scholarly journals THE MECHANISM OF THE INFLAMMATORY PROCESS

1928 ◽  
Vol 11 (6) ◽  
pp. 743-756 ◽  
Author(s):  
Harold A. Abramson
Keyword(s):  
Magnetic Force ◽  
Marked Change ◽  
Polymorphonuclear Leucocyte ◽  
Red Cells ◽  
Fibrin Gels ◽  
Gelatin Gels ◽  
Order Of Magnitude ◽  
And Migration ◽  
Soft Gels ◽  
Mechanical Nature

1. Quartz particles and certain other particles move cataphoretically in certain soft gelatin gels, with the same velocity as in the sol. The speed is a function of the true viscosity of the sol or gel, and it is See PDF for Structure apparently not altered in these soft gels by the presence of gel structure. It is proportional to the applied difference of potential. 2. This finding is compatible with the fact that certain sols undergo gelation with no increase of the true viscosity although a marked change in the apparent viscosity takes place. 3. Red cells in soft gelatin-serum gels show a distinct difference in behavior. They migrate through the sol or gel with a speed that is about twice as great as the leucocytes and quartz particles, which latter particles migrate with the same velocity. This ratio has been found to hold for serum and plasma. The absolute velocities are comparatively slightly decreased by the presence of the gel. 4. In more concentrated or stiffer gels, leucocytes, red cells and quartz particles all move at first with the same velocity. By producing mechanical softening of these gels (shearing from cataphoretic movement of the micells within the cell) the red cells presently resume their previous property of independent migration through the gel. 5. The movements of particles in gelatin gels produced by a magnetic force or the force of gravity are of a different nature than those movements produced by cataphoresis. 6. The mechanical nature of obstruction to the cataphoretic migration of leucocytes and red cells in fibrin gels is briefly described. 7. The correlation of cataphoresis of microscopic particles in gels with the order of magnitude and nature of the potential differences in the capillary wall, lends additional evidence to the theory that polymorphonuclear leucocyte emigration and migration are dependent upon these potential differences.

scholarly journals Expression of wild-type and mutated rabbit osteopontin in Escherichia coli, and their effects on adhesion and migration of P388D1 cells

1995 ◽  
Vol 307 (1) ◽  
pp. 257-265 ◽  
Author(s):  
K Nasu ◽  
T Ishida ◽  
M Setoguchi ◽  
Y Higuchi ◽  
S Akizuki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fluid Phase ◽  
Intradermal Injection ◽  
Polymorphonuclear Leucocyte ◽  
Alpha Subunit ◽  
Wild Type ◽  
Alpha Subunits ◽  
Leucocyte Migration ◽  
And Migration ◽  
Chemotactic Effect

Recombinant wild-type rabbit osteopontin (rOP) and the protein with an aspartate-to-glutamate transposition induced by a point mutation in the rabbit OP cDNA within the Gly-Arg-Gly-Asp-Ser (GRGDS) sequence were expressed in Escherichia coli and purified to homogeneity. P388D1 cells bound rOP in a saturable manner. rOP induced adhesion and haptotaxis of P388D1 cells, whereas mutated rabbit OP (rOPmut) did not. Anti-rOP IgG F(ab′)2 and synthetic GRGDS peptide inhibited rOP-mediated adhesion and haptotaxis of P388D1 cells. Fibronectin (FN)-mediated adhesion of P388D1 cells was markedly inhibited in the presence of fluid-phase rOP. Adhesion of P388D1 cells to rOP was significantly inhibited by anti-[alpha-subunits of VLA4 (alpha 4) and VLA5 (alpha 5)] monoclonal antibodies (mAbs), but not by anti-[alpha-subunit of vitronectin (VN) receptor (alpha V) or Mac-1 (alpha M)] mAb. Adhesion of P388D1 cells to FN and VN was significantly inhibited by anti-alpha V mAb but not anti-alpha 4, -alpha 5 or -alpha M mAb. Haptotaxis of P388D1 cells to rOP was significantly inhibited by anti-alpha V mAb, but not by anti-alpha 4, -alpha 5 and alpha M mAbs, whereas that to FN showed no inhibition with all three mAbs. Haptotaxis of P388D1 cells to VN was significantly inhibited by anti-alpha 5 and -alpha V mAbs but not by anti-alpha 4 and -alpha M mAbs. Similar features of inhibition of adhesion and haptotaxis of P388D1 cells to human OP were observed by mAbs. rOP had no chemotactic effect on P388D1 cells. Significant polymorphonuclear leucocyte migration was observed 3-12 h after intradermal injection of rOP into rabbits.

