Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Flocculation Tests”

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 757 records · Page 42Linked to original sources
PubMed1972

Identification of two Saccharomyces cerevisiae cell wall mannan chemotypes.

We have obtained evidence for two structurally and antigenically different Saccharomyces cerevisiae cell wall mannans. One, which occurs widely and is found in S. cerevisiae strain 238C, is already known to be a neutral mannan which yields mannose, mannobiose, mannotriose, and mannotetraose on acetolysis of the (1 --> 6)-linked backbone. The other, which was found in S. cerevisiae brewer's strains, is a phosphomannan with a structure very similar to that of Kloeckera brevis mannan. S. cerevisiae (brewer's yeast strain) was agglutinated by antiserum prepared against Kloeckera brevis cells. The mannan, isolated from a proteolytic digest of the cell wall of the former, did not react with S. cerevisiae 238C antiserum, whereas it cross-reacted strongly with K. brevis antiserum. Controlled acetolysis cleaved the (1 --> 6)-linkages in the polysaccharide backbone and released mannose, mannobiose, mannotriose, and mannotriose phosphate. Mild acid treatment of the phosphomannan hydrolyzed the phosphodiester linkage, yielding phosphomonoester mannan and mannose. The resulting phosphomonoester mannan reacted with antiserum prepared against K. brevis possessing monoester phosphate groups on the cell surface. alpha-d-Mannose-1-phosphate completely inhibited the precipitin reaction between brewer's yeast mannan and the homologous antiserum. Flocculent and nonflocculent strains of this yeast were shown to have similar structural and immunological properties.

Agglutination Tests↗
PubMed1989

[The use of passive hemagglutination for determining the fibronectin-binding properties of microorganisms].

The authors present the data that evidence in favour of employing fibronectin sensitized formalin-treated red cells for the indication of fibronectin-binding microorganisms (as exemplified by staphylococci) in the passive hemagglutination test (PHAT). The possibility of a quantitative estimation of fibronectin binding by the PHAT is shown. PHAT will help detect higher numbers of fibronectin-binding staphylococci than flocculation on the glass.

Fibronectins↗
PubMed2004

Physical characteristics of polymer complexes in suspension obtained from cellulosic latexes with ondansetron.

Ondansetron is a carbazol with antiemetic properties. It is used primarily to control nausea and vomiting caused by cytotoxic chemotherapy and radiotherapy, as well as in postoperative vomiting in gynecological surgery. Ondansetron has a half-life of approximately 4 h, hence it is a matter of great interest to determine the ideal conditions for the formation of a drug-polymer complex in order to prolong the duration of the therapeutic action. A stability study of the active drug was first carried out on each of the polymers (Aquateric and Aquacoat). The adsorption of ondansetron on the lattices was determined with respect to time, pH and concentration. The results obtained suggest that both polymers are suitable as drug carriers for the controlled-release formulations obtained. We conclude that an acid pH is evidently fundamental in the adsorption process of this drug in the latexes. Moreover, the Aquateric latex would seem to be the best-suited polymer to use as a vehicle for drug delivery.

Adsorption↗
PubMed2005

Biomass selection for optimal anaerobic treatment of olive mill wastewater.

This research was conducted to identify the most efficient biomass out of five different types of biomass sources for anaerobic treatment of Olive Mill Wastewater (OMW). This study was first focused on examining the selected biomass in anaerobic batch systems with sodium acetate solutions (control study). Then, the different types of biomass were tested with raw OMW (water-diluted) and with pretreated OMW by coagulation-flocculation using Poly Aluminum Chloride (PACl) combined with hydrated lime (Ca(OH)2). Two types of biomass from wastewater treatment systems of a citrus juice producing company "PriGat" and from a citric acid manufacturing factory "Gadot", were found to be the most efficient sources of microorganisms to anaerobically treat both sodium acetate solution and OMW. Both types of biomass were examined under different concentration ranges (1-40 g l(-1)) of OMW in order to detect the maximal COD tolerance for the microorganisms. The results show that 70-85% of COD removal was reached using Gadot biomass after 8-10 days when the initial concentration of OMW was up to 5 g l(-1), while a similar removal efficiency was achieved using OMW of initial COD concentration of 10 g l(-1) in 2-4 days of contact time with the PriGat biomass. The physico-chemical pretreatment of OMW was found to enhance the anaerobic activity for the treatment of OMW with initial concentration of 20 g l(-1) using PriGat biomass. This finding is attributed to reducing the concentrations of polyphenols and other toxicants originally present in OMW upon the applied pretreatment process.

