗

PubMed1993

[Body composition, VO2 max and O2 debt max in elite senior high school male cyclists].

This study was performed to evaluate the physical resources for elite male cyclists of senior high school. Nine track cyclists (mean age, 17.4 years) and seven road cyclists (mean age, 17.3 years) were examined for body composition and cardiorespiratory function (VO2 max and O2 debt max), from 1988 to 1992. These measurements were compared with those of elite junior cyclists, and the progress of physiological function due to one-year training was examined for 7 cyclists. The results were as follows: 1. The mean parameters for track cyclists were recorded: percentage body fat (%Fat): 10.3%; lean body mass (LBM): 56.5kg; VO2 max: 3.93l/min, 62.5ml/kg.min; O2 debt max: 8.81l, 139.1ml/kg. 2. The mean parameters for road cyclists were recorded: %Fat: 10.9%; LBM: 54.9kg; VO2 max: 3.78l/min, 61.4ml/kg.min; O2 debt max: 7.89l, 128.4ml/kg. 3. The average %Fat, LBM, LBM/Ht, VO2 max and O2 debt max were not significantly different between track and road cyclists. 4. The average %Fat and VO2 max (ml/kg.min) of track and road cyclists were similar to those of elite junior cyclists. 5. By training for one year, the average VO2 max (ml/kg.min) and O2 debt max (ml/kg) showed a significant increase of approximately 13.6% and 22.6% respectively. These results indicated that through training 9 track and 7 road cyclists had achieved a superior body composition, aerobic work capacity and anaerobic work capacity, equal to those of elite junior cyclists.

Adolescent↗

PubMed1993

[Body composition (densitometry-hydrostatics), skinfold thickness, BMI and their relationships in junior high school girls].

A study was conducted to evaluate body composition (Hydrostatics = Under-Water Weighing), skinfold thickness, and BMI in 97 junior high school girls, aged 12 to 15, in Nagasaki City. Body density was measured by under-water weighing, and the two compartments--fat weight (Fat) and lean body mass (LBM, or fat free weight: FFW)--were calculated using the formulas of Brozek et al. The results were as follows; 1. Mean values of body density were 1.0501 in first grade girls, 1.0476 in the second grade, and 1.0466 in the third grade. 2. Mean values of percentage body fat (% Fat) were 21.1% in the first grade, 22.1% in the second and 22.5% in the third. 3. Lean body mass (LBM) and LBM/Height increased significantly with advance from the first to the third grade. 4. The correlation coefficient between percent body fat and the sum of two skinfold thicknesses, the sum of three skinfold thicknesses, or the sum of seven skinfold thicknesses were 0.81, 0.80, and 0.82 respectively and all statistically significant (p < 0.001). 5. The correlation coefficient between BMI and the sum of two skinfold thicknesses, the sum of three skinfold thicknesses (r = 0.841) or the sum of seven skinfold thicknesses were 0.85, 0.84, and 0.84 respectively, and all statistically significant (p < 0.001). 6. Mean values of BMI, WSR, ASR, and WHR in all subjects (n = 97) were 19.6, 0.72, 0.39 and 0.43 respectively.

Adolescent↗

PubMed1992

Two forms of the low-affinity Fc receptor for IgE differentially mediate endocytosis and phagocytosis: identification of the critical cytoplasmic domains.

We have previously identified two species of the low-affinity human Fc receptor for IgE, Fc epsilon RIIa and Fc epsilon RIIb, which differ only in a short stretch of amino acids at the N-terminal cytoplasmic end. Their differential expressions on B cells and monocytes suggest that Fc epsilon RIIa and Fc epsilon RIIb are involved in B-cell function and IgE-mediated immunity, respectively. Here we show that Fc epsilon RII-mediated endocytosis is observed only in Fc epsilon RIIa-expressing cells, whereas IgE-dependent phagocytosis is observed only in Fc epsilon RIIb-expressing cells, demonstrating the functional difference between Fc epsilon RIIa and Fc epsilon RIIb. Furthermore, site-directed mutagenesis revealed that the tyrosine residue in the Fc epsilon RIIa-specific region is important for endocytosis, and the Asn-Pro residues in the Fc epsilon RIIb-specific region are required for phagocytosis. These findings suggest that endocytosis and phagocytosis are functionally separable phenomena involving distinct amino acid residues.

