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PubMed1985

[Comparative investigations on the precipitation behavior of various protein precipitates in organs and tissues].

The differences of the non-precipitable N-quota in blood plasma, liver, intestine, and muscles after treatment with various precipitants reveal data on the height of protein precipitation in the corresponding body fraction. Organs of hens treated with picric acid (1%), trichloroacetic acid (10%), and sulphosalicylic acid were used for the protein precipitation. Because of contradictory literature data as to the most suitable concentration of sulphosalicylic acid a preliminary determination of the most favourable acid concentration was necessary. The application of a 5% solution of sulphosalicylic acid gave the highest precipitation rate depending on the analyzed organs. In the succession picric acid, trichloroacetic acid, and sulphosalicylic acid nitrogen increases in the soluble supernatant. Furthermore, dependences of the protein precipitation on the kind of the analyzed organs were indicated.

Animals↗

PubMed1956

Studies on non-precipitating antibody. I. The conversion of non-precipitating antibody to a precipitin-like material in vitro.

Brief exposure of serum to alkali in the cold seems to convert non-precipitating antibody to a precipitin-like material. This was disclosed by the following lines of evidence. 1. Immune sera, after addition of antigen and removal of the ensuing precipitates, yielded after alkali treatment more antibody-antigen complex than did sera to which no antigen was added. 2. When immune sera were depleted of precipitating antibody, treated by alkali, and antibody-antigen complex was allowed to precipitate, the resulting supernates formed additional prescipitates upon admixture of specific antigen. No precipitation occurred upon addition of non-specific protein to the treated supemates or the addition of specific antigen to depleted sera not treated by alkali. 3. Alkali-treated immune sera precipitated more antigen than untreated sera.

Antibodies↗

PubMed1986

Apolipoprotein B determination in the dissolved precipitate obtained after precipitation of LDL with polyvinylsulphate. An alternative method for the determination of LDL apolipoprotein B without using ultracentrifugation.

Using a commercially available test for LDL cholesterol (Boehringer Mannheim), a method was developed for determination of LDL apolipoprotein B without using ultracentrifugation. The infranatant obtained by precipitation of serum with polyvinylsulphate was redissolved in a saline citrate solution and incubated with phospholipase A2, phospholipase C, phospholipase D or triglyceride lipase, respectively. When the saline-citrate redissolved precipitate was monitored by electron microscopy, it appeared as a fibriform network. The additional incubation with phospholipase A2, C, D, or triglyceride lipase resulted in a molecularization of LDL particles. By electron microscopy these particles could not be distinguished from LDL particles isolated by ultracentrifugation. In radial immunodiffusion tests, the additional incubation of the redissolved precipitate with phospholipase C or phospholipase D resulted in a total loss of the slight immunoreactivity observed before phospholipase incubation. However, additional incubation with triglyceride lipase resulted in a significant increase in immunoreactivity. Only the additional incubation of the redissolved precipitate with phospholipase A2 resulted in an immunoprecipitation reaction comparable to that with LDL particles isolated by ultracentrifugation. Using a resolubilized and phospholipase A2-incubated precipitate of a pool serum as apolipoprotein B standard, a good correlation was obtained between apolipoprotein B values measured in this dissolved precipitate and those measured in the d greater than 1.006 kg/l fraction isolated by ultracentrifugation (r = 0.95; y = 0.95x + 0.018; n = 44).

Apolipoproteins B↗

PubMed1984

Precipitation of apo E-containing lipoproteins by precipitation reagents for apolipoprotein B.

