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Biomedical subjects

Shinichiro Mori

Publications and source records attributed to Shinichiro Mori.

At least 37 records · Page 2Linked to original sources
PubMed2005

Bilateral orbital tumor as initial presenting sign in human T-cell leukemia virus-1 associated adult T-cell leukemia/lymphoma.

PURPOSE: To report a case of human T-cell leukemia virus type1 (HTLV-1)-associated adult T-cell leukemia/lymphoma (ATLL) whose initial sign was exophthalmos. DESIGN: Case report. METHODS: A 64-year-old Japanese man presented with exophthalmos and choroidal folds of the right eye without general symptoms and received ophthalmologic and laboratory examination, magnetic resonance imaging (MRI), and orbital biopsy. RESULTS: Antibodies against HTLV-1 were extremely high but atypical lymphocytes were not present in the peripheral blood. MRI showed multiple tumorous lesions in both orbits. Orbital biopsy revealed an orbital mass that consisted of atypical lymphocytes originally from T cells and established the diagnosis of lymphoadenopathy type of ATLL. CONCLUSION: Although ocular involvement by ATLL is extremely rare, ATLL can first present in the orbit, and only the results of a biopsy can provide definitive information for its diagnosis.

Antibodies, Viral↗
PubMed2005

Development of high-radiation-sensitive polymer gel for magnetic resonance imaging in three-dimensional dosimetry.

We developed a high radiation sensitive polymer gel by modifying the amounts of the gel components and the temperature for the gel preparation. We evaluated its relaxation time linearity against dose and compared the measured dose distribution with the calculated one. For the relaxation time-dose linearity, irradiations were carried out with a linear accelerator using 6 MV photons and doses ranging from 0-5.0 Gy. The relationship between dose and R(2) value (reciprocal of T(2) relaxation time) was measured and it had good linearity over a wide range (0.3-5 Gy). The measured dose distributions were in good agreement with calculated ones. Since the present gel has higher sensitivity and it is synthesized more easily at lower cost than conventional polymer gels, we expect to see improved three-dimensional (3D) dosimetry using it.

Dose-Response Relationship, Radiation↗
PubMed2005

Outcomes of patients with acute leukaemia who relapsed after reduced-intensity stem cell transplantation from HLA-identical or one antigen-mismatched related donors.

The characteristics of relapse following reduced-intensity stem-cell transplantation (RIST) remain to be clarified. We reviewed the medical records of 19 patients with acute leukaemia [acute myeloid leukaemia (AML), 16; acute lymphoblastic leukaemia (ALL), 3] who relapsed after RIST from related donors using purine-analogue-based regimens. Their median age was 55 years (range, 29-65 years). Median interval between RIST and relapse was 4.9 months (range, 1.8-24.9 months). Three chose not to receive interventions. The remaining 16 patients received withdrawal of immunosuppression (n = 3), chemotherapy (n = 2), donor lymphocyte infusion (n = 10) and second transplantation (n = 7), alone (n = 9) or in combination (n = 7). Four are alive with a median follow-up of 27.6 months (range, 16.0-28.9 months); three in remission and one in relapse. The 2-year overall survival after relapse was 28.9%. Causes of death in 15 patients included progressive disease (n = 7), graft-versus-host disease (n = 5) and infections (n = 3). Cumulative incidences of relapse-related and non-relapse-related deaths at 2 years after relapse were 37% and 32% respectively. Two prognostic factors were identified on univariate analysis: age [P = 0.017; hazard ratio (HR), 1.16; 95% confidence interval (CI), 1.03-1.32], and ALL as underlying disease (P = 0.011; HR, 10.4; 95% CI, 1.73-62.4). Some AML patients who relapse after RIST achieve durable remission with allogeneic immunotherapy-based interventions; however they carry a significant risk of non-relapse mortality.

Acute Disease↗
PubMed2005

Enlarged longitudinal dose profiles in cone-beam CT and the need for modified dosimetry.

