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Y Komatsubara

Publications and source records attributed to Y Komatsubara.

At least 19 recordsLinked to original sources
PubMed2006

DNA strand breaks are not induced in human cells exposed to 2.1425 GHz band CW and W-CDMA modulated radiofrequency fields allocated to mobile radio base stations.

We conducted a large-scale in vitro study focused on the effects of low level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system in order to test the hypothesis that modulated RF fields may act as a DNA damaging agent. First, we evaluated the responses of human cells to microwave exposure at a specific absorption rate (SAR) of 80 mW/kg, which corresponds to the limit of the average whole body SAR for general public exposure defined as a basic restriction in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Second, we investigated whether continuous wave (CW) and Wideband Code Division Multiple Access (W-CDMA) modulated signal RF fields at 2.1425 GHz induced different levels of DNA damage. Human glioblastoma A172 cells and normal human IMR-90 fibroblasts from fetal lungs were exposed to mobile communication frequency radiation to investigate whether such exposure produced DNA strand breaks in cell culture. A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 mW/kg and CW radiation at 80 mW/kg for 2 and 24 h, while IMR-90 cells were exposed to both W-CDMA and CW radiations at a SAR of 80 mW/kg for the same time periods. Under the same RF field exposure conditions, no significant differences in the DNA strand breaks were observed between the test groups exposed to W-CDMA or CW radiation and the sham exposed negative controls, as evaluated immediately after the exposure periods by alkaline comet assays. Our results confirm that low level exposures do not act as a genotoxicant up to a SAR of 800 mW/kg.

Cell Line↗
PubMed2006

Effects of a 2450 MHz high-frequency electromagnetic field with a wide range of SARs on the induction of heat-shock proteins in A172 cells.

In this study, we investigated whether exposure to 2450 MHz high-frequency electromagnetic fields (HFEMFs) could act as an environmental insult to evoke a stress response in A172 cells, using HSP70 and HSP27 as stress markers. The cells were exposed to a 2450 MHz HFEMF with a wide range of specific absorption rates (SARs: 5-200 W/kg) or sham conditions. Because exposure to 2450 MHz HFEMF at 50-200 W/kg SAR causes temperature increases in culture medium, appropriate heat control groups (38-44 degrees C) were also included. The expression of HSP 70 and HSP 27, as well as the level of phosphorylated HSP 27 ((78)Ser) (p-HSP27), was determined by Western blotting. Our results showed that the expression of HSP 70 increased in a time and dose-dependent manner at >50 W/kg SAR for 1-3 h. A similar effect was also observed in corresponding heat controls. There was no significant change in HSP 27 expression caused by HFEMF at 5-200 W/kg or by comparable heating for 1-3 h. However, HSP 27 phosphorylation increased transiently at 100 and 200 W/kg to a greater extent than at 40-44 degrees C. Phosphorylation of HSP 27 reached a maximum after 1 h exposure at 100 W/kg HFEMF. Our results suggest that exposure to a 2450 MHz HFEMF has little or no apparent effect on HSP70 and HSP27 expression, but it may induce a transient increase in HSP27 Phosphorylation in A172 cells at very high SAR (>100 W/kg).

Cell Line, Tumor↗
PubMed2001

Spondyloarthropathies in Japan: nationwide questionnaire survey performed by the Japan Ankylosing Spondylitis Society.

