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PubMedDate not supplied

[The study of a specific activity of a new allogenic antidiphterial immunoglobulin].

A comparative investigation was conducted of several methods for measuring the activity of the diphterial antitoxin in the preparation of allogenic antidiphterial immunoglobulin. The results of the studies made allow recommending the flocculation reaction and statistical method for use at blood transfusion stations in Ukraine when manufacturing the antidiphterial immunoglobulin, due to their informative, economic value and because they can easily be performed.

Animals↗
PubMed2003

Eureka moments.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMedDate not supplied

[A method for recovery of enteroviruses from milk].

A method of detection of enteric viruses in milk was studied. The high protein content of milk and the protein nature of enterovirus allowed the detection of these viruses using the organic acid flocculation method. The poliovirus type 1 (Mahoney strains) and the E.C.H.O.1 isolated from the environment were used as virus model and were inoculated to creamed, half-creamed and whole UHT commercialized milk. The method consists on a milk sample clarification with acid precipitation and centrifugation. The clarified extract is reduced to a final volume of 10 to 15 ml after addition of beef extract powder and protein precipitation. This technique allows the recovery of 26 to 36% of poliovirus type 1 and 10 to 46% of E.C.H.O.1 viruses. In this work, the ferric chloride (FeCl3), added in 0.5 to 1 mM final concentration, was used as an adjuvant for the organic acid precipitation.

Animals↗
PubMed1991

Dimeric ristocetin flocculates proteins, binds to platelets, and mediates von Willebrand factor-dependent agglutination of platelets.

Ristocetin in aqueous solution dimerizes with an equilibrium dissociation constant of 5.0 x 10(-4) M, i.e. approximately 1.1 mg ml-1 (Waltho, J.P., and Williams, D. H. (1989) J. Am. Chem. Soc. 111, 2475-2480). At concentrations of about 1.0 mg ml-1 ristocetin flocculates many proteins, lyses platelets and, in the presence of von Willebrand factor, agglutinates both fresh and formalin-fixed platelets. Because ristocetin exists as both monomeric and dimeric species, we sought to determine which of these forms flocculates proteins and agglutinates platelets. We found that: 1) the initial rate of flocculation of certain proteins, 2) the initial rate of agglutination of formalin-fixed platelets, and 3) the binding of ristocetin to formalin-fixed platelets are higher order solely with respect to the concentration of ristocetin dimers. As to the operative mechanism, it appears that bifunctional dimers cross-link proteins that possess multiple copies of a common recognition site. Preliminary evidence indicates that a recognition site is a beta-turn of the form X-P-G-X'.

Afibrinogenemia↗
PubMedDate not supplied

The influence of charged lipids on the flocculation and coalescence of oil-in-water emulsions. I: Kinetic assessment of emulsion stability.

The influence of various negatively charged lipids on the stability of phospholipid stabilized oil-in-water emulsions in the presence of varying concentrations of calcium chloride was examined by a measurement of the changes in the turbidity of the emulsion over time. The data were described well by the following equation: (Ai - A) = (Ai - A0) exp(-kt) where Ai is the maximum spectrophotometric absorbance achieved in the system, A is the absorbance at time t, A0 is the absorbance at the start of the experiment and k is the flocculation or coalescence rate constant. Plots of k and Ai/A0 vs. concentration of Ca++ provided an indication of the rate and extent of emulsion flocculation/coalescence, respectively. The sodium salts of phosphatidic acid (SPA) and oleic acid (SO) increased the critical flocculation concentration of calcium while sodium phosphatidylinositol (SPI) and sodium phosphatidylserine (SPS) had no effect on the critical flocculation concentration compared to the control emulsion. The addition of all lipid salts increased the rate of flocculation compared to the control emulsion, however, emulsions containing SPI demonstrated the highest values of k. In contrast, emulsions containing SO coalesced to the largest extent, as indicated by large values of Ai/A0. Systems containing charged phosphatides regained some stability in higher concentrations of Ca++ while those containing oleate were comparatively more unstable up to 20 mM Ca++. Based upon the results of the present studies, it appears that phosphatidic acid is the most important fraction of the anionic phosphatides in stabilizing an emulsion in the presence of calcium ion.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Stability↗
PubMed1979

[Nature of immunological changes in ischemic heart disease].

Humoral and cellular immunological paramaters were studied in 3 groups of patients with ischemic heart disease. A distinct correlation was revealed between these parameters and clinical symptoms of the disease. It was shown that an immunological reconstruction took place already in the ischemic stage of coronarosclerosis. This reconstruction is expressed by the growth of hemagglutinating and precipitating antibody titers, as well as by the emergence of sensitized lymphocytes and excretion of the lymphocyte migration inhibiting factor. The use of various homogenates (a normal or atherosclerotic aorta, an infarctial myocardium) or the nonspecific mitogen PHA showed the presence of a specific antigenoactive complex in the blood of patients with ischemic heart disease. The complex was capable of penetrating and affecting the vascular wall as well as of producing antitissular (antivascular) antibodies which, together with the other factors, can help lipoprotein penetration through the arterial wall to form atheromatous plaques.

Adult↗