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Eiichi Tanaka

Publications and source records attributed to Eiichi Tanaka.

At least 55 records · Page 3Linked to original sources
PubMed2003

Hormone replacement therapy improves arterial stiffness in normotensive postmenopausal women.

OBJECTIVES: Aortic stiffness, determined by the pulse wave velocity (PWV), is an independent marker of cardiovascular risk. PWV is mainly influenced by age-associated alterations of arterial wall structure and blood pressure (BP). To determine the impact of hormone replacement therapy (HRT) on arterial compliance in normotensive, postmenopausal women, we examined the effects of HRT on PWV. METHODS: Fifty-six postmenopausal women aged 50-70 years were recruited into the present retrospective study from the patients visiting our menopause clinic. Twenty-seven women who were prescribed HRT (14 on estrogen alone and 13 on estrogen plus progestogen) for several months to 6 years and an age-matched group of 29 women not on HRT were studied (Study 1). Nine postmenopausal women were also studied before and at 4 weeks of the treatment of estrogen replacement therapy (ERT) (Study 2). Brachial to ankle PWV (baPWV), which is correlated with aortic PWV, was determined using an automatic device, BP-203PRE. RESULTS: In Study 1, PWV was significantly correlated with age in both groups (controls: r=0.392, P=0.035; HRT group: r=0.471, P=0.013), and HRT significantly lowered the PWV value at all ages examined (Mean+/-S.D. of baPWV in controls: 1382.2+/-114.1; HRT: 1245.3+/-124.8, P=0.0001). In Study 2, baPWV decreased significantly after ERT (P<0.05), without a significant change in systolic BP (P=0.851). CONCLUSIONS: Estrogen appears to improve arterial compliance independently of BP within 4 weeks.

Adult↗
PubMed2003

Subset-dependent relaxation in block-iterative algorithms for image reconstruction in emission tomography.

This paper presents a row-action maximum likelihood algorithm (RAMLA), in which the relaxation parameter is controlled in such a way that the noise propagation from projection data to the reconstructed image is substantially independent of the access order of the input data (subsets) in each cycle of the sub-iterations. The 'subset-dependent' relaxation parameter lambda(k) (q) is expressed as lambda(k)(q) = beta0/(beta0 + q + gamma k M), where M is the number of angular views, q (0 < or = q < or = M - 1) is the access order of the angular view, k is the iteration number and beta0 and gamma are constants. The constant beta0 deals with the balance of the noise propagation and the constant gamma controls the convergence of iterations. The value of beta0 is determined from the geometrical correlation coefficients among lines of coincidence response. The proposed RAMLA using the subset-dependent (dynamic) relaxation 'dynamic RAMLA (DRAMA)' provides a reasonable signal-to-noise ratio with a satisfactory spatial resolution by a few iterations in the two-dimensional image reconstruction for PET. Dynamic OS-EM (DOSEM) has also been developed, which allows the use of a larger number of subsets (OS level) Msub without loss of signal-to-noise ratio as compared to the conventional OS-EM. DRAMA is a special case of DOSEM, where Msub = M, and it is no more profitable to use DOSEM with a smaller Msub (< M), because DRAMA provides similar performance with the fastest convergence and smallest computer burden. This paper describes the theory, algorithm and the results of the simulation studies on the performance of DRAMA and DOSEM.

Algorithms↗
PubMed2003

High-dose-rate brachytherapy as monotherapy for localized prostate cancer: a retrospective analysis with special focus on tolerance and chronic toxicity.

