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PubMed1975

Renal stone formation. The inhibitory effect of urine on calcium oxalate precipitation.

The mechanism of renal stone formation is not fully understood. This report describes an investigation into the effect of urine on the precipitation of calcium oxalate from dilute solution. Over 33 min a 5 per cent solution of urine caused considerable inhibition of precipitation. The degree of this inhibition was related to the concentration of the original urine. An "artificial urine" composed of 12 solutes present in normal urine had some inhibitory effect, but less than that of equiosmolar true urines. Inhibition was also related to the percentage of urine present. This inhibitory effect may be important in the prevention of renal stone formation in normal people by delaying crystallization until urine reaches the lower urinary tract.

Adolescent↗
PubMed2000

[Etiology and precipitating factors of cyclic vomiting].

The aim of the study was to determine the nature, severity, precipitants and associated features of attacks and the incidence of potential aetiological factors of cyclic vomiting syndrome (CVS). Ten patients (6 boys and 4 girls aged 2-12 years) with CVS, defined as recurrent episodes of vomiting with symptom-free intervals occurring two or more times per year, with episodes having a similar pattern and for which no other cause could be found, ten patients (7 boys and 3 girls aged 7-14 years) with migraine, defined as recurrent headache with symptom-free intervals and at least three of the following symptoms or associated findings: abdominal pain, nausea or vomiting, throbbing headache, unilateral location, associated aura (visual, sensory, motor), relief after sleeping and ten controls (6 boys and 4 girls aged 4-13 years) were studied. The mean age at onset of symptoms in patients with CVS was 3.9 years and the mean number of attacks per year was 4, the average duration of episodes was 20.5 hours and the mean number of school missed days were 6 per year. The mean age at onset of symptoms in patients with migraine was 7.6 years and the mean number of attacks per year was 9.9, the average duration of episodes was 8 hours and the mean number of school missed days were 6.4 per year. A family history of migraine was significantly higher in both groups of patients, compared with controls (p = 0.009). A personal history of headache and/or migraine and associated sign or symptoms like recurrent abdominal pains, limb pain and kinetosis was significantly higher in both patients compared with controls (p < 0.001). CVS is a chronic, disabling condition and is a migraine variant, with attacks usually precipitated by stress and intercurrent infections.

Child↗
PubMed1999

[One simple and efficient method for purification of IgG McAb from mice ascites: caprylic acid/ammonium sulfate precipitation].

Several ascitic IgG McAbs were purificated by caprylic acid/ammonium sulfate precipitation (CA-AS), ammonium sulfate precipitation (AS) and SPA affinity chromatography. Purity of IgG purificated by CA-AS ranged from 87% to 91%, higher than that obtained by CA (65%-70%), lower than that obtained by SPA affinity chromatography (100%). The yield of IgG purificated by CA-AS ranged from 4.8 g/L to 5.5 g/L, lower than that obtained by CA (7.0-7.9 g/L), more higher than that obtained by SPA affinity chromatography (0.6 g/L). The recovery of IgG purificatied by CA-AS ranged from 39.0% to 44.4%, lower than that obtained by CA (56.0%-65.0%), more higher than that obtained by SPA affinity chromatography (7.4%). The ELISA titer of 4E2 or H6McAb was not impaired by purification of CA-AS. The above results suggested that CA-AS is one simple, efficient, rapid and low-cost method for purification of IgG McAb from ascitic fluid.

Ammonium Sulfate↗
PubMedDate not supplied

A method for separation of heparin species from biological samples by ethanol precipitation of compounds solubilized in guanidine hydrochloride.

In this paper we describe a procedure to determine glycosaminoglycan and oligosaccharide composition of biological samples such as cell cultures or tissue explants. We demonstrate that heparin species of different molecular mass can be easily fractionated by sequential ethanol precipitation in 4.0 M guanidine hydrochloride. We studied by gradient polyacrylamide gel electrophoresis fractionation of standard heparin and heparin-derived oligosaccharides by anion-exchange chromatography on DEAE-Sephacel resin eluted by increasing concentration of guanidine hydrochloride. The use of guanidine salts followed by sequential precipitation by increasing ethanol concentration allowed recovery of heparin and heparin-derived oligosaccharides.

