Biomedical subjects

Mitsuhiro Matsumoto

Publications and source records attributed to Mitsuhiro Matsumoto.

At least 19 recordsLinked to original sources

PubMed2006

Novel display technique for reference images for visibility of temporal change on radiographs--color digital summation radiography.

PURPOSE: The present study investigated color digital summation radiography (CDSR) as a novel display technique for reference images for the visibility of temporal change on radiographs. In CDSR, only the parts with temporal differences are displayed in color. Moreover, all other parts are displayed in gray scale. MATERIALS AND METHODS: CDSR was defined as "radiographs combined by the additive color mixture method". The visibility of simulated nodules located in the lung fields and mediastinum was evaluated by 12 radiologists (mean experience, 9.8 years; range, 1-26 years) for 24 conventional radiographs and CDSR for 6 color patterns. A five-point rating system (5, very good; 4, good; 3, adequate; 2, poor; 1, very poor) was used. RESULTS: The mean scores (average +/- standard deviation) for the visibility of simulated nodules were as follows: magenta, 3.88 +/- 0.90; blue, 3.08 +/- 0.72; green, 3.04 +/- 0.86; red, 3.00 +/- 0.98; cyan, 2.71 +/- 0.86; and yellow, 2.50 +/- 0.72. Compared to conventional radiography in gray scale, at 1.21 +/- 0.41, all six color patterns for CDSR displayed significantly improved scores (p<0.001). CONCLUSION: CDSR might represent a useful technique for reference images from chest digital radiography.

Angiography↗

PubMed2006

Evaluation of the usefulness of color digital summation radiography in temporally sequential digital radiographs: a phantom study.

PURPOSE: The purpose of this study was to assess the usefulness of color digital summation radiography (CDSR) for detection of nodules on chest radiographs by observers with different levels of experience. MATERIALS AND METHODS: A total of 30 radiographs of chest phantoms with abnormalities and 30 normal ones were arranged at random. Set A was conventional radiographs only. Set B consisted of both conventional radiographs and CDSR images, which were colored with magenta. Five chest radiologists and five residents evaluated both image sets on a TFT monitor. The observers were asked to rate each image set using a continuous rating scale. The reading time for each set was also recorded. RESULTS: In set A, the performance of chest radiologists was significantly superior to that of the residents (P < 0.05). However, in set B, there was no significant difference in the performance of the chest radiologists and the residents. In both observer groups, the mean reading time per case in set B was significantly shorter than that in set A (P < 0.01). CONCLUSION: By using CDSR, the detection capability of observers with little experience improves and is comparable to that of experienced observers. Moreover, the reading time becomes much shorter using CDSR.

Color↗

PubMed2006

Evaluation of usefulness of color digital summation radiography for solitary pulmonary nodules on chest radiographs.

PURPOSE: The aim of this study was to evaluate the usefulness of novel color digital summation radiography (CDSR) for detecting solitary pulmonary nodules on chest radiographs by observers with different levels of experience. MATERIALS AND METHODS: A total of 30 healthy controls and 30 patients with newly detected solitary pulmonary nodules were evaluated. Six radiologists and five residents evaluated three image sets: set A, current and prior radiographs only; set B, set A with temporal subtraction images; and set C, set A with CDSR. The observers were asked to rate each image set using a continuous rating scale. In addition, the reading time required for each set was recorded. RESULTS: The radiologists showed no significant differences in the mean A(z) value between set A, set B, and set C. However, the residents showed significant differences between set A and set B and between set A and set C. In addition, for set B and set C, the mean reading time per case of all readers was significantly shorter than that for set A. CONCLUSION: The detection capability of observers with little experience is comparable to that of experienced observers when reading radiographs with temporal subtraction images or with CDSR. The usefulness of CDSR is comparable to that of temporal subtraction.

Clinical Competence↗

PubMed2006

Pharmacokinetics of amrubicin and its active metabolite amrubicinol in lung cancer patients.