We measured the solubility of apolipoprotein E (apo E) after precipitation, with heparin-Mn2+ or dextran sulfate-Mg2+, of lipoproteins containing apo B. Data from 46 randomly selected subjects suggest that apo E is readily precipitated by dextran sulfate-Mg2+, but that heparin-Mn2+ preferentially precipitates apo E associated with apo B-containing lipoproteins while leaving the apo E-containing fraction of high-density lipoproteins (HDL) in solution. In a more detailed analysis of three subjects, we measured the lipoprotein association of apo E by column chromatography on agarose beads, before and after its precipitation from plasma. This study confirmed the preferential solubility of apo E associated with HDL lipoproteins. Using plasma from two normolipidemic subjects, we maintained the heparin concentration at 1.30 g/L and varied the manganese concentration from 9.2 to 184 mmol/L. A 46 mmol/L concentration best separated apo E-containing HDL from apo B-containing lipoproteins. Thus, at these final concentrations, heparin-Mn2+ appears to precipitate the apo E associated with apo B-containing lipoproteins, leaving soluble most of the apo E associated with lipoproteins of HDL size.

Apolipoprotein A-I↗

PubMed2001

Effects of bulk precipitation pH and growth period on cation enrichment in precipitation beneath the canopy of a beech (Fagus moesiaca) forest stand.

The effects of bulk precipitation pH and growth period (growing and dormant) on cation enrichment beneath foliage were examined in a beech (Fagus moesiaca) forest stand during a 48-month period. The bulk precipitation pH values ranged from 4.2 to 7.2. The lowest values were observed in winter due to fossil fuel combustion in a nearby big city. The ratio of monthly ion fluxes of throughfall plus stemflow over monthly ion fluxes of bulk precipitation was chosen as an index of cation enrichment and, therefore, as the dependent variable. Bulk precipitation pH and growth period were chosen as independent factors. Precipitation interception (%) by tree canopies was also taken into account. It was found that the pH factor was significant only for H+ ion enrichment suggesting neutralization of H+ ions in the beech canopy, whereas Mg2+ and K+ enrichment were greater in the growing period, probably as a result of leaching. Crown interception was negatively significant for NH4+-N enrichment.

Acid Rain↗

PubMed1952

Immunochemical studies of antitoxin produced in normal and allergic individuals hyperimmunized with diphtheria toxoid. II. A comparison between the immunological properties of precipitating and non-precipitating (skin-sensitizing) antitoxins.

1. The immunological properties of two contrasting types of human antisera, each containing a high titer of diphtheria antitoxin, have been investigated. 2. Sera which contain only non-precipitating antitoxin exhibit most of the properties of atopic reagin-containing sera. This type of antitoxin is capable of sensitizing normal human skin to toxin or toxoid and remains for many weeks in the injected area. It exhibits no Danysz effect, does not fix complement unless very large amounts of serum are used, and can be specifically coprecipitated by addition of precipitating antitoxin and toxin. On the other hand, it is capable of sensitizing guinea pigs to fatal anaphylactic shock. Heating at 56 degrees C. for 4 hours destroys the skin-sensitizing properties and results in almost quantitative conversion to a modified antitoxin which is capable of blocking the wheal and erythema reaction caused by injection of toxoid into sensitized skin. Heating at 56 degrees C. does not result in an appreciable loss of neutralizing power as judged by tests in rabbit and human skin. The anaphylactogenic property of nonprecipitating antibody is likewise unaffected by heat at 56 degrees C. 3. Precipitating antitoxin is incapable of sensitizing normal skin to toxin or toxoid and disappears rapidly from the injected sites. It fixes complement to high titer and sensitizes guinea pigs to fatal anaphylactic shock. It was possible to demonstrate inhibition of the wheal and erythema reaction in sensitized skin by injecting certain mixtures of precipitating antitoxin and toxoid. 4. The two antitoxic sera studied in greatest detail represented extreme cases. Many persons immunized with toxoid developed both precipitating and nonprecipitating antitoxin simultaneously.

Animals↗

PubMed1979

Fc-mediated immune precipitation. II. Analysis of precipitating immune complexes by rate-zonal ultracentrifugation.

