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PubMed1975

The leucocyte adherence inhibtion test in cancer of the large bowel.

A recently introduced assay of cell mediated immunity and humoral inhibitory factors has been evaluated in colorectal cancer patients. Using a perchloric acid extract of adenocarcinoma of the large bowel as antigen, 16/27 patients with colorectal cancer had significant cellular reactivity when their separated peripheral leucocytes were tested in homologous AB serum. In autologous serum only 7/27 had significant reactivity; 6/20 patients with a variety of other malignancies showed sensitization to the colorectal antigen preparation. It is concluded that the leucocyte adherence inhibiton test may offer a simple method of assaying for serum blocking factors in sequential studies but will be of little value in the diagnosis of large bowel cancer.

Adenocarcinoma↗
PubMed1965

The intracellular localization of heme by a fluorescence technique.

A new technique for the intracellular localization of minute amounts of heme and hemoproteins is described. The specimen is treated with 1.5 M perchloric acid in the presence of SH groups, followed by ultraviolet light irradiation in a fluorescence microscope. This fixes the proteins in situ and converts the heme to a porphyrin which fluoresces and is readily visualized. With this technique, hemoglobin has been demonstrated in the nuclei of avian erythrocytes, and in the nuclei of human normoblasts at an earlier stage than previously described. In addition, hemoproteins, presumably cytochromes, have been detected in the cytoplasm and nuclei of myelocytes, in thymus lymphocyte nuclei, in chick embryo liver cytoplasm, and in chick embryo somites.

Animals↗
PubMed1977

Comparative study of carcinoembryonic antigen in rheumatoid synovium, tumour, and normal adult lung.

Material reacting like carcinoembryonic antigen (CEA) in the radioimmunoassay has been extracted from rheumatoid synovial membranes. This CEA activity has been compared to that found in hepatic metastases from colorectal tumours and in normal adult lung. The antigen in the rheumatoid synovium has been shown to be more sensitive to perchloric acid and to isolate with a lower weight than that derived from the tumour and lung. Immunodiffusion studies with anti-CEA indicate that the CEA-like determinants in the rheumatoid synovium have partial identity with tumour CEA and that a significant proportion of them are associated with large molecular weight material. Production of an antiserum to these CEA-like components in the rheumatoid synovium should enable further identification of their relationship to tumour CEA and might allow a better judgement of whether or not they represent the expression of neoantigens in the disease.

Arthritis, Rheumatoid↗
PubMed1987

Quantitative measurement of endotoxin in canine plasma using the new endotoxin-specific chromogenic test.

Endospecy (a lyophilized mixture of factor G-free limulus coagulation enzymes and chromogenic substrate, Boc-Leu-Gly-Arg-pNA) coupled with modified perchloric acid (PCA) pretreatment was carried out for the quantitative measurement of endotoxin in canine plasma. The endotoxin recovery from normal canine plasma was 99.9 +/- 7.7% (n = 20). The full recovery of endotoxin illustrated the applicability of the modified PCA pretreatment to the Endospecy in removal of interfering factors in a canine plasma. The normal canine plasma endotoxin level was less than 3.0 pg.ml-1 when Escherichia coli 0111:B4 endotoxin was used as a reference. The canine plasma endotoxin levels were markedly high(1-40 ng.ml-1) at 5 min after intravenous administration of 25 micrograms.Kg-1 (total 150-200 micrograms).

Animals↗
PubMed1985

Analysis of soman and sarin in blood utilizing a sensitive gas chromatography-mass spectrometry method.