CD1 1b/CD18-Dependent Polymorphonuclear Leucocyte Interaction with Matrix Proteins in Adhesion and Migration

1993 ◽  
Vol 37 (5) ◽  
pp. 569-574 ◽  
Author(s):  
E. LUNDGREN-AKERLUND ◽  
A. M. OLOFSSON ◽  
E. BERGER ◽  
K.-E. ARFORS
Keyword(s):  
Polymorphonuclear Leucocyte ◽  
Matrix Proteins ◽  
And Migration

Hall Currents and the Ejection of Prominences by Sunspots

1949 ◽  
Vol 2 (1) ◽  
pp. 39
Author(s):  
RG Giovanelli
Keyword(s):  
Magnetic Fields ◽  
Electric Fields ◽  
Magnetic Force ◽  
Large Space ◽  
Space Charges ◽  
Surrounding Atmosphere ◽  
Electric And Magnetic Fields ◽  
Order Of Magnitude ◽  
General Movement ◽  
Set Up

During the growth of sunspots induced electric fields may be expected to be set up in the surrounding atmosphere. It is shown that, because of the comparatively low conductivity perpendicular to lines of magnetic force, there are localized regions where large space charges occur, resulting in large electric fields perpendicular to the lines of magnetic force. Consequently both positive and negative charges drift in the same sense in a direction which is at right angles to the electric and magnetic fields, giving rise to a general movement of the gas. The drift velocities are difficult to estimate, but appear to be of the order of magnitude of those found in eruptive prominences.

scholarly journals Red blood cell size is important for adherence of blood platelets to artery subendothelium

Blood ◽  
1983 ◽  
Vol 62 (1) ◽  
pp. 214-217 ◽  
Author(s):  
PA Aarts ◽  
PA Bolhuis ◽  
KS Sakariassen ◽  
RM Heethaar ◽  
JJ Sixma
Keyword(s):  
Red Blood Cells ◽  
Cell Size ◽  
Blood Cells ◽  
Blood Platelets ◽  
Red Cells ◽  
Cell Diameter ◽  
Red Cell ◽  
Human Red Blood Cells ◽  
Platelet Adherence ◽  
Order Of Magnitude

Abstract The hematocrit is one of the main factors influencing platelet adherence to the vessel wall. Raising the hematocrit causes an increase of platelet accumulation of about an order of magnitude. Our studies concern the role of red cell size. We have studied this effect using an annular perfusion chamber, according to Baumgartner, with human umbilical arteries and a steady-flow system. Normal human red blood cells (MCV 95 cu mu) increased platelet adherence sevenfold, as the hematocrit increases from 0 to 0.6. Small erythrocytes from goats (MCV 25 cu mu) caused no increment in adherence in the same hematocrit range. Rabbit erythrocytes (MCV 70 cu mu) caused an intermediate increase in adherence. Red blood cells from newborns (MCV 110–130 cu mu) caused a larger increase in platelet adherence than normal red cells at hematocrit 0.4. These results were further confirmed with large red blood cells from two patients. Experiments with small red cells (MCV 70 cu mu) of patients with iron deficiency showed that platelet adherence was similar to normal red cells, provided the red cell diameter was normal. Small red blood cells of a patient with sideroblastic anemia caused decreased adherence. These data indicate that red cell size is of major importance for platelet adherence. Red cell diameter is more important than average volume. However, for size differences in the human range, the hematocrit remains the dominant parameter.

Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. XI. Estimation of Fish Populations

1959 ◽  
Vol 10 (3) ◽  
pp. 388 ◽  
Author(s):  
JM Thomson
Keyword(s):  
Mortality Rate ◽  
Fish Populations ◽  
Calculation Methods ◽  
Commercial Fish ◽  
Order Of Magnitude ◽  
And Migration

Estimations of populations of six species of commercial fish were carried out by the mark-and-recapture method using modifications of the calculation methods of Petersen and Schnabel. Results from the two methods do not differ in order of magnitude except in occasional months. The estimates, however, are probably unreal, or refer to a part of the population rather than the whole, as it is doubtful whether tagged fish became randomly distributed throughout the population and migration and mortality must have continued during the period of calculation. It was possible to make an estimate of mortality rate but not of the effects of migration, nor of recruitment.

Hyaluronan stimulates tumor cell migration by modulating the fibrin fiber architecture

1999 ◽  
Vol 112 (13) ◽  
pp. 2241-2251 ◽  
Author(s):  
W. Hayen ◽  
M. Goebeler ◽  
S. Kumar ◽  
R. Riessen ◽  
V. Nehls
Keyword(s):  
Cell Migration ◽  
Tumor Cell ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Boyden Chamber ◽  
Fibrin Polymerization ◽  
Fibrin Gels ◽  
Tumor Cell Migration ◽  
And Migration

The glycosaminoglycan hyaluronan, which supports tumor cell migration and metastasis, interferes with fibrin polymerization and leads to increased fiber size and porosity of fibrin clots. Here we have studied the proportionate effect of fibrin polymerization on hyaluronan-mediated migration of glioblastoma cells. The structural and physical properties of hyaluronan-containing fibrin gels were analyzed by turbidity measurement, laser scanning microscopy, compaction assay, and calculation of pore size by liquid permeation. When fibrin polymerized in the presence of hyaluronan or dextran, the resulting gels strongly stimulated cell migration, and migration significantly correlated with fiber mass-to-length ratios and pore diameters. In contrast, cell migration was not induced by addition of hyaluronan to supernatants of already polymerized gels. Hyaluronan-mediated migration was inhibited in fibrin gels by antibodies to alphav- and beta1integrins and the disintegrin echistatin, but not by antibodies to the hyaluronan receptor CD44 (up to 50 microg/ml). As a control, we show that anti-CD44 (10 microg/ml) inhibited cell migration on a pure hyaluronan matrix using a two-dimensional Boyden chamber system. In contrast to three-dimensional migration, the migration of cells on the surfaces of variably structured fibrin gels was not significantly different, indicating that increased gel permeability (porosity) may account for hyaluronan-mediated migration. We conclude that, in complex three-dimensional substrates, the predominant effect of hyaluronan on cell migration might be indirect and requires modulation of fibrin polymerization.

scholarly journals THE OSMOTIC BEHAVIOR OF CRENATED RED CELLS

1944 ◽  
Vol 27 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Eric Ponder
Keyword(s):  
Bulk Modulus ◽  
Red Cells ◽  
Gelatin Gels ◽  
Osmotic Behavior

The anomalously small swelling which the red cells of human oxalated blood undergo in hypotonic plasma is related to the extent to which the cells are crenated. Reasons are given for regarding crenation as corresponding to gelation, and the bulk modulus for crenated cells, calculated from the measurements of swelling in hypotonic plasma, is shown to be of the same order as that for gelatin gels.

The membrane permeability of nonelectrolytes and carbohydrate metabolism of Amazon fish red cells

1978 ◽  
Vol 56 (4) ◽  
pp. 863-869 ◽  
Author(s):  
Hyun Dju Kim ◽  
R. E. Isaacks
Keyword(s):  
Membrane Permeability ◽  
Carbohydrate Metabolism ◽  
Diffusion Mechanism ◽  
Red Cells ◽  
Facilitated Diffusion ◽  
Metabolic Substrates ◽  
Urea Permeability ◽  
Arapaima Gigas ◽  
Electric Eel ◽  
Order Of Magnitude

