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At least 1,621 records · Page 90Linked to original sources
PubMed1983

Characterization of DNA in polyethylene glycol precipitated immune complexes from sera of patients with systemic lupus erythematosus.

The nature and the quantity of DNA present in the circulating immune complexes (ICs) from 30 patients with systemic lupus erythematosus (SLE) was characterized. DNA was extracted from IC enriched material prepared by polyethylene glycol precipitation of serum and the extracted DNA was labelled with 32P-phosphate. The size and the nature of DNA was determined by polyacrylamide gel electrophoresis and autoradiography. The quantity of DNA in the PEG precipitates from sera of 10 clinically active SLE was found to be significantly higher (mean 159 X 10(4) ct/min, range 49.9-807 X 10(4) ct/min) than 10 normal controls (mean 24.7 X 10(4) ct/min, range 8.7-47.8 X 10(4) ct/min). Four different sizes of DNA fragments were detected: 370-470, 150-240, 30-40 and 20 base pairs (bp). DNA of 30-40 bp and 20 bp were frequently present in both SLE and normals, but the other two large sized DNA fragments were particularly prominent in SLE patients. In the majority of samples, DNA fragments appeared double stranded.

Antigen-Antibody Complex↗
PubMed1983

A simple specific method for precipitation of low density lipoproteins.

A simple method is described for precipitation of low density lipoproteins. The results correlate well with those from ultracentrifugation in combination with polyanion precipitation (135 +/- 35 vs 136 +/- 35, r = 0.984, n = 13) or quantitative lipoprotein electrophoresis (r = 0.9287, n = 6394). In addition to lipoprotein analysis, this method may be used for the extracorporeal elimination of plasma low density lipoproteins.

Adult↗
PubMed1978

[Use of the light-dispersion spectroscopy for detection of the precipitation reaction].

The light beating spectroscopy technique was used to detect the precipitation test. The system consisting of human serum globulin--rabbit antiserum against human globulins was studied. A possibility of detecting the precipitation test for much more diluted systems of the antigen and antibody by means of the light beating technique than by the routine visual method was demonstrated.

Animals↗
PubMed1982

Complement-induced solubilization of C-reactive protein-pneumococcal C-polysaccharide precipitates: evidence for covalent binding of complement proteins to C-reactive protein and to pneumococcal C-polysaccharide.

Insoluble precipitates between C-reactive protein and pneumococcal C-polysaccharide were solubilized by fresh but not heat-inactivated human serum. Solubilization was dependent on the C-reactive protein to C-polysaccharide ratio and the serum concentration and proceeded optimally at 37 degrees C. On 12 to 30% sucrose density gradients solubilized complexes sedimented as a broad peak between the 7S region and the bottom of the tube. In C2-deficient human serum, solubilization was delayed by 30 min and then proceeded at a slow rate. Immunoprecipitation experiments indicated that C3, C4, C5, and to a lesser extent C1q were deposited on solubilized complexes. After dissociating solubilized complexes with EDTA, a considerable percentage of C-polysaccharide coprecipitated with C3, C4, and C5, whereas C-reactive protein coprecipitated with only C3. SDS-PAGE analysis of solubilized precipitates indicated the formation of covalent complexes between fragments of C3 and both C-polysaccharide and C-reactive protein.

C-Reactive Protein↗
PubMed1982

The polyethylene glycol precipitation technique and the particle-counting immunoassay for detection of circulating immune complex-like material in liver cirrhosis and septicemia.

Both the PEG-N technique and the PACIA were applied to determine ICLM in sera from patients with liver cirrhosis and gram-negative septicemia, that have been shown to yield positive reactions for endotoxemia with the LAL test. The precision of the PEG precipitation technique, with a stabilized fraction of human HAG of known molecular size used as a calibrator, was satisfactory. In liver cirrhosis, the detectable ICLM was mainly composed of IgG and C3, whereas in gram-negative septicemia IgM, IgG, and C3 were found. PACIA also measured significantly elevated levels of ICLM with rheumatoid factor-binding activity in both patient groups, although the two assay systems did not correlate. PEG precipitates from both patient groups analyzed by gel-chromatography and passive hemolysis test contained large immune aggregates and various amounts of immunoglobulins with specificity directed toward lipid A, the least variable portion of endotoxin. These compositional differences of detected substances may imply the presence of different types of ICLM in patients with liver cirrhosis and gram-negative septicemia.