The formation of immune complexes was studied by analytical rate-zonal ultracentrifugation using isomolar solutions of rabbit anti-human serum albumin IgG and of the corresponding F(ab')2 fragments. The F(ab')2 fragments retained full ability to react with the antigenic determinants and to form genuine antigen-antibody complexes. Thus, the difference between the IgG and the F(ab')2 systems was supposed solely to reflect the lack of the Fc portion. The complexes formed with F(ab')2 fragments in the zone of low and moderate antigen excess were found to be distinctively mor soluble than those formed with intact IgG. The data indicated that there were two kinds of precipitating immune complexes, namely antibody-rich and antigen-rich complexes. In the antibody-excess zone and the first part of the equivalence zone the immune complexes precipitated due to their antibody richness. Antigen-rich complexes formed in the zone of low antigen excess precipitate only in the presence of antibody-rich insoluble complexes. It is believed that this type of precipitation was due to an Fc-Fc interaction. This new function of the Fc portion of IgG was designated Fc-mediated immune precipitation.

Animals↗

PubMed1996

Glaucoma with inflammatory precipitates on the trabecular meshwork: a report of Grant's syndrome with ultrasound biomicroscopy of precipitates.

BACKGROUND: The syndrome of inflammatory precipitates on the trabecular meshwork is a rare form of inflammatory glaucoma that was described by Chandler and Grant in 1968 and subsequently given the eponym Grant's syndrome. METHODS: We present two cases of elevated intraocular pressure associated with inflammatory precipitates on the trabecular meshwork in otherwise relatively quiet eyes, consistent with Grant's syndrome. We review the epidemiology, clinical features, and mechanism of this syndrome. In addition, we demonstrate the use of ultrasound biomicroscopy for imaging angle inflammatory precipitates. RESULTS: Our patients demonstrate the cardinal features of Grant's syndrome, including acute onset, significant elevation of tension, trabecular meshwork precipitates in an otherwise quiet eye, limited response to typical pressure lowering agents, excellent response to topical steroids, evidence of recurrence with bilaterality, and systemic association with sarcoidosis. Ultrasound biomicroscopy proves to be a useful adjunct for pathologic imaging. CONCLUSIONS: The syndrome of glaucoma with inflammatory precipitates on the trabecular meshwork is a rare entity that should be considered as a possible diagnosis of elevated intraocular pressures in otherwise apparently quiet eyes.

Female↗

PubMed1996

Comparison of ethanol plasma-protein precipitation with plasma ultrafiltration and trichloroacetic acid protein precipitation for the measurement of unbound platinum concentrations.

Sample preparation for the measurement of non-protein-bound platinum was evaluated by precipitation of plasma proteins with cold ethanol. The method was compared with the routinely used plasma ultrafiltration and with trichloroacetic acid (TCA) protein precipitation. After incubation of human plasma samples with cisplatin or carboplatin, unbound platinum concentrations were determined applying Amicon Diaflo ultrafiltration membranes and Millipore ultrafree-MC filters. For protein precipitation, 1 ml of cold (-20 degrees C) pure ethanol was added to 0.5 ml of human plasma and the supernatant was collected after 2 h, or 0.5 ml of cold 20% TCA was added to 0.5 ml of plasma. Platinum was analyzed by atomic absorption spectrophotometry (AAS). There was no significant difference between the ethanol and ultrafiltration methods in the unbound platinum concentration. The protein content in the supernatant (1.00 +/- 0.20%) was slightly higher than that in the Amicon (0.58 +/- 0.05%) and Millipore (0.55 +/- 0.04%) ultrafiltrates. On average, the TCA and ethanol method seemed to be equally appropriate. The ethanol precipitation method is concluded to be simple, convenient, and reproducible and has negligible costs.

Blood Proteins↗

PubMed1999

Homogeneous HDL-cholesterol assay versus ultracentrifugation/dextran sulfate-Mg2+ precipitation and dextran sulfate-Mg2+ precipitation in healthy population and in hemodialysis patients.

