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The mechanism of post-haemorrhagic vasopressin release from the neurohypophysis was studied in rats anaesthetized with urethane. Neurohypophysial vasopressin content was determined according to Dekański and plasma renin activity by radioimmunoassay. In animals bled (1.5% body weight) 60 min after induction of anaesthesia and 30 min after bilateral nephrectomy vasopressin content of the posterior pituitary was significantly higher than in sham-nephrectomized rats. However, when haemorrhage was produced 240 min after induction of anaesthesia and 210 min after nephrectomy, the neurohypophysial vasopressin content was low and similar as that in non-nephrectomized animals. It is concluded that in the phase directly following haemorrhage vasopressin release depends on acute activation of the renin-angiotensin system. Other mechanisms, possibly circulatory reflexes, are involved in the late phase, during prolonged anaesthesia. 相似文献
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The geometric and energetic characteristics of root surfaces of two wheat (Triticum L.) varieties, Al tolerant (Inia 66/16) and Al sensitive (Henika), were estimated from experimental water vapor adsorption–desorption data. Roots stressed for around 1 week at pH 4 without and with a toxic aluminium level (0.741 mol m–3) were studied at the tillering and shooting stages. Roots grown continuously at pH 7 were taken as control. The surface properties of the pH 4 stressed roots were apparently the same as those of the control roots whatever the root age. For the roots of both varieties, the surface area and total micropore volume increased markedly after aluminium treatment. The average micropore radius increased significantly for the sensitive wheat, whereas it increased only slightly for the resistant one. Under Al treatment the number of large pores increased while small pores were fewer for both plants, indicating a possible alteration of the build-up of root tissue. The root surface pores were fractal. The fractal dimension of the sensitive wheat roots decreased under Al treatment, whereas for the resistant wheat this remained apparently unchanged. The adsorption energy distribution functions had different shapes for the sensitive and the resistant wheat varieties: the sensitive variety had greater number of high energy adsorption centers, which implies that the root tolerance on Al stress may be connected with lower polarity of the surface. 相似文献
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Lidia Poplawska-Szczyglowska Jan Walewski Barbara Pienkowska-Grela Grzegorz Rymkiewicz Olga Mioduszewska 《Cancer immunology, immunotherapy : CII》1999,16(1):65-68
A 68-year-old man presented with hemiparesis, lymphocytosis, and cerebral lesions on MRI. Flow cytometry of blood, bone marrow
and cerebrospinal fluid showed B-CLL lymphocytes with bright CD20 expression, slg, and absence of CD23 antigen. Fluorescencein situ hybridisation showed trisomy 12 in 50% of analysed peripheral mononuclear cells. The patient died 6 months after the diagnosis.
Rapidly progressive and fatal course of the disease was consistent with known bad prognostic significance of CD20 bright expression
and trisomy 12. 相似文献
227.
Katarzyna Solarska Anna Lewińska Agata Karowicz-Bilińska Grzegorz Bartosz 《Cellular & molecular biology letters》2010,15(1):90-97
Many of the effects of carnitine are ascribed to its antioxidant properties. The aim of this study was to evaluate the antioxidant
properties of carnitine in vitro. Carnitine was found to decolorize ABTS•+, and to protect fluorescein against bleaching induced by AAPH-derived peroxyl radicals and peroxynitrite, thiol groups against
oxidation induced by hydrogen peroxide, peroxyl radicals, hypochlorite and peroxynitrite, and erythrocytes against hemolysis
induced by peroxyl radicals and hypochlorite. These results show that carnitine has a direct antioxidant action against physiologically
relevant oxidants. 相似文献
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Maciej Komosiński Grzegorz Koczyk Marek Kubiak 《Theorie in den Biowissenschaften》2001,120(3-4):271-286
Summary In this paper, a dissimilarity measure for artificial organisms is proposed. The organisms are simulated in the Framsticks
system [10]. Properties of agents are enumerated formally, and the heuristic algorithm for estimating overall phenetic dissimilarity
of two agents is described. An example of performance is shown on two selected organisms. Two clustering experiments with
interesting results are presented using the UPGMA method. The properties of the measure are then discussed. Computer simulations
of complex systems and their characteristics are compared to biological systems, which may bring up ideas for further experiments
related to biology. 相似文献
230.
Grzegorz Nalepa Jill Barnholtz-Sloan Rikki Enzor Dilip Dey Ying He Jeff R. Gehlhausen Amalia S. Lehmann Su-Jung Park Yanzhu Yang Xianlin Yang Shi Chen Xiaowei Guan Yanwen Chen Jamie Renbarger Feng-Chun Yang Luis F. Parada Wade Clapp 《The Journal of cell biology》2013,201(7):997-1012
Mitosis is controlled by a network of kinases and phosphatases. We screened a library of small interfering RNAs against a genome-wide set of phosphatases to comprehensively evaluate the role of human phosphatases in mitosis. We found four candidate spindle checkpoint phosphatases, including the tumor suppressor CDKN3. We show that CDKN3 is essential for normal mitosis and G1/S transition. We demonstrate that subcellular localization of CDKN3 changes throughout the cell cycle. We show that CDKN3 dephosphorylates threonine-161 of CDC2 during mitotic exit and we visualize CDC2pThr-161 at kinetochores and centrosomes in early mitosis. We performed a phosphokinome-wide mass spectrometry screen to find effectors of the CDKN3-CDC2 signaling axis. We found that one of the identified downstream phosphotargets, CKβ phosphorylated at serine 209, localizes to mitotic centrosomes and controls the spindle checkpoint. Finally, we show that CDKN3 protein is down-regulated in brain tumors. Our findings indicate that CDKN3 controls mitosis through the CDC2 signaling axis. These results have implications for targeted anticancer therapeutics. 相似文献