948 resultados para Circulation pulmonaire


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Anti-Semitism existed in Finland during the whole period covered by this study. The immoral acts associated with Jews in the articles were mostly regarded as universal habits, qualities and/or modes of action, that is, unconnected with any particular Finnish Jew. Researchers have tried to explain anti-Semitism in several ways. The theory of Jews as outsiders has been a popular explanation as well as xenophobia, chimerical anti-Semitism and the socio-economic models. The main sources of this study have been over 400 Finnish periodicals and magazines, literature and text books published between 1918 and 1944. This vast number of magazines includes those of the army and the civil guard, religion, humour and the papers of the Finnish extreme right. One can see a distinct foreign and especially German influence in the subjects and phraseology of Finnish anti-Semitic writings between 1918 and 1944. Several known Finnish anti-Semitic writers had some kind of link with Germany. Some Finnish organisations and societies were openly anti-Semitic during this period. There had been cycles in the activity of anti-Semitic writing in Finland, obvious peaks appearing in 1918 1919, 1929 1931, 1933 1938 and 1942 1944. The reason for the 1918 1919 activity was the civil rights which were granted to the Jews in Finland, and the Russian Bolshevik revolution. The worldwide depression from 1929 to 1932 seem to be the reason for new anti-Semitic writing activity. The rise of National Socialism in Germany and the influence this phenomenon had in Finland was the reason for the peak during 1933 1938. During the continuation war 1942 1944 National Socialist Germany was fighting side-by-side with Finland and their anti-Semitic propaganda found easier access to Finland. Of the 433 magazines, journals and newspapers which were used in this study, 71 or 16.4 per cent had at least one article that can be identified as anti-Semitic; especially the magazines of national socialists and other extreme right parties were making anti-Semitic annotations. There were about 50 people known to have written anti-Semitic articles. At least half of these known writers had studied at the university, including as many as 10 priests. Over and above these, there was an even larger number of people who wrote under a pseudonym. The material used suggested that anti-Semitism was not very popular in Finland between 1918 and 1944. Anti-Semitic articles appeared mostly in the magazines of the extreme right, but their circulation was not very large. A proof of the slight influence of these extreme right anti-Semitic ideas is that, beside the tightening of policy towards Jewish immigrants in 1938 and the handing over of eight of these refugees to Germany in 1942, the official policy of Finland never became anti-Semitic. As was stated before, despite the cycles in the number of writings, there does not appear to have been any noticeable change in public opinion. One must also remember that most Finns had not at that period actually met a Jew. The material used suggests that between 1918 and 1944 the so-called Jewish question was seemingly unimportant for most Finns and their attitude to Jews and Jewishness can be described as neutral.

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The circulatory system consists of two vessel types, which act in concert but significantly differ from each other in several structural and functional aspects as well as in mechanisms governing their development. The blood vasculature transports oxygen, nutrients and cells to tissues whereas the lymphatic vessels collect extravasated fluid, macromolecules and cells of the immune system and return them back to the blood circulation. Understanding the molecular mechanisms behind the developmental and functional regulation of the lymphatic system long lagged behind that of the blood vasculature. Identification of several markers specific for the lymphatic endothelium, and the discovery of key factors controlling the development and function of the lymphatic vessels have greatly facilitated research in lymphatic biology over the past few years. Recognition of the crucial importance of lymphatic vessels in certain pathological conditions, most importantly in tumor metastasis, lymphedema and inflammation, has increased interest in this vessel type, for so long overshadowed by its blood vascular cousin. VEGF-C (Vascular Endothelial Growth Factor C) and its receptor VEGFR-3 are essential for the development and maintenance of embryonic lymphatic vasculature. Furthermore, VEGF-C has been shown to be upregulated in many tumors and its expression found to positively correlate with lymphatic metastasis. Mutations in the transcription factor FOXC2 result in lymphedema-distichiasis (LD), which suggests a role for FOXC2 in the regulation of lymphatic development or function. This study was undertaken to obtain more information about the role of the VEGF-C/VEGFR-3 pathway and FOXC2 in regulating lymphatic development, growth, function and survival in physiological as well as in pathological conditions. We found that the silk-like carboxyterminal propeptide is not necessary for the lymphangiogenic activity of VEGF-C, but enhances it, and that the aminoterminal propeptide mediates binding of VEGF-C to the neuropilin-2 coreceptor, which we suggest to be involved in VEGF-C signalling via VEGFR-3. Furthermore, we found that overexpression of VEGF-C increases tumor lymphangiogenesis and intralymphatic tumor growth, both of which could be inhibited by a soluble form of VEGFR-3. These results suggest that blocking VEGFR-3 signalling could be used for prevention of lymphatic tumor metastasis. This might prove to be a safe treatment method for human cancer patients, since inhibition of VEGFR-3 activity had no effect on the normal lymphatic vasculature in adult mice, though it did lead to regression of lymphatic vessels in the postnatal period. Interestingly, in contrast to VEGF-C, which induces lymphangiogenesis already during embryonic development, we found that the related VEGF-D promotes lymphatic vessel growth only after birth. These results suggest, that the lymphatic vasculature undergoes postnatal maturation, which renders it independent of ligand induced VEGFR-3 signalling for survival but responsive to VEGF-D for growth. Finally, we show that FOXC2 is necessary for the later stages of lymphatic development by regulating the morphogenesis of lymphatic valves, as well as interactions of the lymphatic endothelium with vascular mural cells, in which it cooperates with VEGFR-3. Furthermore, our study indicates that the absence of lymphatic valves, abnormal association of lymphatic capillaries with mural cells and an increased amount of basement membrane underlie the pathogenesis of LD. These findings have given new insight into the mechanisms of normal lymphatic development, as well as into the pathogenesis of diseases involving the lymphatic vasculature. They also reveal new therapeutic targets for the prevention and treatment of tumor metastasis and lymphatic vascular failure in certain forms of lymphedema. Several interesting questions were posed that still need to be addressed. Most importantly, the mechanism of VEGF-C promoted tumor metastasis and the molecular nature of the postnatal lymphatic vessel maturation remain to be elucidated.

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STUDIES with rats have shown that during lactation there is an inhibition of luteinising hormone (LH)-dependent physiological events, such as implantation1, and a return to oestrus cyclicity2. This inhibition has been shown to occur only during the intense suckling phase and it has been correlated with the high levels of prolactin present in the circulation at this time. Although exogenous prolactin could substitute for the effects of intense suckling, it could do so only under the permissive influence of minimal suckling stimulus. We have shown that there is, in these conditions, a lowering of LH levels, and that this is due to interference by prolactin with the pituitary responsiveness to LH-releasing hormone (LHRH) (K. Muralidhar, R. M. and N. R. M., unpublished). Using the lactating monkey, we have now demonstrated a similar inhibitory effect of prolactin on pituitary responsiveness to LHRH, suggesting a mechanism by which amenorrhoeic conditions are maintained during lactation.