OBJECTIVES: To evaluate the analytical performance of a new homogeneous HDL-cholesterol assay (Olympus Diagnostica). To investigate possibly discrepant results in chronic hemodialysis patients who commonly exhibit quantitative and qualitative lipoprotein abnormalities, responsible for atherogenic complications in these patients. DESIGN AND METHODS: Serum samples were collected from 50 healthy subjects and 65 chronic hemodialysis patients. HDL-C levels measured by the homogeneous assay were compared with the routine dextran sulfate-Mg2+ precipitation method and the ultracentrifugation/dextran sulfate-Mg2+ precipitation as reference method. RESULTS: The homogeneous assay was linear up to at least 220 mg/dL. The analytical precision was estimated with three different sets of commercial controls and one set of human pooled serum control. The within-day CV ranged between 1.7% and 3.8% and the between-day CV ranged between 1.0% and 2.3%. HDL-C values in both populations correlated highly with the dextran sulfate-Mg2+ precipitation method and the ultracentrifugation/dextran sulfate-Mg2+ precipitation method (r > or = 0.96, bias between -0.9 and 2.3 mg/dL). Lipemia up to triglyceride concentration of 600 mg/dL did not alter the HDL-C value. CONCLUSIONS: The homogeneous assay for HDL-C (Olympus) uses much less sample, is accurate and convenient to handle, and allows full automation. The test should considerably facilitate the screening of individuals at an increased risk of cardiovascular disease, including hemodialysis patients.

Adult↗

PubMed2006

Influence of AgCl precipitates on the precipitation titration of sodium chloride by constant-current coulometry.

The precipitation titration of sodium chloride with electrogenerated silver ion was studied. The production of a precipitate of silver chloride had a significant effect on the titration results because the precipitate involved unreacted chloride or unreacted silver ion. The accuracy of the method was investigated by changing the introduction time of a sodium chloride solution to the coulometric cell during the process of electrolysis, and examining the dependency on the sample size. The accuracy of the measurement of the precipitation titration is discussed.

Automation↗

PubMed1995

In vitro and in vivo studies with different precipitate filter cartridges for H.E.L.P.-LDL-apheresis. Optimization of precipitate filter cartridges.

Heparin-induced extracorporeal LDL-precipitation has successfully been used in lowering high serum cholesterol in patients with coronary heart disease due to familial hypercholesterolemia. In the continuous search to improve treatment facilities we attempted to increase the filtration capacity of low density lipoprotein by the precipitate filter of the H.E.L.P.-system. Therefore, the nominal filtration area was varied by decreasing the pleat count as well as the configuration of the precipitation filter membrane. The device was tested in vitro using fresh frozen plasma from healthy donors as well as in vivo treating 6 patients suffering from familial hypercholesterolemia and 18 patients with the nephrotic syndrome. The data show that the drop in pressure on the filtration side depended on the filtration volume and the filter configuration. Reducing the pleat number and in parallel the nominal filtration area by replacing the standard support on the outside of the membrane by a double or triple thick support results in an increase in plasma volume which can be treated. The optimal results were obtained using filters with a nominal filtration area of 0.8 +/- 0.1 m2 and a triple thick support on the retention side compared to the standard configuration. Therefore, even patients with extreme plasma viscosity such as patients with the nephrotic syndrome can effectively be treated by heparin-induced LDL-precipitation.

Adult↗

PubMed1987

Precipitating and non-precipitating monoclonal antibodies against chicken avidin. Significance of epitope density.

1. Monoclonal antibodies, generated against chicken avidin, were characterized in Ouchterlony's immunodiffusion. 2. Of the nine antibodies three were non-precipitable but six could form clear visible precipitation lines with egg-white avidin in agarose gel. 3. The latter six antibodies could be divided into two groups according to their reactive pattern in immunodiffusion. 4. Antibodies belonging to the first group precipitated both dimeric as well as tetrameric avidin molecules, while those of the second group precipitated only the tetrameric avidin molecules. 5. The relevance of these results to the structure of avidin as well as possibilities to use monoclonal antibodies and the immunodiffusion technique to compare the structure of avidin induced by different factors are discussed.

Animals↗

PubMed2006

Influence of the precipitation agent in the deposition-precipitation on the formation and properties of Au nanoparticles supported on Al2O3.