Amrubicin, a synthetic 9-aminoanthracycline agent, was recently approved in Japan for treatment of small-cell lung cancer and non-small-cell lung cancer. Amrubicin is converted enzymatically to the C-13 hydroxy metabolite amrubicinol, which is active and possesses a cytotoxicity 10 to 100 times that of the parent drug. The purpose of this study was to characterize the pharmacokinetics of amrubicin and its active metabolite amrubicinol. Amrubicin was administered on days 1-3 in 16 patients with advanced lung cancer. The pharmacokinetics analysis of amrubicin and amrubicinol was performed by high-performance liquid chromatography. When 45 mg/m amrubicin was administered in a bolus injection once every 24 hours for 3 consecutive days, the areas under the curves (0 to 72 hours) for amrubicin and amrubicinol were 13,490 and 2585 ng . h/mL, respectively. The apparent total clearance (CLapp) of amrubicin was 15.4 L/h. The area-under-the-curve ratio of amrubicinol to amrubicin was 15.1 +/- 4.6% (mean +/- SD) at doses ranging from 30 to 45 mg/m. Interindividual variability in the enzymatic conversion of amrubicin to amrubicinol was small. In contrast, a large interindividual variability in the CLapp of amrubicin was observed (CV = 49.8%). The areas under the curves of amrubicin and amrubicinol seemed to be associated with the severity of hematologic toxicities. There is a possibility that monitoring of the plasma concentrations of amrubicin and amrubicinol may provide an efficient tool for establishing the optimal dosage of amrubicin in each patient.

Aged↗

PubMed2006

Air microbubbles as MR susceptibility contrast agent at 1.5 Tesla.

Air microbubbles have been investigated recently at high magnetic field strength (2 Tesla or greater) as potential MR susceptibility contrast agents. We used a phantom to measure their susceptibility at 1.5 T to clarify their usefulness for this purpose. The phantom, filled with fresh Levovist suspension at 4 different doses (67 to 125 mg/mL), was continuously scanned with a gradient-echo technique at a temporal resolution of 10 s. The transverse relaxation increase (R2*) by microbubbles demonstrated a time course of exponential decay at each dose (time-constant, 39 to 57 s). The dependency of R2* on microbubble volume fraction was linear, with a slope of 89 s-1 per percentage microbubble volume fraction. Our study represents the first step towards applying microbubbles as susceptibility contrast agents at 1.5 T.

Air↗

PubMed2006

[Successful treatment by voliconazole for pulmonary and adductor magnus muscle aspergillosis induced by immunosuppressive therapy for hypersensitivity pneumonia].

A 74-year-old woman was treated with steroid and cyclosporine A for hypersensitivity pneumonia. To examine the causes of general fatigue and increased levels of beta-D glucan in serum, she was admitted to our hospital. Chest computed tomography (CT) scan revealed nodular opacity with a well-defined margin in the right S1. 67Ga scintigraphy image showed high uptake in the left thigh and CT showed circularly enhanced lesions in the thigh. An ultrasonography-guided needle aspiration and biopsy of the muscle abscess allowed isolation of Aspergillus fumigatus and evidence of necrotic tissues around the granuloma formation. We therefore diagnosed invasive aspergillosis. Because of the poor response to initial therapy with micafungin and itraconazole for 4 weeks, we treated her with voliconazole (VCZ). Spectacular regression of lung lesions and muscle abscesses was rapidly achieved. Furthermore, the high level of beta-D glucan in serum decreased gradually. This case suggests that administration of VCZ can be recommended for deep seated mycoses.

Aged↗

PubMed2005

Phase II study of carboplatin-paclitaxel combination chemotherapy in elderly patients with advanced non-small cell lung cancer.

