Search PubMed⌕ Search

Biomedical subjects

Satoshi Sawada

Publications and source records attributed to Satoshi Sawada.

At least 37 records · Page 2Linked to original sources
PubMed2004

Reduced white matter volume of the caudate nucleus in patients with schizophrenia.

To examine volumetric abnormality, the caudate nucleus was measured in patients with schizophrenia and healthy subjects using magnetic resonance imaging. The absolute and relative volumes of white matter in the caudate nucleus were found to be significantly smaller in patients with schizophrenia compared to those in healthy subjects. There were significant correlations between dosages of neuroleptics during the previous year and absolute gray matter volumes of the caudate nucleus as well as relative white matter volumes in patients with schizophrenia. These findings suggest that reduced white matter volume of the caudate nucleus may be a factor affecting the abnormal connectivity of the corticostriatal loop, and that neuroleptic medication would be related to white matter alteration in patients with schizophrenia. Our result replicates a previous study reporting that there is a lack of negative correlation between age and caudate nucleus volume. We also suggest that the disease process of schizophrenia might interfere with normal aging.

Adult↗
PubMed2004

[CT].

The development of multidetector-row CT(MDCT), which can rapidly scan a large longitudinal volume and enables us to obtain thinner section collimation with a shorter acquisition time, obtained isotropic voxel data for three-dimensional(3D) imaging. Isotropic voxel data enables us to obtain sagittal and coronal images with the spatial resolution which is identical to axial images. Excellent volume data, which was acquired by MDCT, obtain serviceable 3D images by using various reconstruction methods, such as multi-planar reconstruction(MPR), maximum intensity projection(MIP), minimum intensity projection(MinIP), surface rendering, volume rendering and virtual endoscopy. However, relation between Ct and MRI is still complementary even in the times of MDCT.

Humans↗
PubMed2003

Expression of Ku80 in cervical cancer correlates with response to radiotherapy and survival.

To reveal the genes relevant for prediction of cervical cancer after radiotherapy, we previously carried out cDNA microarray experiments on primary cervical cancer comparing patients with a complete response (CR) and those with no change (NC). Some of these genes had already been associated with the radiation response, such as x-ray repair cross-complementing 5 (XRCC5), which was found more in radioresistant tumors than in radiosensitive ones. The aim of this study was to confirm the possible roles of XRCC5 mRNA levels by a real-time polymerase chain reaction method in 20 cervical cancers, and Ku80 protein, which is the gene product of XRCC5, using a histopathologic method of formalin-fixed sections of tumor biopsies in determining tumor response to radiotherapy and survival in 89 patients with cervical cancer. The levels of XRCC5 mRNA were 10(4.82) +/- 10(0.2) copies/microg total RNA in tumor tissues in the CR group (mean +/- standard deviation) and 10(4.95) +/- 10(0.32) copies/microg total RNA in those in the NC group. The levels of XRCC5 mRNA were not significantly different between the CR and NC groups. Histopathologic methods revealed 29.2% (26 of 89) of the patients to be Ku80-negative, with Ku80-positive findings in 70.8% (63 of 89). Of the Ku80-negative patients, 19 had CR, 3 had a partial response (PR), and 4 had NC. Of the Ku80-positive patients, 25 had CR, 22 had PR, and 16 had NC. Ku80-negative tumors showed significantly better responses than Ku80-positive ones, comparing CR and PR/NC responses (p = 0.01). In addition, overall survival was significantly better in the Ku80-negative patients as compared with those who were Ku80-positive (p = 0.04). The results of this study suggest that a low expression of Ku80 protein leads to radiosensitivity in cervical cancer and that Ku80 might play a role in treatment outcome.

Aged↗
PubMed2002

Human papilloma virus (HPV) DNA associated with prognosis of cervical cancer after radiotherapy.