Au nanoparticles supported on Al2O3 were prepared by deposition-precipitation of HAuCl4 with different precipitation agents NaOH and urea. The samples were investigated by means of different characterization techniques such as X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and transmission electron microscopy (TEM). The results show that depending on the precipitation agent, the Au particles have a different Au-Au coordination number and size after calcination at 523 K. Whereas the use of NaOH leads to the formation of Au nanoparticles with a Au-Au coordination number of 6.7 and a mean diameter below 2 nm, those prepared with urea have a mean size of 3.1 nm. The Au-Au coordination number could be determined as 8.6. At the smaller particles obtained with NaOH, hints for Au-O interactions were found. For these particles TEM results advise a rather flat lenticular morphology. Different deposition mechanisms depending on the precipitation agent are discussed as the reason for the formation of nanoparticles with different shapes, sizes, and valence states.

Journal Article↗

PubMed1979

Precipitating and non-precipitating complement consuming IgG subclass antibodies in pigeon breeders' disease.

The sera of patients with pigeon breeder's disease usually contain precipitating serum factors as well as human complement consuming factors as shown by incubation of the serum with pigeon dropping antigens. Although a single serum factor, possibly an IgG antibody, might account for both phenomena, affinity chromatography experiments revealed that the sera of patients with pigeon breeders' disease contain non-recipitating, human complement consuming, serum factors besides precipitating serum factors which are also capable of complement consumption. The non-precipitating serum factors most likely belong to the IgG3 immunoglobulin subclass, whereas the precipitating antibodies belong to the subclasses IgG1 and IgG2.

Alveolitis, Extrinsic Allergic↗

PubMed1986

Affinity precipitation of lactate dehydrogenase with a triazine dye derivative: selective precipitation of rabbit muscle lactate dehydrogenase with a procion blue H-B analog.

A simple methoxylated derivative of the triazine dye, Procion blue H-B, selectively precipitates rabbit muscle lactate dehydrogenase from solution. Optimum protein precipitation occurred at an enzyme subunit:dye ratio of approximately 2:1 and was fully reversible upon addition of competitive ligands such as NADH. With a crude extract of rabbit muscle, affinity precipitation with the dye followed by dissolution with NADH yielded homogeneous lactate dehydrogenase in 97% overall yield.

Animals↗

PubMed1990

An immunochemical analysis of precipitating and non-precipitating idiotype-anti-idiotype reactions.

Two monoclonal IgG3 syngeneic anti-idiotypes are described which form soluble and insoluble complexes with anti-alpha(1----6)dextran hybridoma and myeloma proteins. Specific precipitation was seen when purified anti-alpha(1----6)dextrans were added to ascitic fluid containing IgG3 kappa anti-idiotype. Analysis of the supernatants of the idiotype-anti-idiotype precipitates demonstrated the presence of soluble complexes whose mobilities in polyacrylamide gels could, in some cases, be distinguished from that of free anti-idiotype. An IgG1 kappa anti-idiotype is described which did not form precipitates with anti-alpha(1----6)dextrans unless 3% PEG 6000 was added.

Animals↗

PubMed1975

Some factors affecting fibrinogen precipitation by ristocetin: ultrastructure of precipitates.

Fibrinogen in aqueous solution is precipitated by the antibiotic ristocetin. This reaction is inhibited by albumin and facilitated by low temperature. Resolubilized fibrinogen clots in the presence of thrombin. Ristocetin-precipitated fibrinogen takes the form of fibrils or clumps, composed of irregularly spaced, structure-less particles. The addition of ristocetin to washed platelets suspended in fibrinogen-containing media produces fibrinogen clumps in both the media and in the surface cannalicular system of the platelets. The changes in light transmission (aggregation curves) are due to both platelet aggregation and fibrinogen clumping. The role of the latter is confirmed by the observation that the addition of ristocetin to inert latex particles suspended in fibrinogen solution produces typical aggregation curves. This phenomenon is prevented by the addition of albumin to the media. We conclude that (1) if fibrinogen is present in any artificial system, albumin should be included in the media to prevent fibrinogen precipitation; and (2) statements about aggregation of any particulated materials by ristocetin should not be based solely on light-transmission changes, but should also include a description of the morphologic appearance.

Blood Platelets↗