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Biomedical subjects

T Ohki

Publications and source records attributed to T Ohki.

149 records · Page 9Linked to original sources

Transient focal cortical hypometabolism in idiopathic West syndrome.

Positron emission tomography (PET) using 18F-labeled 2-deoxy-D-glucose was performed serially in 5 infants with idiopathic West syndrome. While tonic spasms persisted, 2 infants had hypometabolism in the bilateral temporo-parieto-occipital regions, which disappeared after cessation of spasms. In 2 other infants, PET revealed focal hypometabolism in the temporal region a few months after the disappearance of tonic spasms, but subsequent PET studies were normal. PET can detect transient metabolic abnormalities of the cerebral cortex which may be associated with the pathophysiology of West syndrome.

Blood Glucose↗

Effect of polytetrafluoroethylene covering of Palmaz stents on the development of intimal hyperplasia in human iliac arteries.

PURPOSE: The occurrence of neointimal hyperplasia within a stent may result in restenosis with recurrent symptoms of end-organ ischemia. This study evaluated the potential of a nonporous covering of a stent to function as a barrier to the formation of intrastent neointimal hyperplasia. MATERIALS AND METHODS: Twelve endovascular stent grafts were used to treat 12 high-risk patients with limb-threatening ischemia secondary to long-segment iliac artery occlusion. A 6-mm, thin-walled polytetrafluoroethylene graft was inserted and anchored to the common iliac artery with use of Palmaz stents. Each stent was covered by graft material over one-half of its length. Control angiograms obtained immediately after graft insertion were compared with follow-up angiograms obtained between 4 and 6 months after the initial procedure. On each angiogram, the region of the stent was magnified by 20x to permit computerized luminal diameter measurements. RESULTS: The mean luminal diameter within the stent was significantly greater on the covered (7.7 mm +/- 0.33 standard deviation) compared with the uncovered (6.7 mm +/- 0.85 standard deviation) portions (P < .01). CONCLUSIONS: Partially covered stents are a unique model for assessing the effects of an extrinsic stent covering on arterial healing and myointimal hyperplasia. These data suggest that a relatively nonporous covering of polytetrafluoroethylene may inhibit stent-related restenosis in iliac arteries.

Aged↗

Stent-graft repair of aorto-iliac occlusive disease coexisting with common femoral artery disease.

PURPOSE: Significant disease or occlusion of the common femoral artery may preclude percutaneous therapy for aorto-iliac occlusive disease. In addition, aorto-iliac angioplasty may not reverse the ischemic symptoms when common femoral artery disease exists. The authors describe the feasibility of endoluminal stent-grafts to treat multilevel aortoiliofemoral occlusive disease. MATERIALS AND METHODS: The authors placed 18 stent-grafts for aorto-iliac occlusive disease in 17 patients with limb-threatening ischemia and significant common femoral artery disease. These procedures were performed as a joint effort between vascular surgery and interventional radiology staff in the operating room. The common femoral artery was occluded in 10 or severely diseased in eight, necessitating endoluminal bypass to the superficial femoral or popliteal artery (n = 7) or to the deep femoral artery (n = 7), or necessitating patch angioplasty of the common femoral artery (n = 4). Stent-grafts were fabricated from 6-mm polytetrafluoroethylene and 29-mm Palmaz stents. RESULTS: All 18 grafts were placed successfully. Follow-up ranged from 3 to 38 months (mean, 21 months). Seven patients died of myocardial infarction; two grafts occluded and one required angioplasty during follow-up, resulting in a primary patency rate of 81% at 2 years. CONCLUSION: Endoluminal stent-graft placement is a useful method of treatment for advanced atherosclerotic aorto-iliac disease, particularly in the presence of common femoral artery disease. This approach avoids an extra-anatomic bypass or a major transabdominal aortic bypass procedure. Longer follow-up with a larger series is needed to ensure the safety and late graft patency comparable to the traditional aortofemoral and iliofemoral bypass grafts.

Adult↗

[The brachytherapy with low dose-rate iridium for prostate cancer].

PURPOSE: Brachytherapy as an option for the treatment of prostate cancer has been commonly performed in USA. As the permanent seeding of the radioactive materials is strictly restricted by the law in Japan, brachytherapy must be performed by the temporary implant. This treatment has been performed at a few facilities in Japan mostly using high dose-rate iridium. Only our facility has been using low dose-rate iridium (LDR-Ir) for prostate cancer. This study evaluates the clinical results of the treatment. PATIENTS AND METHODS: Since December 1997 to December 1999, 26 patients with histologically diagnosed as prostate cancer (Stage B, 92%; Stage C, 8%) underwent brachytherapy. Twenty-two patients received brachytherapy alone, three were treated with a combination of brachytherapy and external beam radiotherapy (ERT) and one was treated with a combination of brachytherapy and neoadjuvant endocrine therapy. Patients ranged in age from 61 to 84 (median 76) years old. Treatment was initiated with perineal needle placement. From 10 to 14 needles were placed through the holes on the template which was fixed to the stabilizer of the transrectal ultrasound probe. After the needle placement. CT scan was performed to draw distribution curves for the treatment planning. LDR-Ir wires were introduced to the sheath and indwelled during the time calculated from dosimetry. Peripheral dose was 70 Gy for the monotherapy of brachytherapy. For the combination therapy, 40 Gy was given by brachytherapy and 36 Gy with ERT afterwards. LDR-Ir wires were removed after completion of the radiation and patients were followed with serum PSA level and annual biopsy. RESULTS: During 2 to 26 (median 12) months follow-up, 8 out of 9 patients with initial PSA level above 20 ng/ml showed PSA failure. All 13 patients with initial PSA level lower than 20 ng/ml were free from PSA failure. Eight out of 11 patients with Gleason's score 7 or higher showed PSA failure, and all 14 patients (including three patients with combined therapy) with Gleason's score 6 or less were free from PSA failure. Annual biopsy was performed in 8 patients, and 4 patients histologically revealed tumor free and 4 patients (two of them showed PSA failure) were tumor positive. No major complication was observed, however, some minor side-effect as irritability was seen in 65% of the patients. CONCLUSIONS: The results showed that brachytherapy with LDR-Ir was an acceptable treatment as long as the patients were selected strictly with PSA level and Gleason's score. A good candidate for this treatment is the patient whose PSA level is lower than 20 ng/ml and Gleason's score is 6 or less. The treatment is effective and safe, but further observation is necessary to reach the conclusion.

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