BACKGROUND: More than 30% of cases of non-small cell lung cancer (NSCLC) arise in patients aged > or =70 years. The efficacy and safety of carboplatin-paclitaxel combination chemotherapy in elderly patients with advanced NSCLC were evaluated in a phase II trial. METHODS: Twenty-five patients aged > or =70 years (median, 76; range, 70-83) with chemotherapy-naive advanced NSCLC were enrolled between January 2001 and July 2003. Additional criteria included the presence of measurable lesions, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate organ function. Patients received carboplatin at an area under the curve of 5 mg/ml/min and paclitaxel at 180 mg/m(2) on the first day of consecutive 3 week periods. RESULTS: The patients included four with stage IIIB, 19 with stage IV and two with recurrent disease. The median number of treatment cycles was three (range, 1-4). One complete response and six partial responses, yielding an objective response rate of 28%, were obtained. The median survival time was 12.3 months and the 1-year survival rate was 52%. Hematological toxicities of grade 3 or 4 included leukopenia (40%), neutropenia (68%) and anemia (4%). Non-hematological toxicities of grade 3 included arthralgia-myalgia (16%) and neuropathy (12%). The objective response rate for patients aged > or =75 years (n = 15) was 26%, and no evidence of excessive toxicity in these patients was apparent compared with those aged <75 years. CONCLUSION: The combination carboplatin-paclitaxel at these doses is a feasible treatment option with a favorable toxicity profile for fit elderly patients with advanced NSCLC.

Age Factors↗

PubMed2005

Full-size digital storage phosphor chest radiography: effect of 4K versus 2K matrix size on observer performance in detection of subtle interstitial abnormalities.

PURPOSE: To compare observer performance in the detection of subtle interstitial abnormalities on 3,520 x 3,520 (4K) matrix and 1,760 x 1,760 (2K) matrix full-size digital storage phosphor (DSP) chest radiographs. MATERIALS AND METHODS: Thirty-five 4K DSP chest radiographs with subtle interstitial abnormalities (n=27) or normal lungs (n=8) were processed with a half-band low-pass filter to produce 2K DSP radiographs. Although the actual matrix size of the 2K DSP radiographs remained 4K, the effective matrix size was reduced to 2K. Four chest radiologists independently evaluated full-sized hard-copy of the 4K and 2K DSP radiographs, and scored the presence of interstitial abnormalities for both right and left lungs on a five-point confidence scale. With findings on high-resolution computed tomography as the reference standard, observer performance was evaluated using multireader-multicase receiver operating characteristic (ROC) analysis. RESULTS: The average area under the ROC curve (Az) values for 4K and 2K DSP radiographs were 0.791+/-0.055 and 0.804+/-0.050, respectively. Both individual and averaged Az values showed no statistically significant differences (p>0.05) between 4K and 2K DSP radiographs. CONCLUSION: Observer performance in the detection of subtle interstitial abnormalities on 4K full-size DSP chest radiographs was equivalent to that on 2K full-size DSP chest radiographs.

Humans↗

PubMed2005

Voxel dimensions required for micromorphologic evaluation of ground-glass opacity on lung high-resolution CT.

PURPOSE: To clarify the appropriate voxel dimensions required for pathologic evaluation of areas with ground-glass opacity on lung high-resolution computed tomography (HRCT). MATERIALS AND METHODS: Synchrotron radiation CT (SRCT) images of autopsied lung speci-mens (n=25) that showed ground-glass opacity on HRCT were reconstructed with 12 different voxel dimensions ranging from 0.006 to 0.6 mm. The specimens were micromorphologically categorized into one of three pathologic groups: alveolar, interstitial, and mixed abnormalities. Each SRCT image was independently diagnosed as one of three pathologic groups by six chest radiologists. The diagnostic accuracy required to estimate the appropriate voxel dimensions was compared among different voxel dimensions by means of the Tukey test. RESULTS: Diagnostic accuracy with voxel dimensions less than or equal to 0.06 mm was significantly higher than that with voxel dimensions of 0.18 mm or more (p<0.01). There was, however, no significance of difference in diagnostic accuracy with voxel dimensions of less than or equal to 0.06 mm. In addition, no significant difference in diagnostic accuracy was found with voxel dimensions of 0.18 mm or more. CONCLUSION: The appropriate voxel dimensions are approximately 0.06 mm for pathologic differentiation of areas with ground-glass opacity on HRCT.

Humans↗

PubMed2004

[PACS for multi-slice CT--seamless integration implementing 3D and 4D workstations].

