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221.
Complement components and terminal complement complex in oesophageal smooth muscle of patients with achalasia. 总被引:3,自引:0,他引:3
Wulf B Storch Volker F Eckardt Theo Junginger 《Cellular and molecular biology, including cyto-enzymology》2002,48(3):247-252
This study investigates whether patients with achalasia exhibit autoimmune reactions with subsequent complement activation within oesophageal smooth muscle, vessels and neurones. Oesophageal muscular biopsies from 8 patients undergoing surgery for achalasia and from 6 patients operated for oesophageal cancer were investigated by immunofluorescence for the presence of the complement components C1q, C4, C3c, C3d, C9 and the C9 neoantigen of the terminal C5b-C9 complement complex. Tissues were also investigated for the expression of immunoglobulins (G,A,M) and of the antigens of rubella and varicella zoster viruses. In addition, sera of both patient groups were tested for the presence of autoantibodies against Auerbach's plexus. The terminal complement complex C5b-C9 was found within muscle cells from all patients with achalasia but in only one specimen from a patient with cancer. Two patients with achalasia also exhibited the terminal complement complex as well as IgM within ganglion cells. Muscle cells stained positive for the complement component C9 in all five patients with achalasia in whom this test was performed but in none of the control tissues. In addition, sera from four patients with achalasia contained antibodies against Auerbach's plexus. Studies for the complement components C1q, C4, C3c and for antigens of rubella and varicella zoster viruses revealed negative results in all patients and controls. The results of this study suggest that a complement activation is involved in the autoimmune pathogenesis of achalasia. However, the triggering mechanism of this phenomenon remains to be determined. 相似文献
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223.
Embryonic skeletogenesis involves proliferation, condensation and subsequent chondrogenic differentiation of mesenchymal precursor cells, and the strains and stresses inherent to these processes have been hypothesized to influence skeletal development. The aim of this study was to determine the effect of growth-mimicking strain on the process of early skeletal development in vitro. To this end, we applied continuous uniaxial strain to embryonic skeletal precursor cells in micromass culture. Strain was applied at different times of culture to specifically address the effect of mechanical loading on the sequential stages of cellular proliferation, condensation and differentiation. We found that growth-mimicking strain at all three times did not affect proliferation or chondrogenic differentiation under the tested conditions. However, the timing of the applied strain did play a role in the density of mesenchymal condensations. This finding suggests that a mechanically dynamic environment, and specifically strain, can influence skeletal patterning. The growth-mimicking micromass model presented here may be a useful tool for further studies into the role of mechanical loading in early skeletal development. 相似文献
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225.
Eric Krenning Roel Docter Bert Bernard Theo Visser 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,676(3):314-320
Thyroid hormone uptake into primary cultured rat hepatocytes was studied using 1-min incubations with radio-iodine-labelled iodothyronines. (1) Uptake of thyroxine indicates two saturable sites apparent Km values of 1.2 nM and 1.0 μM, and non-saturable uptake. Similar kinetics of triiodothyronine uptake have been observed. (2) The high-affinity systems of both hormones are energy-dependent (i.e., inhibited by KCN and oligomycin). It is postulated that these systems represent active transport of thyroid hormone into the cell. (3) Analysis of mutual inhibition by the substrates for the triiodothyronine and thyroxine transport systems indicates that triiodothyromine and thyroxine cross the cell membrane via separate transport systems. (4) Preincubation with ouabain resulted in a decrease in uptake of both triiodothyronine and thyroxine, suggesting that a sodium gradient is essential for this transport. 相似文献
226.
Evelien Schurgers Martijn Moorlag Coenraad Hemker Theo Lindhout Hilde Kelchtermans Bas de Laat 《PloS one》2016,11(2)
To better understand hypercoagulability as an underlying cause for thrombosis, the leading cause of death in the Western world, new assays to study ex vivo coagulation are essential. The zebrafish is generally accepted as a good model for human hemostasis and thrombosis, as the hemostatic system proved to be similar to that in man. Their small size however, has been a hurdle for more widespread use in hemostasis related research. In this study we developed a method that enables the measurement of thrombin generation in a single drop of non-anticoagulated zebrafish blood. Pre-treatment of the fish with inhibitors of FXa and thrombin, resulted in a dose dependent diminishing of thrombin generation, demonstrating the validity of the assay. In order to establish the relationship between whole blood thrombin generation and fibrin formation, we visualized the resulting fibrin network by scanning electron microscopy. Taken together, in this study we developed a fast and reliable method to measure thrombin generation in whole blood collected from a single zebrafish. Given the similarities between coagulation pathways of zebrafish and mammals, zebrafish may be an ideal animal model to determine the effect of novel therapeutics on thrombin generation. Additionally, because of the ease with which gene functions can be silenced, zebrafish may serve as a model organism for mechanistical research in thrombosis and hemostasis. 相似文献
227.