In order to examine phantom length necessary to assess radiation dose delivered to patients in cone-beam CT with an enlarged beamwidth, we measured dose profiles in cylindrical phantoms of sufficient length using a prototype 256-slice CT-scanner developed at our institute. Dose profiles parallel to the rotation axis were measured at the central and peripheral positions in PMMA (polymethylmethacrylate) phantoms of 160 or 320 mm diameter and 900 mm length. For practical application, we joined unit cylinders (150 mm long) together to provide phantoms of 900 mm length. Dose profiles were measured with a pin photodiode sensor having a sensitive region of approximately 2.8 x 2.8 mm2 and 2.7 mm thickness. Beamwidths of the scanner were varied from 20 to 138 mm. Dose profile integrals (DPI) were calculated using the measured dose profiles for various beamwidths and integration ranges. For the body phantom (320-mm-diam phantom), 76% of the DPI was represented for a 20 mm beamwidth and 60% was represented for a 138 mm beamwidth if dose profiles were integrated over a 100 mm range, while more than 90% of the DPI was represented for beamwidths between 20 and 138 mm if integration was carried out over a 300 mm range. The phantom length and integration range for dosimetry of cone-beam CT needed to be more than 300 mm to represent more than 90% of the DPI for the body phantom with the beamwidth of more than 20 mm. Although we reached this conclusion using the prototype 256-slice CT-scanner, it may be applied to other multislice CT-scanners as well.

Head↗
PubMed2005

Cardiovascular circulation and hepatic perfusion of pigs in 4-dimensional films evaluated by 256-slice cone-beam computed tomography.

BACKGROUND: In both cardiac and hepatic disorders it is desirable to accurately visualize the direction and scale of blood flow in the whole organ in pulsating 3-dimensional (D) images, which are known as 4-D images. METHODS AND RESULTS: The present study used 256-slice cone-beam computed tomography (CT) (Athena, Sony-Toshiba) at one rotation per second and a section thickness of 0.5 mm to show the dynamics of cardiovascular circulation and hepatic perfusion by contrast injection in 4-D films of pigs. Four pigs (20 kg each) were anesthetized with isoflurane. The distal tips of the catheters were positioned in the inferior vena cava (IVC) (pigs 1-3) and in the proper hepatic artery (pig 4). Volumetric scanning and injection of contrast material were started simultaneously and continued for 25 s with image reconstruction at 1-s intervals. In pigs 1-3, 4-D filming revealed the dynamics of cardiovascular circulation, first in the IVC, followed by the right ventricle and pulmonary artery, then the left ventricle, left atrium, pulmonary vein, and finally, the right heart disappeared and only the left heart and aorta remained visible. In pig 4, the hepatic arterial trees, followed by the venous trees, could be easily visualized in turn on the 4-D images. CONCLUSIONS: This technology successfully demonstrated cardiovascular circulation and hepatic perfusion in 4-D and will have clinical applicability.

Animals↗
PubMed2005

Prospective trial of high-dose chemotherapy followed by infusions of peripheral blood stem cells and dose-escalated donor lymphocytes for relapsed leukemia after allogeneic stem cell transplantation.

To determine whether induction of graft-versus-host disease (GVHD) improves the outcome of acute relapsed leukemia after stem cell transplantation (SCT), we used high-dose cytarabine (ara-C) followed by infusions of donor-derived buffy coats containing peripheral blood stem cells to treat 12 patients with relapsed leukemia. Donor lymphocyte infusion (DLI) was repeated at least twice over a 5-week interval for patients in whom grade II to IV acute GVHD did not develop after the first DLI. Grade II to IV acute GVHD developed in 4 (33%) of the patients. Chronic GVHD developed in 3 patients, 2 of whom had not experienced acute GVHD. Four (67%) of the 6 patients who developed grade II to IV acute and/or chronic GVHD after DLI responded, but none of the other 6 patients responded. Four (33%) of the patients (2 with acute myelogenous leukemia [AML] and 2 with acute lymphoblastic leukemia [ALL]) achieved complete remission lasting longer than 4 months after the first DLI, but 3 of them had relapses in bone sites. Of these 4 patients, 1 patient with AML and 2 with ALL were alive 8 to 27 months after DLI. These findings indicate that high-dose ara-C combined with megadose DLI may produce durable remission of acute leukemia that has relapsed after SCT when GVHD is induced. The low induction rate of GVHD and extramedullary relapse after remission is achieved with DLI are problems yet to be solved.