Amino Acid Sequence↗

PubMed1992

CT of gastric carcinoma: preliminary results with a new scanning technique.

Usefulness of computed tomography (CT) for the demonstration of gastric carcinoma was evaluated in 250 cases with surgical proof of diagnosis: advanced gastric carcinoma (n = 193), early gastric carcinoma (n = 47), gastric submucosal tumor (n = 8), gastric polyp (n = 1), and benign gastric ulcer (n = 1). CT was performed on prone patients after 400-600 mL of water was orally administered and a 100-mL bolus of nonionic contrast material was injected. Water provided optimal distention and satisfactory contrast to depict the normal gastric wall. Prone positioning allowed visualization of the whole gastric wall except for the fundus and prevented artifacts caused by gas during supine imaging. CT demonstrated gastric tumor as a thickened or abnormally enhanced gastric wall in 95% of advanced carcinomas, 93% of elevated early carcinomas, and 18% of depressed early carcinomas. The authors believe that CT performed with this method is useful and that it should be used in addition to barium and endoscopic studies before surgery is planned.

Carcinoma↗

PubMed1992

Factors contributing to phoneme recognition ability of users of the 22-channel cochlear implant system.

A study was carried out to determine which factors contributed to the vowel and consonant recognition ability of recipients of the 22-channel cochlear implant system. On the basis of the statistical analysis, no isolated factor showed a strong correlation with vowel recognition score. On the other hand, negative correlations were found between patients' consonant recognition scores and postoperative psychophysical percepts such as threshold levels and maximum comfortable loudness levels. However, multiple regression analysis also showed that the combination of lower threshold levels, a larger number of usable electrodes, and wider dynamic ranges contributed to higher consonant recognition scores.

Adult↗

PubMed1992

[Evaluation of the effect of proton pump inhibitors on stomal ulcer].

Four reports on proton pump inhibitors related to the clinical effects on stomal ulcer were reviewed. Two reports were on omeprazole and the other two on lansoprazole, carried out in the pre-marketing stage. They are compared with two reports on H2-receptor antagonists (famotidine and ranitidine), which were also done in the pre-marketing stage. It appears that the proton pump inhibitors bring more rapid ulcer healing than H2-receptor antagonists without severe side effects, and there seems to be no difference in clinical effect between omeprazole and lansoprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1992

[Image analysis of the inner ear with CT and MR imaging: pre-operative assessment for cochlear implant surgery].

Recent progress in magnetic resonance imaging (MRI) has made it possible to obtain detailed images of the inner ear by delineating the lymphatic fluid within the labyrinth. We analyzed CT scans and MR images in 70 ears manifesting profound deafness owing to inner ear lesions and compared their detective ability for inner ear lesions. The following results were obtained. 1) CT scan examination showed slight to extensive ossification of the labyrinth in six ears (9%), whereas MRI examination revealed low to absent signal intensity of the inner ear in nine ears (13%). Therefore, it was concluded that MRI is more sensitive in detecting abnormalities of the inner ear than CT scan. 2) MRI provided useful information as to whether the cochlear turn is filled with lymphatic fluid or obstructed. This point was one of the greatest advantages of MRI over CT scan. 3) Abnormal findings in either or both the CT scan and the MRI were detected in suppurative labyrinthitis occurring secondary to chronic otitis media, bacterial meningitis and in inner ear trauma. However, such abnormal findings were not detected in patients with idiopathic progressive sensorineural hearing loss, ototoxicity or sudden deafness. These findings should be taken into consideration in pre-operative assessment of cochlear implant candidates.

Adult↗

PubMed1991

Facs analysis of myeloid differentiation stages in epiphyseal bone marrow, adjacent to joints affected with rheumatoid arthritis.

