Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PRECIPITATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed1976

Study of the circumoval precipitate in Schistosomiasis japonica by immunofluorescent technic.

The 48-hour circumoval precipitates formed by infected human and rabbit sera on lyophilized Schistosoma japonicum eggs were stained with the corresponding fluorescein-labelled monospecific goat antisera for study under a fluorescent microscope. The three major Ig classes were found to participate in the formation of the precipitate, with major components being IgG and IgM; IgA participated least. IgE and C3 also contributed to the precipitate. The circumoval precipitate on S. japonicum eggs is therefore a complex of different immunoglobulins reactive with antigen(s) from the egg.

Fluorescent Antibody Technique↗
PubMed1975

Physical-chemical properties of precipitated and fractionated allergens from Mycobacterium bovis.

Seven allergens were prepared from cultures of Mycobacterium bovis. The culture filtrates were divided in half and each aliquot precipitated with either ammonium sulfate or trichloroacetic acid to prepare purified protein derivatives (PPD). These samples of PPD-bovis were analyzed for nitrogen, carbohydrate, RNA and DNA. Physical tests, such as: cellulose acetate electrophoresis, disc gel electrophoresis, ultracentrifugation, isoelectricfocusing and gel filtration were also performed. Precipitation with ammonium sulfate provided PPD's with less impurities than those precipitated with trichloroacetic acid although there was little difference in the allergenic activity of the products precipitated by either method. Several lots of PPD-bovis were fractionated by means of ultrafiltration and the fractions analyzed by many of the above chemical and physical tests as well as tests for amino acid composition and allergenic activity. The greatest amount of protein was found in the fractions with an apparent molecular weight in excess of 300,000. The carbohydrate was usually distributed in proportion to the amount of protein in each fraction while the nucleic acids were predominately found in the higher molecular weight fractions. The amino acid analysis and allergenic activity of the various molecular weight fractions provided data that would support the theory that the various fractions are polymers of a small molecular weight sub-unit. The number of amino acid residues were calculated and the minimum molecular weight of the tubercular protein estimated to be 8700. The estimated molecular weights of the fractions and the amino acid data concur with those previously reported for proteins from other mycobacteria.

Allergens↗
PubMed1975

Immune precipitation of immunoglobulin producing polysomes from mouse myeloma cells.

MPC-11 myeloma cells synthesizing IgG were labeled in vitro with 3H-uridine and the cell lysates, or purified polysomes treated with rabbit antiserum against the purified MPC-11 protein. The specificity of the immune precipitation was tested by rabbit anti-egg albumin and by precipitation of polysomes from "non-producer" myeloma and HeLa cells. The specific precipitation was 10 to 15% of the total cytoplasmic RNA for the IgG-producing clone of MPC-11 and about 2% for the non-producer clone or HeLa cells. Up to 20% of the total polysomal and ribosomal RNA were precipitated from the IgG producing clone. This value correlated with the IgG synthesis of these cells which is also about 20% of the total protein produced. The results suggest that myeloma cells produce a relatively large quantity of IgG due to the presence of a large amount of specific m-RNA molecules.

Animals↗
PubMed2002

WMO questionnaire on recording precipitation gauges: state-of-the-art. World Meteorological Organization.

To receive information on recording precipitation gauges used operationally by national meteorological services the World Meteorological Organization started a worldwide inquiry. This included the type of recording precipitation gauge (RPG), their manufacturer, measuring system applied, number of RPGs used, methods of recording and data transmission, orifice area size and installation heights, heating and windshield application as well as the question on the need to organising global intercomparisons of RPG measurements. The results of the 118 responses received (out of 180 countries) are presented and discussed. They show that there is a great variety in instruments and methods of observation of precipitation intensity used not only worldwide but also in the same country. This variety exceeds by far the variety in manual standard precipitation gauges.

Data Collection↗
PubMed2002

The effect of preincubation of seed crystals of uric acid and monosodium urate with undiluted human urine to induce precipitation of calcium oxalate in vitro : implications for urinary stone formation.

