scholarly journals Evaluation of Interferences in Rate and Fixed-Time Nephelometric Assays of Specific Serum Proteins

1999 ◽  
Vol 45 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Xavier Bossuyt ◽  
Norbert Blanckaert
Keyword(s):  
Serum Proteins ◽  
Fixed Time ◽  
The Other ◽  
Serum Samples ◽  
Negative Interference ◽  
Specific Serum ◽  
Interference Studies ◽  
Good Agreement

Abstract We performed interference studies for IgG, IgA, IgM, haptoglobin, and α1-antitrypsin assayed in serum, using either fixed-time nephelometry on the BN 100 from Behring or rate nephelometry on two analyzers from Beckman Instruments. For clear serum samples, results for IgG, IgA, IgM, and haptoglobin obtained with the three nephelometers showed good agreement. Values for α1-antitrypsin in clear sera were lower with the BN 100 than with the Array 360 or Immage. In lipemic samples, the BN 100 gave higher values than the Array 360 or Immage for all analytes except IgG. Addition of Intralipid to serum produced atypical reactions with the BN 100 (fixed-time nephelometry) but not with the Array 360 or Immage (rate nephelometry). The interference of lipemia on the BN 100 was also seen when the Beckman antibody was used, indicating that the effect was reagent-independent. For hemolyzed samples, the BN 100 gave higher values than the Array 360 or Immage for haptoglobin but not for the other analytes. Addition of increasing amounts of a hemolysate to serum revealed a negative interference in all assay systems. This effect was more pronounced with the Beckman reagent than with the Behring reagent in all three nephelometers and was independent of the type of instrument (fixed-time vs rate nephelometry).

scholarly journals Kinetic Spectrophotometric Method for the Determination of Ranitidine and Nizatidine in Pharmaceuticals

2002 ◽  
Vol 85 (6) ◽  
pp. 1316-1323 ◽  
Author(s):  
Mohamed I Walash ◽  
Fathalla Belal ◽  
Fawzia Ibrahim ◽  
Mohamed Hefnawy ◽  
Manal Eid
Keyword(s):  
Spectrophotometric Method ◽  
Reaction Pathway ◽  
Kinetic Method ◽  
Fixed Time ◽  
Borate Buffer ◽  
The Other ◽  
Average Recovery ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

Abstract An accurate and simple kinetic method is described for the determination of ranitidine and nizatidine in pure form and in pharmaceuticals. The method is based on the reaction of the compounds with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole in pH 7.4 borate buffer at 60°C for a fixed time of 25 min for both compounds. The absorbance of the reaction product is measured at 495 nm for ranitidine and nizatidine. Calibration graphs were linear over the concentration range of 2–20 μg/mL, with limits of detection of 0.13 (3.7 × 10−7M) and 0.25 μg/mL (7.5 × 10−7M) for ranitidine and nizatidine, respectively. The proposed method was applied successfully to the determination of ranitidine in tablets and ampoules with average recoveries of 100.26 ± 0.69 and 100.29 ± 0.59%, respectively, and to the determination of nizatidine in capsules with an average recovery of 104.26 ± 0.44%. The results obtained are in good agreement with those obtained by the other methods used for comparison. A proposal of the reaction pathway is also presented.

151 PROTEOMICS ANALYSIS OF PREGNANCY-SPECIFIC SERUM PROTEINS IN BOVINE

2006 ◽  
Vol 18 (2) ◽  
pp. 183 ◽  
Author(s):  
D. I. Jin ◽  
H. R. Lee ◽  
H. R. Kim ◽  
H. J. Lee ◽  
J. T. Yoon ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Early Pregnancy ◽  
Serum Proteins ◽  
Optical Resolution ◽  
Variable Region ◽  
Serum Samples ◽  
Proteomics Analysis ◽  
Specific Serum ◽  
Specific Proteins ◽  
Immunoglobulin Gamma

