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PubMedDate not supplied

[Quantitative determination of proteins in the cytosol fractions of human and rat sex steroids after precipitation with protamine sulfate].

A simple procedure is developed for estimation of proteins after precipitation with protamine sulfate in cytosol fraction of human tissues-target dor sex steroids (prostate adenoma, cancer of prostate, mammalian gland cancer) and in similar target tissues of rats (ventral prostate and uterus). Human blood serum did not interfere with the protein estimation after the protamine sulfate precipitation. This method for estimation of protein using protamine sulfate might be critically important in calculation of the binding capacity of target-tissues with sex steroids (quantitative estimation of receptors), especially in human tissues because the interference of blood proteins is eliminated. The efficiency of the procedure developed was confirmed by comparative study of binding capacity of the tissues of prostate adenoma, cancer of prostate and mammalian gland cancer towards 3H-17 beta-estradiol and 3H-dihydrotestosterone, calculated per total protein and the protein precipitated by protamine sulfate.

Animals↗
PubMed1984

Studies on the procurement of coagulation factor VIII: selective precipitation of factor VIII with hydrophilic polymers.

Early work on the purification of factor VIII using polyethylene glycol (PEG) indicated that other polymers might also be used to precipitate factor VIII leaving fibrinogen in solution. Recently polyvinylpyrrolidone (PVP) has also been advocated for this purpose. In this study, different concentrations and molecular weights of hydroxyethyl starch, dextran, PEG, PVP, Ficoll, Percoll and albumin were examined for their ability to precipitate the factor VIII complex from cooled (not frozen) fresh CPD plasma. At optimal concentrations near quantitative recovery of VIIIR:Ag and VIII:CAg was achieved in 2 hr with minimal precipitation of fibrinogen or total protein. The best separations were observed with hydroxyethyl starch, albumin or Ficoll. PVP and PEG gave inferior purifications. Results for cryoprecipitate and intermediate-purity factor VIII concentrate were inferior to those obtained with plasma. Simple pre-concentration of plasma prior to chilling is an attractive alternative for large scale continuous production.

Chemical Precipitation↗
PubMed1984

Basic relationships in precipitating antigen-antibody systems: a comparison of a simple theory with experiment.

Theoretical predictions from a simple theory for a homogeneous system with respect to some fundamental functional relations between amount of precipitate or extent of turbidity, initial antigen (Ag) respectively antibody (Ab) concentration, and solubility of immune complexes (ICs) are discussed in comparison with experimental results in a heterogeneous system. Experiments were performed with the aim to render possible and intuitive picture of the relationships considering different aspects. It was found that the theory derived from the equilibrium state of the reaction is also able to describe the non-equilibrium state in a qualitatively correct manner. The influence of Ab affinity on precipitation is discussed. Moreover, it is shown that the theory developed by Pauling et al. in the 1940's although too simple in several details, does, however, consider the most important basic principles of more extensive theories developed by other authors. Precisely because of its simplicity, this model may be a useful help in the discussion of precipitate formation on a molecular level.

Antigen-Antibody Complex↗
PubMed1983

A comparative study of complement components in polyethylene glycol precipitated immune complexes from patients with ovarian cancer and patients with rheumatoid arthritis.

Circulating immune complexes and complement components C1q, C3 and C4 were measured following polyethylene glycol precipitation of serum from patients with ovarian cancer (OC), patients with rheumatoid arthritis (RA) and control patients (CP). The C3 and C4 content of the precipitated material was significantly greater in those patients with OC in comparison to those with RA or CP, while the C1q content did not differ significantly between the two groups of patients. A statistically significant correlation between IgG, C3 and C4 levels was found in the immune complexes of both groups of patients. C1q levels correlated significantly with IgG immune complex levels in patients with RA and CP, but did not in patients with OC. These data illustrate that immune complexes from patients with OC differ from complexes precipitated from RA sera and normal sera in their complement content. It is suggested that the largely unsuccessful attempts to detect immune complexes in sera from patients with ovarian cancer, using assays dependent on the binding of C1q may be related to differences in solubility of complexes from these patients in comparison to complexes present in non-neoplastic conditions.

Antigen-Antibody Complex↗
PubMed1980

Long-term immunotherapy with aqueous and aluminum-precipitated grass extracts.

The incidence of reactions and changes in specific IgE and IgG were measured during three to four years of immunotherapy with the aluminum-precipitated and glycerosaline grass extracts. Therapy with aluminum-precipitated extract resulted in far fewer local and systemic reactions and higher mean extract doses were obtained with this preparation. The decline in specific IgE was similar in both treatment groups. However, the higher individual and total doses in the group receiving the aluminum-precipitated extract were accompanied by significantly higher levels of specific IgG (blocking) antibody.

Aluminum↗
PubMed1981

[Monotypic IgM euglobulin precipitating upon exposure to air at room temperature].

A monoclonal lambda IgM euglobulin with peculiar precipitable characteristics in vitro was found in the serum of a patient with Waldenström macroglobulinaemia. The precipitation was observed at room temperature only when serum was exposed to air. Covalent disulphide bonds probably contribute to the mechanism involved in the formation of precipitate in this case.