BACKGROUND: Previous studies demonstrated that crystals of uric acid (UA) and sodium urate (NaU) can induce the precipitation of calcium oxalate (CaOx) from its inorganic metastable solutions, but similar effects have not been unequivocally shown to occur in urine. The aim of this investigation was to determine whether preincubation of these seeds with urine alter their ability to induce deposition of CaOx from solution and thus provide a possible explanation for discrepancy of results obtained from aqueous inorganic solutions and undiluted urine. MATERIALS AND METHODS: The effects of commercial seed crystals of UA, NaU and CaOx (6 mg/100 ml) on CaOx crystallization were compared in a solution with the same crystals that had been preincubated for 3 hours with healthy male urine. A Coulter Counter was used to follow the crystallization and decrease in soluble (14) C-oxalate was measured to determine the deposition of CaOx. The precipitated particles were examined by scanning electron microscopy (SEM). The preincubated seeds were demineralized and proteins released were analyzed by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: Analysis of (14) C-oxalate data revealed that while treated UA seeds did not affect CaOx deposition, those of NaU and CaOx inhibited the process by 51.9 (p<0.05) and 8.5% (p<0.05) relative to their respective untreated counterparts. Particle size analysis showed that the average modal sizes of particles precipitated in the presence of treated seed crystals of UA, NaU, and CaOx were very similar to those deposited in the presence of their respective untreated controls. These findings were confirmed by SEM which also showed that seed crystals of UA and NaU, untreated and treated, were attached like barnacles upon the surfaces of CaOx crystals which themselves were bigger than those precipitated in the presence of CaOx seeds. SDS-PAGE analysis of the demineralized treated seeds showed that they all selectively adsorbed urinary proteins, and perhaps other urinary macromolecules and low molecular weight components, on their surface. CONCLUSIONS: It was concluded that preincubation with urine, such as occurs in vivo, only slightly reduces the ability of seed crystals of CaOx, but not of UA, to cause deposition of CaOx. The most striking effect was on NaU seeds where the preincubation quite dramatically attenuated their promotory effect on the mineral deposition. This may explain the discrepancy between findings of studies carried out in inorganic solutions and undiluted human urine. This stresses the invalidity of directly extrapolating results obtained in inorganic solutions to likely effects in urine and more importantly, on stone formation.

Calcium Oxalate↗
PubMed1992

Precipitation of asthma attacks in Melanesian adults by sodium metabisulphite.

Seven Melanesian asthmatic patients were challenged with substances that have been shown to precipitate asthma attacks in asthma patients in developed countries. Patients were challenged in a double-blind fashion using placebo and active substances. The active substances were tartrazine, sodium metabisulphite, aspirin and betel nut. All 7 patients were challenged with tartrazine and sodium metabisulphite; 5 were challenged with aspirin also, but only 2 were challenged with betel nut. Asthma attacks were precipitated by sodium metabisulphite in 3 patients. No other substances precipitated asthma. As sodium metabisulphite is a common food additive, these results suggest that processed foods introduced into developing countries may have an important role in precipitating asthma attacks in susceptible persons.

Adult↗
PubMed2003

Precipitants of psychiatric patient assaults on staff: preliminary empirical inquiry of the Assaulted Staff Action Program (ASAP).

Although there has been extensive empirical research on the characteristics of psychiatric patient assailants and their staff victims, there has been a dearth of empirical research on the nature of the precipitants of these patient/staff interactions. Building on the few earlier studies, this year-long, retrospective, empirical study of patient precipitants was conducted within the context of the Assaulted Staff Action Program (ASAP) in ten public sector health care facilities. Excessive sensory stimulation, staff restrictions on patient behaviors (restraints), and acute psychosis were the most frequently occurring precipitants. There were no specific patterns to patient assailant and staff victim characteristics by assault precipitant. The implications of this study and future research needs are addressed.

Adolescent↗
PubMed2006

Precipitants of psychiatric patient assaults on staff: three-year empirical inquiry of the Assaulted Staff Action Program (ASAP).

Patient violence toward health care staff is a complex function of person x event x environment model. Thirty-five years of research on the characteristics of patient assailants and staff victims has yielded no predictive markers and researchers are examining other possible components of the model. The precipitants, or motivation, for assaults is one area of inquiry. Although research to date has been sparse, acute psychosis, excessive sensory stimulation, and staff restrictions on patient behaviors (denial of services, privileges, etc.) appear to be common precipitants. This paper continued this inquiry over a three-year period. The most common precipitants were denial of services, acute psychosis, and excessive stimulation. No statistically significant interactions were obtained for patient / staff victim variables and these precipitants.

Adolescent↗
PubMed1991

Precipitation with polyethylene glycol and density-gradient ultracentrifugation compared for determining high-density lipoprotein subclasses HDL2 and HDL3.

The purpose of this study was to compare quantification of cholesterol in high-density lipoprotein subfractions HDL2 and HDL3 by precipitation with polyethylene glycol (PEG) with that by density-gradient ultracentrifugation. Fresh serum samples from 32 fasting, obese children were analyzed with precipitation reagent "Quantolip" (Immuno AG), and then fractionated with a Beckman TL 100 ultracentrifuge with a swinging-bucket rotor. After centrifugation we carefully removed the supernate with a syringe and measured the cholesterol from each fraction enzymatically with CHOD-PAP reagent (Boehringer Mannheim). The low-density lipoprotein (LDL-), HDL2-, and HDL3-cholesterol values measured by ultracentrifugation did not differ significantly from those obtained by precipitation; the correlation coefficients (r) between the two methods were 0.96 for LDL, 0.75 for HDL2, and 0.96 for HDL3. The relatively simple PEG precipitation method used in this study measures total HDL and its major subclasses HDL2 and HDL3 with accuracy and precision comparable with those of the well-established ultracentrifugation method.