Antigen-Antibody Complex↗
PubMed1982

High-density lipoprotein subfractions as measured by differential polyanionic precipitation and rate zonal ultracentrifugation.

Recent interest in the putative protective role of high-density lipoprotein (HDL) and its subfractions against atherosclerosis has highlighted the need for a rapid, simple subfractionation procedure. Here we compared HDL subfractionation by two recently developed polyanionic-precipitation methods with the values obtained by rate zonal ultracentrifugation. A similar result for total HDL cholesterol was obtained by all three methods. However, HDL2 cholesterol as measured by the precipitation procedures was significantly higher than the zonal value, and HDL3 was lower. This reflects the different underlying principles involved in the separations and highlights the need for a clearer understanding of the functional roles of the HDL fractions.

Adult↗
PubMed1982

[Carbohydrate content of lipoproteins after sequential precipitation with phosphotungstate magnesium chloride].

A method is described for rapid determination of protein-bound carbohydrates in human lipoproteins. The method is based on a successive precipitation of lipoproteins with sodium phosphotungstate and magnesium chloride. After purification of the separated lipoproteins by a twofold reprecipitation, a colorimetric determination of hexoses, hexosamines and N-acetylneuraminic acid (sialic acid) is performed. The coefficients of variation in the series are between 3.2% and 7.3%. The results for lipoprotein-bound carbohydrates after precipitation are compared with the corresponding values after separation by ultracentrifugation. The concentrations of hexoses, hexosamines and N-acetylneuraminic acid in the 3 lipoprotein classes VLDL, LDL and HDL of control persons are reported.

Carbohydrates↗
PubMed1980

[Nature of fibrinogen B-soluble fibrin monomer complexes precipitable by ethanol and 2-naphthol].

The molecular composition of fibrinogen B, which is formed after addition of 2-naphthol solution in ethanol to pathological blood plasma was studied. The precipitate was found to contain native fibrinogen as well as fibrin monomer possessing fibrinopeptides B. Some proteins similar to the molecular forms of cold-insoluble blood plasma globulin were revealed. The data obtained suggest that fibrinogen B represents soluble complexes of monomeric fibrin with fibrinogen and probably with cold-insoluble globulin. The mechanisms of formation of these complexes and their precipitation by ethanol and 2-naphthol are discussed.

Chemical Precipitation↗
PubMed1994

A case presentation: precipitate in the central venous line: what went wrong?

Occlusion of small-bore central venous lines with a calcium/phosphate precipitate during medication administration is a concern for NICUs attempting to provide adequate nutrition for extremely low birth weight infants. This case presentation provides data for and reports the investigation of one central venous line precipitation incident. It also examines calcium/phosphate solubility in parenteral nutrition solutions and explores the effects of heparin, aminophylline, and L-cysteine on solubility. The role of L-cysteine as an essential amino acid for neonates is addressed, and recommendations for reducing the likelihood of a central venous line occlusion are given.

Aminophylline↗
PubMed1994

The distribution of calcium salt precipitates in the core, periphery and shell of cholesterol, black pigment and brown pigment gallstones.

Calcium bilirubinate, palmitate, carbonate and phosphate have been identified in the cores of cholesterol and pigment gallstones, suggesting a role for precipitated calcium salts in the early events of gallstone formation. Previous studies that compared the calcium salt contents of cholesterol and pigment stones required destruction of gallstone structure. We have used scanning electron microscopy with windowless energy-dispersive x-ray microanalysis to determine the prevalence of calcium salts in a series of cholesterol (n = 105), black pigment (n = 35) and brown pigment (n = 6) gallstones obtained from 146 consecutive patients undergoing cholecystectomy. These techniques provide specific identification of cholesterol and individual calcium salts as they occur within the core, periphery and shell of gallstones without destroying stone structure. Calcium precipitates more than 0.5 micron in diameter can be detected in a cholesterol background at a detection limit of 0.01% by weight. Calcium salts were detected in the centers of 88% of cholesterol and 100% of black (p < 0.05 vs. cholesterol) and brown pigment stones. Calcium bilirubinate was identified in the cores of 54% of cholesterol and in all pigment stones (p < 0.001 black pigment vs. cholesterol). Calcium palmitate was detected in all brown pigment stones, in 39% of cholesterol stones (p < 0.001 vs. brown pigment) and in 31% of black stones (p < 0.01 vs. brown pigment). Peripheral calcium salts were detected less in cholesterol (19%) than in black or brown stones (100%, p < 0.05). Fourteen percent of cholesterol and black pigment stones were surrounded by shells containing mostly calcium carbonate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

[Contraceptive hormones, vascular risk and abnormal precipitation of serum gamma-globulins (author's transl)].