A PACS system for data management in multi-slice CT examination was upgraded using interactive 3D and 4D workstations and network computing technology. We categorized the original PACS (CT-PACS) as follows: (1) a fault-tolerant system linked with the hospital information system (HIS) and radiology information system (RIS); (2) an interactive network system using a workstation with real-time 3D and 4D reconstruction; (3) a system for research and development of software for 3D image analysis on the CT-PACS system. Because of the use of cooperative diagnostic supporting tools, no major problems occurred in daily clinical practice or research and education. In conclusion, CT-PACS with real-time 3D and 4D workstations was found to be helpful to radiologists and researchers in reading and analyzing large volumetric data.

Computer Communication Networks↗

PubMed2004

[Examination of optimal radiation quality in the lead equivalent examination of X-ray protective clothing].

To determine the effective lead thickness of the apron for radiation protective clothing, i.e., the lead equivalent, a method of performing the lead equivalent examination is provided in the Japanese Industrial Standards (JIS). We proposed a method of computation using an attenuation coefficient, and examined the measurement accuracy and optimal radiation quality using both methods. We were able to compute the lead equivalent with sufficient accuracy when using radiation quality of about 60 keV in the range of radiation quality examined. This technique was also examined in the measurement used for the marketing of radiation protective clothing.

Lead↗

PubMed2003

Cognitive conditions of pathologically confirmed dementia with Lewy bodies and Parkinson's disease with dementia.

The relationship between dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD) has been insufficiently described, and it is still problematic. Twenty-nine cases of DLB and 10 cases of PDD were investigated in the present study. DLB cases disclosed a significantly older disease onset and shorter disease duration than PDD cases (p<0.01 each). However, they showed no significant difference in dementia onset or dementia duration (p>0.05 each). Motor symptoms (parkinsonism) were suspected as the cause of the younger disease onset in PDD cases. Compared with 10 age-matched cases of definite Alzheimer's disease, both 19 DLB cases and 6 PDD cases had significantly better scores in the final test of mini-mental state examination (MMSE) and revised version of Hasegawa's Dementia Scale (HDSR) within 12 months before death, although no significant differences between DLB and PDD were indicated. DLB and PDD were suspected to show cognitive impairment of similar severity in the terminal stage. They would thus be difficult to classify as completely different entities.

Age of Onset↗

PubMed2003

Autonomic dysfunctions in dementia with Lewy bodies.

Twenty-nine cases of both clinically and neuropathologically diagnosed dementia with Lewy bodies (DLB) were retrospectively examined for autonomic symptoms. Twenty-eight cases showed some kind of autonomic dysfunction. Urinary incontinence (97 %) and constipation (83 %) were the two most common. Although urinary retention and episodic hypotension causing syncopal attacks were less common, the frequency was still high (28 % each). There were 18 cases (62 %) with severe autonomic failure. These 28 cases showed similar tendencies, with no significant differences between the subtypes of DLB (brainstem, limbic, and neocortical types or common and pure forms). We found that DLB of all pathological subtypes exhibits some kind and level of autonomic symptoms.

Aged↗

PubMed2003

Diffuse alveolar damage after ZD1839 therapy in a patient with non-small cell lung cancer.

ZD1839 is an orally active inhibitor selective for the epidermal growth factor receptor tyrosine kinase and has shown promise in the treatment of non-small cell lung cancer (NSCLC). We now present a case of diffuse alveolar damage (DAD) that developed in a 67-year-old man treated with ZD1839. On day 8 of ZD1839 administration, the patient complained of dyspnea and a new-ground glass opacity was apparent on a chest X-ray and computed tomography scan. Despite high-dose steroid therapy, the patient died 13 days after the first administration of ZD1839. Postmortem analysis of lung tissue revealed a pattern of DAD. No evidence of infection or of other specific etiologies was apparent. This case is the first reported of respiratory failure after ZD1839 treatment in a patient with NSCLC. Physicians should therefore be aware of the potential pulmonary toxicity of ZD1839.

Administration, Oral↗

PubMed2003

On-column refolding and characterization of soluble human interleukin-15 receptor alpha-chain produced in Escherichia coli.