PURPOSE: To examine retrospectively fractionated high-dose-rate brachytherapy as monotherapy for localized prostate cancer with special focus on tolerance and toxicity, especially chronic toxicity. MATERIALS AND METHODS: Between May 1995 and October 2001, 43 patients with localized prostate cancer were treated with high-dose-rate brachytherapy without external beam irradiation at Osaka University Hospital. The stage was T1, T2, T3, and T4 in 8, 14, 18, and 3 patients, respectively. The adenocarcinoma was well, moderately, or poorly differentiated in 12, 16, and 15 patients, respectively. The median initial prostate-specific antigen level was 19.3 ng/mL (range 3.8-233.0). Thirty-eight patients also received hormonal therapy. Metallic needles were implanted transperineally under real-time ultrasound guidance, followed by a dose optimization program. Patients were irradiated twice daily at intervals of >6 h. A total dose of 54 Gy in nine fractions within 5 days (48 Gy in eight fractions within 5 days for the first 7 cases) was administered in one implant session. The median follow-up was 24 months (range 1-76). RESULTS: Radiation Therapy Oncology Group acute toxicity of Grade 4, 2, and 1 occurred in 1 (2%), 12 (28%), and 8 (19%) patients, respectively. Five patients had late toxicity: one with rectal ulcer (Grade 2) and four with rectal bleeding (Grade 1). The volume receiving 100% of the prescribed dose showed significant correlations with the incidence of acute and chronic toxicities (p = 0.005 and p = 0.014, respectively). The 3-year actuarial overall survival, local control, and biochemical no evidence of disease rate was 94%, 100%, and 55%, respectively. The crude biochemical control rate for low, intermediate, and high-risk patients was 100% (5 of 5), 80% (8 of 10), and 61% (17 of 28), respectively. CONCLUSIONS: High-dose-rate brachytherapy as monotherapy was found to be feasible and well tolerated. It showed a low chronic toxicity rate without any event of Radiation Therapy Oncology Group of Grade 3 or greater.

Adenocarcinoma↗
PubMed2003

Results of radical distal pancreatectomy with en bloc resection of the celiac artery for locally advanced cancer of the pancreatic body.

BACKGROUND: Locally advanced cancer of the pancreatic body involving the celiac and/or common hepatic arteries is often considered unresectable. Radical distal pancreatectomy with en bloc resection of these arteries without reconstruction was recently introduced to treat these tumors. However, experience is still limited. This study reviewed the safety and utility of the operation. PATIENTS AND METHODS: We retrospectively studied the charts of 13 patients who underwent radical distal pancreatectomy. RESULTS: Unplanned arterial reconstruction was required in three patients due to accidental injury. The postoperative mortality rate was 0% despite a morbidity rate of 62%. Patient's intractable abdominal and/or back pain was completely relieved immediately after surgery. Contrary to expectations, postoperative diarrhea was mild. The surgical margins, including the retroperitoneum, were clear histologically (R0 resection) in all patients. The 1- and 2-year survival rates were 51% and 14%, respectively, and median survival was 12.2 months. The site of recurrence was the liver in six patients and retroperitoneum in one. CONCLUSIONS: Distal pancreatectomy with en bloc resection of the celiac artery is feasible and safe, offers a high resectability rate, and has dramatic analgesic effect. Local control of disease is excellent despite frequent hepatic recurrence.

Aged↗
PubMed2003

Isolated paracaval subsegmentectomy of the caudate lobe of the liver.

BACKGROUND: The caudate lobe of the liver is divided into three subsegments based on the portal blood supply: the Spiegel lobe, the paracaval portion (S1r), and the caudate process. An isolated paracaval (S1r) subsegmentectomy is indicated for a small hepatocellular carcinoma localized within S1r. Because this challenging procedure has not been described, we report the details of successful surgical technique. METHODS: The portal pedicle isolation technique provides easy access to the S1r portal pedicle. A tape is passed along the midline of the anterior surface of the vena cava and its lower end is passed through the caudate parenchyma dorsoventrally to establish a landmark for the left border of S1r. A liver-splitting anterior approach is used to open the interlobar plane widely to the precaval tape. As exposing the vena cava and the root of the right hepatic vein, parenchymal dissection is advanced to the right and then, upward. RESULTS: The procedure was performed successfully in a 51-year-old man with hepatitis B who had a 2-cm hepatocellular carcinoma in S1r. Blood loss was 645 ml. CONCLUSIONS: An isolated paracaval subsegmentectomy of the caudate lobe can be performed successfully, although it is likely to remain an uncommonly used procedure.

