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Matrix metalloproteinases are considered to play an important role in tumor invasion and metastasis. To elucidate the involvement of MMP-1 in human colorectal carcinoma, we performed immunohistochemical analysis on tissues from 20 colorectal adenomas and 142 colorectal adenocarcinomas, including 27 intramucosal carcinomas and 115 invasive carcinomas. MMP-1 was not expressed in any of the 20 cases of colorectal adenoma examined. In contrast, 108 of 142 cases (76.1%) with colorectal adenocarcinoma showed immunoreactivity for MMP-1 in the carcinoma cells themselves. Expression of MMP-1 was also identified in stromal cells around the carcinoma. We investigated the relationship between pathological features in colorectal carcinoma and MMP-1 immunoreactivity of the tumor cells. MMP-1 expression was less frequent in intramucosal carcinomas and weaker than that in invasive carcinomas (P < .0001). Among the 115 cases of invasive carcinomas, MMP-1 immunoreactivity was significantly correlated with the depth grading of tumor invasion (P < .05), tumor growth pattern (P < .05), the presence of lymphatic invasion (P < .05), venous invasion (P < .05), neural invasion (P < .05), lymph node metastasis (P < .005), hepatic metastasis (P < .05), and increasing stages of Dukes' classification (P < .05). In situ hybridization, using an MMP-1 oligonucleotide probe, confirmed the presence of MMP-1 mRNA in colorectal carcinoma cells themselves. Expression of MMP-1 mRNA was detected by the reverse transcription polymerase chain reaction method in cultured human colorectal carcinoma cell lines and colon carcinoma tissue obtained at surgery. These findings suggest that the expression of MMP-1 is one of the important factors related to tumor invasion and metastasis in colorectal carcinoma.

症例は53歳, 女性. 慢性腎不全に対する維持透析施行中, 1998年5月初旬, シャント側である右前腕部に腫瘤出現するも放置. 1998年7月1日, 腫瘤が急激に増大したため, カラードプラーエコー施行. シャント下の橈骨動脈から生じた動脈瘤の診断を得て, 7月2日, 動脈瘤摘出術を施行した. 術中, 橈骨動脈には数箇所穿刺痕が認められ, また, 病理組織学的診断でも橈骨動脈から生じた仮性動脈瘤の所見であったことから, 誤った穿刺によって生じた仮性動脈瘤と診断した. 術後経過は良好で, シャントも温存でき, 患者は9月5日退院となった. シャントの動脈瘤様変化や表在化した動脈に生じた仮性動脈瘤の報告はしばしばみられるが, 今回の我々の症例のように, 誤穿刺によってシャント下の本来の動脈に生じた仮性動脈瘤の報告例は調べ得た限りでは認められず, 非常に稀な症例と考え, 若干の文献的考察を加え報告する.

A process consisting of the deposition of amorphous silicon at low temperatures and subsequent annealing has been proposed for fabricating a boron-doped polycrystalline silicon film with a low resistivity. This process realized large grain growth up to 3 to 5 μm, leading to a low resistivity of 1.4 mΩ.cm, which one-half to about one-third compared with that of direct deposited boron doped polysilicon. In addition to this, extremely low deposition temperature (∼350 o C) using a Si 2 H 6 /B 2 H 6 mixture attained uniform boron concentration across the wafers

A process consisting of the deposition of amorphous silicon at low temperatures and subsequent annealing has been proposed for fabricating a boron-doped polycrystalline silicon film with a low resistivity. This process realized large grain growth up to 3 to 5 μm, leading to a low resistivity of 1.4 mΩ.cm, which one-half to about one-third compared with that of direct deposited boron doped polysilicon. In addition to this, extremely low deposition temperature (∼350 o C) using a Si 2 H 6 /B 2 H 6 mixture attained uniform boron concentration across the wafers

The change in surface morphology of polysilicon due to oxidation was examined by cross section electron microscopy. The protuberance growth during oxidation at a planarized polysilicon surface, from which the initial surface roughness and bumps were eliminated, was experimentally revealed. It is indicated that the thickness of the protuberance region exceeds that of the polysilicon layer prior to the oxidation, while the top surfaces of the protuberances are oxidized. Its protuberance growth means that excess silicon atoms induced by compressive stress resulted from an intergranular oxidation. We propose a new model of the protuberance growth based on the silicon creep mechanism.

We consistently performed computer fluid dynamics (CFD) analysis in a reactor (macroscale analysis) and deposition profile analysis on a submicron hole (microscale analysis) for Si low-pressure chemical vapor deposition (LPCVD). For the gaseous phase and the surface reaction of the SiH4 source gas, we adopted the dominant reaction model, which involved two intermediates, SiH2 and Si2H6, and was based on the Kleijn Model. We analyzed the fluid flow, heat transfer and chemical reactions throughout the entire batch-type reactor, and estimated the Si growth rate, gaseous species concentration, and relative contributions of SiH4, SiH2 and Si2H6 to Si growth. Moreover, the Si-filling profile on a submicron hole was predicted by topography simulation in which the parameters were the growth rate, the relative contribution and the sticking coefficient of each species. The relationship between the relative contribution of SiH2, which has a high sticking coefficient, to Si growth and the hole-filling capability was quantitatively clarified from the results of a combination of the two analyses. The hole-filling capability at the wafer edge was deteriorated by the influence of SiH2 gas produced in the decomposition of Si2H6 gas, which was diffused from outside the wafer. This effect became considerable with increasing temperature. Reducing the wafer pitch will be effective in improving the hole-filling capability because both the SiH2 generation reaction in the region between wafers and SiH2 gas diffusion from outside the wafer will be inhibited.

Compositional change of the superconducting transition temperature T c has been examined for the hot-pressed ceramics of (Ba, Sr)(Pb, Bi)O 3 and Ba(Sn, Pb, Bi)O 3 . Results for both systems are summarized as the T c contour maps of respective composition diagrams, which proved to be highly anisotropic with respect to composition coordinates. Temperature dependence of the normal resistivity, the Hall coefficient, and the lattice constant were also measured as function of composition. These results are discussed in connection with the T c characteristics, and also with the previously reported pressure effect shown by these materials.