Gas chromatography with electron impact mass spectrometry and selected ion monitoring provided a simple and sensitive method for measuring organophosphorus compounds sarin and the two isomers of soman (isomer I and isomer II) in blood. These compounds were extracted from blood or isotonic saline using a modification of the method developed by Sass et al. Blood was deproteinized with perchloric acid before extraction. The acid-induced degradation of the organophosphorus compounds could be minimized by neutralizing the acid immediately after deproteinizing. In saline and blood, 81% of the extractable soman and 74% of the extractable sarin was recovered with a single extraction. The overall recovery of added organophosphorus was less in blood than in saline because of the binding of organophosphorus to blood constituents, probably various enzymes and proteins. A time-dependent decrease in extractable organophosphorus was found in whole blood but not in saline. Although soman isomer II was degraded in blood faster than soman isomer I, no significant difference in the affinities of these two isomers to acetylcholinesterase was observed.

Acetylcholinesterase↗
PubMed1996

Determination of the endogenous phosphorylation state of B-50/GAP-43 and neurogranin in different brain regions by electrospray mass spectrometry.

Electrospray mass spectrometry coupled to liquid chromatography was utilized to measure two PKC neuronal substrates, B-50/GAP-43 and neurogranin, in single rat brain areas. Aliquots of perchloric acid extracts were directly injected and mass spectra recorded. At elution times of 14.2 and 27.0 min two molecular species of MW 7450 and 23 602 Da were observed. These values are in excellent agreement for the expected MW for rat neurogranin and B-50/GAP-43. The presence of molecular species shifted by 80 mass units in both cases indicates that these proteins are present in phosphorylated forms in cortical and hippocampal extracts.

Animals↗
PubMed1969

Acetylcholine and related enzymes in the neural lobe and anterior hypothalamus of the rabbit.

1. Acetylcholine (ACh), cholinesterases and choline acetyltransferase (choline acetylase) were estimated in the neural lobe and hypothalamus of the adult male rabbit. Acetylcholine was also estimated in the neural lobes and hypothalami of some other mammals.2. Acetylcholine-like activity was measured by bio-assay using the leech dorsal muscle preparation.3. Characterization experiments indicated that about 90% of the activity measured was due to acetylcholine.4. Mean acetylcholine content in the neural lobe of the rabbit, after extraction with perchloric acid, was 4.38 +/- 0.98 mug/g fresh tissue, and 4.87 +/- 1.53 mug/g in the hypothalamus.5. Acetylcholine was also found to be present, in comparable concentrations, in the neural lobe of man and in the neural lobes and hypothalami of ox, rat and hedgehog.6. Acetylcholinesterase, present in the neural lobe and hypothalamus of the rabbit, hydrolysed 1.74 +/- 0.11 mu-moles of substrate/min/g and 3.78 +/- 0.60 mu-moles substrate/min/g fresh tissue respectively.7. The concentration of butyrylcholinesterase was about one tenth that of acetylcholinesterase in both tissues.8. Choline acetyltransferase present in the neural lobe and in the hypothalamus synthesized 87 +/- 22 mug ACh/hr/g fresh tissue and 378 +/- 149 mug respectively.

Acetylcholine↗
PubMed1994

Specific interference with the determination of the tumour-associated glycoprotein 72 by human anti-idiotypic antibodies formed after treatment with the anti-tumour-associated glycoprotein 72 antibody B72.3.

Recorded concentrations of the tumour-associated glycoprotein 72 (TAG-72) in ovarian cancer patients after repeated infusion of the antibody B72.3 were found to be falsely elevated when measured with an homologous immunometric assay involving the anti-TAG-72 antibody B72.3 (Test 1), or with an heterologous assay involving CC49 capture and B72.3 detector antibodies (Test 2). Test 1 yielded falsely elevated values up to 10(4) kU/l. Test 2 gave slightly false positive elevations up to 10(2) kU/l for only some of the samples with very high false-positive values in Test 1. The interfering serum components bound to Protein G-Sepharose and could be precipitated with perchloric acid or by heating serum samples to 100 degrees C. Addition of non-specific murine immunoglobulins only partly suppressed false-positive values in both tests. Our results suggest that this interference is caused by human anti-B72.3 IgG induced by B72.3 application, which to some extent specifically binds to determinants of the B72.3 antibody. Heat extraction of serum samples effectively eliminated interferences probably caused by anti-idiotypic antibodies, but did not affect real TAG-72.

