Biomedical subjects

Hitoshi Shibuya

Publications and source records attributed to Hitoshi Shibuya.

At least 19 recordsLinked to original sources

PubMed2006

Multiple myeloma associated with sialyl salivary-type amylase.

BACKGROUND: There have been several reports describing a notable hyperamylasaemia in patients with multiple myeloma. Such amylase-producing myelomas have been mainly described in the context of concomitant salivary-type hyperamylasaemia, with sialyl salivary-type amylase identified in a portion of those cases. We investigated the incidence of the production of sialyl salivary-type amylase in serum of multiple myeloma patients. METHODS: Eleven patients (6 male and 5 female) who had been diagnosed as having multiple myeloma were enrolled in this study. Sialyl salivary-type amylase was detected by isoamylase electrophoresis and HPLC analysis, and identified by detecting either abnormal neuraminidase-sensitive band through isoamylase electrophoresis or abnormal extra-elution peak of amylase by means of HPLC analysis. RESULTS: Sialyl salivary-type amylase was detected in 7 out of 11 (63.6%) patients. Median total amylase activity was 154 U/l (range 109-43020). Isoamylase electrophoretic patterns of patients' serum were normal in 5 patients (71.4%) out of 7 patients and salivary-dominant in 2 (50.0%) out of 4 patients. CONCLUSIONS: We consider that there is no significant relationship between total serum amylase level and amylase isoenzyme pattern in the incidence of production of sialyl salivary-type amylase with multiple myeloma.

Aged↗

PubMed2006

Brachytherapy of stage II mobile tongue carcinoma. Prediction of local control and QOL.

BACKGROUND: There is no consensus as to the prognostic model for brachytherapy of tongue carcinoma. This study was designed to evaluate the prognostic factors for local control based on a large population under a unified treatment policy. RESULTS: Between 1970 and 1998, 433 patients with stage II tongue squamous cell carcinoma were treated by low-dose-rate brachytherapy. This series included 277 patients treated with a linear source with a minimum follow-up of 3 years. A spacer was introduced in 1987. The primary local control rates were 85.6%. CONCLUSION: In the multivariate analysis, an invasive growth pattern was a significant factor for local recurrence. The disease-related survival was influenced by old age and an invasive growth pattern. A spacer lowered mandibular bone complications. The growth pattern was the most important factor for recurrence. Brachytherapy was associated with a high cure rate and the use of spacers brought about good quality of life (QOL).

Adult↗

PubMed2006

Esophageal carcinoma: evaluation with high-resolution three-dimensional constructive interference in steady state MR imaging in vitro.

PURPOSE: To determine the usefulness of high-resolution three-dimensional (3D) constructive interference in steady state (CISS) MRI for evaluating mural invasion and morphologic features in esophageal carcinomas. MATERIALS AND METHODS: Twenty-four esophageal specimens with carcinomas were studied with a 1.5-T system using a 4-cm-diameter loop coil. High-resolution 3D-CISS MR images were obtained with a field of view (FOV) of 80 mm, matrix of 256 x 256, and section thickness of 0.5 mm (voxel size of 0.05 mm(3)). 3D-CISS MR images were compared with histopathologic findings, and virtual MR endoscopic images were compared with macroscopic findings at surgery. RESULTS: 3D-CISS MR images clearly depicted the normal esophageal wall as consisting of eight layers, which correlated well with the histologic layers. In 22 of 24 esophageal carcinomas (92%), the depth of mural invasion visualized with 3D-CISS MRI correlated well with the histopathologic staging. In all 24 carcinomas (100%), virtual MR endoscopic images clearly depicted the macroscopic types of the carcinomas, including adjacent lymph node swelling. CONCLUSION: High-resolution 3D-CISS MRI has a high diagnostic accuracy for evaluating mural invasion and macroscopic findings in esophageal carcinomas, and may be applicable to preoperative histopathologic staging and morphologic evaluation.

Aged↗

PubMed2006

Sliding thin slab, minimum intensity projection of the lung in asymptomatic subjects: lower limits of lung attenuation, without airways.