To identify early pregnancy-specific serum proteins in bovine, we performed proteomics analysis using blood serum samples of pregnant and non-pregnant Holstein dairy cattle Days 21 and 35 after AI. A total of eight pregnant and eight non-pregnant cattle were used for collection of the blood samples. The global proteomics approach was exploited by the use of 2-D gel electrophoresis and mass spectrometry to sort out pregnancy-specific proteins. Serum proteins within isoelectric point ranges of 4.0 to 7.0, 6.0 to 9.0, and 5.5 to 6.7 were analyzed separately by 2-D electrophoresis with three replications of each sample. The stained gels were scanned and calibrated at an optical resolution of 63.5 �m/pixel using a GS-710 imaging densitometer (Bio-Rad Laboratories, Philadelphia, PA, USA). A total of approximately 1200 spots were detected in 2-D gels stained with Coomassie-blue. In the comparison of serum samples from pregnant and non-pregnant cattle, nine pregnancy-specific spots were detected unanimously in Day 21 and Day 35 serum samples. Pregnancy-specific proteins were identified as transferrin, albumin, IgG2a heavy chain constant region, and immunoglobulin gamma heavy chain variable region by means of MALDI-TOF-MS (PerSeptive Biosystems, Framingham, MA, USA). Even though the identified spots were abundant serum proteins, their molecular weights and pI values were different from those of the main serum proteins. Most proteins identified in this analysis appeared to be related with pregnancy-specific subunits or fragments of transferrin, albumin, and IgG. One of the pregnancy-specific proteins, transferrin, is known to be related to iron transport during pregnancy. Western blot analysis using polyclonal anti-transferrin antibody revealed specific transferrin expression in the serum samples from the pregnant cattle but no detectable expression in the serum samples from the non-pregnant cattle. Our results revealed composite profiles of key proteins involved in early pregnancy and suggest the potential use of identified proteins to detect early pregnancy in bovine.

scholarly journals Computer-supported Detection of M-Components and Evaluation of Immunoglobulins after Capillary Electrophoresis

2001 ◽  
Vol 47 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Magnus Jonsson ◽  
Joyce Carlson ◽  
Jan-Olof Jeppsson ◽  
Per Simonsson
Keyword(s):  
Capillary Electrophoresis ◽  
Decision Support ◽  
Protein Separation ◽  
Serum Proteins ◽  
Cost Effective ◽  
Clinical Samples ◽  
Serum Samples ◽  
Computerized Decision Support ◽  
Cost Effective Method ◽  
Mathematical Algorithms

Abstract Background: Electrophoresis of serum samples allows detection of monoclonal gammopathies indicative of multiple myeloma, Waldenström macroglobulinemia, monoclonal gammopathy of undetermined significance, and amyloidosis. Present methods of high-resolution agarose gel electrophoresis (HRAGE) and immunofixation electrophoresis (IFE) are manual and labor-intensive. Capillary zone electrophoresis (CZE) allows rapid automated protein separation and produces digital absorbance data, appropriate as input for a computerized decision support system. Methods: Using the Beckman Paragon CZE 2000 instrument, we analyzed 711 routine clinical samples, including 95 monoclonal components (MCs) and 9 cases of Bence Jones myeloma, in both the CZE and HRAGE systems. Mathematical algorithms developed for the detection of monoclonal immunoglobulins (MCs) in the γ- and β-regions of the electropherogram were tested on the entire material. Additional algorithms evaluating oligoclonality and polyclonal concentrations of immunoglobulins were also tested. Results: CZE electropherograms corresponded well with HRAGE. Only one IgG MC of 1 g/L, visible on HRAGE, was not visible after CZE. Algorithms detected 94 of 95 MCs (98.9%) and 100% of those visible after CZE. Of 607 samples lacking an MC on HRAGE, only 3 were identified by the algorithms (specificity, 99%). Algorithms evaluating total gammaglobulinemia and oligoclonality also identified several cases of Bence Jones myeloma. Conclusions: The use of capillary electrophoresis provides a modern, rapid, and cost-effective method of analyzing serum proteins. The additional option of computerized decision support, which provides rapid and standardized interpretations, should increase the clinical availability and usefulness of protein analyses in the future.