Adolescent↗
PubMed1979

[Experiments to obtain and test a cell-culture rotavirus-precipitating antigen].

The location of the rotaviral precipitating antigen and the possibility for its production from cattle rotaviral strains adapted on cell cultures of calf kidney were investigated. Highest titer antigen was produced by concentration with ammonium sulfate simultaneously from the maintaining medium and from the cell monolayer. Comparative studies on the antigenic and physico-chemical properties of the cell-cultural and the faeces rotaviral precipitating antigen were made. The identity of both antigens was proven by the immunodiffuse reaction and by their resistance to ether and tripsine. A considerably higher temperature sensitivity was established of the cell-cultural precipitating antigen as compared to that from faeces. The precipitating antigen was used for confirming the presence of antirotaviral antibodies in the serums of cattle, man and sheep.

Animals↗
PubMed1986

[Precipitating monoclonal antibodies to 1 of the antigenic determinants of streptococcal group-A polysaccharide].

Monoclonal antibodies (MCA) to streptococcal group A polysaccharide (A-PS) were prepared. Precipitating MCA are directed to the determinant common for A-PS and streptococcal group L polysaccharide (L-PS). The antibodies react in the immunodiffusion test and give identity reaction in A- and L-PS tests. Other MCA are non-precipitating but react with A-PS studied by immunoenzyme method. The reasons for the formation of precipitating and non-precipitating MCA to different antigenic determinants of A-PS are discussed.

Animals↗
PubMed1987

[Mixed gel precipitation in the analysis of monoclonal antibodies against determinants of the carcinoembryonic antigen].

Mixed gel precipitation technique was used in the study of 5 monoclonal antibodies (MA) to carcinoembryonic antigen (CEA). The method is based on specific inclusion of MA into the precipitate formed by the antigen and polyclonal antibodies to it. The test-system for the determination of nonspecific cross-reacting antigen (NCA) has demonstrated that MA 2D10 are directed to the determinant, common for CEA and NCA, whereas MA 3C12 and 2G10 give no reaction with NCA. The specificity of MA 192 and 35 correlated with the previously established one. Mixed gel precipitation technique is recommended for primary screening and study of MA specificity to any precipitating antigen.

Animals↗
PubMed1988

Butorphanol-precipitated withdrawal in opioid-dependent human volunteers.

The subjective, physiological and behavioral effects of hydromorphone, naloxone and butorphanol, an opioid agonist/antagonist analgesic, were studied in adult, male, methadone-dependent volunteers living on a clinical research ward. Drug conditions included saline placebo, 4 and 8 mg of hydromorphone HCl, 0.375, 0.75, 1.5, 3 and 6 mg of butorphanol tartrate and 0.1 and 0.2 mg of naloxone HCl. Drug conditions, given by i.m. injection, were tested in five subjects under double-blind conditions in 2.5-hr experimental sessions. Physiologic measures and subject- and observer-rated behavioral responses were measured before dosing and for 2 hr after drug administration. Hydromorphone decreased pupil diameter, and significantly increased ratings of "Good Effects" on the subjective measures. Naloxone precipitated opioid abstinence which was measurable on several subject- and observer-rated behavioral measures and physiological measures. Butorphanol produced effects which were generally similar to the effects of naloxone, indicating that butorphanol doses precipitate withdrawal signs and symptoms when administered to methadone-dependent humans. There were some differences in the withdrawal syndromes precipitated by naloxone vs. butorphanol, suggesting that multiple mechanisms may be involved in opioid withdrawal precipitation.

Adult↗
PubMed1986

Mianserin attenuates naloxone-precipitated withdrawal signs in rats acutely or chronically dependent upon morphine.