PURPOSE: A sliding thin slab, minimum intensity projection (STS-MinIP) is considered to be useful for detecting diseases that decrease lung attenuation. For evaluating these diseases, it would be useful to ascertain the lower limits of normal lung attenuation, allowing a division between normal and subnormal attenuation. However, normal lung attenuation may vary depending on respiratory status, anatomical position, and patient background factors. Our aim was to determine whether the lower limits of lung attenuation, without airways, in asymptomatic subjects using STS-MinIP varies under different conditions. MATERIALS AND METHODS: The study subjects were 43 volunteers without pulmonary symptoms. STS-MinIP was performed at full inspiration and full expiration at three levels of the lung. The lower limits of lung attenuation were compared among the three lung levels and between full inspiration and full expiration, the sexes, age groups, smokers and nonsmokers, and the right and left lungs. RESULTS: The lower limits of lung attenuation had significantly different Hounsfield unit values among lung levels, between the sexes at full inspiration, and between age groups at full expiration. CONCLUSION: This study shows that the lower limits of lung attenuation are influenced by lung fields, sex, and, on expiration, age.

Adult↗

PubMed2006

Sliding thin slab, minimum intensity projection imaging for objective analysis of emphysema.

PURPOSE: The aim of this study was to determine whether sliding thin slab, minimum intensity projection (STS-MinIP) imaging is more advantageous than thin-section computed tomography (CT) for detecting and assessing emphysema. MATERIALS AND METHODS: Objective quantification of emphysema by STS-MinIP and thin-section CT was defined as the percentage of area lower than the threshold in the lung section at the level of the aortic arch, tracheal carina, and 5 cm below the carina. Quantitative analysis in 100 subjects was performed and compared with pulmonary function test results. RESULTS: The ratio of the low attenuation area in the lung measured by STS-MinIP was significantly higher than that found by thin-section CT (P < 0.01). The difference between STS-MinIP and thin-section CT was statistically evident even for mild emphysema and increased depending on whether the low attenuation in the lung increased. Moreover, STS-MinIP showed a stronger regression relation with pulmonary function results than did thin-section CT (P < 0.01). CONCLUSION: STS-MinIP can be recommended as a new morphometric method for detecting and assessing the severity of emphysema.

Aged↗

PubMed2006

Acute and late genitourinary toxicity of conformal radiotherapy for prostate cancer.

PURPOSE: The aim of this study was to identify predictive factors for genitourinary (GU) toxicity in prostate cancer patients who underwent conformal radiotherapy (CRT). MATERIALS AND METHODS: In this study we analyzed 154 cases of T1-3N0M0 prostate adenocarcinoma and evaluated the occurrence rate of acute and late GU toxicity and the duration of acute toxicity according to clinical parameters: age, transurethral resection of the prostate prior to CRT, hormone therapy, CRT dose, length of planning target volume (PTV). RESULTS: Altogether, 41% of the patients developed grade 2 or higher acute GU toxicity. Longer PTV was significantly associated with a higher incidence of acute GU toxicity (>7 cm, 53%; <or=7 cm, 31%; P = 0.003), and hormone therapy prolonged the duration of the toxicity (P = 0.007). Grade 1 or higher late GU toxicity developed in 23% of the patients, and the 2-year late GU toxicity-free survival rate was 79%. Acute GU toxicity was significantly associated with the late GU toxicity-free survival rate (grade 0-1, 88.7%; grade 2-4, 73.2%; P = 0.0007). CONCLUSION: The length of PTV and hormone therapy were predictive factors for acute GU toxicity. Furthermore, acute GU toxicity was the most important predictive factor for late GU toxicity.

Acute Disease↗

PubMed2006

Correlations between 18F-FDG uptake by bone marrow and hematological parameters: measurements by PET/CT.