Chemical Precipitation↗
PubMed1981

[HDL phospholipids determination after precipitation by concanavalin A (author's transl)].

The interest in the HDL phospholipids determination for cardiovascular disease investigations leads us to study its determination by an easy and accurate procedure: precipitation of lipoproteins bound to apo B with concanavalin A and determination of phospholipids in the supernatant by an enzymatic procedure. From our preliminary study, we refuse the heparin Mn Cl2 precipitation. Our method is compared with phosphotungstate Mg Cl2 precipitation procedure.

Chemical Precipitation↗
PubMed1981

Protein nitrogen unit precipitation procedure for allergenic extracts: collaborative study.

Protein nitrogen unit (NU) determination is one of the methods used to test and label the concentration of allergenic extracts. This recently standardized method is applicable to all allergenic extracts. One PNU/mL is equivalent to 1 X 10(-5) mg nitrogen determined to be in the material precipitated from 1 mL allergenic extract by phosphotungstic acid (PTA), a protein precipitant. The nitrogen is quantitated by the Kjeldahl method or another analytical method of equivalent accuracy and precision. A collaborative study of the optimized PNU precipitation method in which 6 samples were analyzed in duplicate by 6 laboratories using the Kjeldahl method for the determination of nitrogen yielded a mean of 0.1358 mg N/mL, a repeatability standard deviation and coefficient of variation of 0.0071 mg N/mL and 5.23%, respectively, and a reproducibility standard deviation and coefficient of variation of 0.0188 mg N/mL and 13.84%, respectively. The method has been adopted official first action.

Allergens↗
PubMedDate not supplied

Formation of precipitate in priming solutions for extracorporeal perfusion.

A precipitate observed in Hartman's solution used to prime a cardiopulmonary bypass circuit was identified as calcium carbonate. Analysis of the chemical equilibrium showed that the precipitation was caused by sodium bicarbonate added to prevent acidosis. Although this practice is acceptable for haemic primes, in which buffers and albumins will prevent precipitation, it should not be done with non-haemic primes prior to bypass.

Bicarbonates↗
PubMed1995

[Precipitation of pH-adjusted local anesthetics with sodium bicarbonate].

Sodium bicarbonate has been added to various local anesthetics for shortening the onset time. We often noticed the precipitate in the pH-adjusted local anesthetics several minutes after adding the bicarbonate. We confirmed that this drug interaction was caused by large changes in pH. We have analyzed the precipitates by mass spectrometry and infrared absorption spectrum and have revealed it as unionized base forms of local anesthetics. Since these forms tend to be insoluble, we must limit the amount of 7% sodium bicarbonate. This study proposes a guideline for adding 7% sodium bicarbonate to the various local anesthetics. The amount of 7% sodium bicarbonate which can be added to bupivacaine without precipitation is below 0.02 ml. In cases of mepivacaine and lidocaine, allowable amount of 7% sodium bicarbonate is 0.5 ml. It is not known whether this lower dose of 7% sodium bicarbonate compared with the recent reports is effective or not. Further clinical investigation may be necessary.

Anesthetics, Local↗
PubMed1977

Isolation and physical characterization of hyaluronic acid prepared from bovine nasal septum by cetylpyridinium chloride precipitation.

Raw extract in 2 m CaCl2 of bovine nasal septum cartilage was eluted from 4 per cent agarose gel to give a "void volume" Fraction v-4, which was indistinguishable in composition and behavior on viscometric and sedimentation analysis from the densest fraction obtained by associative centrifugation in a cesium chloride density gradient. The sulfated proteoglycan was precipitated (Fraction A) by cetylpyridinium chloride from acidic solutions of Fraction v-4 or of dialyzed raw ectract. Neutralization under conditions of low ionic strength precipitated a further small fraction (B), which contained from 0.5 to 1 per cent of the uronic acid in the original extract. Analysis by associative and dissociative density gradient centrifugation demonstrated that Fraction B resembled in effective density known samples of hyaluronic acid from other sources. Gel chromatography of proteolytic digests of Fractions A and B on 6 per cent agarose indicated that cetylpyridinium chloride precipitation essentially separated sulfated proteoglycan (A) from hyaluronic acid (B). A viscosity-average molecular weight of about 5 x 10(5) was estimated for a sample of Fraction B purified in a dissociative (4 M guanidine hydrochloride + CsCl) density gradient. Sedimentation velocity data were consistent with this result. Analysis of hexosamines showed that the sample contained 96 per cent glucosamine, confirming the identification of hyaluronic acid. The proteoglycan fraction (A) resembled "subunits" in its sedimentation behavior.

Amino Acids↗
PubMed1993

[Co-precipitation of pepsin with products from the enzymatic synthesis of peptides as a factor limiting the effectiveness of the enzyme].