Interleukin-15 receptor alpha-chain (IL-15Ralpha) is a member of the new cytokine receptor family, which possesses the sushi domain. To investigate the biochemical and biophysical characteristics of soluble human IL-15Ralpha (shIL-15Ralpha), shIL-15Ralpha was recombinantly expressed in Escherichia coli. The shIL-15Ralpha containing a six histidine-tag was expressed as inclusion bodies, which were solubilized with urea, immobilized on a Ni-nitrilotriacetic acid column, and refolded by a decreasing gradient of urea concentration. The refolded shIL-15Ralpha exhibited a highly flexible structure, neutralized human interleukin-15-induced cell proliferation effectively, and bound to its ligand with the same affinity as human IL-15Ralpha on the cell surface, as demonstrated by circular dichroism, a cell proliferation assay, and surface plasmon resonance, respectively. Thus, we succeeded in refolding shIL-15Ralpha to an active form on an affinity column.

Amino Acid Sequence↗

PubMed2003

Expression of constitutively activated EGFRvIII in non-small cell lung cancer.

The epidermal growth factor receptor (EGFR) variant type III (variously called EGFRvIII, de2-7 EGFR or deltaEGFR) has an in-frame deletion of the extracellular domain and is found in numerous types of human tumors. Since EGFRvIII has been reported to be tumor-specific and has oncogenic potential, it is being investigated as a potential therapeutic target. Because the cell-specific expression of EGFRvIII in lung has not been well documented, we examined the expression of EGFRvIII in 76 non-small cell lung cancers (NSCLCs) and 10 non-neoplastic lung tissues by immunohistochemistry using a new monoclonal antibody specific for this variant receptor. We found a higher incidence (30 of 76, 39%) of enhanced EGFRvIII expression in NSCLC than previously described. Interestingly, the presence of EGFRvIII was also observed in several normal tissue components of lung (e.g., normal bronchial epithelium). Given the high prevalence of EGFRvIII in NSCLC, a newly developed phospho-specific (activated) EGFR antibody was employed for immunohistochemical analysis that permitted visualization of activated EGFR and/or EGFRvIII in tumors. This study presents evidence, for the first time, that EGFRvIII expressed in human tumors is phosphorylated and hence activated. Our results suggest that the sustained activation of EGFRvIII is implicated in the pathogenesis of NSCLC and thus EGFRvIII is a potential therapeutic target in this challenging disease.

3T3 Cells↗

PubMed2003

Absence of gallium uptake in unicentric and multicentric Castleman's disease.

Castleman's disease is a rare and poorly understood condition involving lymph nodes at various sites, predominantly in the mediastinum. Individuals with this disease often present with lymphadenopathy and general symptoms suggestive of lymphomatous disease, and they are at risk of developing malignant lymphoma. It is thus important to distinguish Castleman's disease from other lymphoproliferative disorders. 67Ga scintigraphy is a non-invasive and practical diagnostic tool for the investigation of patients with lymphoproliferative disorders. However, the value of this technique for the diagnosis of Castleman's disease is not clear. Here, we describe five consecutive patients with various types of Castleman's disease and show that none of these individuals exhibited 67Ga uptake. Our results suggest the potential value of 67Ga scintigraphy in both the diagnosis and management of Castleman's disease.

Adult↗

PubMed2003

[A case of loxoprofen sodium-induced bronchiolitis obliterans organizing pneumonia (BOOP)].

A 78-year-old man was referred to our department because of an abnormal shadow on the chest radiograph and liver dysfunction after lung resection for lung cancer. Following the operation, loxoprofen sodium was administered to control his chest pain. A chest radiograph on admission showed airspace consolidation in the right lower lung field. In addition, leukocytosis and elevation of CRP were observed. Although piperacillin sodium was given to him, airspace consolidation on a chest radiograph was increased. A bronchoalveolar lavage fluid study showed that total cell counts and proportion of lymphocytes were increased, and the CD4/CD8 ratio was 1.77. A transbronchial lung biopsy specimen revealed organizing pneumonia with Masson bodies. Furthermore, a lymphocyte stimulation test for loxoprofen sodium was positive. From the clinical course, laboratory data and pathologic findings, we considered this case to be loxoprofen sodium-induced BOOP. Withdrawal of loxoprofen sodium and treatment with corticosteroid resulted in marked improvement of the clinical findings. Although a rare occurrence, it is important to recognize that BOOP can be caused by loxoprofen sodium.

Aged↗