Bacteria↗
PubMed2000

Immune response to diphtheria booster vaccine in the Baltic states.

A study was done to measure baseline levels of immunity to diphtheria and antibody responses to different doses of diphtheria vaccine in study participants in the three Baltic states. Diphtheria booster vaccines containing either 3 (Estonia and Lithuania), 6 (Latvia), or 12 (Latvia) limit of flocculation units of diphtheria toxoid were administered to 2315 adults. Diphtheria antibody levels were tested before and 1-2 months after vaccination. Before vaccination, 40% of the participants in Estonia, 32% in Lithuania, and 38% in Latvia had antibody levels <0.01 IU/mL, the level for minimum protection. After vaccination, 79% of the participants in Estonia, 83% in Lithuania, and 81% in Latvia had antibody levels >0. 1 IU/mL, the minimum level for full protection. However, in each of the countries, about one-third of the 40- to 49-year-old participants would have benefited from additional doses of vaccine. There was not a significantly different antibody response among persons receiving the three different doses. Age and the level of prevaccination immunity had a modifying effect on the response to vaccination; however, sex did not.

Adult↗
PubMed1972

Polyelectrolyte flocculation as an aid to recovery of enteroviruses from oysters.

A simple and rapid method for recovering enteroviruses from oysters is described. A polycation sewage flocculant promoted cohesion of oyster solids and thereby aided separation of these from the viruses. Recovery of 80 to 100% of experimentally inoculated virus was achieved, and the suspension or extract obtained could be inoculated directly into tissue cultures or concentrated first for greater sensitivity.

Antibodies↗
PubMed2003

Elimination of shrimp endogenous peroxidase background in immunodot blot assays to detect white spot syndrome virus (WSSV).

False positive results were obtained in immunodot blot assays to detect white spot syndrome virus when horseradish peroxidase-conjugated sheep anti-mouse immunoglobin (Ig) serum was used as a secondary antibody with 3-3'-diaminobenzine tetrahydrochloride dihydrate as the detection substrate. The cause was considered to be a reaction of shrimp endogenous peroxidase (POD) with the substrate. In experiments designed to inhibit POD activity, 9 different reagents were used at different concentrations and for different treatment times. EDTA, sodium azide, HEPES-Na, NaHSO3, H2O2 and phenylthiourea (PTU) were able to inhibit POD activity by 44, 60, 64, 67, 79, and 90%, respectively. Phenylmethylsulfonyl fluoride did not inhibit POD, and neither periodic acid nor H2O2 in methanol were appropriate due to the formation of flocculant precipitates when added to shrimp extracts. It was concluded that of the treatments tested, 10 mM PTU for 2 h yielded optimal inhibition and that such pretreatment of samples eliminates false positive results in immunodot blot assays.

Animals↗
PubMed1985

Preliminary evaluation of the ELISA as a tool for the detection of rotaviruses in activated sewage sludge.

Samples of activated sludge were taken in three different treatment plants near Nancy (France) and in West Berlin (F.R.G.), and were investigated for their content of rotaviruses. After elution with beef extract (0.25%, pH 7.3) and ultrasonication, the samples were concentrated by protamine flocculation and, in a few cases, in parallel by ultracentrifugation. A commercially available ELISA test kit (Rotazyme, Abbott Diagnostics) was routinely used for rotavirus detection. Although both the Rotazyme and a laboratory-designed ELISA gave positive results for the suldge concentrates, confirmation with a blocking test and electron microscope (EM) was negative in all cases so far investigated. Therefore, the exclusive use of ELISA cannot be recommended for similar investigations as it may lead to false positive results. In this light, an additional verification step with neutralizing antibodies should be included by the ELISA kits' manufacturers to enable a quick confirmation of the user's results.