Adult↗
PubMed2005

Clinical potentials for dynamic contrast-enhanced hepatic volumetric cine imaging with the prototype 256-MDCT scanner.

OBJECTIVE: To achieve dynamic contrast-enhanced hepatic volumetric cine imaging, we developed a prototype 256-MDCT scanner. This study examined the feasibility of the technique for human hepatic imaging in three hepatocellular carcinoma patients. CONCLUSION: Volumetric cine imaging successfully visualized dynamic contrast enhancement of the hepatocellular carcinoma. It is helpful to evaluate the phase of contrast enhancement or for functional studies of the head, renal artery, coronary artery, and liver.

Aged↗
PubMed2004

Carcinoembryonic antigen messenger RNA expression using nested reverse transcription-PCR in the peripheral blood during follow-up period of patients who underwent curative surgery for biliary-pancreatic cancer: longitudinal analyses.

PURPOSE: Outcome for patients with biliary-pancreatic cancer is still poor, despite curative operation. We investigated the clinical significance of molecular detection of circulating cancer cells in the blood as an early indicator of relapse during follow-up of patients who underwent a curative operation for biliary-pancreatic cancer. PATIENTS AND METHODS: We followed 53 patients who underwent a curative operation for biliary-pancreatic cancer between 1996 and 2001. We used reverse transcription-PCR in the peripheral blood to evaluate carcinoembryonic antigen (CEA) mRNA expression for molecular detection of circulating cancer cells. Follow-up examinations every 3 months after surgery included CEA mRNA expression in the blood, serum CEA, serum carbohydrate antigen 19-9 (CA19-9), and computed tomography or magnetic resonance imaging. RESULTS: Sixteen of 53 patients (30.2%) were diagnosed with a recurrence by imaging studies. The CEA mRNA detection rate in the peripheral blood of these 16 patients was 75% compared with 5.4% in the 37 patients without relapse (P < 0.001). Sensitivity of CEA mRNA, CEA, and CA19-9 serum levels was 75.0%, 50.0%, and 68.8%, respectively. Similarly, specificity was 94.6%, 64.9%, and 81.1%, respectively. CEA mRNA was expressed in the blood, even though tumor markers CEA and CA19-9 were within the normal range in patients with relapse. CEA mRNA expression in the blood, as well as the serum level of CA19-9, tended to be detected a few months earlier than detection by imaging modalities. CONCLUSIONS: During the follow-up of patients who undergo a curative operation for biliary-pancreatic cancer, CEA mRNA expression in the peripheral blood might be a useful and early indicator of relapse.

Adult↗
PubMed2004

Value of magnetic resonance cholangiopancreatography with secretin stimulation in the evaluation of pancreatic exocrine function after pancreaticogastrostomy.