Animals↗
PubMed1996

Rapid sampling, cell inactivation and evaluation of low extracellular glucose concentrations during fed-batch cultivation.

A method for rapid extracellular sampling, cell inactivation and handling of a large number samples has been developed and evaluated. This method might be used during experiments, where concentrations of extracellular components in the range of some milligrams per litre has to be evaluated. The analysis should be performed by enzymatic or colorimetric analysis and is shown to be suitable for measuring low nutrient concentrations present in fed-batch cultivation. The test organisms were Escherichia coli and Saccharomyces cerevisiae and the model substance was glucose. Using this technique, the sample can be taken in less than 0.15 s, a time during which negligible glucose is shown to be consumed from the sample. The glucose consumption is stopped by a rapid pH decrease using perchloric acid in a defined concentration that depended on the organism studied. This concentration was chosen in order to avoid cell lysis that could affect the glucose concentration by the intracellular release of glucose containing compounds and thereby expose them to the acid. It was seen that the sample mixed rapidly with the acid and that no hydrolysis of glucose related compounds interfered with the analysis. The samples were neutralised and the precipitation centrifuged to minimise the effect on the chosen enzymatic analysis. This analysis was modified and the accuracy determined in order to analyse concentrations in the milligram range. A method to increase the handling of a large number of samples was also devised which is based on measurements on microtiter plates and allows samples to be evaluated with a high statistical accuracy with minimum sample waste in a short time. The ability of the method is shown by a study of the metabolic response of a shift in glucose feed, as followed by glucose analysis.

Cell Division↗
PubMed2004

Spectrophotometric determination of clozapine based on its oxidation with bromate in a micellar medium.

A simple and sensitive spectrophotometric method was developed for the determination of clozapine in its dosage forms. The method is based on the reaction of the drug with potassium bromate in a perchloric acid medium to produce an intense yellow colored species exhibiting a maximum absorption at 308 nm. Beer's law is obeyed for up to 12.0 microg ml(-1) with a correlation coefficient (n = 6) of 0.9998 and a detection limit (3S(b)) of 0.1 microg ml(-1). The molar absorptivity is 1.986 x 10(4) l mol(-1) cm(-1). The various experimental parameters affecting the development and stability of the colored oxidation product were carefully studied and optimized. The proposed method was successfully applied to the determination of clozapine in its dosage forms. The results obtained were in good agreement with those obtained using the B.P. official method.

Antipsychotic Agents↗
PubMed1994

31P and 13C nuclear magnetic resonance studies of macrophages.

Biochemical events associated with differentiation and activation of monocyte-macrophage cell lines are of major interest in the understanding of pathophysiological processes as well as in research on immunopharmacological modulation of these cells. Nuclear magnetic resonance is the technique of choice for kinetic studies of metabolic events under such experimental conditions. This approach was used with the P388-D1 model of mature macrophages. Cells primed in vivo were triggered in vitro during NMR analysis and the results were compared to those from chemiluminescence tests performed simultaneously. Three preliminary phases were achieved: (i) 31P and 13C NMR spectroscopy of perchloric acid extracts, (ii) optimization of culture and perfusion conditions with validation of macrophage viability and functionality, and (iii) development of a data processing technique to improve the time resolution of kinetic studies. Based on their phosphocreatine content, cells primed in vivo exhibited maturation than control cells. After the respiratory burst of primed macrophages was triggered by concanavalin A, 31P NMR spectra reflected both a transient increase in ADP phosphorylation and intracellular acidification. 13C NMR studies indicated an acceleration of metabolism following in vitro triggering. The phenomenon was associated with an increased glucose consumption, implicating the hexose monophosphate shunt. These occurred concomitantly with the appearance of new peaks attributed to phosphorylated sugars.

