649 research outputs found

    Expression patterns of chondrocyte genes cloned by differential display in tibial dyschondroplasia

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    AbstractTibial dyschondroplasia (TD) appears to involve a failure of the growth plate chondrocytes within growing long bones to differentiate fully to the hypertrophic stage, resulting in a mass of prehypertrophic chondrocytes which form the avascular TD lesion. Many biochemical and molecular markers of chondrocyte hypertrophy are absent from the lesion, or show reduced expression, but the cause of the disorder remains to be identified. As differentiation to the hypertrophic state is impaired in TD, we hypothesised that chondrocyte genes that are differentially expressed in the growth plate should show altered expression in TD. Using differential display, four genes, B-cadherin, EF2, HT7 and Ex-FABP were cloned from chondrocytes stimulated to differentiate to the hypertrophic stage in vitro, and their differential expression confirmed in vivo. Using semi-quantitative RT-PCR, the expression patterns of these genes were compared in chondrocytes from normal and TD growth plates. Surprisingly, none of these genes showed the pattern of expression that might be expected in TD lesion chondrocytes, and two of them, B-cadherin and Ex-FABP, were upregulated in the lesion. This indicates that the TD phenotype does not merely reflect the absence of hypertrophic marker genes, but may be influenced by more complex developmental mechanisms/defects than previously thought

    Introducing Volcanica: The first diamond open-access journal for volcanology

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    Welcome to Volcanica's first issue! Our community of editors and Volcanica supporters are excited to present you with our inaugural issue of peer-reviewed volcano research. This editorial accompanies the first issue of Volcanica so that we can provide you with some background to the Volcanica initiative, explain some of the evidence-based motivation for starting a new journal, and explore ways in which we can improve universal access to published research. We discuss our model of "diamond open access", which isĀ entirely free for authors to publish and free for everyone to read. We will explain how this model is possible and state explicitly the challenges related to how this project can be sustainable and scalable. Finally, we will signpost the information you may need to publish with Volcanica as we continue to grow

    Book Reviews

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    Die hartJou Harl en Lewe. Deur A. J. Brink. Bl. 248. Gemustreer. RI6,95. Pretoria: Femina. 1982.The physiology of digestionExperiments and Observations on the Gastric Juice and the Physiology of Digestion. By William Beaumonr. 1st ed. 1&33. Reprinted in facsimile for the Classics ofMedicine Library, Division of Gryphon Editions Ltd, Birmingham, Alabama, 1980.Bone in Clinical Orthopaedics: A Study in ComparativeOsteology. Ed. by G. Sumner-Smith. Pp. xvi + 435. Illustrated. R94,25. Philadelphia: W. B. Saunders. 1982.Tamoxifen in breast cancerThe Role of Tamoxifen in Breast Cancer. Ed. by S. Iacobelli, M. E. Lippman and G. R. Della Cuna. Pp. xii + 124. Illustrated. 523,12. New York: Raven Press. 1982.Under the Influence. A History ofNitrous Oxide and OxygenAnaesthesia. By W. D. A. Smith. Pp. xxviii + 188. Illustrated. R33,50. London: Macmillan. 1982.Clinical internal medicine in the agedClinical Internal Medicine in the Aged. By R. W. Schrier. Pp. vii + 324. Illustrated. R61,-. Philadelphia: W. B. Saunders. 1982.Genital Infection by Chlamydia Trachomatis (Current Topicsin Infection, No. 2). By J. D. Oriel and G. L. Ridgway. Pp. viii + 144. Illustrated. R32,20. London: Edward Arnold. 1982.Placental Function Tests. By T. Chard and A. Klopper. Pp. viii + 94. Illustrated. DM42,-. Berlin: Springer-Verlag. 1982.Therapeutic Heat and Cold. 3rd ed. Ed. by J. F. Lehmann. Pp. xiv + 641. Illustrated. Baltimore: Williams & Wilkins. 1982

    Inverse Association between trans Isomeric and Long-Chain Polyunsaturated Fatty Acids in Pregnant Women and Their Newborns: Data from Three European Countries

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    Background: trans unsaturated fatty acids are thought to interfere with essential fatty acid metabolism. To extend our knowledge of this phenomenon, we investigated the relationship between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFA) in mothers during pregnancy and in their infants at birth. Methods: Fatty acid composition of erythrocyte phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was determined in Spanish (n = 120), German (n = 78) and Hungarian (n = 43) women at the 20th and 30th week of gestation, at delivery and in their newborns. Results: At the 20th week of gestation, the sum of trans fatty acids in PE was significantly (p < 0.01) lower in Hungarian [0.73 (0.51), % wt/wt, median (IQR)] than in Spanish [1.42 (1.36)] and German [1.30 (1.21)] women. Docosahexaenoic acid (DHA) values in PE were significantly (p < 0.01) higher in Hungarian {[}5.65 (2.09)] than in Spanish [4.37 (2.60)] or German [4.39 (3.3.2)] women. The sum of trans fatty acids significantly inversely correlated to DHA in PCs in Spanish (r = -0.37, p < 0.001), German (n = -0.77, p < 0.001) and Hungarian (r = -0.35, p < 0.05) women, and in PEs in Spanish (r = -0.67, p < 0.001) and German (r = -0.71, p < 0.001), but not in Hungarian (r = -0.02) women. Significant inverse correlations were seen between trans fatty acids and DHA in PEs at the 30th week of gestation (n = 241, r = -0.52, p < 0.001), at delivery (n = 241, r = -0.40, p < 0.001) and in cord lipids (n = 218, r = -0.28, p < 0.001). Conclusion: Because humans cannot synthesize trans isomeric fatty acids, the data obtained in the present study support the concept that high maternal trans isomeric fatty acid intake may interfere with the availability of LCPUFA both for the mother and the fetus. Copyright (C) 2011 S. Karger AG, Base

    Geophysical Observations of Taliks Below Drained Lake Basins on the Arctic Coastal Plain of Alaska

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    Lakes and drained lake basins (DLBs) together cover up to āˆ¼80% of the western Arctic Coastal Plain of Alaska. The formation and drainage of lakes in this continuous permafrost region drive spatial and temporal landscape dynamics. Postdrainage processes including vegetation succession and permafrost aggradation have implications for hydrology, carbon cycling, and landscape evolution. Here, we used surface nuclear magnetic resonance (NMR) and transient electromagnetic (TEM) measurements in conjunction with thermal modeling to investigate permafrost aggradation beneath eight DLBs on the western Arctic Coastal Plain of Alaska. We also surveyed two primary surface sites that served as nonlake affected control sites. Approximate timing of lake drainage was estimated based on historical aerial imagery. We interpreted the presence of taliks based on either unfrozen water estimated with surface NMR and/or TEM resistivities in DLBs compared to measurements on primary surface sites and borehole resistivity logs. Our results show evidence of taliks below several DLBs that drained before and after 1949 (oldest imagery). We observed depths to the top of taliks between 9 and 45 m. Thermal modeling and geophysical observations agree about the presence and extent of taliks at sites that drained after 1949. Lake drainage events will likely become more frequent in the future due to climate change and our modeling results suggest that warmer and wetter conditions will limit permafrost aggradation in DLBs. Our observations provide useful information to predict future evolution of permafrost in DLBs and its implications for the water and carbon cycles in the Arctic
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