BACKGROUND/PURPOSE: The aim of this study was to assess the value of magnetic resonance cholangiopancreatography with secretin stimulation (secretin-MRCP) in evaluating the remnant pancreatic exocrine reserve after pancreaticogastrostomy with pancreaticoduodenectomy. METHODS: Forty-three patients who had undergone pancreaticoduodenectomies and who were given pancreaticogastrostomies for reconstruction were studied. Dynamic MRCPs, using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence were obtained before and up to 10 min after secretin administration. The morphologic features and diameter of the main pancreatic duct were monitored and graded before and after secretin stimulation. The results were compared with those of endoscopic findings, secretin stimulation testing with a collection of pancreatic fluid, N-benzoyl- L-tyrosyl-p-aminobenzoic acid (BT-PABA) excretion testing, and fecal chymotrypsin concentration. RESULTS: The results of secretin-MRCP were classified into three distinct groups: a good-secretion group (group 1; n=22; 51%), a moderate-secretion group (group 2; n=10; 23%), and a poor-secretion group (group 3; n=11; 26%). This MRCP classification correlated significantly with the concentrations of the pancreatic enzymes p-type amylase, lipase, and trypsin in the gastric juice. The BT-PABA test value was 59.8% in group 1, 46.1% in group 2, and 46.5% in group 3, and was significantly higher in group 1 than in groups 2 or 3. The fecal chymotrypsin concentration was 20.5 U/g in group 1, 14.5 U/g in group 2, and 0.7 U/g in group 3, and there was a significant correlation between the MRCP classification and fecal chymotrypsin concentration. CONCLUSIONS: MRCP with secretin stimulation favorably reflected the presence of remnant pancreatic exocrine function. Therefore, secretin-MRCP is a feasible and effective follow-up examination method to evaluate remnant pancreatic exocrine function after pancreaticogastrostomy.

4-Aminobenzoic Acid↗
PubMed2004

Early central nervous system complications after reduced-intensity stem cell transplantation.

To investigate clinical characteristics of early central nervous system (CNS) complications after reduced-intensity stem cell transplantation (RIST), we reviewed the medical records of 232 patients who had undergone RIST for hematologic diseases at our institutions between September 1999 and June 2003. All patients had received purine analog-based preparative regimens. Stem cell sources comprised granulocyte colony-stimulating factor-mobilized blood from HLA-identical or 1 locus-mismatched related donors (n = 151), unrelated bone marrow (n = 44), or unrelated cord blood (n = 37). Graft-versus-host disease prophylaxis incorporated cyclosporine with or without methotrexate. Diagnosis of CNS complications was based on clinical, radiologic, and microbiological findings. CNS complications occurred in 18 patients (7.8%), with a median onset of 22 days, and were infectious (n = 1), metabolic (n = 15), or cerebrovascular (n = 2). Symptoms included seizures (n = 7), visual disturbance (n = 2), headache (n = 8), nausea (n = 8), vomiting (n = 6), impaired consciousness (n = 16), and hemiparesis (n = 3). Complications improved promptly in 10 patients, and 8 patients died without improvement within 30 days. Multivariate analysis with logistic regression identified umbilical cord blood transplantation as a significant risk factor for early CNS complications (odds ratio, 14.5; 95% confidence interval, 3.7-56.9; P <.0001). CNS complications are a significant problem after RIST, particularly with umbilical cord blood. Limbic encephalopathy is an unrecognized subtype of neurotoxicity after umbilical cord blood transplantation.

Adult↗
PubMed2004

Allogeneic hematopoietic stem cell transplantation with a reduced-intensity conditioning regimen for treatment of metastatic renal cell carcinoma: single institution experience with a minimum 1-year follow-up.

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of allogeneic hematopoietic stem cell transplantation with a reduced-intensity conditioning regimen (RIST) for interferon-alpha-refractory metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS: Of 26 patients referred to the National Cancer Center Hospital for possible RIST between June 2000 and April 2002, an HLA-identical relative was identified for 12 patients. Nine patients underwent RIST. The conditioning regimen consisted of fludarabine 180 mg/m2 or cladribine 0.66 mg/kg, plus busulfan 8 mg/kg and rabbit antithymocyte globulin 5 mg/kg. Graft-vs-host disease (GVHD) prophylaxis was cyclosporine alone. RESULTS: All patients achieved engraftment without grade III to IV nonhematologic regimen-related toxicity. All patients achieved complete donor-type chimerism without donor lymphocyte infusion by day 60. Four patients developed acute GVHD, and four developed chronic GVHD. One patient (11%) achieved partial response. As of July 2003, six patients were alive at median follow-up of 681 days. The actuarial overall survival rate was 89% at 1 year and 74% at 2 years. The overall survival rate tended to be higher in the 12 patients with a matched donor than in the other 14 patients without a matched donor (p = 0.088). CONCLUSION: Our RIST procedure is feasible without severe toxicity. The efficacy of RIST for RCC should be confirmed in phase II/III clinical trials.