scholarly journals Responses of the Pheromone-Binding Protein of the Silk Moth Bombyx mori on a Graphene Biosensor Match Binding Constants in Solution

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 499
Author(s):  
Caroline Bonazza ◽  
Jiao Zhu ◽  
Roger Hasler ◽  
Rosa Mastrogiacomo ◽  
Paolo Pelosi ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Binding Protein ◽  
Binding Constants ◽  
Isoamyl Acetate ◽  
The Other ◽  
Oxide Surface ◽  
Binding Assays ◽  
Pheromone Binding Protein ◽  
Silk Moth ◽  
Good Agreement

An electronic biosensor for odors was assembled by immobilizing the silk moth Bombyx mori pheromone binding protein (BmorPBP1) on a reduced graphene oxide surface of a field-effect transistor. At physiological pH, the sensor detects the B. mori pheromones, bombykol and bombykal, with good affinity and specificity. Among the other odorants tested, only eugenol elicited a strong signal, while terpenoids and other odorants (linalool, geraniol, isoamyl acetate, and 2-isobutyl-3-methoxypyrazine) produced only very weak responses. Parallel binding assays were performed with the same protein and the same ligands, using the common fluorescence approach adopted for similar proteins. The results are in good agreement with the sensor’s responses: bombykol and bombykal, together with eugenol, proved to be strong ligands, while the other compounds showed only poor affinity. When tested at pH 4, the protein failed to bind bombykol both in solution and when immobilized on the sensor. This result further indicates that the BmorPBP1 retains its full activity when immobilized on a surface, including the conformational change observed in acidic conditions. The good agreement between fluorescence assays and sensor responses suggests that ligand-binding assays in solution can be used to screen mutants of a binding protein when selecting the best form to be immobilized on a biosensor.

scholarly journals Associations between the thyroid panel and serum protein concentrations across pregnancy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Barbara Lisowska-Myjak ◽  
Agnieszka Strawa ◽  
Hanna Zborowska ◽  
Artur Jakimiuk ◽  
Ewa Skarżyńska
Keyword(s):  
Serum Proteins ◽  
Thyroid Stimulating Hormone ◽  
Second Trimester ◽  
Serum Concentrations ◽  
Metabolic Processes ◽  
Serum Samples ◽  
Serum Parameters ◽  
Active Regulation ◽  
Potential Use

AbstractEstablishing any characteristic associations between the serum parameters of thyroid function and serum proteins in pregnancy may aid in elucidating the role of the thyroid gland in the regulation of pregnancy-specific metabolic processes and in selecting candidate biomarkers for use in their clinical assessment. Concentrations of thyroid stimulating hormone (TSH), free tri-iodothyronine (fT3) and free thyroxine (fT4), six electrophoretically separated protein fractions (albumin, alpha-1-, alpha2-, beta-1-, beta-2- and gamma-globulins), representative proteins—albumin (ALB), transferrin (TRF), alpha-2-macroglobulin (AMG) and ceruloplasmin (CER) were measured in 136 serum samples from 65 women in their consecutive trimesters of pregnancy. The concentrations of TSH, fT4 and fT3 were significantly correlated (p < 0.05) with the concentrations of the albumin, alpha-2- and beta-1 globulin fractions. Significant correlations (p < 0.05) which were positive between fT4 and ALB and negative between fT4 and TRF were established throughout pregnancy. Significant negative correlations (p < 0.05) were demonstrated for fT3 with alpha-2-globulin, AMG and CER. Changes in the serum concentrations of thyroid hormones seen between the trimesters were found to correlate with the concentrations of high-abundance serum proteins. Opposite directions of correlations between fT4 and ALB and fT4 and TRF observed throughout pregnancy may indicate the shared biological role of these parameters in maintaining maternal homeostasis and they suggest their potential use in the clinic as a simple biomarker panel. A negative correlation of fT3 with CER in the second trimester possibly reflects their involvement in the active regulation of metabolic processes.