Enzyme-Linked Immunosorbent Assay↗
PubMed1966

A double-blind comparison of a new antidepressant, protryptiline, with imipramine and amitryptiline.

Protryptiline, a new antidepressant, was evaluated in a double-blind study. Results were compared with those obtained in similar groups of patients treated with imipramine and amitryptiline. After full psychiatric and medical assessment, patients were rated on a "target-symptom" scale, were assessed weekly and underwent a number of tests before and after treatment, including a hemogram and estimations of serum bilirubin, cephalin flocculation and serum protein values. Observations were made over four to six weeks. The starting dosage was 10 mg. protryptiline three times daily with a maximum of 60 mg. daily. Beneficial responses occurred in 13 of 20 patients (65%). Protryptiline-treated patients had the earliest response to drug treatment, 11 showing some improvement within the first week. Twelve patients (60%) had side effects, mainly minor, indicative of anticholinergic activity. One developed leukopenia which was reversible, and one showed increased excitement; in both, therapy was discontinued. Protryptiline gave clinical results that compared favourably with those of antidepressants of established value. While toxic effects should be carefully watched for, further trials are warranted to decide whether protryptiline possesses special or new advantages in psychopharmacotherapy.

Amitriptyline↗
PubMed2004

Toxicological characterization of the new water cleaning product and its waste by-product.

Water extracts genotoxicity of the coagulant produced from industrial waste (red mud and waste base) and its waste mud remained after waste water treatment by the coagulation/flocculation process were studied. Tests were conducted in order to confirm nontoxicity of this new product prior to commercial production and usage and also to recommend a safe way for a handling and disposal of the remaining waste material. The toxicity investigation included (i) determining frequency of the cell survival, (ii) the Ames assays, (iii) micronucleus assay, and (iv) cell proliferation kinetics (expressed as mitotic index). These techniques were also employed in toxicity testing of the different concentrations of metal salts, zinc chloride, and lead nitrate in this case since these two elements were present in high concentrations in the waste water intended for the purification with the new coagulant. Mixture of metal salts in the concentrations that represent maximum allowed values for water extracts of technological waste was also tested. Two strains of Salmonella typhimurium, TA98, and TA100 were used for determining cytotoxicity and for the Ames test, while the cytogenetic investigations were performed on human peripheral blood lymphocytes. Water extracts of the coagulant and its waste mud did not induce a significant increase of the micronuclei in human peripheral blood lymphocytes. They also did not disturb lymphocyte proliferation kinetics in vitro. As regards lead nitrate it proved not to be cytotoxic on bacterial strains in the tested concentration range (1-100 mg/L), whereas zinc chloride showed cytotoxic effect for the concentrations above 25 mg/L. The Ames test results for the noncytotoxic concentrations of these metals were negative. Comparing to the negative control a significantly higher number of the micronuclei was determined after the treatment of the whole blood with 100 mg/L of zinc chloride, as well as with 10 and 100 mg/L of lead nitrate. A linear, dose dependent increase was obtained for both salts. Similar results were obtained on the basis of the mitotic index.

Cell Division↗
PubMed2004

Turbidity-based monitoring of particle concentrations and flocculant requirement in wastewater pre-treatment.