OBJECTIVE: The Japan Ankylosing Spondylitis Society conducted a nationwide questionnaire survey of spondyloarthropathies (SpA) in 1990 and 1997, (1) to estimate the prevalence and incidence, and (2) to validate the criteria of Amor and the European Spondylarthropathy Study Group (ESSG) in Japan. METHODS: Japan was divided into 9 districts, to each of which a survey supervisor was assigned. According to unified criteria, each supervisor selected all the clinics and hospitals with potential for SpA patients in the district. The study population consisted of all patients with SpA seen at these institutes during a 5 year period (1985-89) for the 1st survey and a 7 year period (1990-96) for the 2nd survey. RESULTS: The 1st survey recruited 426 and the 2nd survey 638 cases, 74 of which were registered in both studies. The total number of patients with SpA identified 1985-96 was 990 (760 men, 227 women). They consisted of patients with ankylosing spondylitis (68.3%), psoriatic arthritis (12.7%), reactive arthritis (4.0%), undifferentiated SpA (5.4%), inflammatory bowel disease (2.2%), pustulosis palmaris et plantaris (4.7%), and others (polyenthesitis, etc.) (0.8%). The maximum onset number per year was 49. With the assumption that at least one-tenth of the Japanese population with SpA was recruited, incidence and prevalence were estimated not to exceed 0.48/100,000 and 9.5/100,000 person-years, respectively. The sensitivity was 84.0% for Amor criteria and 84.6 for ESSG criteria. CONCLUSION: The incidence and prevalence of SpA in Japanese were estimated to be less than 1/10 and 1/200, respectively, of those among Caucasians. The adaptability of the Amor and ESSG criteria was validated for the Japanese population.

Adult↗
PubMed1996

[Clinical characteristics and genetic background of secondary amyloidosis associated with rheumatoid arthritis in Japanese].

In order to examine the clinical characteristics and genetic background of secondary amyloidosis associated with rheumatoid arthritis, we analyzed clinical features and HLA typing of 85 patients in a multicenter study. Eighty-five patients with secondary amyloidosis associated RA were studied. The diagnosis of secondary amyloidosis were made on histological findings by biopsy or autopsy. The most common biopsy site was gastrointestinal tract (79.5%). Clinical symptom and the frequency at the time of diagnosis were; diarrhea (35 cases), abdominal pain (22 cases) and vomiting and nausea (16 cases). Abnormalities and the frequency in a laboratory test included proteinuria (49 cases), increased serum creatinine (32 cases), anemia (30 cases) and hematuria (15 cases). Twenty-eight patients were dead and 57 patients were alive at the time of the study. The average duration between diagnosis of amyloidosis and death was 19.4 +/- 18.5 (SD) months among the dead patients. The average duration after diagnosis of amyloidosis was 24.2 +/- 19.5 (SD) months in surviving patients. The causes of death were renal failure complicated with heart failure (6 patients), heart failure alone (3 patients) and renal failure alone (2 patients). Fifty-nine patients in the control group who were negative to amyloid deposition on biopsies at more than one site in the gastrointestinal tract, were clinically compared with patients in the amyloidosis group. No difference were noted in the age of RA occurrence and the stage between the two groups. As to the class, however, the number of patients with severe functional disorder (class 3 or severe) was larger in the amyloidosis group. There were no significant difference between the two groups in Lansbury's activity index. On hematology, biochemistry and urinalysis, the incidences of increased white blood cell count, anemia, increased platelet count, increased serum creatinine, hypoproteinemia, hypoalbuminemia, increased IgA, and increased urine and blood BMG were statistically significantly higher in the amyloidosis group than in the control group. HLA-A, -B, -C, and DR-locus antigens were compared in the 53 patients in the amyloidosis group and in the 59 subjects in the control group. There were no significant differences in frequency of HLA-A, and -B antigens between two groups. Frequency of CW7 antigen was significantly decreased in the amyloidosis group (13.2%) than in the control group (39.0%). Frequency of DR1 antigen was decreased in the amyloidosis group (3.8%) than in the control group (22.0%), although the difference was not significant. These findings suggest the possible involvement of genetic factors in the occurrence of amyloidosis. It is suggested that the occurrence of amyloidosis is suppressed by some genes which are linked with CW7 antigen.

Adolescent↗
PubMed1996

[Examination of percutaneous minocycline hydrochloride injection therapy for hepatic cyst by one puncture method].