Acute Disease↗
PubMed2004

Physical performance evaluation of a 256-slice CT-scanner for four-dimensional imaging.

We have developed a prototype 256-slice CT-scanner for four-dimensional (4D) imaging that employs continuous rotations of a cone-beam. Since a cone-beam scan along a circular orbit does not collect a complete set of data to make an exact reconstruction of a volume [three-dimensional (3D) image], it might cause disadvantages or artifacts. To examine effects of the cone-beam data collection on image quality, we have evaluated physical performance of the prototype 256-slice CT-scanner with 0.5 mm slices and compared it to that of a 16-slice CT-scanner with 0.75 mm slices. As a result, we found that image noise, uniformity, and high contrast detectability were independent of z coordinate. A Feldkamp artifact was observed in distortion measurements. Full width at half maximum (FWHM) of slice sensitivity profiles (SSP) increased with z coordinate though it seemed to be caused by other reasons than incompleteness of data. With regard to low contrast detectability, smaller objects were detected more clearly at the midplane (z = 0 mm) than at z = 40 mm, though circular-band like artifacts affected detection. The comparison between the 16-slice and the 256-slice scanners showed better performance for the 16-slice scanner regarding the SSP, low contrast detectability, and distortion. The inferiorities of the 256-slice scanner in other than distortion measurement (Feldkamp artifact) seemed to be partly caused by the prototype nature of the scanner and should be improved in the future scanner. The image noise, uniformity, and high contrast detectability were almost identical for both CTs. The 256-slice scanner was superior to the 16-slice scanner regarding the PSF, though it was caused by the smaller transverse beam width of the 256-slice scanner. In order to compare both scanners comprehensively in terms of exposure dose, noise, slice thickness, and transverse spatial resolution, K=Dsigma2ha3 was calculated, where D was exposure dose (CT dose index), sigma was magnitude of noise, h was slice thickness (FWHM of SSP), and a was transverse spatial resolution (FWHM of PSF). The results showed that the K value was 25% larger for the 16-slice scanner, and that the 256-slice scanner was 1.25 times more effective than the 16-slice scanner at the midplane. The superiority in K value for the 256-slice scanner might be partly caused by decrease of wasted exposure with a wide-angle cone-beam scan. In spite of the several problems of the 256-slice scanner, it took a volume data approximately 1.0 mm (transverse) x 1.3 mm (longitudinal) resolution for a wide field of view (approximately 100 mm long) along the zeta axis in a 1 s scan if resolution was defined by the FWHM of the PSF or the SSP, which should be very useful to take dynamic 3D (4D) images of moving organs.

Biophysical Phenomena↗
PubMed2004

[Splenic marginal zone lymphoma associated with antiphospholipid antibodies].

A 61-year-old woman experienced a high fever with anemia and APTT prolongation after suffering a herpes zoster virus infection. Physical examination revealed a large splenomegaly without lymphadenopathy. Laboratory evaluations were positive for lupus anticoagulant (LA) and monoclonal IgM-kappa protein. LA was associated with the presence of anti-beta2GPI antibody, anti-cardiolipin antibody, and anti-prothrombin antibody. Moreover, the results of factors IX, XI, and XII assays and CRP and FDP-E were disturbed. A splenectomy was performed, and a splenic marginal zone lymphoma (SMZL) was diagnosed. All hematological findings rapidly recovered after the splenectomy. No thrombotic events occurred after the splenectomy even though thrombosis prophylaxis was not performed. The clinical course suggested that the SMZL-producing antibody induced immunological abnormalities in the labolatory tests. Since the patient suffered disease progression soon after the splenectomy, an autologous peripheral stem cell transplantation with rituximab administration was performed.