Animals↗
PubMed2000

[Impacts of forest and precipitation on runoff and sediment in Tianshui watershed and GM models].

This paper analyzed the impacts of foret stand volume and precipitation on annual erosion modulus, mean sediment, maximum sediment, mean runoff, maximum runoff, minimum runoff, mean water level, maximum water level and minimum water level in Tianshui watershed, and also analyzed the effect of the variation of forest stand volume on monthly mean runoff, minimum runoff and mean water level. The dynamic models of grey system GM(1, N) were constructed to simulate the changes of these hydrological elements. The dynamic GM models on the impact of stand volumes of different forest types(Chinese fir, masson pine and broad-leaved forests) with different age classes(young, middle-aged, mature and over-mature) and that of precipitation on the hydrological elements were also constructed, and their changes with time were analyzed.

Chemical Precipitation↗
PubMed2002

[A case with multiple myeloma in which serum forms gel precipitation upon exposure to air].

We present the case of a 69-years-old man who was admitted to hospital with multiple myeloma. IgG-kappa type monoclonal protein was detected in the serum. When we separated the serum obtained from blood sample of the patient and the lid of the collecting tube was opened, the patient's serum became gelled immediately. When the lid of the collecting tube remained closed, the patient's serum did not become gelled even at 4 degrees C. Moreover, the gelled serum of the patient did not resolve at 56 degrees C. Taken together, these results indicated that gel formation of the patient's serum may not be due to cryoglobulin. It was found that the pH of the patient's serum elevated to pH 8.0 quickly after exposed to air. It was also found that the patient's serum, but not the sera of other IgG-kappa multiple myeloma patients, became gelled as soon as PBS of pH 8.0 was added. These results highly suggest that the patient's serum becomes gelled at pH 8.0. However, the isoelectric focusing of isolated precipitation in the patient showed fractions around the pH 8.5-8.7 zone, which was different from the pH at which the precipitation began to form. We think that this may be the first report of a multiple myeloma patient whose serum becomes gelled after exposed to air.

Aged↗
PubMed2002

[Heparin-induced extacorporeal low-density lipoprotein-lipoprotein alpha-fibrinogen precipitation in 36 cases].

OBJECTIVE: To observe the efficacy of heparin-induced extracorporeal low-density lipoprotein-lipoprotein alpha- fibrinogen precipitation (HELP) in clearing blood lipids. METHODS: Thirty-six patients were subjected to extracorporeal plasma lipid separation procedures that utilized heparin to induce the formation of the complex consisted of heparin, low-density lipoprotein cholesterol (LDL-C), lipoprotein and fibrinogen which was precipitated and consequently separated from the plasma. Blood samples were obtained from the patients both before and after the procedures to assay serum total cholesterol (CH), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), LDL-C, apoliprotein A (ApoA) and apoliprotein B (ApoB). RESULT: Significant differences were observed between the pre- and postoperative levels of lipoprotein (P<0.001). CONCLUSION: Plasma lipoprotein can be partly cleared by way of HELP.

Adult↗
PubMed2002

Arsenic removal efficiency and mechanisms by electro-chemical precipitation process.

This research was conducted to investigate the efficiency and mechanisms of arsenic (As) removal from a contaminated water by using the electro-chemical precipitation (ECP) process, with the operating conditions as follows: initial As concentration of 0.5-5 mg/L, 0.1 M KCl, electrical gradient of 200 V/m and initial pH higher than 3. The laboratory-scale ECP unit was able to reduce As to within the WHO drinking water standard of 0.01 mg/L in 20 min. The Cl- salt was found to yield better As removal efficiencies than the NO3- salt probably because NO3- ions interfered with the production of OH- and Fe(OH)3, important for As removal. X-ray fluorescence and X-ray diffractometric analysis revealed maghemite (Fe2O3) and angelellite (Fe4As2O11) to be the major compounds present in the precipitated sludge. The percent Fe2O3 and Fe4As2O11 contents of the dried ECP sludge were 98.29% and 0.26%, respectively. From a mass balance analysis, As removal in the ECP process was due to: incorporation in and adsorption on the ECP sludge--64.9-94.9%, conversion to arsine (AsH3) gas--10.5-15.6%, adsorption on the electrode plates and reactor walls--0.03-1.1%, residual in the supernatant--0.2-0.4%, and unaccounted for--1.2-19.8%.