Carcinoma, Hepatocellular↗
PubMed2003

Results of low- and high-dose-rate interstitial brachytherapy for T3 mobile tongue cancer.

PURPOSE: To evaluate the treatment results of low-dose-rate (LDR) and high-dose-rate (HDR) interstitial brachytherapy (ISBT) for T3 mobile tongue cancer. MATERIAL AND METHODS: Between 1974 and 1992, 61 patients with T3 mobile tongue cancer were treated with LDR ISBT using (192)Ir hairpins with or without single pins. In addition, between 1991 and 1999, 14 patients were treated with HDR ISBT. For nine patients treated with ISBT alone, the total dose was 59-94 Gy (median 72 Gy) within one week in LDR ISBT and 60 Gy/10 fractions/5 days in HDR ISBT. For 66 patients treated with a combination therapy of external beam radiotherapy (EBRT) and ISBT, the total dose was 12.5-60 Gy (median 30 Gy) of EBRT and 50-112 Gy (median 68 Gy) within 1 week in LDR ISBT or 32-60 Gy (median 48 Gy)/8-10 fractions/5-7 days in HDR ISBT. RESULTS: The 2- and 3-year local control rates of all patients were both 68%. The 2- and 3-year local control rates of patients treated with LDR ISBT were both 67%, and those with HDR ISBT were both 71%. The local control rate of patients treated with HDR ISBT was similar to those with LDR ISBT. CONCLUSIONS: ISBT for T3 mobile tongue cancer is effective and acceptable. The treatment result of HDR ISBT is almost similar to that of LDR ISBT for T3 mobile tongue cancer.

Adult↗
PubMed2003

Prospective study of HDR (192Ir) versus MDR (137Cs) intracavitary brachytherapy for carcinoma of the uterine cervix.

PURPOSE: The aim of this study was to compare the results of high-dose rate (HDR) and medium-dose rate (MDR) intracavitary brachytherapy for carcinoma of the uterine cervix on the basis of a prospective study and to determine the dose rate conversion factor (DRCF) from low-dose rate (LDR) to MDR via HDR, because a DRCF of 0.54 from LDR to HDR has been widely accepted. MATERIALS AND METHODS: Between August 1991 and July 1999, 104 patients were entered into this trial to compare results between HDR (n=54) and MDR (n=50). Three patients were excluded from this study, leaving 54 HDR patients and 47 MDR patients eligible. Method and dose of external beam radiotherapy were the same for both groups. For HDR intracavitary brachytherapy, point A dose was adjusted to 32 Gy/4 fractions for stages I and II, to 30 Gy/4 fractions for stage III, and to 22.5 Gy/3 fractions for stage IV. The corresponding values for MDR were 35.6 Gy/4 fractions, 34 Gy/4 fractions, and 25.5 Gy/3 fractions. The average dose rate at point A was 30 Gy/hour (9.0-65.2) for HDR and 1.7 Gy/hour (1.3-2.2) for MDR. We assumed a DRCF of 0.9 from MDR to HDR. RESULTS: The 3-year cause-specific survival rates for HDR were 85%, 83%, 75%, and 0% for stages I, II, III, and IV, respectively. The corresponding figures for MDR were 100%, 82%, 58%, and 40%. Six of the HDR patients (11%) and 2 of the MDR patients (4%) developed Kottmeier's grade 2 or 3 late complications. A DRCF of 0.6 from LDR to MDR could be derived from a DRCF of 0.9 from MDR to HDR and one of 0.54 from LDR to HDR. CONCLUSIONS: There were no statistically significant differences in cause-specific survival and incidence of late complications between HDR and MDR. A DRCF of 0.6 from LDR to MDR could be determined. However, because the results of this trial were preliminary, a further study is needed.

Adult↗
PubMed2003

Finite element analysis of knee injury risks in car-to-pedestrian impacts.