The effects of the atypical antidepressant and serotonin antagonist mianserin on the expression of opiate withdrawal was examined using an acute and a chronic model of morphine dependence. In the first experiment, rats, trained to perform a food-reinforced, autoshaped lever touch response, were injected with naloxone (5 mg/kg) 4 hr after treatment with a single moderate dose of morphine (15 mg/kg). Mianserin (0.25, 1.0 and 2.5 mg/kg) attenuated the naloxone-induced suppression of autoshaped responding. Colonic temperatures were also monitored. Morphine treatment resulted in significant hyperthermia, while precipitation of withdrawal by naloxone produced hypothermia. Mianserin also attenuated the naloxone-induced hypothermia. In the second experiment, rats were implanted s.c. with a single 75-mg morphine or placebo pellet. Withdrawal was precipitated with naloxone (5 mg/kg) 24, 48 and 120 hr post implantation. Mianserin (2.5 mg/kg) blocked or attenuated signs of withdrawal precipitated by naloxone. Naloxone-precipitated weight loss was also attenuated 48 and 120 hr post implantation. At 120 hr post implantation, rats were decapitated 1 hr after the administration of naloxone and trunk blood was collected. Mianserin did not block the naloxone-induced rise in plasma corticosterone levels. Thus, several signs of withdrawal (e.g., behavioral effects, weight loss and hypothermia) seem to involve serotonergic mediation and can be blocked by mianserin, while others (e.g., rise in plasma corticosterone), which may be unaffected by mianserin, may be a reflection of a compensatory response to withdrawal stress, rather than a mediator of maladaptive consequences of withdrawal that are not mediated by serotonin.

Animals↗
PubMed1988

Precipitation of abstinence in nordiazepam- and diazepam-dependent dogs.

Dogs were made dependent on p.o. administered diazepam (24 or 36 mg/kg/day) or nordiazepam (18 mg/kg/day). Flumazenil (2, 6 or 18 mg/kg) administered p.o. once a week according to a Latin Square design precipitated abstinence in both groups of dogs. Abstinence was evaluated using a Nordiazepam Precipitated Abstinence Scale (NPAS) of various signs of abstinence and by counting seizure episodes. Flumazenil caused dose-related increases in the NPAS scores of both diazepam- and nordiazepam-dependent dogs; the slopes of the two dose-response lines were not different. Both groups of dogs also had both clonic and tonic-clonic seizures after flumazenil administration. CGS-8216 (2, 6 or 18 mg/kg) administered p.o. did not cause a dose-related elevation in NPAS scores for either group of dogs but clonic and tonic-clonic seizures were seen. Thus, flumazenil precipitates the benzodiazepine abstinence syndrome, as evidenced by tremors, tachypnea and other signs, including seizures, whereas CGS-8216 may have some selectivity in precipitating seizures without other signs of abstinence.

Analysis of Variance↗
PubMed1987

[Specific precipitation assay of bone and liver isoenzymes of serum alkaline phosphatase].

Wheat Germ Agglutinin (WGA) precipitates bone and biliary isoenzymes of serum alkaline phosphatase, when liver and intestinal isoenzymes remain in the supernatant. Biliary and intestinal isoenzymes--when present--are evaluated with electrophoresis. Isoenzymes content in precipitate and supernatant is studied by electrophoresis and heat-inactivation. The results of WGA technique are compared to those obtained with heat-inactivation. Heat inactivation reproducibility is poor when compared to WGA precipitation. Differences are found when data of 61 sera are studied. Since a reference method is lacking, results are correlated with other biological parameters, specific of hepato-biliary pathology, and with clinical data, such as metastasis localisation. This study shows that lectin precipitation yields more accurate results than heat-inactivation.

Alkaline Phosphatase↗
PubMed1977

Precipitating antibody against protease of Corynebacterium pyogenes in pigs.

Antibody in sera from pigs carrying an abscess associated with Corynebacterium pyogenes and healthy pigs was examined by the agar gel diffusion test. In the test, the concentrated culture fluid containing the protease of C. pyogenes was used as antigen. As a result, precipitating antibody was demonstrated in sera from 25 of 30 abscessed pigs and a few of the healthy pigs. When the relationship between precipitating antibody and protease was examined by the immunoelectrophoresis and gel filtration of the concentrated culture fluid, the antibody was shown in the same position as the protease. From the result, it was clear that the precipitating antibody was against the protease of C. pyogenes. All the proteases produced by 27 strains of C. pyogenes of porcine and bovine origin were serologically identical with one another. They were, however, serologically different from those of Staphylococcus aureus, Bacillus cereus, and B. subtilis. In the inhibition test, the proteolytic activity of C. pyogenes was inhibited by the serum of the abscessed pig. It was also inhibited by healthy pig serum. From the results, it seems that the determination of precipitating antibody may be useful for the diagnosis of C. pyogenes infection.

Abscess↗
PubMedDate not supplied

Preparation of drugs used in hyperacidity. Part I. Effects of pH of precipitation on the neutralizing properties of alumina gels.

Alumina gels were obtained from sodium aluminate by addition of 3 N HNO3, HCl or H2SO4 solutions or by saturation with gaseous CO2. The effect of several physicochemical factors (pH of precipitation, kind and concentration of precipitating agent, temperature) on the neutralizing properties of the obtained forms of Al(OH)3 was investigated. The linear correlation between the pH of precipitation and the neutralizing properties was found. The effect of different precipitating anions on the acid-consuming capacity and the rate of neutralization of 0-1 N HCl was established.

Aluminum Hydroxide↗