Arsenic↗
PubMed1975

Staphylococcus aureus in cystic fibrosis: antibiotic sensitivity and phage types during the latest decade. Investigation of the occurrence of protein A and some other properties of recently isolated strains in relation to the occurrence of precipitating antibodies.

During the recent decade, 1651 isolates of Staphylococcus aureus from 111 patients with cystic fibrosis have been tested for antibiotic sensitivity and half of the isolates have been phage typed. All the patients were followed in one clinic and the policy of antibiotic treatment was consistent during this period. The results show a dynamic situation where "epidemic" phage types during recent years have been gradually replaced by other types and, during the same period, the prevalence of strains resistant to more than one antibiotic decreased. Multiresistant strains including strains resistant to methicillin were infrequent in these patients. From 23 per cent of the patients, the same strains were repeatedly isolated for more than 1 year despite an apparently successful chemotherapy. Recently isolated strains were found to produce cellbound as well as extracellular protein A. Ninety-one per cent of the strains produced extracellular lipase and only 8 per cent were resistant to mercury chloride. Eighty-one per cent of the patients produced precipitating antibodies agains S. aureus as judged by crossed immunoelectrophoresis. The investigated properties of S. aureus were not significantly correlated with the occurrence of precipitating antibodies against these bacteria. The possible significance of protein A in the pathology of the respiratory tract infection is discussed.

Anti-Bacterial Agents↗
PubMed2003

Treatment of the solution extracted from metal contaminated soils by reverse osmosis and chemical precipitation.

In this study a process for the remediation of soils contaminated by lead or copper is proposed, consisting of the operations in sequence: soil flushing, membrane treatment, acidification, and metal precipitation. Pb(II) and Cu(II) extraction from a synthetically contaminated soil using a 0.05 M EDTA aqueous solution were investigated in column. The metal removal efficiencies and the final soil metal concentration were 98.2% and 37.96 mg/g respectively for lead and 95.4% and 59.20 mg/kg for copper. The extracted solutions were concentrated through a membrane treatment to reduce the water content up to the 75% and to obtain a permeate metal concentration in compliance with the Italian Environmental Regulation. The recovery of the used EDTA from the retentate solution, with recovery yield of at least 85.4%, was also obtained through acidification. Metal precipitation from the filtered solution was then performed according two different methods, achieving metal removal yield of more than 99.4%.

Chelating Agents↗
PubMedDate not supplied

[Cytotoxicity of ferric chloride used as an adjuvant of organic acid precipitation].

The objective of this study was the amelioration of the organic acid precipitation technique currently used as a secondary stage for viruses concentration using ferric chloride (FeCl3) as an adjuvant. To carry out this work successfully, we have studied the cytotoxicity effect of FeCl3 towards cell lines usually used for the investigation of enteric viruses. Two kinds of african green monkey kidney cells, MA104 and BGM, were used as a cellular model. The results showed that optimum concentration of FeCl3 for either BGM or MA104 cell survival and organic acid precipitation varies from 0.5 to 1 mM. The cytotoxicity test used in this work was simple, easy to realize and gives an appreciable information about the cytotoxicity dose of a given biological and chemical product.

Animals↗
PubMed2004

Some magnetic field effects on in situ precipitated calcium carbonate.

Magnetic field (MF) (B = 0.4 T) effects were studied on CaCO3 precipitated from Na2CO3 and CaCl2 solutions, which at 30 degrees C were exposed for 30 min to the field. One of the impurity ions Mg2+, Zn2+, Fe2+, SO4(2-), HPO4(2-) at 10(-5) mol l(-1) concentration was also added to CaCl2 or Na2CO3, respectively. The changes of zeta potential, pH and light absorbance (at lambda = 543.2 nm) of the slurry after CaCO3 precipitation were measured on the time. In some experiments changes in the deposited amounts of CaCO3 due to MF treatment were determined on glass plates. MF affected all the parameters measured and the effects depended on the kind of impurity ion present.

