Acceleration of Haemolysis in Relation to Chemical Structure

1939 ◽  
Vol 16 (1) ◽  
pp. 38-48 ◽  
Author(s):  
ERIC PONDER
Keyword(s):  
Cell Surface ◽  
Bile Salt ◽  
Chemical Structure ◽  
Red Cell ◽  
Measurable Effect ◽  
Ring Compounds ◽  
Kinetics Of

1. Benzene and its halogenated derivatives are accelerators of saponin and bile salt haemolysis. The order of effectiveness is benzene<chlor-benzene<brom-benzene<iodo-benzene. The addition of two halogens is more effective than the addition of one, and again the order is Cl<Br<I. In the case of the di-chlor-benzenes, the order of effectiveness is ortho>meta>para, and the addition of three Cl increases the accelerating power more than does the addition of two Cl. 2. Naphthalene and its halogenated derivatives are also accelerators, and again the order of effectiveness is Cl<Br<I. The addition of the halogen in the β position is more effective than the addition in the α position. 3. Anthracene does not produce appreciable acceleration, perhaps because of its insolubility, but acceleration is produced by its isomer, phenanthrene. The 5-ring compounds which have been examined are too insoluble to produce any measurable effect; of the 4-ring compounds, only estrin and estriol have been examined, and these are inhibitors. 4. Benzene is concentrated at the red cell surface, the amount taken up being roughly linear with the concentration to which the cells are exposed. Acceleration can be observed when there are too few molecules in the system to form even a monolayer. 5. If an accelerator such as benzene is washed off the cells immediately, no accelerating effect remains, but if some time is allowed to elapse before the washing, effects irreversible by washing can be detected. 6. The investigation has brought to light certain hitherto undescribed peculiarities in the kinetics of acceleration, and these are discussed in detail.

scholarly journals THE KINETICS OF PROGRESSIVE REACTIONS IN SYSTEMS CONTAINING SAPONIN, DIGITONIN, AND SODIUM TAUROCHOLATE

1953 ◽  
Vol 36 (5) ◽  
pp. 723-732 ◽  
Author(s):  
Eric Ponder
Keyword(s):  
Cell Surface ◽  
Sodium Taurocholate ◽  
Red Cell ◽  
Cell Surfaces ◽  
Internal Phase ◽  
Percentage Hemolysis ◽  
The Moment ◽  
Kinetics Of

The relations between lysin concentration, percentage hemolysis at the moment at which the lysin concentration is reduced by dilution, and the amount of hemolysis which follows the dilution as a result of the reaction being "progressive" point to there being an "internal" phase at the red cell surfaces, in which the lysin is less affected by the dilution than in the system as a whole. A second possibility, i.e. that the combination of lysin molecules with certain components of the cell surface has an ultimate effect on neighboring components which depend on the former for their stability cannot, however, be ruled out. In systems containing digitonin or sodium taurocholate, this internal phase, once formed, seems to be almost unaffected by the dilution of the system; i.e., these lysins are very firmly held at the cell surfaces. In systems containing saponin the lysin is less firmly attached, so that dilution of the system affects its concentration appreciably.

Functions of red cell surface proteins

Vox Sanguinis ◽  
2007 ◽  
Vol 0 (0) ◽  
pp. 070807042627006-??? ◽  
Author(s):  
G. Daniels
Keyword(s):  
Cell Surface ◽  
Surface Proteins ◽  
Red Cell ◽  
Cell Surface Proteins

scholarly journals Analysis of Immunity to Febrile Malaria in Children That Distinguishes Immunity from Lack of Exposure

2009 ◽  
Vol 77 (5) ◽  
pp. 1917-1923 ◽  
Author(s):  
Philip Bejon ◽  
George Warimwe ◽  
Claire L. Mackintosh ◽  
Margaret J. Mackinnon ◽  
Sam M. Kinyanjui ◽  
...  
Keyword(s):  
Cell Surface ◽  
Antibody Response ◽  
Observational Studies ◽  
Asymptomatic Infection ◽  
Bed Nets ◽  
Bed Net ◽  
Red Cell ◽  
Vaccine Trials ◽  
Net Use ◽  
Malaria Episodes