PURPOSE: The importance of human papilloma virus (HPV) infection in the outcome of cervical cancer after radiotherapy remains unknown. Our study explored whether the HPV status of tumors is associated with the outcome of radiotherapy in patients with cervical cancer. METHODS AND MATERIALS: A total of 84 patients with cervical cancer (6 Stage I, 10 Stage II, 49 Stage III, and 19 Stage IV) who underwent definitive radiotherapy between January 1995 and June 2000 were included in this study. Tumor samples were obtained from all patients by punch biopsy before radiotherapy. The presence of HPV and its type were analyzed by polymerase chain reaction (PCR) based assay using the consensus primers for E6 and L1 regions. Actuarial methods were used to calculate overall survival and disease-free survival. RESULTS: A total of 42 patients (50%) had cancer recurrence after radiotherapy. HPV-positive tumors were found in 76.2% (64 cases) of patients. HPV-negative patients survived for significantly shorter time periods compared to the HPV-positive patients in the overall survival (p = 0.007) and the disease-free survival (p = 0.005). According to multivariate analysis, HPV status is a significant predictor of both overall (p = 0.02) and disease-free survival time (p = 0.005). CONCLUSION: The results of this study suggest that HPV-negative patients with cervical carcinoma have a significantly poorer prognosis after radiotherapy, and HPV status may be used as a marker to optimize the treatment of patients with this type of cancer.

Adenocarcinoma↗
PubMed2002

Synergistic cell-killing effect of a combination of hyperthermia and heavy ion beam irradiation: in expectation of a breakthrough in the treatment of refractory cancers (review).

We studied the sensitivity against heavy ion beam and hyperthermia on radioresistant procaryote, Deinococcus radiodurans, for the purpose of cancer therapy. First, we examined the decrease of the survival rate and molecular weight of DNA purified from this cell by acid heat treatment. These decreases were recognized by heating at 55 degrees C below pH 5.0. Then, we assumed that the decrease in survival of D. radiodurans in vivo and damage to its DNA in vitro by acid heating were due to the release of purine rings from the phosphodiester backbone of DNA molecules, i.e., depurination. Second, we investigated the relation between LET (linear energy transfer) and RBE (relative biological effectiveness) on D. radiodurans dry and wet cells using AVF cyclotron at the TIARA facility of JAERI-Takasaki, Japan. These cells were irradiated with carbon (12C5+) ion beam at LET of about 100 keV/microm, neon (20Ne8+) ion beam at LET of about 300 keV/microm and oxygen (16O6+) ion beam at LET of about 400 keV/microm. The peak in the figure of the relation between LET and RBE value was found to increase according to the increase of LET value from 100 keV/microm. Third, we conducted combination treatment with 4.8 kGy of alpha-particles, i.e., boron 10 neutron captured beam induced by Kyoto University Research Nuclear Reactor operated at 5 MW, and hyperthermia at 52 degrees C, which caused the synergistic killing effect on D. radiodurans wet cells. However, being dissimilar to the case of gamma-irradiation, the interval incubation at 30 degrees C in the medium between both treatments could inhibit the recovery of survival.

Combined Modality Therapy↗
PubMedDate not supplied

Stenting of the superior mesenteric artery as a preoperative treatment for total pancreatectomy.

The patient was 58-year-old male with mucinous cyst adenocarcinoma of the pancreas. Prior to total pancreatectomy, preoperative CT and angiography showed a high-grade arteriosclerotic stenosis of about 1.0 cm in length in the ostium of the superior mesenteric artery (SMA), as well as the development of collateral vessels in the area around the head of the pancreas. A stent was placed in the SMA stenosis to preserve intestinal blood flow in the SMA region after total pancreatectomy, which was performed 25 days after stent placement. The postoperative SMA blood flow was favorable, with no postoperative intestinal ischemia, and the patient had an uneventful postoperative course.

Blood Vessel Prosthesis Implantation↗
PubMedDate not supplied

Usefulness of CT during renal arteriography: a case of percutaneous radiofrequency ablation for renal cell carcinoma.

A 64-year-old man with a unilateral 15 mm diameter renal cell carcinoma underwent percutaneous radiofrequency ablation (RFA) assisted by CT during renal arteriography (angio-CT). Prior to placement of the needle electrode, a 5 Fr angio-catheter was placed in the right renal artery, and angio-CT was performed before, during and after the procedure. Since multiple angio-CT can be performed using a small amount of diluted contrast agent, RFA can be monitored without impairing renal function. As a result, this imaging combination was found to be useful for determining the end point of ablation.

Carcinoma, Renal Cell↗
PubMedDate not supplied

Radiological follow-up of new compression fractures following percutaneous vertebroplasty.