The aim of this study was to investigate the correlations between (18)F-FDG uptake by bone marrow and various hematological parameters. Forty-eight patients who underwent FDG-PET/CT studies and also received hematological examinations within 5 days before or after the PET study were included in this study. All patients had not received chemotherapy. FDG uptake by bone marrow was measured as a standardized uptake value (SUV) on three-dimensional PET/CT fusion images, and the uptake ratio (UR) of the SUV of bone marrow to the SUV of longitudinal dorsal muscle was calculated. The correlations between the SUV and the UR of bone marrow and various hematological parameters were evaluated. Bone marrow FDG uptake was strongly correlated with the white blood cell counts but was not significantly correlated with the red blood cell and platelet counts. The neutrophil count was significantly correlated with bone marrow FDG uptake but the lymphocyte count was not. FDG uptake by bone marrow was specifically correlated with the neutrophil count, suggesting that the FDG uptake by bone marrow reflects marrow metabolism that is mainly regulated by granulocyte progenitors and stimulated by endogenous hematopoietic growth factors. They may also be helpful in interpreting PET images, especially for diagnosing bone marrow involvement by malignancy.

Adult↗

PubMed2006

In-vivo visualization of radiation-induced apoptosis using (125)I-annexin V.

BACKGROUND: As apoptosis occurs in tumors within a short time after irradiation, the detection of the frequency of apoptosis may be useful as an indicator of the effect of treatment. For the evaluation of apoptosis under these conditions, tissue extraction from patients is indispensable. AIM: To develop a noninvasive imaging technique to measure and monitor apoptosis in tumor cells caused by X-irradiation using (125)I-radiolabeled annexin V. METHODS: The tumors used were human ependymoblastomas, which were transplanted into nude mice. The tumors were irradiated at 2, 5 or 10 Gy. (125)I-annexin V was administered intravenously 6 h after irradiation. In the 5 Gy irradiation group, the isotope was injected at various time intervals (3, 6 and 12 h) after irradiation. Three hours after the injection, the mice were sacrificed, the tumors were quickly removed and frozen sections were prepared at 6 and 40 microm thickness using a cryomicrotome. In autoradiographic imaging, the tumor-to-muscle ratios were compared in the respective irradiated groups. In addition, apoptosis detection by the in-situ end-labeling (Klenow) assay was conducted on the same sections. The number of Klenow-positive cells was counted in 100 x fields for each section. RESULTS: Both autoradiography and immunohistochemical staining showed a significantly higher frequency of apoptosis in the neoplasms in all irradiated groups than in the control group (P<0.05). Although immunohistochemical staining revealed a peak apoptosis frequency in the 5 Gy irradiated group, autoradiography revealed a peak in the group receiving a lower dose than 5 Gy. When the time from irradiation to annexin injection was varied, both imaging methods showed a peak apoptosis frequency in the group receiving the injection 6 h after irradiation. CONCLUSION: It is possible to predict the effect of treatment in cancer in a noninvasive manner by apoptosis imaging in vivo after radiotherapy.

Animals↗

PubMed2005

The structural characteristics of radiation oncology in Japan in 2003.

PURPOSE: To ascertain the basic structural characteristics of radiation oncology facilities in Japan, we conducted a national survey on their status in 2003. The aims of the survey included the following: present status of radiation treatment facilities, equipment, personnel, patient loads, and other factors. METHODS AND MATERIALS: A mail survey verified each potential facility delivering megavoltage radiation therapy and collected data on treatment devices, other equipment, personnel, new patients, and so on. Responses were obtained from 100% of potential facilities. RESULTS: A total of 726 facilities delivered radiation therapy, with 859 megavoltage devices, 203 RALS (remote after-loading system) and other radioactive sources, with 941 FTE (full-time employee) radiation oncologists including 369 FTE Japanese Society of Therapeutic Radiation Oncology-certified radiation oncologists, 1555 FTE radiation therapists, and 70 FTE physicists in 2003. Megavoltage devices included two heavy ion units and four proton units. In total, there were 149,793 new patients and 146,351 (98%) by external irradiation; 4379 (3%) were treated by brachytherapy with or without external irradiation. Eighty-six percent of the facilities had treatment-planning computers, but 4% had no treatment-planning capability. Six percent (44 facilities) of all facilities used hyperthermia, 12% (85 facilities) intraoperative radiation therapy, and 2% (12 facilities) intensity-modulated radiation therapy. CONCLUSION: Facilities surveys continue to provide a source of census data on radiation oncology in Japan, allowing comparisons among facility groups and over time.

Brachytherapy↗

PubMed2005

Apparent diffusion coefficient measurements with diffusion-weighted magnetic resonance imaging for evaluation of hepatic fibrosis.