Antibodies, Anticardiolipin↗
PubMed2002

Length and quality of survival after external-beam radiotherapy with concurrent continuous 5-fluorouracil infusion for locally unresectable pancreatic cancer.

PURPOSE: The purpose of this study was to evaluate whether external-beam radiotherapy (EBRT) with concurrent continuous 5-fluorouracil (5-FU) infusion affects the length and quality of survival in patients with locally unresectable pancreatic cancer. METHODS: Thirty-one patients with histologically proven locally advanced and unresectable pancreatic cancer without distant metastases were evaluated in this prospective randomized trial. Sixteen patients received EBRT (50.4 Gy/28 fractions) with concurrent continuous infusion of 5-FU (200 mg/m(2)/day), whereas 15 patients received no chemoradiation. The length and quality of survival was analyzed and compared for the two groups. RESULTS: The median survival of 13.2 months and the 1-year survival rate of 53.3% in the chemoradiation group were significantly better than the respective 6.4 months and 0% in the group without chemoradiotherapy (p = 0.0009). The average monthly Karnofsky score, a quality of life indicator, was 77.1 in the chemoradiation group, which was significantly higher than the 65.5 in the group without chemoradiotherapy (p < 0.0001). The number of hospital days per month of survival was significantly less in the chemoradiation than in the no-therapy group (12.3 vs. 19.0 days, p < 0.05). In the chemoradiation group, 5 patients (31%) had a partial response, and 9 (56%) had radiologically stable disease at a median duration of 6.1 months. The patients who had chemoradiation had a lower rate of liver and peritoneal metastases than patients without chemoradiotherapy (31% vs. 64%). Of 10 patients who experienced pain before chemoradiation, 8 (80%) received pain relief that lasted a median of 5.2 months. CONCLUSIONS: EBRT with concurrent continuous 5-FU infusion increased the length and quality of survival as compared to no chemoradiotherapy and provided a definite palliative benefit for patients with unresectable pancreatic cancer.

Adult↗
PubMedDate not supplied

Volumetric cine imaging for cardiovascular circulation using prototype 256-detector row computed tomography scanner (4-dimensional computed tomography): a preliminary study with a porcine model.

This is a preliminary demonstration of volumetric cine imaging of cardiovascular circulation in domestic pigs using a prototype 256-detector row computed tomography (CT) scanner. The scan range is approximately 120 mm in the craniocaudal direction, with a 0.5-mm slice thickness. The thin sections can be used to create cine loops in multiple planes. Thus, the 256-detector row CT scanner overcomes some of the limitations of present helical CT methods.

Animals↗
PubMedDate not supplied

Real-time volumetric imaging of human heart without electrocardiographic gating by 256-detector row computed tomography: initial experience.

OBJECTIVE: The feasibility of human cardiac imaging using a prototype 256-detector row cone-beam computed tomography (256CBCT) scanner without electrocardiographic gating was examined. METHODS: Two healthy male volunteers were examined by contrast-enhanced 256CBCT. The number of detectors was 912 x 256, each measuring approximately 0.5 mm x 0.5 mm at the center of rotation. The craniocaudal coverage was approximately 100 mm after reconstruction by the Feldkamp-Davis-Kress algorithm. The effective time resolution was 500 milliseconds using a half-scan algorithm. RESULTS: Serial enhancement of the left ventricular myocardium was detected. The right and left coronary arteries at proximal and distal segments were depicted without significant blurring. Although the left ventricular wall motion on cine images was not smooth over time, it was possible to measure ventricular volume and ejection fraction. CONCLUSIONS: Using the 256CBCT, it was possible to visualize the coronary arteries, myocardial perfusion, and ventricular contraction simultaneously during a single acquisition.

Algorithms↗