In vehicle-pedestrian collisions, lower extremities of pedestrians are frequently injured by vehicle front structures. In this study, a finite element (FE) model of THUMS (total human model for safety) was modified in order to assess injuries to a pedestrian lower extremity. Dynamic impact responses of the knee joint of the FE model were validated on the basis of data from the literature. Since in real-world accidents, the vehicle bumper can impact the lower extremities in various situations, the relations between lower extremity injury risk and impact conditions, such as between impact location, angle, and impactor stiffness, were analyzed. The FE simulation demonstrated that the motion of the lower extremity may be classified into a contact effect of the impactor and an inertia effect from a thigh or leg. In the contact phase, the stress of the bone is high in the area contacted by the impactor, which can cause fracture. Thus, in this phase the impactor stiffness affects the fracture risk of bone. In the inertia phase, the behavior of the lower extremity depends on the impact locations and angles, and the knee ligament forces become high according to the lower extremity behavior. The force of the collateral ligament is high compared with other knee ligaments, due to knee valgus motions in vehicle-pedestrian collisions.

Accidents, Traffic↗
PubMed2003

Long-term survival after radical resection of advanced pancreatic cancer: a case report with special reference to CD8+ T-cell infiltration.

A 65-yr-old man who underwent pancreaticoduodenectomy with portal vein resection for pancreatic cancer is alive 8 yr after surgery. Originally, computed tomography (CT) revealed an 8-cm tumor in the pancreatic head. The tumor had infiltrated the portal vein, but grew expansively, so there was neither biliary obstruction nor jaundice. Pancreaticoduodenectomy with resection of the portal vein was performed for pancreatic cancer. Many tumor-infiltrating lymphocytes were seen within cancer cell nests on routine histopathology. We performed immunostaining for CD8, and found that a large number of the lymphocytes were CD8+ T cells. The patient's prognosis was considered poor because the tumor was large and had infiltrated the portal vein. We suspect that long-term survival may be related to the response of CD8+ T cells to the cancer.

Aged↗
PubMed2003

Risperidone in the treatment of acute confusional state (delirium) due to neuropsychiatric lupus erythematosus: case report.

Acute confusional state (delirium) appears as one of the common neuropsychiatric manifestations of systemic lupus erythematosus (SLE). It has been suggested that neuropsychiatric SLE (NP-SLE) could promote the occurrence of drug-induced extrapyramidal symptoms (EPS). Atypical antipsychotics have been thought to be useful in management of delirium because of their low incidence of adverse effects including EPS. However, no reports of the use of atypical antipsychotics in delirium due to NP-SLE have been published. Here we report a case of NP-SLE presenting an acute confusional state (delirium), which was successfully managed by risperidone.

Acute Disease↗
PubMed2003

[Case of systemic sclerosis presenting with alveolar hemorrhage and positive anti-neutrophil cytoplasmic myeloperoxidase antibody(MPO-ANCA) without pathological renal involvement].

We report a 54-year-old woman with systemic sclerosis who presented alveolar hemorrhage. She noticed shortness of breath in May 1997. She was diagnosed having interstitial pneumonitis and systemic sclerosis with sclerodactylia of bilateral fingers in December. She developed bloody sputum and dyspnea suddenly on March 12, 1999. Bloody lavage fluid with hemosiderin-laden macropharge was observed by bronchial fiber scopic examination. The elevated level of MPO-ANCA was detected without anti-DNA antibody. Administration of intravenous methylprednisolone(1g per day, 3 days) followed by 40 mg per day of prednisolone achieved complete response, and MPO-ANCA level was decreased. Mild proteinuria and microhematuria was detected on admission, but renal biopsy revealed no findings of crescent formation or angiitis. With coadministration of oral cyclophosphamide she doesn't have any renal involvement or recurrence of alveolar hemorrhage during these four years. MPO-ANCA level remains negative. Alveolar hemorrhage, which is uncommon pulmonary event in systemic sclerosis, is often coexist with renal angiitis in the context of "pulmo-renal syndrome". MPO-ANCA is said to be related to pulmo-renal syndrome and is sometimes induced by D-penicillamine. This patient is really important in considering the pathogenesis of alveolar hemorrhage because she had no renal vasculitic lesions or D-penicillamine intake.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2002

A new method for preventing pulse pileup in scintillation detectors.