scholarly journals Quantification of Serum Proteins Using Capillary Electrophoresis

1995 ◽  
Vol 32 (5) ◽  
pp. 493-497 ◽  
Author(s):  
M A Jenkins ◽  
M D Guerin
Keyword(s):  
Capillary Electrophoresis ◽  
Gel Electrophoresis ◽  
Serum Proteins ◽  
Clinical Laboratory ◽  
Charged Particles ◽  
Protein Electrophoresis ◽  
Agarose Gel Electrophoresis ◽  
Serum Samples ◽  
Routine Clinical Laboratory ◽  
Sample Dilution

Capillary electrophoresis is a technique that can be automated for the separation of charged particles. By investigating suitable sample dilution and injection time and adhering to a strict washing procedure we have been able to quantify paraproteins in serum samples. This has enabled us to use the technique of capillary electrophoresis for the provision of serum protein electrophoresis in a routine clinical laboratory. We present our findings of 260 serum samples, which included 76 samples with paraproteins analysed by both capillary electrophoresis (EC) and high resolution agarose gel electrophoresis (HRAGE). CE was able to detect all the monoclonal bands detected by HRAGE, and, in particular, better able to detect IgA monoclonal bands occurring in the beta region. The major advantages of CE over HRAGE relate to the automated nature of CE with the elimination of the need for a densitometer.

APPLICATION OF A NEW HAMILTONIAN OF INTERACTION TO THREE-DIMENSIONAL STRUCTURES

2004 ◽  
Vol 18 (09) ◽  
pp. 1351-1368
Author(s):  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN ◽  
VOICU DOLOCAN
Keyword(s):  
Experimental Data ◽  
Cohesive Energy ◽  
Noble Gases ◽  
Three Dimensional ◽  
The Other ◽  
Ionic Crystals ◽  
Coupling Constant ◽  
Good Agreement

Using a new Hamiltonian of interaction we have calculated the cohesive energy in three-dimensional structures. We have found the news dependences of this energy on the distance between the atoms. The obtained results are in a good agreement with experimental data in ionic, covalent and noble gases crystals. The coupling constant γ between the interacting field and the atoms is somewhat smaller than unity in ionic crystals and is some larger than unity in covalent and noble gases crystals. The formulae found by us are general and may be applied, also, to the other types of interactions, for example, gravitational interactions.

Detection of Protein Changes in Serum of Workers following Inhalation Exposure to Toluene Diisocyanate Vapors

1992 ◽  
Vol 8 (6) ◽  
pp. 407-413 ◽  
Author(s):  
Adam B. Czuppon ◽  
Boleslaw Marczynski ◽  
Xaver Baur
Keyword(s):  
Serum Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Inhalation Exposure ◽  
Staining Intensity ◽  
Peak Height ◽  
Toluene Diisocyanate ◽  
Serum Samples ◽  
Chi Square ◽  
Challenge Tests

Serum samples of 10 workers undergoing occupational type inhalative challenge tests by toluene diisocyanate (TDI) were investigated by anion-exchange fast-protein-liquid-chromatography (FPLC) and polyacrylamide-gel electrophoresis (PAGE-SDS). Their serum chromatography profiles were compared to those of 20 unexposed individuals. The peak height of the first prealbumin peak in sera of workers after inhalative challenge tests was significantly different (p > 0, 01 Chi-square test) compared to that obtained before exposure and to that of unexposed subjects. In addition, qualitative changes of these peaks were also noted in sera of workers exposed to TDI. In the cases of exposed individuals, that peak was more diffuse with some shoulders and less symmetric in appearance. Similarly, PAGE-SDS of the serum proteins, followed by silver nitrate staining, revealed a different banding pattern after in vivo TDI exposure. One of the serum components at approximately 15 kD showed an increase of staining intensity after exposure (n = 10), compared to unexposed subjects or to patients before exposure. This serum fraction has not yet been identified. The results here demonstrate that it is possible to detect changes of serum proteins in TDI-exposed individuals within a relatively short analysis time. This could be useful for biological monitoring of exposure, since no method for such is yet available.