The purpose of the present study was to ascertain chronological changes in the analgesic effects of percutaneous vertebroplasty (PVP) on osteoporotic vertebral compression fractures and to radiologically follow new compression fractures after PVP. Seventy-six patients (206 vertebral bodies) were followed radiologically for a mean of 11.5 months. A visual analog scale (VAS; 0-10) was used to assess pain severity, and frontal and lateral plain radiographs of the thoracic and lumbar vertebrae were taken 1-3 days and 1, 4, 10, and 22 months after PVP. The average VAS score was 7.2 +/- 2.0 (mean pain score +/- standard deviation) before PVP, 2.5 +/- 2.3 at 1-3 days after PVP, 2.2 +/- 2.3 at 1 month, 1.9 +/- 2.2 at 4 months, 1.8 +/- 2.4 at 10 months, and 1.0 +/- 0.2 at 22 months. A new compression fracture was confirmed in 56 vertebral bodies in 28 patients (36.8%), affecting 38 adjacent vertebral bodies (67.8%), 17 nonadjacent vertebral bodies (30.4%), and 1 treated vertebral body (1.8%). A new compression fracture occurred within 1 week of PVP in 2 vertebral bodies (3.6%), between 1 week and 1 month after PVP in 22 (39.3%), between 1 and 3 months in 12 (21.4%), between 3 and 6 months in 12 (21.4%), and after more than 6 months in 8 (14.3%). PVP was highly effective in relieving the pain associated with osteoporosis-induced vertebral compression fractures, and this analgesia was long lasting. Radiological follow-up observation revealed new compression fractures in about one-third of patients. More than half of these new compression fractures occurred in adjacent vertebral bodies within 3 months of PVP.

Contrast Media↗
PubMedDate not supplied

Percutaneous vertebroplasty for osteoporotic compression fracture: multivariate study of predictors of new vertebral body fracture.

PURPOSE: To investigate the risk factors and relative risk of new compression fractures following vertebroplasty. METHODS: Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis. A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty. Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors. RESULTS: We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae. New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae. Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4.633). None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein.

Aged, 80 and over↗
PubMedDate not supplied

Clinical assessment of percutaneous radiofrequency ablation for painful metastatic bone tumors.

PURPOSE: To investigate the pain-alleviating effects of radiofrequency ablation (RFA) on metastatic bone tumors in relation to tumor size, combined therapy, and percent tumor necrosis rate following RFA. METHODS: Subjects comprised 24 patients with 28 painful metastatic bone tumors. A 17G internally cooled electrode was inserted into the tumor for CT guidance and ablation was performed. Bone cement was injected following RFA for 4 tumors involving a weight-bearing bone, while 5 tumors were treated using combined RFA and external irradiation. Percent necrosis rate of the tumor was measured using contrast-enhanced computed tomography 1 week after RFA. RESULTS: Improvement in the visual analog scale (VAS) score was 4.6 +/- 2.2 for large tumors (> 5 cm, n = 12), 3.7 +/- 1.8 for medium-sized tumors (3.1-5.0 cm, n = 11), and 3.5 +/- 1.7 for small tumors (< or = 3 cm, n = 4), with no significant differences noted among tumor sizes. Improvement in the VAS score was 3.5 +/- 1.3 for the 4 tumors in the RFA + bone cement group, 3.2 +/- 1.9 for the 5 tumors in the RFA + radiation therapy group, and 4.8 +/- 2.2 for the 18 tumors in the RFA group. No significant differences were identified between groups. The improvement in the VAS score was 3.8 +/- 2.3, 4.0 +/- 1.9, and 4.7 +/- 2.6 in patients with tumor necrosis rates of 0-49%, 50-74%, and 75-100%, respectively. No significant association was observed among these three groups. CONCLUSION: Percutaneous RFA therapy was effective in relieving pain due to metastatic bone tumors. No relationships appear to exist between initial response and tumor size, combined therapy, and percent tumor necrosis.

Adult↗
PubMedDate not supplied

An unusual arterial supply of the kidney from the opposite renal artery.

We describe an extremely rare case with a supplementary artery arising from an opposite renal artery without renal anomalies in position and in form. An unusual artery crossing the aorta can be suggested by contrast-enhanced computed tomography. A renal cell carcinoma is supplied by the branch of the opposite renal artery.

Aortography↗
PubMedDate not supplied

MR findings of clear cell sarcoma: two case reports.

We report two patients with clear cell sarcomas arising from tendons in the ankle and knee. In the current cases, calcifications, fluid-fluid levels and the marked hypointense areas are not seen within the masses. In the differential diagnosis of the mass developing in the tendons and aponeuroses, when these signs are absent, the probability of clear cell sarcoma is higher.