A new method for preventing pulse pileup in scintillation detectors is proposed. In the new method (G-INT), the energy of an event is calculated from the 'gated integral' of the pulse signal and the period of integration. The period of integration is not fixed but is shortened by the arrival of the succeeding pulse so as to avoid post-pulse pileup. The effect of pre-pulse pileup is corrected by subtracting the remnant energy of the preceding pulses, which is calculated from the gated integral of the preceding pulse. To avoid error due to short pulse intervals, pre- and post-pulse deadtimes are imposed. The method is similar to Wong's method (W-SUM) that depicts the energy by the 'weighted sum' of the current signal and the integrated signal. The performance of G-INT has been studied by Monte Carlo simulation in comparison with W-SUM, the variable sampling-time technique and simple delay-line clipping. It is shown that G-INT provides the smallest degradation in pulse height resolution for a given count rate capability. The difference between G-INT and W-SUM is explained by the difference in the amount of statistical noise involved in the gated integral and in the weighted sum.

Algorithms↗
PubMed2002

Wedge resection of the portal bifurcation concomitant with left hepatectomy plus biliary reconstruction for hepatobiliary cancer.

BACKGROUND/PURPOSE: We report our experience performing wedge resection of the portal bifurcation and transverse suture closure in patients undergoing left hepatectomy and caudate lobectomy plus biliary reconstruction for hepatobiliary cancer. METHODS: The procedure was performed in three patients with hilar or intrahepatic cholangiocarcinoma. After confirming that tumor invasion of the portal bifurcation was not circumferential, the portal trunk and the right posterior and right anterior portal branches were isolated and clamped. Wedge resection of the portal bifurcation was performed, taking care to secure a clear surgical margin. The edges of the portal vein were approximated, using guy-sutures in the dorsal and ventral edges and a temporary central guy-suture, and portal reconstruction was carried out using a continuous transverse suture. After unclamping, good portal flow was confirmed by color Doppler ultrasonography. RESULTS: The procedure was completed successfully in all three patients; the average time of portal vein occlusion was 15 min. Two patients had postoperative complications: bile leakage and wound infection, but no patient developed postoperative hepatic failure or died. The three patients are alive without recurrence at 2, 11, and 22 months after the operation. CONCLUSIONS: Wedge resection of the portal bifurcation is easier and simpler than using a venous patch or performing segmental resection.

Bile Duct Neoplasms↗
PubMed2002

Tackler's bony spur in sumo wrestlers: a report of two cases.

We examined two sumo wrestlers who had tackler's bony spur. In football players, these spurs are secondary to subperiosteal hematoma formation from repeated direct blows by an opponent or from ill-fitting shoulder pads. The initial charge of sumo wrestling is similar to a tackle in American football. Our two patients had had repeated direct blows by opponents on the initial wrestling charge. The tackler's bony spurs of our two patients were located on the lateral aspect of the humeral shaft just distal to the deltoid insertion, and there was no involvement of the anterior mass of the brachialis muscles or elbow. We consider that tackler's bony spurs are sometimes, but not often, seen in sumo wrestlers.

Adolescent↗
PubMed2002

Polymorphisms in the methylenetetrahydrofolate reductase gene were associated with both the efficacy and the toxicity of methotrexate used for the treatment of rheumatoid arthritis, as evidenced by single locus and haplotype analyses.

