Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012739 (disseminated intravascular coagulation)
 8,673 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Allen Video-enhanced contrast/differential interference contrast (AVEC-DIC) microscopy was used in conjunction with video intensification immunofluorescence microscopy to demonstrate that organelles and vesicle (particles) can move in either direction along microtubular linear elements in fibroblasts [Hayden et al., 1983]. Since it is not possible to determine the number of microtubules making up a linear element with light microscopy alone, AVEC-DIC microscopy was used in conjunction with whole-mount electron microscopy to show bidirectional transport along a single microtubule [Hayden and Allen, 1984]. These studies demonstrate that the structural polarity of the microtubule does not determine the direction of particle motion, and since dynein is an asymetric molecule, a simple microtubule-dynein-particle hypothesis cannot explain bidirectional transport along a single microtubule. Very little is known about regulation of particle transport in most cell types. Human embryonic lung fibroblasts grown on glass coverslips were serum-deprived for 24 hours and re-fed with serumless medium; the particle translocations/5 minutes were then determined. The cells were then re-fed with either serumless medium, serum-containing medium, or serumless medium containing some bioactive factor, and the particle translocations/5 minutes were again determined for the same cells. Medium containing 10% fetal bovine serum inhibited particle translocation by 51.8%. Of the bioactive factors tested, only vasopressin produced a significant reduction in particle translocations (38%). This suggests that protein kinase C or calcium/calmodulin kinase could be involved in regulating particle transport.
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PMID:Microtubule-associated organelle and vesicle transport in fibroblasts. 318 Feb 46

It was recently shown that, in addition to the well-established microtubule-dependent mechanism, fast transport of organelles in squid giant axons also occurs in the presence of actin filaments [Kuznetsov et al., 1992, Nature 356:722-725]. The objectives of this study were to obtain direct evidence of axoplasmic organelle movement on actin filaments and to demonstrate that these organelles are able to move on skeletal muscle actin filaments. Organelles and actin filaments were visualized by video-enhanced contrast differential interference contrast (AVEC-DIC) microscopy and by video intensified fluorescence microscopy. Actin filaments, prepared by polymerization of monomeric actin purified from rabbit skeletal muscle, were stabilized with rhodamine-phalloidin and adsorbed to cover slips. When axoplasm was extruded on these cover slips in the buffer containing cytochalasin B that prevents the formation of endogenous axonal actin filaments, organelles were observed to move at the fast transport rate. Also, axoplasmic organelles were observed to move on bundles of actin filaments that were of sufficient thickness to be detected directly by AVEC-DIC microscopy. The range of average velocities of movement on the muscle actin filaments was not statistically different from that on axonal filaments. The level of motile activity (number of organelles moving/min/field) on the exogenous filaments was less than on endogenous filaments probably due to the entanglement of filaments on the cover slip surface. We also found that calmodulin (CaM) increased the level of motile activity of organelles on actin filaments. In addition, CaM stimulated the movement of elongated membranous organelles that appeared to be tubular elements of smooth endoplasmic reticulum or extensions of prelysosomes. These studies provide the first direct evidence that organelles from higher animal cells such as neurons move on biochemically defined actin filaments.
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PMID:Movement of axoplasmic organelles on actin filaments from skeletal muscle. 795 51

The effects of E. coli endotoxin (ET) on human erythrocyte cytosolic free calcium concentration ([Ca2+]i) and membrane calcium pump (Ca(2+)-Mg(2+)-ATPase) activity were observed in vitro. The changes of erythrocyte [Ca2+]i, Ca(2+)-Mg(2+)-ATPase activity, calmodulin activity, the deformability of erythrocytes, membrane protein electrophoresis, and the fluidities of membrane lipids were investigated in the ET-induced disseminated intravascular coagulation (DIC) model to study the significance of erythrocyte factors in the occurrence of microangiopathic hemolytic anemia. The [Ca2+]i of human erythrocytes was 86 +/- 9.2 nmol/L in normal cells, and it was increased to 124 +/- 22 nmol/L, 174 +/- 41 nmol/L and 220 +/- 92.1 nmol/L, respectively, when the erythrocytes were incubated with 0.5 mg/ml, 1 mg/ml and 2 mg/ml ET, respectively. At the same time, the Ca(2+)-Mg(2+)-ATPase activities decreased from 1031 +/- 131 nmol/mg.h in normal to 870 +/- 182 nmol/mg.h, 684 +/- 124 nmol/mg.h and 718 +/- 144.4 nmol/mg.h in groups receiving 0.5 mg/ml, 1 mg/ml and 2 mg/ml ET, respectively (P < 0.01). The [Ca2+]i of rabbit erythrocytes was elevated from 76.6 +/- 14.9 nmol/L in normal to 224 +/- 74 nmol/L (P < 0.01), and the Ca(2+)-Mg(2+)-ATPase activity was inhibited from 220 +/- 26.8 nmol/mg.h in normal to 146.1 +/- 30.6 nmol/mg.h during ET-induced DIC in vivo. In addition, erythrocyte deformability decreased and the membrane protein electrophoresis showed changes in the 4.5 KD band area. However, there was no significant difference in the calmodulin activity and fluidities of membrane lipids of erythrocytes in DIC rabbits. These results suggest a possible alternative mechanism for the formation of microangiopathic hemolytic anemia in ET-induced DIC rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The changes in erythrocyte calcium is one of the mechanisms of anemia formation in rabbit endotoxin-induced DIC]. 824 17