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At least 1,531 records · Page 85Linked to original sources
PubMed1984

A solid-phase, enzyme-linked immunosorbent assay for a human lung tumor-associated antigen.

A solid-phase, enzyme-linked immunosorbent assay (ELISA) for a human lung tumor-associated antigen (LTA) was based on immobilized LTA that was detected with the use of an antiserum raised in a goat against a highly purified antigen preparation. Bound goat antibodies were detected in a series of steps that included incubation with a) biotinylated rabbit antibodies to goat immunoglobulins, b) glucose oxidase conjugated to avidin, and c) peroxidase and the substrates glucose and 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid). The absorbance of the final product was measured at 405 nm, and its formation was dependent on substrate incubation time and antibody concentration. The antigen was immobilized and highly purified, and the goat antiserum was bound to and eluted from an immobilized crude antigen column before use. The ELISA could detect less than 1 ng antigen and was able to discriminate extracts of normal lung tissue from those of lung tumor. As was found earlier with a radioimmunoassay for the same antigen, normal human serum could inhibit in the ELISA but only when used at high concentration, indicating levels of antigen or antigen-like activity in the 100-200 ng/ml range. With the use of this assay, 3 lung cancer patients were monitored 6-12 months prior to death. In all 3 patients, LTA levels rose dramatically 2-4 months before the patients died; in 2 patients the levels exceeded 3,000 ng/ml just before death. In contrast, in 2 of these patients, carcinoembryonic antigen levels remained essentially unchanged, with no more than a twofold increase prior to death.

Antigen-Antibody Reactions↗
PubMed1978

Multilayer film elements for clinical analysis: general concepts.

Dry, thin films containing all necessary reagents for clinical analysis by colorimetry have been designed. Reagents in a matrix of hydrophilic polymer are coated on top of a transparent plastic base. A white isotropically porous polymer spreading layer, 80% void volume, is coated over the reagent layer(s). In the analysis, a drop (typically 10 microliter) of undiluted serum or other fluid is touched to the spreading layer. The fluid spreads rapidly and uniformly through the pore structure, filling a void volume corresponding to the drop volume. Water and low-molecular-weight components diffuse from the spreading layer into the reagent layer(s), initiating the reaction sequence. The spreading layer acts also as a white optical diffuser for reflection densitometry. Optical reflection density is linearized through use of the function developed by Williams and Clapper [J. Opt. Soc. Am. 43, 595 (1953)] to convert reflection to transmission density. A wide variety of chemical assays are compatible with this format. As an example, for the glucose film we found coefficients of variation of 1.5% in predicting glucose concentrations in control sera during 20 days. Results for glucose concentrations in several hundred patients' sera by the present method were very cose to those obtained with the Center for Disease Control's hexokinase reference method.

Blood Glucose↗
PubMed1978

Organization and projections of the neurons in the dorsal tegmental area of the rat.

The organization and projection of the neurons in the dorsal tegmental area at the locus coeruleus level of the rat have been investigated by means of the horseradish peroxidase (HRP) method, combined with monoamine oxidase staining to identify the noradrenaline (NA) neurons. Judging from the anatomical aspects elucidated in this study, this area is composed of various different cell groups. Although the functional role of these neuronal groups remains to be determined, the present study strongly suggests that the dorsal tegmental area participates in important regulation of several brain functions.

Animals↗
PubMed1977

Identification of glycoproteins and proteins at synapses in the central nervous system.

