Stereospecific polymerization of higher α-olefins with the solvay type catalyst TiCl3/Cp2Ti(CH3)2

Polymerizations of higher α-olefins (C₁₀–C₂₀) were carried out at 40°C in heptane, using the following three catalysts which differ in the isospecificity for propene polymerization: Solvay type TiCl₃/Cp₂TiMe₂((A) highly isospecific), Solvay type TiCl₃/AlEt₃((B) isospecific) and TiCl₃.3Py/MgCl₂/AlEt₃((C) aspecific). The isospecificity of the catalysts was found to decrease in the following order: (A) ? (B) ? (C), which agrees well with the results obtained in propene polymerization. The crystallinity of these polymers is discussed in brief.     

Blood Flow and Leukocyte Adhesiveness Are Reduced in the Microcirculation of a Peritoneal Disseminated Colon Carcinoma

Dynamic behavior of leukocytes in the microcirculation of solid tumor tissue was visualized using a fluorescent labeling technique combined with the use of a real-time confocal laser-scanning microscope (CLSM) system. Colon tumor cells (RCN-9) were inoculated into the peritoneal cavity of male Fischer 344 rats. Tumor-free rats were similarly injected with physiological saline (intraperitoneally). Ten days after tumor inoculation, the mesentery was exteriorized and subjected to vital microscopic observation under the CLSM system. Leukocytes were labeled with rhodamine 6G (100 g kg^–1, intravenously), and their behavior within the microvessels (10–30 m in diameter) was analyzed both in the solid tumor tissues and the normal mesentery. Wall shear rate was calculated from the measured values of vessel diameter and erythrocyte flow velocity. In tumor microvasculature of tumor-bearing rats, the centerline erythrocyte velocity (0.73 ± 0.58 mm s^–1, mean±standard deviation) and wall shear rate (210 ± 151 s^–1 were significantly lower than those of the tumor-free rats (1.27 ± 0.83 mm s^–, 344 ± 236 s^–1, respectively). Despite such reduced flow conditions, flux of the rolling leukocytes as well as density of the adhered leukocytes both decreased significantly in tumor microvasculature as compared with normal controls. The methods developed in this work show promise in improving our understanding of tumor biology and pathophysiology. © 1998 Biomedical Engineering Society. PAC98: 8722Fy, 8745Hw, 8745Ft, 8764-t, 4262Be     

Role of fibronectin-stimulated tumor cell migration in glioma invasion in vivo: clinical significance of fibronectin and fibronectin receptor expressed in human glioma tissues

In order to clarify the role of fibronectin in glioma invasion in vivo, we analyzed the relationship between fibronectin-stimulated cell migration and adhesion in 14 primary glioma cells and the expression of fibronectin and the fibronectin receptor in the corresponding tumor tissues. The tumors comprised nine glioblastomas (GB) and five anaplastic gliomas (AG) consisting of two astrocytomas, two oligoastrocytomas and one ependymoma. All glioma cells tested in the primary cell culture were found to migrate to fibronectin in a dose-dependent manner. The extent of cell migration to fibronectin was not significantly different for the GB and AG groups. On the other hand, cell adhesion to fibronectin in the AG was much stronger than that in the GB group. Immunohistochemistry demonstrated that fibronectin positively stained in the extra-cellular matrix (ECM) in eight cases and that the fibronectin receptor was positive in tumor cell membranes in 10 cases. In addition, cellular fibronectin isoforms containing ED-A and ED-B sequences were found to be immunolocalized in the tumor cells and the ECM of GB. These isoforms were also specifically expressed in tumor vessels within tumor tissues, but not in those within normal brain tissues. Cell migration tended to be expressed more strongly by glioma cells derived from tumor tissues in which fibronectin was posi-tively immunolocalized in the ECM than from tissues with negative fibronectin in the ECM. Four glioma cells derived from GB whose tumor cells did not positively stain for fibronectin receptors migrated much less extensively to fibronectin than other glioma cells whose tissues showed positive staining for the fibronectin receptor. Of these four GB, two had loss of heterozygosity in the locus of fibronectin receptor b1 gene. These results suggest that fibronectin deposited in the extracellular matrix of tumors, which can be derived from both plasma and the tumor cell itself, strongly promotes the migration of glioma cells, and that expression of the fibronectin receptor may play a critical role in the biological behavior of the tumor cells, particularly in fibronectin-stimulated cell migration in vivo.© Kluwer Academic Publishers 1998     

Concurrent chemoradiotherapy for esophageal cancer: comparison between intermittent standard-dose cisplatin with 5-fluorouracil and daily low-dose cisplatin with continuous infusion of 5-fluorouracil

Background Although current standard treatment for advanced esophageal cancer is intermittent standard-dose cisplatin with 5-fluorouracil (5-FU) (ISD-FP), daily low-dose cisplatin with continuous infusion of 5-FU (CLD-FP) is advocated for equivalent effectiveness and lower toxicity. The feasibility of these two concurrent chemoradiotherapeutic protocols was retrospectively reviewed for local control rate, overall survival, toxicity, and compliance in a single institutional situation.Methods Concurrent chemoradiotherapy, using 60Gy of radiation and ISD-FP or CLD-FP was non-randomly scheduled for 29 patients between June 1994 and March 2001.Results Complete response in the irradiated volume at the end of primary treatment was shown by 8 of 15 and 9 of 14 patients in the ISD-FP and CLD-FP groups, respectively. The projected overall survival rate at 2 years was 55% for stage III patients and 13% for stage IV. Median survival times were 14 months versus 15 months in the ISD-FP and CLD-FP groups, with no significant difference. Toxicities were similar, including two treatment-related deaths in each group. Chemotherapy was completed for 10 of 15 and 11 of 14 patients in the ISD-FP and CLD-FP groups, respectively. Modification of the planned regimen was more often required for the CLD-FP group.Conclusion CLD-FP therapy has no apparent advantage over ISD-FP therapy from the perspective of compliance and safety. A randomized phase II clinical trial comparing ISD-FP and CLD-FP, currently being performed, is expected to provide further information.     

Urologic area

In this review, the clinical experience of a three-dimensional(3D) image at urologic area are described. There are some methods for reconstructive 3D image of Multi-slice CT. Maximum intensity projection (MIP) is usefulness for detection of vascular anatomy. Multi-planar reconstruction (MPR) is usefulness for relation with circumference organs. Therefore the opportunities of angiography decreased. It seems that an applied range of a 3D image spreads more in future.