Theo Odijk 《Journal of biological physics》2015,41(1):1-7
A tentative scaling theory is presented of a tree swaying in a turbulent wind. It is argued that the turbulence of the air within the crown is in the inertial regime. An eddy causes a dynamic bending response of the branches according to a time criterion. The resulting expression for the penetration depth of the wind yields an exponent which appears to be consistent with that pertaining to the morphology of the tree branches. An energy criterion shows that the dynamics of the branches is basically passive. The possibility of hydrodynamic screening by the leaves is discussed. 相似文献
228.
Samar H. K. Tareen Martina Kutmon Michiel E. Adriaens Edwin C. M. Mariman Theo M. de Kok Ilja C. W. Arts Chris T. Evelo 《Genes & nutrition》2018,13(1):17
Background
Metabolic flexibility is the ability of cells to change substrates for energy production based on the nutrient availability and energy requirement. It has been shown that metabolic flexibility is impaired in obesity and chronic diseases such as type 2 diabetes mellitus, cardiovascular diseases, and metabolic syndrome, although, whether it is a cause or an effect of these conditions remains to be elucidated.Main body
In this paper, we have reviewed the literature on metabolic flexibility and curated pathways and processes resulting in a network resource to investigate the interplay between these processes in the subcutaneous adipose tissue. The adipose tissue has been shown to be responsible, not only for energy storage but also for maintaining energy homeostasis through oxidation of glucose and fatty acids. We highlight the role of pyruvate dehydrogenase complex–pyruvate dehydrogenase kinase (PDC-PDK) interaction as a regulatory switch which is primarily responsible for changing substrates in energy metabolism from glucose to fatty acids and back. Baseline gene expression of the subcutaneous adipose tissue, along with a publicly available obesity data set, are visualised on the cellular network of metabolic flexibility to highlight the genes that are expressed and which are differentially affected in obesity.Conclusion
We have constructed an abstracted network covering glucose and fatty acid oxidation, as well as the PDC-PDK regulatory switch. In addition, we have shown how the network can be used for data visualisation and as a resource for follow-up studies.229.
Harold L. PrattJr Theo C. Pratt Danielle Morley Susan Lowerre-Barbieri Angela Collins Jeffrey C. Carrier Kristen M. Hart Nicholas M. Whitney 《Environmental Biology of Fishes》2018,101(4):515-530
Nurse sharks have not previously been known to migrate. Nurse sharks of the Dry Tortugas (DRTO) mating population have a highly predictable periodic residency cycle, returning to the Dry Tortugas Courtship and Mating Ground (DTCMG) annually (males) or bi- to triennially (females) during the June/July mating season. For 23 years we have followed the movements of 76 recaptured adults of a total of 115 tagged adults. Telemetry detections of 40 females tagged with acoustic transmitters show that most tagged and presumably post-partum females are continuously present in the DRTO in the fall, winter and early spring following the June mating season but these females depart in late March to early May. Detections reveal these females avoid the DTCMG completely during the next mating season, returning from late summer to fall. Telemetry records of nine of 17 adult males that co-habited with these females in the DTCMG depart DRTO waters every July. Both sexes may overwinter in the DRTO. Between 2011 and 2016 three males and five females with transmitters were detected to move up the west coast of Florida outside of the mating season as far north as the waters off Tampa Bay (335 km). Six others were only detected in the lower Florida Keys (292 km). Nine sharks returned to DRTO; one returned six times. Some overwintered and some resumed courtship in June, demonstrating both resident and migratory contingents within their population, partial migration and an ability to navigate with high spatial and temporal precision. 相似文献
230.
Jo Rycroft-Malone Kate Seers Ann Catrine Eldh Karen Cox Nicola Crichton Gill Harvey Claire Hawkes Alison Kitson Brendan McCormack Christel McMullan Carole Mockford Theo Niessen Paul Slater Angie Titchen Teatske van der Zijpp Lars Wallin 《Implementation science : IS》2018,13(1):138