ABSTRACT In studies of immunity to malaria, the absence of febrile malaria is commonly considered evidence of “protection.” However, apparent “protection” may be due to a lack of exposure to infective mosquito bites or due to immunity. We studied a cohort that was given curative antimalarials before monitoring began and documented newly acquired asymptomatic parasitemia and febrile malaria episodes during 3 months of surveillance. With increasing age, there was a shift away from febrile malaria to acquiring asymptomatic parasitemia, with no change in the overall incidence of infection. Antibodies to the infected red cell surface were associated with acquiring asymptomatic infection rather than febrile malaria or remaining uninfected. Bed net use was associated with remaining uninfected rather than acquiring asymptomatic infection or febrile malaria. These observations suggest that most uninfected children were unexposed rather than “immune.” Had they been immune, we would have expected the proportion of uninfected children to rise with age and that the uninfected children would have been distinguished from children with febrile malaria by the protective antibody response. We show that removing the less exposed children from conventional analyses clarifies the effects of immunity, transmission intensity, bed nets, and age. Observational studies and vaccine trials will have increased power if they differentiate between unexposed and immune children.

scholarly journals THE ELECTROPHORETIC MOBILITY OF HUMAN ERYTHROCYTES—WHOLE CELLS, GHOSTS, AND FRAGMENTS

1938 ◽  
Vol 22 (1) ◽  
pp. 1-5 ◽  
Author(s):  
W. H. Byler ◽  
H. M. Rozendaal
Keyword(s):  
Cell Surface ◽  
Electrophoretic Mobility ◽  
Human Erythrocytes ◽  
Red Cell ◽  
Chicken Serum ◽  
Whole Cells ◽  
Slow Change ◽  
Foreign Substance ◽  
Pure Salt

The electrophoretic mobility of human red cell ghosts decreases in the presence of chicken serum. The decrease is not directly due to the presence of adsorbed material but to a change which is catalyzed by the foreign substance. It is suggested that abnormal serum materials resulting from disease may serve as catalysts. Fragments of broken cells have the same mobility as whole cells at first, then decrease even in pure salt suspension, while the whole cells remain essentially unchanged for hours. The results suggest that the slow change of whole cells, the change of ghosts in the presence of foreign serum, and the change of fragments are all manifestations of the same modification of structure or composition of the cell surface.

Supercritical Fluid Deposition of Ruthenium Thin Films: A Kinetic Study

2007 ◽  
Vol 992 ◽  
Author(s):  
Christos F. Karanikas ◽  
James J. Watkins
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Deposition Temperature ◽  
Zero Order ◽  
Measurable Effect ◽  
Deposition Rates ◽  
Reaction Pressure ◽  
Deposition Kinetics ◽  
First Order ◽  
Kinetics Of

AbstractThe kinetics of the deposition of ruthenium thin films from the hydrogen assisted reduction of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II), [Ru(tmhd)2cod], in supercritical carbon dioxide was studied in order to develop a rate expression for the growth rate as well as to determine a mechanism for the process. The deposition temperature was varied from 240°C to 280°C and the apparent activation energy was 45.3 kJ/mol. Deposition rates up to 30 nm/min were attained. The deposition rate dependence on precursor concentrations between 0 and 0.2 wt. % was studied at 260°C with excess hydrogen and revealed first order deposition kinetics with respect to precursor at concentrations lower then 0.06 wt. % and zero order dependence at concentrations above 0.06 wt. %. The effect of reaction pressure on the growth rate was studied at a constant reaction temperature of 260°C and pressures between 159 bar to 200 bar and found to have no measurable effect on the growth rate.

Protective antigens of bloodstage Plasmodium knowlesi parasites

1984 ◽  
Vol 307 (1131) ◽  
pp. 159-169 ◽  
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Plasmodium Knowlesi ◽  
Surface Antigens ◽  
Red Cell ◽  
Cell Surface Antigens ◽  
Susceptible Host ◽  
Protective Antigens ◽  
Stage Of Development

The simian malaria Plasmodium knowlesi provides many favourable features as an experimental model; it can be grown in vivo or in vitro . Parasites of defined variant specificity and stage of development are readily obtained and both the natural host and a highly susceptible host are available for experimental infection and vaccination trials. Proteins synthesized by erythrocytic P. knowlesi parasites are characteristic of the developmental stage, as are the alterations that the parasite induces in the red cell surface. Erythrocytic merozoites are anatomically and biochemically complex, their surface alone is covered by at least eight distinct polypeptides. Immune serum from merozoite-immunized rhesus recognizes many parasite components, especially those synthesized by schizonts. All of the merozoite surface components and some of the schizont-infected red cell surface antigens are recognized by such immune sera. Rhesus monkeys rendered immune by repeated infection may by contrast recognize comparatively few antigens; a positive correlation was established for these ‘ naturally ’ immunized monkeys between protection and antibody directed against a 74000 molecular mass antigen. Im m unization with this purified antigen confers partial protection. O ther putative protective antigens have been identified by monoclonal antibodies that inhibit merozoite invasion of red cells in vitro . The antigens recognized by inhibitory monoclonal antibodies are synthesized exclusively by schizonts and are processed, at the time ofschizont rupture and merozoite release, to smaller molecules that are present on the merozoite surface. The multiplicity of protective antigens is clearly demonstrated by the fact that seven distinct merozoite surface antigens are recognized by three different inhibitory monoclonals. None of the protective antigens identified are variant or strain specific.

scholarly journals The fusion kinetics of influenza hemagglutinin expressing cells to planar bilayer membranes is affected by HA density and host cell surface.