5,10-Methylenetetrahydrofolate reductase (MTHFR), a key enzyme involved in folate metabolism, has two common polymorphisms that affect enzyme activity. The objective of this study was to examine whether there was a correlation between the genotype or haplotype of the MTHFR gene and the efficacy or toxicity of methotrexate (MTX) in the treatment of rheumatoid arthritis. MTX-treated rheumatoid arthritis patients (n = 106) were selected from outpatient clinics and used for a retrospective study to examine the correlation between genotypes or haplotypes concerning polymorphisms of the MTHFR gene, and the efficacy or toxicity of MTX. Estimation of the haplotype frequencies was performed by maximum likelihood estimation based on expectation maximization algorithm. Single locus analysis examining each locus separately showed that patients with 1298C were receiving significantly lower doses of MTX compared to patients without [P < 0.05, relative risk (RR) = 2.18, 95% confidence interval (CI) 1.17-4.06], while a higher rate of overall MTX toxicity was observed in patients with 677T than those without (P < 0.05, RR = 1.25, 95% CI 1.05-1.49). An estimation of haplotype frequencies showed that there was no 677T-1298C haplotype in the population. Posterior distribution of the diplotype configuration for each individual was concentrated on a single configuration. Patients with the 677C-1298C haplotype were receiving lower doses of MTX than those without (P < 0.05, RR = 2.14, 95% CI 1.13-4.07), while subjects with 677T-1298A had a higher frequency of side-effects from MTX (P < 0.05, RR = 1.42, 95% CI 1.11-1.82). Both single locus and haplotype analyses suggest that polymorphisms within the MTHFR gene are associated with both the efficacy and toxicity of MTX in rheumatoid arthritis patients. Pharmacokinetic studies are necessary to prove the association.

Antirheumatic Agents↗
PubMed2002

Pulmonary hypertension in systemic lupus erythematosus: evaluation of clinical characteristics and response to immunosuppressive treatment.

OBJECTIVE: To clarify the clinical features of systemic lupus erythematosus (SLE) complicated with pulmonary hypertension (PH) and to evaluate the efficacy of immunosuppressive treatment. METHODS: Case records were reviewed for 194 patients with SLE who were admitted to Aoyama Hospital of Tokyo Women's Medical University between 1992 and 1999. There were 12 patients with PH [8 SLE and 4 SLE + systemic sclerosis (SSc) overlap syndrome]. These patients were compared with 59 age and sex matched patients with SLE for clinical characteristics and laboratory findings. The efficacy of treatments for PH was also evaluated. RESULTS: In our cohort of 194 patients with SLE, 6.2% had PH. The plasma thrombin-antithrombin III complex and plasma D-dimer levels were significantly higher in patients with PH compared with those without PH. Eight patients with PH (4 SLE and 4 SLE + SSc) were treated with corticosteroids (CS) +/- cyclophosphamide (CYC). Right ventricular systolic pressure (RVSP) was improved in 7 of 8 patients. In 6 of 7 responders to the therapy, the treatment was started as soon as they were diagnosed with PH. PH relapsed in 2 patients treated with oral CS +/- CS pulse therapy, but their RVSP was decreased again by immunosuppressive treatment. CONCLUSION: CS +/- CYC was effective for PH associated with SLE. Immunosuppressive treatment should be performed during the early stage of PH to improve prognosis.

Adult↗
PubMed2002

Comparison of the Rau method and the Larsen method in the evaluation of radiographic progression in early rheumatoid arthritis.

OBJECTIVE: To investigate the usefulness of the radiographic scoring method proposed by Rau, et al for evaluation of joint damage in patients with early rheumatoid arthritis (RA). METHODS: Radiographs of hands and feet of 30 prospectively observed patients with early RA were assessed by the Rau method, the Larsen method, and count of erosive joints. The standardized response mean (SRM) was used to estimate the sensitivity to change of each method of assessment. RESULTS: Although the Rau method evaluates only the amount of bony erosion, nearly equivalent radiographic progression was observed with the Rau and the Larsen methods. Radiographic changes in the first year were sensitively identified by all 3 methods (SRM for Rau method 0.83, Larsen method 0.88, and count of erosive joints 0.84). However, in the period from 2 to 6 years after entry into the study, sensitivity to change was maintained with use of the Rau (SRM 1.38) and Larsen (SRM 0.95) methods, but not by count of erosive joints (SRM 0.49). While an apparent ceiling effect was observed after 2 years in count of erosive joints, no ceiling effects were noted for the Rau and Larsen methods. CONCLUSION: Our study showed that the usefulness of the Rau method is equivalent to the Larsen method in clinical assessment of radiographic progression in early RA.

Arthritis, Rheumatoid↗