Immune responses of Texel sheep to excretory/secretory products of adult Haemonchus contortus

Parasitology ◽  
1994 ◽  
Vol 108 (3) ◽  
pp. 351-357 ◽  
Author(s):  
H. D. F. H. Schallig ◽  
M. A. W. van Leeuwen ◽  
W. M. L. Hendrikx
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Haemonchus Contortus ◽  
Lymphocyte Proliferation ◽  
The Other ◽  
Proliferation Index ◽  
Serum Samples ◽  
Immunoblotting Analysis ◽  
Molecular Weights ◽  
Secretory Products

SUMMARYThe excretory/secretory (E/S) products of adult Haemonchus contortus comprise of at least 15 polypeptides with molecular weights ranging from 10 to > 100 kDa. These E/S products induce an immune response in infected Texel sheep, as demonstrated by specific IgGI levels and a significant lymphocyte proliferation index. Moreover, immunoblotting analysis revealed that sera of primary H. contortus-infected sheep specifically recognize a 24 kDa E/S product. In addition, sera of challenged sheep react strongly with a 15 kDa E/S product. The other E/S products of H. contortus showed immunoreactivity with serum samples of Haemonchus-infected sheep as well as with samples of sheep harbouring other trichostrongylid infections. These cross-reacting epitopes are the main cause of the lack of specificity of an E/S material- based ELISA. This ELISA can differentiate Haemonchus infections from Nematodirus battus infections, but not from Ostertagia circumcincta or Trichostrongylus colubriformis infections.

The Structural Framework of Pictorial Balance

Perception ◽  
1996 ◽  
Vol 25 (12) ◽  
pp. 1419-1436 ◽  
Author(s):  
Paul Locher ◽  
Sharon Gray ◽  
Calvin Nodine
Keyword(s):  
Visual Arts ◽  
Structural Features ◽  
Original Compositions ◽  
The Other ◽  
Global Integration ◽  
Artistic Style ◽  
Structural Framework ◽  
Museum Professionals ◽  
Balance Structure ◽  
Good Agreement

Two experiments were performed to examine how the subjective balance of a painting is created by its structural features and to determine if balance influences the way people look at paintings. Stimuli consisted of sixteen reproductions of twentieth-century paintings varying in artistic style and a reconstructed less-balanced version of each. Participants in experiment 1 determined the location of the balance center of each composition, assigned ‘weights’ to the pictorial features which contributed to the location of the balance center, and rated the picture for balance. It was found that design and museum professionals and individuals untrained in the visual arts were in good agreement as to the structural framework underlying the balance organization of a painting. For all participants, disruption of the balanced organizations of the original compositions led to reliable shifts in the location of the perceived balance centers of the originals compared with their less-balanced perturbations. Additionally, it was observed that particular features as such were not the origin of the balance phenomenon; rather, judgments concerning the balance structure and its center were dependent on the global integration of information across a wide area of the display field, but especially from its central region. Last, the subtle changes in balance structure between versions resulted in lower ratings of balance being assigned to the less-balanced perturbations by the design professionals only; the other two participant groups evaluated overall balance of the versions as comparable. In experiment 2, eye movements of a different group of untrained individuals were recorded as they performed similar tasks on the art stimuli. It was found that disruption of the balance structure of the original representational but not abstract compositions resulted in different regions of the original and perturbed versions being visually explored. Findings of both experiments are related to theoretical notions of balance.

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