To analyze the differentiation stages of myeloids statistically, we adopted a two-color FACS system and used appropriate monoclonal antibodies belonging to CD15, CD16 and CD11b. By using HL60 treated with DMSO or human bone marrow MNCs from patients with rheumatoid arthritis, it was proved that with this system, myeloids could be clearly separated according to differentiation stages. Furthermore, the number of myeloids at certain stages of differentiation in the epiphyseal bone marrow of patients with RA or OA was measured. Nine of 15 samples from RA patients showed immature and relatively mature myeloids, while none of the 8 OA samples did. When the proportions of myeloids in epiphyseal bone marrow MNCs were compared with the clinical features, disease subsets in RA and the degree of synovitis, seemed to be important factors for abnormal myelopoiesis.

Adult↗

PubMed1991

[A case report of primary malignant fibrous histiocytoma of the lung].

In this paper, a case of a 59-year-old female of primary malignant fibrous histiocytoma (MFH) of the lung is reported. The patient, who had dyspnea as a main complaint, presented with an abnormal shadow in the chest about 20 years ago, and rapid increase of the shadow has been recognized from one year ago. A pulmonary tumor of the left upper lobe was diagnosed by chest CT, bronchography, pulmonary arteriography. A left pneumonectomy was performed and metastases in lymph nodes and pleural dissemination were recognized. The tumor was 11 X 8 X 6 cm, white, multiple nodular, and solid with a clear border. Histologic examination showed the storiform pleomorphic type of MFH mixed with fibroblastoid cells and histiocytoid cells. Ga scintigram, bone scintigram, and CT conducted before and after the surgery did not show metastasis, but the patient died due to respiratory insufficiency caused by metastasis to the right pleura at 9 months after surgery.

Female↗

PubMed1990

[Changes of the threshold level in patients with 22-channel cochlear implant].

Psychophysical responses of the patients to electrical stimulation were examined in order to clarify long-term effects of the cochlear implant in 9 patients who had received a 22-channel cochlear implant. Measured items were the minimal threshold level (T-level), the maximum comfortable level (C-level), and the dynamic range between T- and C-level. Measurements were repeated for each electrode every three months over more than 6 months. Following results were obtained. 1) The changes of the T-level were classified into four types as follows, a type with no change, a type with gradual decrease, a type with decrease in two to three months followed by gradual increasing threshold and a type with gradual increasing just after surgery. Even in a last type, the maximum increase in the T-level did not exceed 200 microA and, in most cases, these changes were stabilized within a few months after implantation. 2) The dynamic range gradually increased. It was obvious in both in the middle and apical electrodes, while such increased threshold was not observed in the basal electrodes. 3) In some cases, a few basal electrodes could not been used since they caused uncomfortable sensation or those dynamic ranges became below a certain extent. As a result, it was suggested that the electrical stimulation had not induced serious degeneration of the ganglion cells and the auditory nerve fibers. The reduction in the number of usable electrodes might be due to the surgical trauma to the intracochlear tissue. Therefore, exposing of the scala tympani should be minimal in order to avoid the damage of the cochlea.

Adult↗

PubMed1990

[A case of malignant fibrous histiocytoma of the cecum].

A case of primary malignant fibrous histiocytoma (MFH) of the cecum was reported. Patient was a 52-year-old female, and complained of right lower abdominal pain. The barium enema and abdominal computed tomography demonstrated a localized mass involving the entire circumference of the cecum. Right hemicolectomy was performed and the resected specimen revealed a tumor of 8 X 6 X 5 cm in size extending to the entire circumference of the cecum. The histopathological examination revealed a storiform pattern, which was diagnostic of MHF. The tumor proliferated chiefly in the subserous tissue and partially infiltrated the tunica muscularis propria. The postoperative course was uneventful and she showed no sign of recurrence at 15 months after operation. This is the ninth reported case of primary MFH in digestive organs.

Cecal Neoplasms↗

PubMed1989

Strain dependency of B and T lymphoma development in immunoglobulin heavy chain enhancer (E mu)-myc transgenic mice.