The monoclonal anti-ethinyl-estradiol antibody previously found in the serum of a woman on oral contraceptives, was precipitated by 25% saturated ammonium sulfate à 22 degrees C. This simple test has been used to investigate the possible relationship between abnormally precipitating gamma-globulins (GAP) and the vascular risk of the pill. Four groups of women were studied: --50 women who had never used the pill; --100 women on oral contraceptives; --30 women who had stopped the pill; --17 women had experienced venous or arterial thrombosis during oral contraception. The results obtained indicate: 1) that a GAP increase is nearly always associated with the thrombotic events (90% of the cases in group 4); 2) that the presence of GAP is seen only in part of the women population on oral contraceptives representing approximately 30% of the total population investigated as indicated by a bimodal distribution. 3) that the GAP remain increased for months and even years after the pill was discontineud. The significance of this test is discussed. It is proposed that the presence of GAP in the serum appears to be related to the presence of ethinyl-estradiol binding antibodies. This hypothesis is verified by experiments in progress.

Adolescent↗
PubMed1996

Low dose aspirin in patients with ischemic heart disease may precipitate secondary myocardial infarction.

We conducted a retrospective case-control study to compare the frequency of myocardial infarction (MI) or unstable angina (UA) precipitated by aspirin-induced upper gastrointestinal (GI) bleeding among patients with and without ischemic heart disease(IHD), and to determine whether the risk of MI or UA is related to the hemoglobin level on admission. Of the 51 patients admitted to the hospital between 1987 and 1994 because of aspirin-induced upper GI bleeding, 33 had ischemic heart disease. The prevalence of MI and UA inpatients with IHD and aspirin-induced upper GI bleeding was significantly higher than in patients without IHD (42% vs. 5.5% respectively) (P < 0.005). Of the patients with upper GI bleeding and a hemoglobin concentration of 5-8 g/dl, 75% had either MI or UA in comparison to 50% and 18% of the patients with hemoglobin concentrations of 8-10 and 10-14 g/dl respectively. We conclude that low dose aspirin therapy may precipitate MI or UA, especially in patients with IHD, by inducing upper GI bleeding. Patients with IHD who use low dose aspirin to prevent MI should be instructed how to identify emerging symptoms of peptic ulcer as well as the initial signs of upper GI bleeding. Early diagnosis and treatment of these patients might prevent the induction of secondary MI or UA.

Aged↗
PubMed1996

Calcium in milk products precipitates intestinal fatty acids and secondary bile acids and thus inhibits colonic cytotoxicity in humans.

Dietary calcium may reduce the risk of colon cancer, probably by precipitating cytotoxic surfactants, such as secondary bile acids, in the colonic lumen. We previously showed that milk mineral, an important source of calcium, decreases metabolic risk factors and colonic proliferation in rats. We now report the effects of the habitual intake of milk calcium on metabolic risk factors in healthy subjects. A double-blind, cross-over metabolic study was performed in 13 healthy males. Placebo milk products (calcium, 3 mM) were compared with regular milk products (calcium, 30 mm). In each 1-week period, the habitual diet was recorded, and urine and feces were collected for 1 and 3 days, respectively. Milk calcium significantly increased fecal pH and fecal excretion of phosphate (132%), total fat (139%), free fatty acids (195%), and bile acids (141%), indicating intestinal complexation. In fecal water, the concentrations of long-chain fatty acids, secondary bile acids (deoxycholic and lithocholic acid), neutral sterols, and phospholipids were about halved (P <0.05). Consistent with these changes in soluble hydrophobic surfactants, calcium decreased the cytotoxicity of fecal water from 68 +/- 9 to 28 +/- 12% (P < 0.005). Calcium in milk products precipitates luminal cytotoxic surfactants and thus inhibits colonic cytotoxicity. Therefore, habitual dietary calcium may contribute to a nutritional modulation of colon cancer risk.

Adult↗
PubMed1992

[Micronization of phenytoin by precipitation].