Porcine pepsin behaviour during the synthesis of peptide p-nitroanilides and esters has been studied. In many cases, especially when long-chain peptides, such as Z-Ala-Ala-Phe-Leu-Ala-Ala-OMe, were synthesized, pepsin disappeared from the solution, being entrapped by the product precipitate rather than inactivated. Sorption of the enzyme on the product might be partially responsible for this effect. The active enzyme could be eluted from the precipitate by NaCl and isopropanol. Non-proteolytic proteins (lysozyme, bovine albumin, carbonic anhydrase) could also co-precipitate with pepsin.

Amino Acid Sequence↗
PubMed1977

[On precipitation in clinical dextran solutions (author's transl)].

Dextran precipitation has the same molecular weight distribution as the raw material. However, there are also high molecular shares of associates (aggregates). Precipitation which can be caused by change of temperature passes three stages: 1. Formation of dextran associated. 2. Growth of a dextran film (micro gel) 3. Exsiccation and precipitation.

Chemical Precipitation↗
PubMed1976

The conformational requirements for the mechanical precipitation of hemoglobin S and other mutants.

The mechanical stability of human hemoglobin mutants was studied for the specific effects of single and double amino acid substitutions, the ligand state of each chain, and the effect of hybrids between oxy and cyanmet partners on precipitability. It was found that the beta6Glu leads to Val and the beta73 Asp leads to Asn mutations increased the degree of mechanical precipitation in the liganded but not in the deoxy form. When these mutations occurred on the same chain, the effects were approximately additive. Heat labile mutants such as Hb Gun Hill and Hb Leiden exhibited mechanical instability, but probably through a different mechanism, as very little dependence on ligand state was apparent. Studies with valency hybrids of HbS(alpha2 betas2-and-alpha2 betas2 where = cyanmet) revealed that instability was primarily determined by the state of the betas chain, which must be liganded to confer instability on the tetramer. A good agreement between surface activity and mechanical precipitability of these mutants has been found.

Chemical Precipitation↗
PubMed1976

Serum factors precipitating with bovine lens extract in cataract patients and noncataract patients.

The present study tested the assertion that there exists exclusively in persons with senile cataracts a serum factor capable of precipitating with gamma crystallin extract from bovine lens. The results of this work do not support this assertion without the imposition of rigid specifications regarding test solution concentrations and observation time. Among the 84 subjects tested, 2 individuals had posterior subcapsular cataracts. The precipitates resulting from incubation with serum from these individuals were similar to those resulting from incubations with serum from senile cataract patients. The present study did not confirm the existence of exclusive serum factors capable of precipitating with gamma crystallin extract in patients with senile cataracts.

Adult↗
PubMed1976

Effect of platelet antiserum on the precipitation of soluble fibrin by endotoxin.

Rabbits were injected with a platelet antiserum to examine the role of thrombocytopenia of the precipitation of soluble fibrin by endotoxin.dotoxin. Platelet antiserum removed more than 98% of the circulating platelets, and the resulting thrombocytopenia with platelet counts below 10,000 per mul persisted during the entire 10 hr-period of the experiment. Leukocyte counts were not significantly influenced by the platelet antiserum. Since the rabbits were treated with high doses of heparin, activation of intravascular coagulation by the antiserum did not occur. Precipitation of soluble fibrin was achieved by injection of endotoxin into rabbits with ancrod-induced circulating soluble fibrin. Thrombocytopenia did not prevent the occurrence of glomerular microclots after ancrod and endotoxin administration. On the contrary, if endotoxin was injected into antiserum- and heparin-treated rabbits with circulating soluble fibrin, glomerular microclot formation occurred even in a higher percentage than in control rabbits treated with absorbed platelet antiserum. This investigation indicates that platelet antiserum-induced thrombocytopenia does not protect against precipitation of soluble fibrin by en

Ancrod↗
PubMed2000

Streamlined synthesis of substituted 2-aminothiazoles using tandem precipitative and polymer-assisted reactions.

The tactical combination of classical product precipitation and subsequent modification of precipitated products using polymer-assisted transformations has been employed in the preparation of substituted 2-aminothiazole derivatives. 2-aminothiazoles were precipitated in parallel as hydrobromide monohydrate salts, directly redissolved, and reacted further using polymer-supported reagents to afford free-based 2-aminothiazoles, aminothiazoyloxamates, and aminothiazoylamides.

Antiviral Agents↗
PubMed1998

Apatite precipitation after incubation of biphasic calcium-phosphate ceramic in various solutions: influence of seed species and proteins.

The dissolution-precipitation process for calcium-phosphate ceramics in contact with biological fluid was studied by incubating blocks of biphasic calcium phosphate composed of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) in different solutions: ionic simulated body fluid (SBF) without protein or SBF that contained various proteins and macromolecules separately (fibronectin, vitronectin, albumin, and poly-L-glutamic acid). Transmission electron microscopy studies revealed that apatite-precipitated microcrystals appeared around ceramic crystals as a result of secondary nucleation; microcrystals were in continuity with the lattice planes of the HA crystals but in a different direction from that of beta-TCP; the size of the precipitates was smaller when fibronectin, vitronectin, and poly-(L-glutamic acid) were present in SBF as compared to SBF without protein; and fibronectin and vitronectin initiated crystal nucleation in the void spaces between the ceramic crystals.

Apatites↗