Adolescent↗
PubMedDate not supplied

A case of metastatic bone tumor of missed lung cancer showing unusual manifestations on chest radiogram.

We encountered a patient who had a primary unknown carcinoma with lumbago caused by lumbar vertebral metastasis as the initial chief complaint. Autopsy revealed primary pulmonary adenocarcinoma. Abnormal findings noted on plain chest radiogram and chest CT led to misdiagnosis as inflammatory changes. The primary lesion was poorly differentiated pulmonary adenocarcinoma that could not be diagnosed correctly using the diagnostic criteria of these diagnostic modalities.

Adenocarcinoma↗
PubMedDate not supplied

CT perfusion of the liver during selective hepatic arteriography: pure arterial blood perfusion of liver tumor and parenchyma.

PURPOSE: To quantify pure arterial blood perfusion of liver tumor and parenchyma by using CT perfusion during selective hepatic arteriography. METHODS: A total of 44 patients underwent liver CT perfusion study by injection of contrast medium via the hepatic artery. CT-perfusion parameters including arterial blood flow, arterial blood volume, and arterial mean transit time in the liver parenchyma and liver tumor were calculated using the deconvolution method. The CT-perfusion parameters and vascularity of the tumor were compared. RESULTS: A complete analysis could be performed in 36 of the 44 patients. For liver tumor and liver parenchyma, respectively, arterial blood flow was 184.6 +/- 132.7 and 41.0 +/- 27.0 ml/min/ 100 g, arterial blood volume was 19.4 +/- 14.6 and 4.8 +/- 4.2 ml/100 g, and arterial mean transit time was 8.9 +/- 4.2 and 10.2 +/- 5.3 sec. Arterial blood flow and arterial blood volume correlated significantly with the vascularity of the tumor; however no correlation was detected between arterial mean transit time and the vascularity of the tumor. CONCLUSION: This technique could be used to quantify pure hepatic arterial blood perfusion.

Aged↗
PubMedDate not supplied

Preoperative chemolipiodolization of the whole liver for hepatocellular carcinoma.

BACKGROUND: Preoperative transarterial chemoembolization is not routinely recommended before hepatectomy for resectable hepatocellular carcinoma. This study evaluated the effect of preoperative whole-liver chemolipiodolization. PATIENTS AND METHODS: A retrospective comparison of background characteristics, operative results and long-term outcome was performed between 36 patients with chemolipiodolization confined to the tumor (selective group) and 23 patients with chemolipiodolization also involving the noncancerous liver (whole-liver group). RESULTS: There were no serious side-effects in either group and the operative outcome did not differ between the two groups. Tumor diameter was significantly greater in the selective group, but other pathological characteristics were comparable. The 5-year disease-free and overall survival rates for the selective and whole-liver groups were 11.9% and 33.0% (p=0.0191) and 44.9% and 73.2% (p=0.0121), respectively. CONCLUSION: These results indicate that preoperative whole-liver chemolipiodolization reduces postoperative recurrence and prolongs survival in patients undergoing resection of hepatocellular carcinoma.

Antibiotics, Antineoplastic↗
PubMedDate not supplied

Peripheral vascular coil for peripheral MR angiography: phantom-based comparison with body coil by SNR, CNR, and visual evaluation.

AIM: To evaluate the image quality of MR angiography (MRA) with a peripheral vascular coil. MATERIALS AND METHODS: A peripheral vascular coil, a technical coil used in MRA of the pelvis and lower extremities, has 12 individual coil elements arranged in six pairs. We evaluated the performance of a peripheral vascular coil for image quality, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and visual evaluation by comparing it to a body coil using a phantom. RESULTS: SNR with the peripheral vascular coil was 1.5-2.2 times higher than that with the body coil in vertical distance, and 1.6-1.8 times higher in horizontal distance. CNR with the peripheral vascular coil was 2.1-3.8 times higher than that with the body coil. Visual evaluation with the peripheral vascular coil was 1.1-1.2 times higher than with the body coil in spin echo sequences, and 1.2-1.9 times higher in 3D fast spoiled GRASS (3D-FSPGR) sequences. CONCLUSION: The peripheral vascular coil for peripheral MRA is robust and accurate in evaluating peripheral vascular diseases.

Arterial Occlusive Diseases↗