Synaptic plasma membranes, synaptic junctions, and postsynaptic densities have been isolated from rat brain, the proteins resolved by polyacrylamide gel electrophoresis, and the glycoproteins identified. The synaptic junction is composed of a spectrum of polypeptides which range in Mr from 13,000 to 250,000. The overall pattern is similar to synaptic plasma memranes; however, the relative proportions of the polypeptides are distinctive. The postsynaptic density fraction consists primarily of one band with an Mr of 52,000. Polypeptides with an Mr of 55,000, and another five of higher Mr, make up the remaining protein. The polypeptides of the postsynaptic density fraction must be reduced with mercaptoethanol in order to permeate the polyacrylamide gel. Therefore, postsynaptic density proteins are cross-linked by disulfide bonds into supramacromolecular aggregates. Glycoproteins which bind concanavalin A were identified in synaptic junctions by studying the binding of 123I-concanavalin A directly to the polypeptides resolved on the polyacrylamide gels. Only four bands, each with an Mr greater than 95,000, bind concanavalin A. In contrast, the pattern of concanavalin A-binding polypeptides in synaptic plasma membranes is distinctive and more complex. In the postsynaptic density fraction, most of the concanavalin A binding occurs to a glyco-component which migrates at the dye front. These data, together with previous cytochemical data using concanavalin A-ferritin conjugates, indicate a limited and select group of high Mr concanavalin A glycoproteins resides within the synaptic cleft of asymmetric type synapses. Whereas a select group of polypeptides bind concanavalin A, all polypeptides resolved in the synaptic junction fraction are glycoproteins and contain galactosyl or galactosyl-like residues, since they label with tritiated borohydride following galactose oxidase treatment. This suggests that the carbohydrate composition of individual glycoproteins is different.

Animals↗
PubMed1995

Tear glucose estimation--an alternative to blood glucose estimation.

Dextrostix, being very sensitive to measure glucose level by glucose oxidase method, was chosen to measure tear glucose level to evaluate the relationship of tear glucose to blood glucose level in 94 cases. It was found that in our population the measurement of tear glucose has definite value in interpretation of glucose status of individual. So, it was suggested to use this simple method of detection of tear glucose to interpret hyperglycaemic state of the patients. The present study was undertaken (1) to sort out a definite relationship between tear and plasma glucose concentration and (2) to devise a rapid method for detection of tear glucose level semiquantitatively with glucose oxidase impregnated strips and to evaluate its role as indicator of plasma glucose level.

Blood Glucose↗
PubMed1996

Chronic tonsillitis in children: activation of polymorphonuclear cells from peripheral blood and tonsillar tissue. In vitro production of MPO, ECP and EPX.

Activation of polymorphonuclear cells (PMNs), neutrophils and eosinophils, occurs in response to infections. Myeloperoxidase (MPO) is an enzyme contained in neutrophils with toxic activity for many microorganisms including bacteria. Fosinophil cationic protein (ECP) and eosinophil X protein (EPX) are released by activated eosinophils in response to different inflammatory stimuli. Determination of serum levels of MPO, ECP and EPX permits assessment of the state of activation of these cells. The purpose of this study was to evaluate the state of activation of neutrophils and eosinophils present in tonsillar tissue and peripheral blood from 30 children (18 boys and 12 girls) undergoing tonsillectomy for chronic tonsillitis. For determination of serum levels of MPO, ECP and EPX, peripheral blood samples were obtained at the time of surgery: PMNs were separated by erythrosedimentation from peripheral blood and from tonsillar tissue after surgery and cultured for 7 days. The cells were plated (10(5) well) and the plates were incubated in 5% CO(2), 7% O(2), 80% N(2). After 2, 24, 48, 72, 96, 120, 144 h, supernatants were removed from the cultures of both tonsillar tissue and peripheral blood PMNs for determination of in vitro release of MPO, ECP and EPX. The assays were carried out using a radioimmunotechnique (RIA, Pharmacia) and the concentrations of the three proteins (mean/6 wells) for each time were expressed in mu g/l. The data suggest activation of PMNs in children with chronic tonsillitis.

Adult↗
PubMed1977

[Continuous flow measurement of glycemia by the modified Trinder method].

An automatic continuous flow method on autoanalyser of the second generation is described. The peculiarity of this work was the presentation of a manifold glucose oxydase consuming little reagent compared with those at present in daily use. A study concerning the precision, the reproducibility and the contamination is presented. Correlations with a hexokinase technic together with the possibility of working at a wavelength of 340 nm are also studied.

Autoanalysis↗
PubMed2004

The role of enzymes produced by white-rot fungus Irpex lacteus in the decolorization of the textile industry effluent.