Minocycline hydrochloride (MINO) at a dose of 500 mg (in principle) was injected into each of 11 hepatic cysts/10 cases (mean maximum diameter: 12.6 cm) that exhibited symptoms or a tendency toward growth by percutaneous transhepatic one puncture method, and the relation between therapeutic efficacy and pH of cystic fluid was examined. The efficacy was evaluated by abdominal CT after 3 months, and when a shrink of 50% or more in the maximum diameter was observed, it was judged as marked response. Marked effect was observed in 9 lesions of 11 (82%). This MINO injection therapy by one puncture method is very safe, simple and useful. Reduction in intra-cystic pH was not always related to the therapeutic efficacy, so involvement of cytotoxicity of MINO was suggested in degenerating the cystic epithelial cells.

Adult↗
PubMed1995

The risk of cancer in rheumatoid patients in Japan.

In order to clarify the risk of cancer development in patients with rheumatoid arthritis (RA), the incidence of malignant tumors during a follow-up period was investigated in RA patients at the Center for Adult Diseases, Osaka, Japan. Six hundred and fifty-five eligible rheumatoid patients (131 males, 524 females) who were admitted to our institute between 1980 and 1989 were matched against the files of the Osaka Cancer Registry. Among them, a total of 26 patients (5 males, 21 females) were noted to have developed some kinds of cancer. The female RA patients demonstrated a significantly higher incidence of all cancers than the general population, with an observed/expected (O/E) ratio of 1.71 (95% confidence interval = 1.06-2.62). Cancer of the buccal cavity/pharynx and thyroid cancer also showed a higher incidence in female RA patients, with O/E ratios of 12.93 and 2.74, respectively.

Adult↗
PubMed1993

Aggressive pulmonary metastasectomy for soft tissue sarcomas.

BACKGROUND: To evaluate the efficacy of aggressive pulmonary metastasectomy for treating soft tissue sarcomas, the clinical data on the surgical management of 23 patients with extensive pulmonary metastases from soft tissue sarcomas were reviewed. METHODS: Between January 1973 and April 1991, 9 male patients and 14 female patients were treated. Their ages ranged from 13-68 years (median, 42 years). Twenty-one patients (91%) had bilateral and multiple metastases, and two patients had solitary metastasis. The number of resected metastatic nodules ranged from 1-110 (mean, 30.5). As an initial surgical approach, median sternotomy was used on 18 patients and lateral thoracotomy on 5 patients. Eleven patients underwent two or more explorations for recurrent metastases using lateral thoracotomy. The neodymium:yttrium-aluminum-garnet (Nd:YAG) laser was adopted in 10 patients since 1986. RESULTS: The actuarial 2-year and 5-year survival rates after the first pulmonary resection were 49.7% and 24.8%, respectively. Histologic type (alveolar soft part sarcoma versus synovial sarcoma, P < 0.025), histologic grade (G1 and G2 versus G3, P < 0.01), and metastatic localization (subpleural versus extrapleural, P < 0.005) were the most significant prognostic factors for aggressive pulmonary metastasectomy of soft tissue sarcomas. Application of laser surgery, absence of local recurrences, and absence of extrapulmonary metastases before pulmonary resection also correlated with better prognosis with borderline significance. CONCLUSIONS: Aggressive pulmonary metastasectomy for soft tissue sarcomas is a recommended procedure, even in the case of extensive metastases. The combination of median sternotomy and Nd:YAG laser-assisted surgery is a useful technique, especially in bilateral multiple pulmonary metastases.

Adolescent↗
PubMed1993

Prognostic significance of bone metastases in patients with metastatic prostate cancer.

BACKGROUND: The distribution of bone metastases on a bone scan has not been duly considered when assessing the prognosis of metastatic prostate cancer. METHODS: The medical records of 76 patients with newly diagnosed, untreated metastatic prostate cancer were reviewed. According to the distribution of bone metastases on the initial bone scan, we divided the patients into three groups: Group I (having bone metastases exclusively within the pelvis and the lumbar spine), Group II (having bone metastases exclusively outside these bones), and Group III (having bone metastases in both areas). RESULTS: Among the responders to androgen deprivation, those in Group I survived significantly longer than did those in Groups II or III. Because the extent of the disease and the distribution of histologic differentiation in Groups I and II were similar, the results indicate that the presence of bone metastases outside the pelvis and the lumbar spine is predictive of short survival time. This prediction was not possible when the extent of disease (EOD) grading system was used. CONCLUSION: The distribution of bone metastases on the initial bone scan should be considered as a variable for the prognostic stratification of patients with metastatic prostate cancer.