PURPOSE: To evaluate the use of apparent diffusion coefficient (ADC) measurements based on diffusion-weighted MRI (DWI) to assess stage of liver disease. MATERIALS AND METHODS: A total of 31 patients who underwent both a liver biopsy and DWI and 132 patients who only underwent DWI were enrolled. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). The 31 patients consisted of 21 patients with chronic hepatitis and 10 with cirrhosis (Child-Pugh stage A in nine and stage B in one), and the 132 patients consisted of 56 patients with cirrhosis (Child-Pugh stage A in 41, stage B in 10, and stage C in five), 42 with chronic hepatitis, and 34 with normal liver function. The ADCs in the liver parenchyma were measured using DWI with relatively low b factors (b = 0.01 and 128.01 seconds/mm(2)) and were compared among the HAI scores and among patients with cirrhosis, chronic hepatitis, and normal liver function. RESULTS: The ADCs decreased as the fibrosis score in the HAI increased, and the correlation was statistically significant (P < 0.0001). No relationship between the ADCs and the necroinflammation scores in the HAI was found. The ADCs decreased as the stage of liver disease progressed or as the Child-Pugh stage progressed, and these relationships were statistically significant (P < 0.0001). CONCLUSION: ADC measurements are potentially useful for the evaluation of fibrosis staging in the liver.

Adult↗

PubMed2005

Interstitial brachytherapy and neck dissection for Stage III squamous cell carcinoma of the mobile tongue.

The purpose of this study is to describe the cause-specific survival rate, local control rate, salvage rate of neck metastasis, and post-treatment eating and speaking conditions for stage III mobile tongue squamous cell carcinomas and its subgroups. Between 1968 and 1999, 117 previously untreated patients with stage III mobile tongue carcinomas underwent mainly brachytherapy with external beam irradiation (EBRT) and neck dissection. A multivariate analysis was performed for the cause-specific survival rate on the various factors. The 1-, 3- and 5-year cause-specific survival rates for all patients were 76%, 54% and 54%, respectively. The 1-, 3- and 5-year primary control rates for all patients were 67.6%, 63.4% and 59.2%, respectively. There were statistically significant differences in cause-specific survival rates among stage III subgroups of T3N0, T1-2N1 and T3N1 (p = 0.0002). Our treatment method for patients with stage III mobile tongue squamous cell carcinoma was effective and acceptable.

Adult↗

PubMed2005

Prognostic value of brain perfusion single-photon emission computed tomography (SPECT) for language recovery in patients with aphasia.

AIM: To determine the prognostic value of brain perfusion single-photon emission computed tomography (SPECT) in patients with aphasia after a stroke. METHODS: Brain perfusion SPECT with 99mTc-ethyl cysteinate dimer (99mTc-ECD) was used in 16 right-handed patients with aphasia after a left-sided cerebrovascular accident (CVA) in the early chronic period after the onset of CVA. The region of interest (ROI) method was used to calculate the relative regional cerebral blood flow (rCBF) in each cerebral lobe, the thalamus, the putamen and the cerebellum as ratios to the count in the left cerebellar hemisphere. The Standard Language Test of Aphasia (SLTA) was performed twice, once at the same time as SPECT, a mean of 2.3 months after CVA onset (early SLTA), and again a mean of 17.0 months after CVA onset (late SLTA). In addition to the overall language function score, scores for taking dictation (Dictation), oral reading (Speaking) and comprehension (Comprehension) were calculated, and the correlations with each of the rCBF values were evaluated. RESULTS: Left temporal CBF correlated with the late Dictation score; bilateral frontal, bilateral temporal and right parietal CBF correlated with the late Speaking score; and right frontal, left temporal and left occipital CBF correlated with the late Comprehension score. CONCLUSION: Brain perfusion SPECT in the early chronic stage was shown to be useful for predicting recovery from aphasia, recovery of oral reading, ability to take dictation and comprehension.

Aged↗

PubMed2004

Long-term change in size of cerebral infarction: predictive value of brain perfusion SPECT using statistical parametric mapping.