1995 ◽  
Vol 106 (5) ◽  
pp. 783-802 ◽  
Author(s):  
G B Melikyan ◽  
W D Niles ◽  
F S Cohen
Keyword(s):  
Cell Surface ◽  
Fusion Protein ◽  
Pore Formation ◽  
Surface Proteins ◽  
Fusion Pore ◽  
Planar Bilayer ◽  
Bilayer Membranes ◽  
Pore Evolution ◽  
Fusion Pores ◽  
Kinetics Of

Time-resolved admittance measurements were used to follow formation of individual fusion pores connecting influenza virus hemagglutinin (HA)-expressing cells to planar bilayer membranes. By measuring in-phase, out-of-phase, and dc components of currents, pore conductances were resolved with millisecond time resolution. Fusion pores developed in stages, from small pores flickering open and closed, to small successful pores that remained open until enlarging their lumens to sizes greater than those of viral nucleocapsids. The kinetics of fusion and the properties of fusion pores were studied as functions of density of the fusion protein HA. The consequences of treating cell surfaces with proteases that do not affect HA were also investigated. Fusion kinetics were described by waiting time distributions from triggering fusion, by lowering pH, to the moment of pore formation. The kinetics of pore formation became faster as the density of active HA was made greater or when cell surface proteins were extensively cleaved with proteases. In accord with this faster kinetics, the intervals between transient pore openings within the flickering stage were shorter for higher HA density and more extensive cell surface treatment. Whereas the kinetics of fusion depended on HA density, the lifetimes of open fusion pores were independent of HA density. However, the lifetimes of open pores were affected by the proteolytic treatment of the cells. Faster fusion kinetics correlated with shorter pore openings. We conclude that the density of fusion protein strongly affects the kinetics of fusion pore formation, but that once formed, pore evolution is not under control of fusion proteins but rather under the influence of mechanical forces, such as membrane bending and tension.

Bovine trypanosomiasis: the red cell kinetics of Ndama and Zebu cattle infected withTrypanosoma congolense

Parasitology ◽  
1979 ◽  
Vol 78 (3) ◽  
pp. 271-286 ◽  
Author(s):  
J. D. Dargie ◽  
P. K. Murray ◽  
Max Murray ◽  
W. R. T. Grimshaw ◽  
W. I. M. McIntyre
Keyword(s):  
Zebu Cattle ◽  
Red Cell ◽  
Isotopic Methods ◽  
Initial Drop ◽  
Bone Marrow Function ◽  
Cell Synthesis ◽  
Underlying Processes ◽  
Kinetics Of ◽  
Cell Volumes ◽  
Erythropoietic Response

SUMMARYThe responses of susceptible Ndama and Zebu cattle to needle challenge withTrypanosoma congolensewere followed using parasitological, haematological and radio-isotopic methods and compared with those of corresponding uninfected animals. In both breeds, infection became patent at the same time but peak parasitaemias were significantly lower, were attained later and were of short duration in the Ndama. All infected animals became anaemic, the severity of which correlated with the level and duration of parasitaemia. However, even when parasites could no longer be detected in the blood, packed cell volumes showed little tendency to recover. The anaemia was due to increased intravascular red cell destruction and was more pronounced in the Zebu. Haemodilution was not a feature. Increased red cell synthesis occurred in infected animals of both breeds but particularly in the Zebu; this accounted for the capacity to maintain packed cell volume levels following the initial drop associated with parasitaemia. However, in most cases red cell synthesis was less than expected from the degree of anaemia, suggesting impairment of bone marrow function. Measurement of red cell iron utilization indicated that this was due to defective iron re-utilization from degraded red cells arising from reticulo-endothelial blockade. It is concluded that the anaemia in this disease and its underlying processes are broadly in line with the number of parasites in the blood and that the superior resistance of the Ndama cattle lies in their ability to control parasitaemia rather than their capacity to mount a more efficient erythropoietic response.

scholarly journals Modeling the Coalescence Kinetics of Cell Surface Receptor Clusters

2011 ◽  
Vol 100 (3) ◽  
pp. 254a
Author(s):  
Kathrin Spendier ◽  
James L. Thomas ◽  
Vasudev M. Kenkre
Keyword(s):  
Cell Surface ◽  
Cell Surface Receptor ◽  
Surface Receptor ◽  
Receptor Clusters ◽  
Kinetics Of
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