scholarly journals VENOM HEMOLYSIS AFTER SPLENECTOMY, INCLUDING THE RESISTANCE OF THE ERYTHROCYTES OF NORMAL DOGS TO THE HEMOLYTIC ACTIVITY OF COBRA VENOM

1917 ◽  
Vol 25 (2) ◽  
pp. 195-210 ◽  
Author(s):  
John A. Kolmer
Keyword(s):  
Hemolytic Activity ◽  
Cobra Venom ◽  
Salt Solutions

1. The resistance of erythrocytes of dogs to the hemolytic activity of cobra venom is increased after splenectomy. 2. This increased resistance was observed as early as 4 days after splenectomy and usually persisted for a period of about 3 weeks, when the resistance gradually decreased to normal or slightly beyond. 3. The decrease of resistance to the hemolytic activity of venom for the erythrocytes of splenectomized dogs following the primary increase is apparently coincident with the anemia following splenectomy. An intercurrent infection, such as distemper, tends to reduce the resistance of erythrocytes to venom. 4. An increased resistance of the erythrocytes to hypotonic salt solutions was found with all the splenectomized dogs in which these tests were made. Increased resistance to hypotonic salt solutions apparently persists for a longer period than the increased resistance to cobra venom. 5. As the lysis of erythrocytes by venom is dependent upon the presence of certain lipoidal substances within the cells, and as the spleen may exercise an influence over the lipoidal contents of corpuscles and serum, it is suggested that the increased resistance of erythrocytes to the hemolytic activity of venom after splenectomy is due to alterations in the lipoid content of the erythrocytes.

scholarly journals REVERSIBLE INACTIVATION OF TYPHUS RICKETTSIAE

1954 ◽  
Vol 38 (2) ◽  
pp. 169-179 ◽  
Author(s):  
Marianna R. Bovarnick ◽  
Emma G. Allen
Keyword(s):  
Salt Solution ◽  
Hemolytic Activity ◽  
Coenzyme A ◽  
Salt Solutions ◽  
Freezing And Thawing ◽  
Reversible Inactivation ◽  
Low Concentrations ◽  
Isotonic Salt Solution

Rickettsiae that have been frozen and thawed in isotonic salt solutions show greatly decreased toxicity for mice, hemolytic activity, respiration, and infectivity for eggs. All these properties can be partially restored by incubation of the rickettsiae in the presence of DPN and coenzyme A for 2 hours at 34°C. The extent of both inactivation and of subsequent reactivation is markedly affected by the presence of low concentrations of sucrose during the process of freezing and thawing. It has been shown that DPN is present in rickettsial suspensions and that in preparations that have not been frozen, the DPN sediments with the rickettsiae. After freezing in isotonic salt solution the DPN becomes non-sedimentable.

Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

1983 ◽  
Vol 41 ◽  
pp. 446-447
Author(s):  
William F. Tivol ◽  
Murray Vernon King ◽  
D. F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Heavy Atom ◽  
Isomorphous Substitution ◽  
X Ray Diffraction ◽  
Salt Solutions ◽  
X Ray ◽  
Isomorphous Replacement ◽  
Structure Factors ◽  
Diffraction Structure ◽  
The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Solution behavior of quenched or strongly charged polyampholytes in aqueous-salt solutions

2019 ◽  
Vol 94 (2) ◽  
pp. 35-44 ◽  
Author(s):  
G. Toleutay ◽  
◽  
A.V. Shakhvorostov ◽  
S.K. Kabdrakhmanova ◽  
S.E. Kudaibergenov ◽  
...  
Keyword(s):  
Salt Solutions ◽  
Solution Behavior ◽  
Aqueous Salt Solutions
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