A focus of infarction is surrounded by hypoperfused areas. The present study was undertaken to examine the long-term changes in the size of infarcts, the relationship between the size of an infarct and the extent of the surrounding hypoperfused areas, and the background of such changes. The subjects of this study were 11 patients with ischemic lesions of the brain who had undergone brain SPECT ((99m)Tc-ethyl cysteinate dimer) within 1 week after initial MRI, and who underwent MRI again more than half a year later. Statistical parametric mapping (SPM) was conducted to detect significantly hypoperfused areas on the SPECT images. Relative size of significantly hypoperfused areas on SPM and infarcts on T(2)-weighted MR images were measured. The patients were divided into two groups based on the percentage of the infarct's size relative to the size of the surrounding hypoperfused areas (75-125 and 0-39%). Infarcts in the '75-125%' group showed little change in size, while in the '0-39%' group infarcts increased slowly until it reached the same rate as the former group. All patients with infarct in the '0-39%' group were noted to have severe stenosis of the internal carotid arteries bilaterally. Patients having severe stenosis of the internal carotid artery often had a slowly enlarging infarct. SPM seems to be useful in predicting the ultimate size of the infarct.

Adult↗

PubMed2004

Diagnostic value of antiagalactosyl IgG antibodies in rheumatoid arthritis.

Our objective in this study was to explore the diagnostic value of antiagalactosyl IgG antibodies in rheumatoid arthritis (RA). The study comprised 266 Japanese patients with systemic autoimmune diseases, including 60 with RA. Human agalactosyl IgG was prepared enzymatically, and the serum levels of antiagalactosyl IgG antibodies were determined using a lectin enzyme immunoassay. Serum IgG and IgM rheumatoid factors (RF) were measured using laser nephelometry for IgM (LN-RF) and an enzyme-linked immunosorbent assay for IgG (IgG-RF). Antiagalactosyl IgG antibodies were significantly more common in patients with RA than in those without (78% vs. 18%, odds ratio (OR) 16.51, 95% confidence interval (CI) 8.12-33.58, p<0.0001). Patients with RA also had a higher frequency of LN-RF than those without RA (75% vs. 28%, OR 7.81, 95% CI 3.91-15.58, p< 0.001). The specificity of antiagalactosyl IgG antibodies for RA was significantly higher than that of LN-RF (82% vs. 72%, p<0.0011). There was a significant correlation between titers of antiagalactosyl IgG antibodies and C-reactive protein levels. Antiagalactosyl IgG antibodies are more specific markers for RA than conventional LN-RF, and may provide useful information for the diagnosis of RA.

Antibodies↗

PubMed2004

Simple new technique for sonographic measurement of the thyroid in neonates and small children.

PURPOSE: The aim of this study was to determine whether the ratio of the thyroid width (Th) to the trachea width (Tr) is a useful technique for sonographic estimation of thyroid size in neonates and small children. METHODS: We prospectively performed sonographic examination of the thyroid gland in 30 pediatric subjects ranging in age from 1 week to 12 years. The sum of the maximum width of the left thyroid lobe and the maximum width of the right lobe was considered the Th. Each subject's thyroid was classified as small, normal sized, or large on the basis of the Th value in reference to the subject's body height. The ratios of the Th to the Tr were then calculated and compared among the 3 groups by 1-way analysis of variance. Correlation and regression analyses were performed to determine the correlation between body height and Tr. A p value of less than 0.05 was considered significant. RESULTS: The mean Th/Tr ratios (+/- standard deviations) for the 3 groups were as follows: small, 1.25 +/- 0.19; normal sized, 2.09 +/- 0.19; and large, 4.10 +/- 2.42. The difference in the Th/Tr ratios between the 3 groups was statistically significant (p < 0.0001). A significant positive correlation was found between Tr and body height (p < 0.001; r = 0.85). CONCLUSIONS: The Th/Tr ratio is a simple, practical parameter for estimating the size of the thyroid gland in neonates and small children.

Anthropometry↗

PubMed2004

Differentiation between completely hyalinized uterine leiomyomas and ordinary leiomyomas: three-phase dynamic magnetic resonance imaging (MRI) vs. diffusion-weighted MRI with very small b-factors.