The textile industry wastewater has been decolorized efficiently by the white rot fungus, Irpex lacteus, without adding any chemicals. The degree of the decolorization of the dye effluent by shaking or stationary cultures is 59 and 93%, respectively, on the 8th day. The higher level of manganese-dependent peroxidase (MnP) and non-specific peroxidase (NsP) was detected in stationary cultures than in the cultures shaken. Laccase activities were equivalent in both cultures and its level was not affected significantly by the culture duration. Neither lignin peroxidase (LiP) nor Remazol Brilliant Blue R oxidase (RBBR ox) was detected in both cultures. The absorbance of the dye effluent was significantly decreased by the stationary culture filtrate of 7 days in the absence of Mn (II) and veratryl alcohol. In the stationary culture filtrate, three or more additional peroxidase bands were detected by the zymogram analysis.

Basidiomycota↗
PubMedDate not supplied

[Study of monoamine oxidase from human placenta mitochondria by the chemoluminescence method].

The activity of monoamine oxidase from human placenta mitochondria was determined with 2-phenylethylamine and benzylamine as substrates by the generation of hydrogen peroxide in a conjugated luminol-peroxidase system, using the chemiluminescence method. The monoamine oxidase was found to oxidize at a high rate MAO substrates and revealed high sensitivity to clorgyline, a specific inhibitor of monoamine oxidase type A. It was shown that the use of the chemiluminescence technique for determining the monoamine oxidase activity gives the results that are fully consistent with those obtained by other methods.

Female↗
PubMed2001

Effects of inhibitors on chicken polymorphonuclear leukocyte oxygenation activity measured by use of selective chemiluminigenic substrates.

Chicken heterophil polymorphonuclear leukocytes (CPMNLs) have NADPH oxidase activity, but lack myeloperoxidase (MPO). Stimulation of CPMNLs by phorbol 12-myristate 13-acetate or chicken opsonified zymosan results in luminol-dependent chemiluminescence (CL) activity, which is small relative to that of human peroxidase-positive neutrophils (HPMNLs), as well as lucigenin-dependent CL, comparable to HPMNL responses. Inhibitors were used to investigate and characterize the CL activity of CPMNLs. Inhibition constants were calculated, using Dixon inhibition analysis, or were reported as the concentration producing 50% inhibition of the magnitude of CL responses. Azide and cyanide are effective inhibitors of luminol CL in HPMNLs, although these peroxidase inhibitors do not inhibit either luminol or lucigenin CL of CPMNLs. Since these agents also inhibit eosinophil peroxidase, lack of inhibition of CPMNL CL indicates that the small percentages of peroxidase-positive eosinophils in CPMNL preparations are not responsible for the luminol CL observed. Iodoacetate and fluoride, pre-oxidase and pre-peroxidase inhibitors of glycolytic metabolism, effectively inhibit lucigenin and luminol CL activities in CPMNLs. Superoxide dismutase competitively inhibits lucigenin and luminol CL in CPMNLs, but catalase is an ineffective inhibitor. Although luminol is efficiently dioxygenated by a MPO-dependent mechanism in HPMNL, use of peroxidase-deficient CPMNLs indicates that this substrate does not exclusively measure peroxidase activity.

Acridines↗
PubMed2004

Heterologous expression of lignin peroxidase of Phanerochaete chrysosporium in Pichia methanolica.

The cDNA encoding for lignin peroxidase of Phanerochaete chrysosporium was expressed in the Pichia methanolica under the control of the alcohol oxidase (AUG1) promoter which was followed by either the lignin peroxidase leader peptide of Phanerochaete chrysosporium or the Saccharomyces cerevisiae alpha-factor signal peptide. Both peptides efficiently directed the secretion of lignin peroxidase from the recombinant yeast cell. The extracellular lignin peroxidase activity in two recombinants was 932 U l(-1) and 1933 U l(-1). The purity of the recombinant product was confirmed by SDS-PAGE.

Cloning, Molecular↗