Animals↗
PubMed2004

Simple and extractionless high-performance liquid chromatographic determination of rosiglitazone in human plasma and application to pharmacokinetics in humans.

A simple and extractionless HPLC method using fluorescence detection was developed for the determination of rosiglitazone in human plasma. After deproteinization using perchloric acid the plasma samples were directly injected onto the HPLC system. The mobile phase was composed of acetonitrile (52%) and 20 mm ammonium acetate (48%, pH 7.5), and analysis was run at a flow rate of 0.2 mL/min with the detector operating at 247 nm for excitation wavelength and at 367 nm for emission wavelength, respectively. The method has a mean recovery of 97%, while the intra-day and inter-day precisions were all less than 7%. This method is simple, specific, sensitive and requires only a small plasma volume with short analytical time, and is suitable for the determination of plasma rosiglitazone in routine measurements for pharmacokinetic studies.

Acetates↗
PubMed1986

Identification of phosphorylethanolamine in 31P-NMR spectra of human peripheral blood lymphocytes.

The 31P-NMR spectrum of intact human peripheral blood lymphocytes contains a large unidentified peak in the phosphomonoester region. The pH dependency of the 31P-NMR chemical shift of this peak in perchloric acid extracts of peripheral blood lymphocytes was recorded. It was compared to the pH dependency of the chemical shift of phosphorylethanolamine, phosphorylcholine, and ribose 5-phosphate in model solutions. An excellent agreement was found between the behavior of phosphorylethanolamine and the unidentified peak. To further substantiate this assignment phosphorylethanolamine was added to extracts and the pH titrations were repeated. The added phosphorylethanolamine gave exactly the same chemical shift as the unidentified peak and no difference was observed with pH titrations. The concentration of phosphorylethanolamine in human peripheral blood lymphocytes was estimated by 31P NMR to be 2.4 mumol/10(9) cells (range 0.9-4.3/10(9) cells, n = 4).

Animals↗
PubMed1995

HPLC with o-phthalaldehyde precolumn derivatization to measure total, oxidized, and protein-bound glutathione in blood, plasma, and tissue.

This HPLC assay with o-phthalaldehyde precolumn derivatization is used to measure the total, oxidized, and protein-bound forms of glutathione in human blood, plasma, and rat tissue. Total glutathione (i.e., sum of reduced, oxidized, and protein-bound fractions) was determined after reduction with dithiothreitol and protein precipitation with perchloric acid (PCA). A preliminary selective blockage of free sulfhydryl groups with N-ethylmaleimide was necessary to evaluate the different oxidized forms. The assay showed high sensitivity (< 0.05 pmol injected) and good precision (within-day CVs of 5.5% to 6.4%), recovery (101% +/- 4%), and linearity (r > 0.999). Samples, after PCA acidification, were stable at room temperature and 4 degrees C for 3 days, and at -20 degrees C and -80 degrees C for > 1 month. The method (involving automated derivatization) not only is very rapid and simple but also allows immediate processing of many different biological samples.

Animals↗
PubMed1998

Simple high-performance liquid chromatography method for the simultaneous determination of serum caffeine and paraxanthine following rapid sample preparation.

A simple reversed-phase high-performance liquid chromatography (HPLC) method for the simultaneous determination of caffeine and paraxanthine in human serum is described. Serum proteins are precipitated with perchloric acid and the resulting supernatant neutralized for direct injection onto an HPLC column. The method uses a phosphate-methanol mobile phase (85:15, v/v) at pH 4.9 with a flow-rate of 1.75 ml/min and quantitation is by UV absorbance at 274 nm. Elution times are approximately 18 min for caffeine and 8 min for paraxanthine. Theobromine and theophylline have elution times of 5.4 and 9.4 min and do not interfere in the assay. The intra-assay and between-assay means for precision and accuracy for both drugs are: 4.5% C.V. and 3.3% deviation. The sensitivity of the method is 50 ng/ml for each drug.