PURPOSE: To assess the possibility of differentiating between completely hyalinized leiomyomas and ordinary leiomyomas by using diffusion-weighted (DW) magnetic resonance imaging (MRI) (DWI) employing very small b-factors (b = 1.51 and 55.3 seconds/mm(2)) in comparison with three-phase dynamic MRI. MATERIALS AND METHODS: The subjects were 25 patients with 52 histopathologically confirmed uterine leiomyomas. All leiomyomas were divided into two histopathologic subtypes (5 completely hyalinized leiomyomas and 47 ordinary leiomyomas). For each leiomyoma, the enhancement index (EI) at three-phase dynamic MRI and apparent diffusion coefficient (ADC) were obtained and then compared. RESULTS: The EIs at second and third dynamic phases clearly differentiated the two types of leiomyomas without overlap of values. ADCs also clearly differentiated the two types of leiomyomas without overlap of values. Moreover, there were significant positive correlations between ADCs and EIs at all dynamic phases (r = 0.41-0.50, P < 0.01). CONCLUSION: Not only three-phase dynamic MRI but also DWI with very small b-factors could be useful for differentiating completely hyalinized leiomyomas from ordinary leiomyomas.

Adult↗

PubMed2004

Magnetic resonance imaging of the metal clip in a breast: safety and its availability as a negative marker.

PURPOSE: This study assesses magnetic resonance (MR) safety of the stainless-steel clip inserted after stereotactic-guided directional vacuum-assisted biopsy (DVAB) of the breast, and evaluates its imaging value. METHODS: We used a sausage as a substitute breast and inserted the clip into it. The MR images of the substitute were scanned using a breast coil, and it was then dissected. After the substitute experimentation, MR scanning of the breast was performed using a dynamic contrast enhanced technique, in which a clip was placed after DVAB for suspicion of ductal carcinoma was seen as grouped amorphous calcifications on mammography. RESULTS: On every magnetic resonance image of the substitute, the clip was seen as a spotty signal void, with no surrounding artifact. There was no movement and no evidence of increased clip temperature on dissected of the substitute, confirming the safety of breast MR with a clip in place. There was no patient complaint of feeling heat or pain during the MRI examination and there were only biopsy scars on the surgically excised breast specimen material. On the breast MR images, a spreading region of the tumor adjoining the position of the signal void was identified as an early enhancing lesion. CONCLUSIONS: The safety and reliability of breast MR examination using a mammotome clip was demonstrated by both the mock examination and the breast examination. It is possible to localize of tumor spread regions based on the marker position using the clip as a negative signal marker.

Breast Neoplasms↗

PubMed2004

Determination of the depth of 50% of maximum ionization, I50, for electron beams by the divided difference method.

A new characterization of depth-ionization parameters for electron beams is empirically deduced from our data analysis based on the divided difference method (the DD method), which employs the numerical differential of an ionization curve. The important feature of the present method is that it does not necessarily require normalized percent depth-ionization (NPDI) data. The depth of 50% of maximum ionization, I50, which is an important parameter for electron beam dosimetry, can be deduced from the analysis of an unnormalized (or partial) depth-ionization (UDI) curve obtained over a short interval of depth. The values of I50 determined by the DD method are in agreement to within 0.1 mm for energies of 4, 6, and 9 MeV, compared with the ones determined by the TG-51 protocol method (or the conventional method), and the difference was 0.9 mm for 12 and 15 MeV. The dose at the reference depth, dref, calculated from I50 by the DD method, is found to be in agreement with TG-51 to within 0.1%. The field size dependence of the DD method using UDI data was studied for three field sizes: 6 x 6, 10 x 10, and 20 x 20 cm2. For all energies, the discrepancies of I50 as determined by both methods were 0.9 mm on average for the 6 x 6 cm2 fields and 0.6 mm for the other two field sizes. This dependence was remarkable for 6 x 6 cm2 fields for 12 and 15 MeV, and the discrepancies shown by the DD method were 1.2 mm for 12 MeV and 1.8 mm for 15 MeV, respectively. Since the reference field size in clinical dosimetry is usually 10 x 10 cm2, this dependence will not affect clinical dosimetry. The DD method could be an alternative option for checking beam quality in dose calibration.

Algorithms↗