The removal of particulate organic material in the first step of wastewater treatment may result in significant savings of reactor volume and energy at wastewater treatment plants, because the organic loading to pursuing unit operations can be reduced. This article describes experiments into the possibility of using turbidity measurements as a tool to quantify the concentration of particles in raw wastewater and, based on the result, assess the organic polymer requirement. A feed forward polymer dosing strategy based on a fixed polymer to influent-turbidity ratio was developed and tested. The experimental work confirms that turbidity measurements can be used to quantify particulate COD. For the investigated wastewater (both untreated and flocculated samples) a linear relationship was found in a wide range of particulate COD (100-900 mg O2 x l(-1)) and turbidity (50-450 NTU). On-line turbidity measurements showed that the particle concentrations in the tested municipal wastewater varied significantly. During dry weather conditions the turbidity fluctuated from 100 to 400 NTU, while in rainy periods fluctuations of 100 to >1,000 NTU were measured. The tested turbidity-related polymer dosing method could be used to create different, constant levels of particle removal, despite large particle concentration variations in the influent. Moreover, it resulted in higher removal efficiencies and a more stable operation compared to the dosing of fixed polymer dose per unit of volume.

Chemical Precipitation↗
PubMed1999

[Immunoblotting for the serodiagnosis of syphilis. A candidate to replace the Nelson-Mayer test].

The lipid antigens used in the Bordet-Wassermann and prepared by Landsteiner and Marie for syphilis tests from 1909 to 1949 were non specific but have certain common features with the spirochete body. For more than forty years the Bordet-Wassermann reaction, associated with flocculation (Kahn) or agglutination (Kline-VDRL) was used to detect cases of tremonematosis despite frequent false positives reactions due to other infections. In 1949, the Nelson and Mayer test was introduced. This test was based on a rigorously specific reaction based on an antigen of live virulent Treponema pallidum. Culture being impossible, the strain had to be, and still is, maintained by weekly passage on rabbit testicles. These manipulations are very dangerous and the technique is difficult, being performed only in specialized laboratories. This test however made it possible to identify the specificity of lipid tests and led to the development of specific immunofluorescent reactions (FTA) in 1959 and of hemagglutination test (TPHA) in 1969. In 1980, we introduced a simple treponemic reaction (FTA or TPHA) associated with a lipid reaction (VDRL) for screening. The specificity of these tests is not however perfect and the Nelson test remains useful as a highly specific reaction. A simple test with comparable specificity was long awaited and is now available with immunoblotting as for HIV, boreliosis and pertussis, etc. We propose this new reaction to replace the Nelson test because it is specific, is sensitive early, distinguishes between IgG and IgM and is not dangerous to manipulate. We have tested it in over one hundred selected sera of CSF from subjects with recent, former or nervous syphilis as well as cases susceptible of producing false positive reactions and have concluded that immunoblotting is highly specific and sensitive. We recommend official approval of this test to replace the Nelson test.

Humans↗
PubMed1996

Detection of a single viable Cryptosporidium parvum oocyst in environmental water concentrates by reverse transcription-PCR.

Current methods for detection of Cryptosporidium parvum oocysts in water are time-consuming and difficult. We have developed a reverse transcription (RT)-PCR which can detect the presence of a single viable oocyst spiked into concentrated environmental water samples. The test is based on the detection of mRNA from a C. parvum heat shock protein (hsp). The synthesis of hsp was induced by a short 45 degrees C incubation followed by oocyst lysis by a freeze-thaw process. Hsp70 mRNA, produced only from viable oocysts, was then isolated by hybridization to oligo(dT)25-coated magnetic beads. Detection was achieved by RT-PCR amplification of a 590-bp region of hsp70 mRNA specific for C. parvum. To test the method, samples of reticulated, reservoir, bore, and river water were concentrated by chemical flocculation and Percoll-sucrose gradient centrifugation and then spiked with dilutions of oocysts. In all four of the water types examined, the detection of single oocysts was possible by RT-PCR combined with Southern hybridization. RT-PCR products were not obtained from formalin-inactivated oocysts. An RNA internal positive control fragment was synthesized that was included with each reaction to guard against RT-PCR false-negative results that may be caused by the presence of inhibitory substances. However, when the magnetic beads were used to extract and concentrate mRNA, no inhibition was observed. The technique is versatile, straightforward, and rapid (1 day) and provides a sensitive and economic means of screening concentrated water samples for the presence of C. parvum.

Animals↗