Caffeine↗
PubMed1991

Ion chromatographic methods for the detection of starch hydrolysis products in ruminal digesta.

Dionex high-performance ion chromatographic methods were evaluated for separation and quantitation of plant sugars and starch digestion products in the ruminal digesta of cattle. Mono- and disaccharides were eluted from a Dionex CarboPac PA1 column with sodium hydroxide used isocratically or as a pH gradient. Maltooligosaccharides which had a degree of polymerization (DP) less than 30 glucose residues were eluted in 60 min by a sodium hydroxide eluent containing a sodium acetate gradient. Carbohydrates were detected amperometrically. Responses were linear (r2 greater than 0.99) for glucose, disaccharides and maltooligosaccharides (DP less than 8). Precipitation and solid-phase extraction methods were evaluated for clean-up of samples of feedstuffs, ruminal contents, and bacterial culture fluids. Perchloric acid precipitation hydrolyzed sucrose but did not affect recoveries of cellobiose, isomaltose or maltose. Ethanol in concentrations of 79 and 86% precipitated maltooligosaccharides having chain lengths larger than 14 and 9 glucose residues, respectively. Maltooligosaccharide recoveries from solid-phase extraction columns varied with maltooligosaccharide size and column packing. Recoveries were greater than 94% for short chains (DP less than 6) eluted from phenyl-substituted columns and variable for all oligosaccharides eluted from C18 columns. Applications of these methods are presented and include: (1) detection of sugars in ruminant feed, (2) monitoring changes in ruminal sugars after feeding and (3) monitoring changes in extracellular sugars and oligosaccharides in the culture fluids of the ruminal bacterium, Bacteroides ruminicola.

Animals↗
PubMed1999

Detection of dexamethasone in the cornea and lens by NMR spectroscopy.

BACKGROUND: To study the penetration and metabolism of dexamethasone phosphate in the cornea and lens from rabbit following topical administration. METHODS: After topical administration of 0.1, 1 and 10% dexamethasone phosphate solutions, respectively, the cornea and lens were removed and extracted with either perchloric acid (PCA) or with chloroform/methanol to study the lipophilic and hydrophilic metabolites of the drug. The extracts were analyzed with 1H and 19F NMR spectroscopy. RESULTS: Using 19F NMR spectroscopy, both dexamethasone and dexamethasone phosphate were detected simultaneously in the extract of the cornea and lens obtained from the eyes denuded of the epithelium before the treatment. Using 10 and 1% drug solutions, the signals from dexamethasone were also detectable in the 1H NMR spectra among many endogenous metabolites. CONCLUSION: 1H and 19F NMR spectroscopy was shown to be a useful method in the study of penetration and metabolism of dexamethasone in the eye, particularly because both the lipophilic and hydrophilic metabolites of the drug could be detected simultaneously.

Animals↗
PubMed1990

Distribution of high mobility group proteins in different tissues of rats during aging.

The distribution of high mobility group (HMG) proteins has been studied in the liver, brain, kidney, lung, spleen, testis, thymus, and heart of young (19 weeks) and old (118 weeks) rats. These proteins were extracted with perchloric acid, fractionated by CM-Sephadex column chromatography, and analysed by acetic acid-urea polyacrylamide slab gel electrophoresis. As compared with that in young rats, the level of total HMG proteins in the old increased in liver and lung, decreased in thymus, heart, brain, and kidney, and remained unchanged in spleen and testis. In particular, the levels of HMG 1 and 2 were maximum in the thymus of young rats and dropped drastically in the old. However, the amount of HMG 17 was high in the spleen of both young and old rats, though it was comparatively higher in the former. Such age-dependent variation in the level of HMG proteins of different tissues denotes indirectly differences in the functional state of chromatin, and in growth and activity of cells, during aging.

Aging↗