Clinical results of endovascular stent graft repair for fifty cases of thoracic aortic aneurysms

Between February 1995 and December 1997, 50 cases (55 lesions) of thoracic aortic aneurysms including 20 cases of aortic dissections were treated with an endovascular technique using the stent grafts. All patients were treated in the operating room under general anesthesia and the stent grafts were implanted through 18 Fr. or 20 Fr. sheaths via femoral arteries under fluoroscopic guidance. The stent graft was composed of several units of self-expanding stainless-steel Z stents covered with an ultra-thin polyester fabric. Stent graft deployment was technically successful in 53 of 55 lesions (delivery success rate: 96.4%). Exclusion of the aneurysms and entry closing without endoleak were achieved within two weeks after the operation in 43 of 53 lesions (initial success rate: 81.1%). Endoleak was found in 10 lesions (minor endoleak: 8 and major endoleak: 2 lesions). Two patients died in the periopertive period of delivery failures as injury to external iliac artery and damage to the delivery sheath caused by tortuous and narrow access routes. Endovascular stent graft repair of thoracic aortic aneurysms is minimally invasive operation in comparison with conventional surgical graft replacement with extracorporeal circulation. These early results suggest that the stent graft repair is possibly safe and useful treatment for the patients of thoracic aortic aneurysms especially in high risk patients. However, careful long-term follow-up is necessary to prove the value and the effects of this endovascular treatment and improvement of the stent graft system and technical training of endovascular surgery for operators are required to reduce the delivery failure and to determine the stent graft repair is reliable treatment.     

A narrow beam 1.3-μm-super luminescent diode integrated with aspot-size converter and a new type rear absorbing region

The device structure and performance of 1.3-μm narrow beam superluminescent diodes (NB-SLD's), which consist of a spot-size converter and a new type rear absorbing region, are reported. A butt-jointed selectively grown spot-size converter (SSC) is employed to realize the narrow beam characteristics. The rear absorbing region is designed as a taper structure with a part of the region is inclined from the active-stripe axes. In order to investigate the effects of both SSC length and active-region length on device performance, two types of NB-SLDs, whose SSC and active-region lengths differ, are fabricated. An electrode to sweep out photoexcited carriers in the absorption region is formed on one device. By comparing the characteristics of these devices, we clarify that a 500-μm-active-region device is suitable for high-output power operation, and a 400-μm-active-region device is suitable for realizing short coherent length. The light-output power is 13.9 mW at 200-mA-injection current for the former device, and the full-width at half-maximum (FWHM) of the spectrum is 62.6 nm (calculated coherence length is 26.5 μm) for the latter device. Very small spectral modulation index (0.015 at 5 mW-output power) is attained by grounding the absorption-region electrode. For the SSC length, a 300-μm SSC device shows very narrow far-field patterns (FFPs) and very good fiber-coupling characteristics. The FWHM of horizontal and vertical FFPs are 8.9 and 10.6°, respectively. Because of this narrow beam divergence, the coupling efficiency of -1.9 dB to a flat-end 4-μm spot-size fiber is obtained without lenses. The alignment tolerance of this device to the fiber for both horizontal and vertical direction is more than 3 μm at a loss of when -1 dB from the optimum coupling     

Current forging technology for integrated type steel forgings for nuclear steam supply system components

This brief review concerns the trend in using large size, integrated type steel forgings for nuclear steam supply system components as intended for easier in-service inspection (ISI).To achieve this trend, unique forging techniques have been developed.The forging techniques corresponding to each integrated type steel forging product together with a brief explanation of the development of forging facilities as well as a future aspects are introduced.     