Phenytoin was micronized by precipitation from its ammonia, ethanol, propanol, isopropanol and glacial acetic acid solutions. The precipitation was accomplished by either solvent evaporation, cooling of the solution or water addition into organic solvent solutions. The smallest particle size was obtained by evaporation of 20% ammonia solution.

Chemical Precipitation↗
PubMedDate not supplied

[Contraceptive hormones, vascular risk and abnormal precipitation of serum gamma-globulins (author's transl)].

The monoclonal anti-ethinyl-estradiol antibody previously found in the serum of a woman on oral contraceptives, was precipitated by 25% saturated ammonium sulfate à 22 degrees C. This simple test has been used to investigate the possible relationship between abnormally precipitating gamma-globulins (GAP) and the vascular risk of the pill. Four groups of women were studied: --50 women who had never used the pill; --100 women on oral contraceptives; --30 women who had stopped the pill; --17 women who had experienced venous or arterial thrombosis during oral contraception. The results obtained indicate: 1) that a GAP increase is nearly always associated with the thrombotic events (90% of the cases in group 4); 2) that the presence of GAP is seen only in part of the women population on oral contraceptives representing approximately 30% of the total population investigated as indicated by a bimodal distribution; 3) that the GAP remain increased for months and even years after the pill was discontinued. The significance of this test is discussed. It is proposed that the presence of GAP in the serum appears to be related to the presence of ethinyl-estradiol binding antibodies. This hypothesis is verified by experiments in progress.

Adolescent↗
PubMed1977

[Enzyme diagnosis in lipaemic sera before and after polyanion precipitation with heparin and magnesium chloride (author's transl)].

The method for the determination of enzymic activity in turbid, lipaemic sera, which involves clearing by polyanion precipitation with heparin and magnesium chloride, was critically reviewed. In the diagnosis of diseases of the liver and pancreas, which are frequently associated with hyperlipoproteinaemia, only residual enzyme activities are measured in the cleared serum after polyanion treatment. In the measurement of glutamate dehydrogenase and in the Phadebas test for alpha-amylase, the enzymes are inactivated by treatment with heparin and magnesium chloride. On the other hand, as a result of polyanion precipitation gamma-glutamyl transferase is transferred, together with lipoproteins and chylomicrons, to the lipid-rich supernatant. Acid phosphatase also exhibits only residual activity in cleared serum. The activity of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, leucine arylamidase, cholinesterase, creatine kinase, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase, and the activity of alpha-amylase in the Merckotest are not affected by polyanion treatment of the serum.

Anions↗
PubMed1998

[Determination of fibrinogen levels in the horse with the heat-precipitation methods of Schalm and Millar].

The purpose of this study was to investigate the usefulness of two heat-precipitation techniques (Schalm- and Millar-method) as screening tests to measure plasma fibrinogen concentration in horses. Based on the measurement of samples from 108 different horses, the coefficient of correlation (CC) for the relationship between the results with the Schalm- and with the reference-method (Jacobsson) were much lower (r = 0.78) than between the Millar- and Jacobsson-method (r = 0.94). Furthermore the Schalm-method was less precise as reflected by the greater coefficient of variation (CV, within-run precision) with a sample of low-limit fibrinogen concentration (CV = 47.4 %) and with a sample of high fibrinogen concentration (CV = 35.6 %) than the Millar-method (CV = 11.1 resp. 2.9 %). In 40 healthy horses, aged 3 to 19 years, fibrinogen values ranged from 1.82 to 4.94 g/l (2.5-97.5 %-quantil). The Millar-Method is recommended as a simple and suitable heat-precipitation assay for fibrinogen determination in the horse.

Animals↗
PubMed1980

Life events and depressive disorder reviewed. II. Events as precipitating factors.

I reviewed studies examining the hypothesis that life events may precipitate a depressive disorder. Although some contradictory results exist, the majority of studies demonstrate that depressed patients experience more stressful events in the months that precede the onset of their disorder than do normal controls or schizophrenics. In calculating relative risk figures, it seems that depressive risk is increased by a factor of about 5 or 6 for the six months after an event. Certain events, such as undesirable, loss, or severely threatening events, are particularly likely to precede a depression. These results suggest that stressful events can bring about depressive episodes, but most of the evidence that supports this conclusion emanates from retrospective studies, and corroborating prospective studies are definitely needed. Furthermore, not all depressives report precipitating events, so other causal factors are also operative.

Adjustment Disorders↗