The membrane permeability to nonelectrolytes and carbohydrate metabolism were examined in red cells obtained from the Amazon fishes including the electric eel (Electrophorus electrocus), the arawana (Osteoglossum bicirrhosum), the pirarucu (Arapaima gigas), the lungfish (Lepidosireti paradoxa), and the armored catfish (Pterygoplichthys). Glucose permeability was fastest in the electric eel, followed by the lungfish. The red cells of the arawana were only slightly permeable to glucose. Both the armored catfish and the pirarucu red cells were found to be totally impermeable to glucose. There was no evidence for the presence of the facilitated diffusion mechanism for glucose transport in any of these fish red cells. In sharp contrast with glucose, red cells of all five species were quite permeable to ribose and urea. Urea permeability of red cells decreased in order of magnitude with the lungfish > the electric eel > the arawana > the armored catfish [Formula: see text] the pirarucu. The urea permeability of the lungfish was inhibited in the presence of phloretin.Of the two metabolic substrates, glucose but not ribose was metabolized to lactate with a concomitant contribution to ATP maintenance by the lungfish red cells. Even though the glucose-impervious pirarucu cells could not utilize glucose, ribose was readily metabolized by the pirarucu cells.

scholarly journals Least-squares reverse time migration of marine data with frequency-selection encoding

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. S233-S242 ◽  
Author(s):  
Wei Dai ◽  
Yunsong Huang ◽  
Gerard T. Schuster
Keyword(s):  
Least Squares ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Data Set ◽  
Frequency Selection ◽  
Time Migration ◽  
Order Of Magnitude ◽  
Marine Data ◽  
And Migration ◽  
Encoding Method

The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share the same receiver locations, thus limiting the usage to seismic surveys with a fixed spread geometry. We implement a frequency-selection encoding strategy that accommodates data with a marine streamer geometry. The encoding functions are delta functions in the frequency domain, so that all the encoded shots have unique nonoverlapping frequency content, and the receivers can distinguish the wavefield from each shot with a unique frequency band. Because the encoding functions are orthogonal to each other, there will be no crosstalk between different shots during modeling and migration. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is comparable to conventional RTM for the Marmousi2 model and a marine data set recorded in the Gulf of Mexico. With more iterations, the LSRTM image quality is further improved by suppressing migration artifacts, balancing reflector amplitudes, and enhancing the spatial resolution. We conclude that LSRTM with frequency-selection is an efficient migration method that can sometimes produce more focused images than conventional RTM.

scholarly journals Red blood cell size is important for adherence of blood platelets to artery subendothelium

Blood ◽  
1983 ◽  
Vol 62 (1) ◽  
pp. 214-217 ◽  
Author(s):  
PA Aarts ◽  
PA Bolhuis ◽  
KS Sakariassen ◽  
RM Heethaar ◽  
JJ Sixma
Keyword(s):  
Red Blood Cells ◽  
Cell Size ◽  
Blood Cells ◽  
Blood Platelets ◽  
Red Cells ◽  
Cell Diameter ◽  
Red Cell ◽  
Human Red Blood Cells ◽  
Platelet Adherence ◽  
Order Of Magnitude

The hematocrit is one of the main factors influencing platelet adherence to the vessel wall. Raising the hematocrit causes an increase of platelet accumulation of about an order of magnitude. Our studies concern the role of red cell size. We have studied this effect using an annular perfusion chamber, according to Baumgartner, with human umbilical arteries and a steady-flow system. Normal human red blood cells (MCV 95 cu mu) increased platelet adherence sevenfold, as the hematocrit increases from 0 to 0.6. Small erythrocytes from goats (MCV 25 cu mu) caused no increment in adherence in the same hematocrit range. Rabbit erythrocytes (MCV 70 cu mu) caused an intermediate increase in adherence. Red blood cells from newborns (MCV 110–130 cu mu) caused a larger increase in platelet adherence than normal red cells at hematocrit 0.4. These results were further confirmed with large red blood cells from two patients. Experiments with small red cells (MCV 70 cu mu) of patients with iron deficiency showed that platelet adherence was similar to normal red cells, provided the red cell diameter was normal. Small red blood cells of a patient with sideroblastic anemia caused decreased adherence. These data indicate that red cell size is of major importance for platelet adherence. Red cell diameter is more important than average volume. However, for size differences in the human range, the hematocrit remains the dominant parameter.

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