Long-term results of preoperative hyperthermo-chemo-radiotherapy (HCR) for patients with esophageal carcinoma invading neighboring structures (T4)

PATIENTS: A total of 180 patients with esophageal carcinoma invading the neighboring structures (T4) were surgically treated by esophagectomy and reconstruction in the Department of Surgery II, Kyushu University from January 1965 to April 1997. Any of these cases with distant node metastasis and demonstrating organ metastasis or a combined resection of adjacent structures were excluded from this study. As a result, twenty-six patients treated with preoperative hyperthermo-chemo-radiotherapy (HCR Group), 39 treated either with preoperative radiotherapy or preoperative chemo-radiotherapy (R or CR Group) and 23 non-treated patients (Non-tx Group) were thus entered in this study. RESULTS: The 3-year survival rates after esophagectomy in HCR Group, R or CR Group and Non-tx Group were 26.5%, 0% and 9%, respectively, while the 5-year survival rate of the HCR group was 15.9%. The group with preoperative HCR thus showed a significantly more favorable outcome than R or CR Group and Non-tx Group. (p < 0.05). DISCUSSION: The significant difference observed in the prognosis was thought to be due to the reinforced effect of local regulation due to hyperthermia. Our data thus suggest that preoperative HCR contributes to the prolonged post-operative survival for carcinoma of the esophagus invading the neighboring structures.     

Development of thick wall 2.25Cr-1MoNiNb steel forgings for steam generators of fast breeder reactors

The large and thick forgings made of 2.25Cr-1MoNiNb steel are required for vessel material of steam generator (SG) of the fast breeder reactor SNR 300.In order to study the feasibility of 2.25Cr-1MoNiNb steel heavy section forging, chemical composition, melting practice and ingot making, hot working and heat treatment conditions were investigated. The following recommendations were derived: (1) 0.04% C, 0.10% ΔNb, (2) application of electro-slag remelting process, (3) grain refining by hot working, (4) two-step austenitizing at 1020°C.Based on these recommendations, the actual products such as hollow cylinders with maximum 290 mm thickness, solid bars with 420 mm diameter and forged plates with maximum 185 mm thickness could be supplied for application in the helical coiled SG of the SNR 300. Statistical analysis of the products showed the sufficient and isotropic material properties, which fulfill the requirements of the basic safety rules.     

Fatty acid synthetase from the Harderian gland of guinea pig: biosynthesis of methyl-branched fatty acids

Fatty acid synthetase was isolated from guinea pig Harderian gland. This enzyme complex exhibited a unique character as compared with the fatty acid synthetase from the liver of the same animal. The former enzyme produced many odd-numbered and methyl-branched fatty acids in the presence of methylmalonyl-CoA. These fatty acids are characteristic components of the lipid secreted from this gland. The chemical structure of this lipid has been identified as 1-O-alkyl-2,3-diacylglycerol by previous work from this laboratory (Yamazaki, T., Seyama, Y., Otsuka, H., Ogawa, H., & Yamakawa, T. (1981) J. Biochem. 89, 683-691). Apparent Km values (5 X 10(-6) M) for acetyl-CoA and propionyl-CoA were the same, but the Vmax for propionyl-CoA was much higher than that for acetyl-CoA. The pI value of the fatty acid synthetase from Harderian gland was 5.3, and the molecular weight of the enzyme was 9 X 10(5) daltons. The beta-ketoacyl reductase had pro-S stereospecificity and the enoly reductase had pro-R stereospecificity for NADPH. The results presented in this paper indicate that the fatty acid synthetase from guinea pig Harderian gland can produce a set of fatty acids needed for the synthesis of the lipid secreted from this gland, and that the fatty acid synthetase has a characteristic organ specificity.     

Human late-receptor potential and its clinical use in dyschromatopsia

The off response of the P III component isolated by aspartate in the human eyecup in vitro showed an initial rapid decay followed by a slow decay. The rapid decay in the human ERG originates mainly in cones. The rapid decay was also observed in human subjects. The spectral sensitivity curve of the rapid decay was found to be shifted toward short wavelengths in all nine protanopes tested. In these cases of protanopia, anomalous cone functions were indicated.