The transgenic mice were produced by injecting eggs of B6 and C3H/HeJ mice with the human E mu-myc gene. Preferential development of B lymphomas was observed in the B6 transgenic mice, whereas the C3H/HeJ transgenic mice developed mostly T lymphomas. The phenotypic activation of B lineage cells but not of T lineage cells was detected in the prelymphomatous transgenic mice of both strains. The transgene was similarly expressed in B and T cells of the transgenic mice of both strains. These results suggest that a high incidence of T lymphomas in the C3H/HeJ transgenic mice may not be due to the preferential activation of or the preferential E mu-myc expression in T lymphocytes. When the bone marrow or fetal liver cells from the prelymphomatous transgenic mice of both strains were transferred into irradiated normal C3H/HeJ mice, most of the recipients developed T lymphomas. Moreover, even when irradiated B6 mice received the hematopoietic stem cells from the prelymphomatous B6 transgenic mice, the incidence of T lymphoma increased up to 50%. These findings suggest that B6 and C3H/HeJ mice might provide the environment that supports the development or growth of B and T lymphomas, respectively, and that such an environment could be modified by irradiation of the mice.

Animals↗

PubMed1989

Structure and function of Fc epsilon receptor II (Fc epsilon RII/CD23): a point of contact between the effector phase of allergy and B cell differentiation.

The Fc epsilon receptor II (Fc epsilon RII/CD23) has been proposed to have multiple functions as a membrane-bound or soluble molecule: a function in B cell growth and differentiation and a role in the effector phase of IgE-mediated immunity. We recently demonstrated the presence of two forms of Fc epsilon RII (Fc epsilon RIIa and Fc epsilon RIIb) whose structures differ only at their N-terminal cytoplasmic regions. The regulatory mechanisms of their expression strongly suggest that Fc epsilon RIIa and Fc epsilon RIIb function in B cells and in the effector cells of IgE-mediated immunity, respectively. To elucidate the function of soluble Fc epsilon RII/CD23 (sFc epsilon RII) the recombinant soluble molecule was produced. This recombinant receptor could competitively block the IgE binding of eosinophils, monocytes and even basophils and could inhibit the IgE-mediated function of effector cells such as monocytes. These findings suggested that sFc epsilon RII could competitively regulate the function of effector cells in IgE-mediated immunity and that the recombinant sFc epsilon RII could be applied clinically for the control of allergic reactions. The expression of Fc epsilon RII on Fc epsilon RII-negative B and T cell lines by cDNA transfection resulted in homocytic aggregation. The function of Fc epsilon RII on B cells as an adhesion molecule was also demonstrated.

B-Lymphocytes↗

PubMed1989

Elevated activity of myeloid growth factor in bone marrow adjacent to joints affected by rheumatoid arthritis.

Myeloid growth activity of rheumatoid arthritis (RA) and normal serum was measured with a newly developed simple method. Abnormally high titers of this activity were found in the bone marrow blood serum adjacent to joints with RA where abnormal myelopoiesis had been found. Maximal activity for myeloid growth was found at a molecular weight of 70 kDa in gel filtration of serum, different from the size of any known factors involved with myelopoiesis.

Adult↗

PubMed1989

[A case of dumbbell neurogenic tumor in the posterior mediastinum].

We have recently experienced a dumbbell tumor that developed in the posterior mediastinum in a 64-year-old male. The patient suffered from dorsalgia one year and a half previously. Chest X-ray examinations revealed a well-defined boundary in the right posterior mediastinum. Myelography followed by computerized tomographic scanning (CT) revealed that the tumor developed in a paravertebral area linked with a vertebral canal through an intervertebral foramen and destructed a rib in growing in the paraspinal muscular layer. Longitudinal incision of about 10 cm was made downward from immediately above the first thoracic spinous process, and the chest was opened by posterolateral incision extending into the muscles of the back in an arc shape. The tumor was entirely excised by additional laminectomy. Since malignant schwannoma was diagnosed histologically, Linac X-ray of 50 Gray was given. The patient is now enjoying his healthy daily life with no postoperative complication 2 years after operation. Myelography followed by CT was proved to be quite useful in evaluating a relationship between the tumor and the spinal cord in the diagnosis of this disease.

Humans↗