Calcium Carbonate↗
PubMed1992

Novel fractionation of proteins using novobiocin as a precipitating agent: application to ribosomal proteins from the archaebacterium Sulfolobus acidocaldarius and Escherichia coli.

A fractionation method involving precipitation of proteins with novobiocin has been developed to separate ribosomal proteins of the archaebacterium Sulfolobus acidocaldarius. Four groups of proteins were obtained corresponding to those precipitated with 0.2, 0.5 and 1.0 mg/ml novobiocin and the proteins soluble at 1.0 mg/ml novobiocin. The same procedure was also successful for the fractionation of ribosomal proteins from Escherichia coli. Two dimensional gel electrophoresis showed that proteins present in each group were distinct with only a minor contamination of proteins from other groups. Our results indicate that proteins with similar charge and molecular weight can be separated by this method. This procedure may have applications for the fractionation of other complex protein mixtures.

Bacterial Proteins↗
PubMedDate not supplied

"Cracked-mud" ciprofloxacin precipitates on a corneal graft.

The authors describe an extreme case of ciprofloxacin deposition on the corneal graft of a 67-year-old man with a history of penetrating keratoplasty for corneal ulcer and perforation, who presented with dense, gray deposits on the anterior corneal surface after being treated with ciprofloxacin for an epithelial defect. The deposits resolved after ciprofloxacin was discontinued. The non-physiologic pH of the drug formulation is thought to trigger corneal precipitates, and it remains to be seen whether fourth-generation fluoroquinolones will have a lower incidence of ocular precipitates.

Aged↗
PubMed2005

[The light diffusion technique for estimation of the size of urine particles in patients with type 2 diabetes mellitus in the Tamm-Horsfall protein precipitation].

Tamm-Horsfall uroprotein accounts for more than 50% of the urinary proteins in healthy individuals. In abnormalities, it creates a favorable background for detecting smaller-sized uroproteins and for diagnosing pathological processes from the results of native urine tests. In this connection, there is a need for precipitating Tamm-Horsfall glycoprotein while applying laser correlation spectroscopy to analyze the size of urine particles in patients with type 2 diabetes mellitus. Eighty patients with this condition concurrent with different stages of diabetic nephropathy and 23 apparently healthy individuals were examined. The findings suggest that the subfraction urine composition before and after Tamm-Horsfall protein precipitation is different in apparently healthy individuals and patients with type 2 diabetes mellitus concurrent with diabetic nephropathy. This is most likely to be due to the change in the qualitative composition of protein as renal lesion progresses, to the specific features of protein excretion at different stages of a pathological process, and to different concentrations of other low and high molecular-weight proteins.

Adult↗
PubMed1992

Infrared spectroscopic method for analysis of precipitates on a cell culture dish.

A new quick infrared spectroscopic method was developed and applied to analyze precipitates formed by cultured cells on a Petri dish. This IR method allows a dish to be placed directly on the sample beam window of a normal double beam IR spectrometer. Placing a blank dish on the reference beam window of the spectrometer compensates for the high background absorption due to the dish on the sample beam window and enables an identifiable spectrum to be obtained. Using this technique with a Petri dish, a high correlation factor of 0.998 was found between the PO4 peak absorbance and the weight of synthetic hydroxyapatite in the range of 0.5-2.5 mg/cm2. The IR pattern, however, showed a shift in the positions of the absorption band and the appearance of ghost peaks. Using a thin based Petriperm dish, these difficulties were overcome producing a correlation factor of 0.992 at the lower range of 0.05-1.45 mg/cm2. Application of this technique to the precipitates formed on a Petri dish by rat bone marrow derived cells showed the presence of collagen and apatite-like substance.

Absorption↗
PubMed2006

[The research on preparing CeO2 nanocrystalline by homogeneous precipitation method].

CeO2 nanocrystallines were prepared by homogeneous complexed-precipitation method, using cerous nitrate and ammonium tartrate as raw materials. The effects of cerous tartrate complex compound and the way of producing precipitation on the particle size of samples were investigated. The samples were characterized by XRD, TEM and SEM. The SEM micrograph shows that the foam exhibits a perforated porousness stereostructure in shape, and the HRTEM picture of the particles reveals the clear crystal lattice. All the results indicate that the samples were CeO2 nanocrystalline.

Cerium↗