159 research outputs found

    Lidar measurement of stratospheric aerosol at Syowa Station, Antarctica

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    Lidar measurement on Antarctic aerosols were made during the Antarctic Middle Atmosphere (AMA) period, 1983 to 1985, at Syowa Station. Topics measured are winter enhancement aerosol layer and volcanic effect of El Chichon on the Antarctic stratosphere aerosols. The large depolarization ratio (maximum value was about 0.8) seems to support sublimation growth of ice crystals. The lidar measurements showed a meaningful time lag between aerosol content increase and depolarization ratio increase. Considering the balloon observations made in early winter, it was speculated that an increase in large particle number concentration also contributed to the winter enhancement. The El Chichon cloud spread to the Antarctic region by the beginning of 1983. The temporal change of integrated backscatter coefficient shows a clear decay pattern, although strong winter enhancement superposes

    Lidar observation of the mesospheric sodium layer in Antarctica

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    The mesospheric sodium layer has been observed at Syowa Station in Antarctica during the wintering period of the 26th Japanese Antarctic Research Expedition. A lidar observation of the polar middle atmosphere at the station has been performed as a part of the Middle Atmosphere Program since 1983. At first stratospheric aerosols have been observed by the system based on a ruby laser. In 1985 a new transmitting system consisting of a tunable dye laser was added to that system to observe the sodium layer, too. The characteristics of the lidar system are given. The results of the mesospheric sodium layer observed on 42 nights during the period from March to October, 1985 are also given

    Mineralogical and Chemical Features of Dust Particles Collected in the Troposphere over Desert Areas and over Japan

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    Siberian Branch of Russian Academy金沢大学大学院自然科学研究科名古屋大学Chinese Academy of Science熊本県立大学Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

    Overexpression of the p53-inducible brain-specific angiogenesis inhibitor 1 suppresses efficiently tumour angiogenesis

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    The brain-specific angiogenesis inhibitor 1 gene has been isolated in an attempt to find fragments with p53 “functional” binding sites. As reported herein and by others, brain-specific angiogenesis inhibitor 1 expression is present in some normal tissues, but is reduced or lost in tumour tissues. Such data and its particular structure prompted the hypothesis that brain-specific angiogenesis inhibitor 1 may act as a mediator in the local angiogenesis balance. We herein demonstrate that brain-specific angiogenesis inhibitor 1 over-expression suppresses tumour angiogenesis, delaying significantly the human tumour growth in immunodeficient mice. The inhibitory effect of brain-specific angiogenesis inhibitor 1 was documented using our intravital microscopy system, strongly implicating brain-specific angiogenesis inhibitor 1 as a mediator in the control of tumour angiogenesis. In contrast, in vitro tumour cell proliferation was not inhibited by brain-specific angiogenesis inhibitor 1 transfection, whereas some level of cytotoxicity was assessed for endothelial cells. Immunohistochemical analysis of tumour samples confirmed a reduction in the microvessel density index in brain-specific angiogenesis inhibitor 1-overexpressing tumours. At messenger level, moderate changes could be detected, involving the down-regulation of vascular endothelial growth factor and collagenase-1 expression. Furthermore, brain-specific angiogenesis inhibitor 1 expression that was lost in a selection of human cancer cell lines could be restored by wild-type p53 adenoviral transfection. Brain-specific angiogenesis inhibitor 1 should be considered for gene therapy and development of efficient drugs based on endogenous antiangiogenic molecules

    Genetic alterations on chromosome 17p associated with response to radiotherapy in bulky cervical cancer

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    Chromosome 17 alterations are found in more cancers than those of any other chromosome, and frequently involve the p53 gene on 17p13. The aim of this study was to identify the correlations between the presence of loss of heterozygosity (LOH) and microsatellite instability (MI) on chromosome 17p13 in patients with cervical cancer and the patients’ response to radiotherapy. A total of 50 patients were treated with definitive radiotherapy. We performed biopsies and took specimens from the tumour and venous blood of all patients. Tumour and normal DNAs were analysed by polymerase chain reaction for genetic losses and instability at three polymorphic microsatellite loci mapped to 17p13. Nineteen of the 50 tumours (38%) displayed a genetic alteration (GA) on 17p13, 16 (32%) were found to have LOH, and three (6%) showed MI. The sizes of the tumours of the GA-positive patients were significantly greater than those of the GA-negative patients (P = 0.009). The mean tumour diameter of all patients was 6 ± 2.4 cm. We divided the patients into those with tumours smaller than 6 cm in diameter (n = 26) and those with tumours equal to or greater than 6 cm in diameter (n = 24). The former group survived significantly longer compared to the latter group (P = 0.0002). Among the patients with < 6 cm tumours, all six GA-positive patients are alive with no evidence of disease (NED), whereas of the 20 GA-negative patients, 18 have NED and two are alive with disease (AWD) or suffered cancer-caused death (CD). Thus, there was no correlation between GA and radiotherapy response in the tumours smaller than 6 cm. However, among the patients with ≥ 6 cm tumours, two of the GA-positive patients have NED and 11 are AWD/CD, whereas seven of the GA-negative patients have NED and four are AWD/CD. Among the patients with ≥ 6 cm tumours, the response to radiotherapy of the GA-positive patients were significantly poorer than those of the GA-negative patients (P = 0.02). In addition, the GA-negative patients survived significantly longer compared to the GA-positive patients (P = 0.026). The results of this study suggest that GA increases with tumour growth. Improved success in the management of bulky cervical cancer requires a better understanding of its biological behaviour. © 1999 Cancer Research Campaig
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