Adenocarcinoma↗
PubMed1993

[Survey for primary tumor site in patients with initial clinical presentation of bone metastasis].

Among the patients who were examined with bone scintigraphy between April 1985 and March 1991, there were 27 patients whose initial clinical manifestation was bone metastasis and who were surveyed for the primary tumor site. The primary tumor site could be identified in 20 patients (74%), consisting of 9 patients with lung cancer, 3 with prostate cancer, 3 with hepatoma, 2 with renal cancer, and one each with thyroid cancer, adrenal cancer, and pleural malignant mesothelioma. In 17 of the 20 patients, the primary site had been detected within two months after presentation. Examinations which were helpful in identifying the primary site included chest radiography, sputum cytology, abdominal sonography, serum prostatic acid phosphatase level and pathologic examination of biopsy specimens. 99mTc-PMT scintigraphy was useful in the diagnosis of the hepatoma when accumulation was observed at the metastatic sites. In 2 patients, lung cancer had been recognized using follow-up chest radiography 3 and 6 months after presentation, respectively. One patient was diagnosed at autopsy as having adrenal cancer. In 7 patients the primary site remains unknown. Histology examination of the biopsy specimen performed in 6 of these patients revealed 4 to be adenocarcinoma and 2 undifferentiated carcinoma. The average survival period of the 17 patients who died was 9.5 months. Four patients are alive, and the outcome in the remaining 6 could not be determined.

Adult↗
PubMed1993

Epidural compression of the spinal cord caused by vertebral osteoblastic metastasis of prostate carcinoma. A case report.

A 71-year-old man with prostate cancer developed epidural compression of the spinal cord caused by bony protuberances expanding from a vertebral osteoblastic metastasis. Pathologic examination of the metastatic lesion showed that both tumor and thickened vertebral trabeculae broke through the cortex and formed bony protuberances. The periosteal new bone appeared not to arise from a reactive periosteum but from the tumor breaking through the cortex. A biologic interaction between the tumor and the host may be responsible for the rare periosteal new bone formation.

Adenocarcinoma↗
PubMed1991

Breast cancer with bone-only metastases. Visceral metastases-free rate in relation to anatomic distribution of bone metastases.

The medical records of 82 patients with breast cancer with bone-only metastases were reviewed. According to the distribution of the metastases by bone scan at the time they were first documented, the patients were divided into three groups: Group A (patients who had bone metastases exclusively cranial to the lumbosacral junction), Group B (patients who had bone metastases exclusively caudal to the junction), and Group C (patients who had bone metastases both cranial and caudal to the junction). Group A had a significantly higher visceral metastases-free rate than Groups B or C. Serial bone scans and radiographs of Group A patients revealed that bone lesions cranial to the junction rarely developed into visceral metastases and that bone lesions extending caudal to the junction frequently developed into visceral metastases. These results indicate that the presence of bone metastases caudal to the lumbosacral junction is predictive of visceral metastases.

Adult↗
PubMed1988

Multivariate analysis for histologic prognostic factors in soft tissue sarcomas.

To investigate histologic prognostic factors in soft tissue sarcomas (STS), multivariate analysis was performed on 236 patients with complete clinical information. These included 141 males and 95 females with an age range from 1 to 85 years (median, 47.6 years). Histologically, malignant fibrous histiocytoma (33.5%) was the most common type followed by synovial sarcoma (11%), liposarcoma (10%), rhabdomyosarcoma (7%), and leiomyosarcoma (7%). Monofactorial analysis revealed that sex, depth, location, histologic grade, cellularity, frequency of mitosis, and necrosis were significant prognostic factors. By multivariate analysis, only frequency of mitosis and depth of tumors were proved to be of prognostic significance. The prognostic importance of the frequency of mitosis as shown in previous and the present studies indicates that further investigation of the cell proliferation in patients with STS is required.

Age Factors↗