Ektachem Slides for Direct Potentiometric Determination of Sodium in Plasma: Effect of Natremia, Blood pH, and Type of Electrolyte Reference Fluid on Concordance with Flame Photometry and Other Potentiometric Methods

1992 ◽  
Vol 38 (1) ◽  
pp. 114-118 ◽  
Author(s):  
Ann Boeyckens ◽  
Jan Schots ◽  
Hugo Vandenplas ◽  
Freedy Senesael ◽  
Wim Goedhuys ◽  
...  
Keyword(s):  
Gastrointestinal Disease ◽  
Flame Photometry ◽  
Direct Potentiometry ◽  
Blood Ph ◽  
Ph Dependency ◽  
Analytical Recovery ◽  
The One

Abstract With electrolyte reference fluid (ERF)00, results from Kodak Ektachem slides for the direct potentiometric assay of sodium in plasma were significantly correlated with results from flame photometry, but also appeared to be systematically higher, especially in hypernatremic patients. Indirect potentiometry with the Technicon RA-1000 yielded intermediate values. In 23 hypernatremic patients with greater than or equal to 6 mmol/L difference in sodium between Ektachem ERF00 and flame photometry, a clinical survey disclosed the frequent association of large between-method differences with renal failure, diabetes mellitus, and gastrointestinal disease. However, there was no correlation between differences in sodium on the one hand and anion gaps or (lipo)protein concentrations on the other, nor did in vitro addition studies implicate metabolites that often accumulate in the above-mentioned disorders. Unlike indirect methods, sodium measurements by direct potentiometry on Ektachem and Corning were influenced by in vitro changes of pH between 7.0 and 7.9. However, in a group of patients that included many acidotic individuals, between-method differences in sodium appeared not significantly correlated with in vivo blood pH. Use of the equitransferant ERF04 on Ektachem strongly diminishes the systematic differences with flame photometry, reduces the pH-dependency of the results to that of the direct Corning method, and brings the mean analytical recovery of sodium to below 95% (instead of 115% previously) without affecting the ability of Ektachem slides to avoid spuriously low results in the presence of increased (monoclonal) protein concentrations.

Issues with the Assay of Factor VIII Activity in Plasma and Factor VIII Concentrates

2000 ◽  
Vol 84 (12) ◽  
pp. 942-948 ◽  
Author(s):  
Henry Kingdon ◽  
Kenneth Mann ◽  
Gilbert White ◽  
Roger Lundblad
Keyword(s):  
Factor Viii ◽  
Hemophilia A ◽  
Coagulation Factors ◽  
Chromogenic Substrate ◽  
In Vitro Measurements ◽  
Factor Viii Concentrates ◽  
The One

SummaryA review of the literature suggests that assays accurate for the determination of factor VIII in plasma samples may not necessarily retain this accuracy when used for the determination of factor VIII in high-purity factor VIII concentrates such as Hemofil ® M. Review of assay data suggests that it is imperative to obtain maximal activation of the factor VIII in the sample with thrombin when using an assay system of isolated coagulation factors such as the two-stage assay or the various chromogenic substrate assays. Based on a combination of ease and reproducibility of performance and correlation of in vivo and in vitro measurements, it is recommended that the one-stage activated partial thromboplastin time performed with plasma from an individual with severe hemophilia A be used for the measurement of factor VIII potency. Chromogenic substrate assays can be used if care is taken to assure optimal activation of factor VIII by thrombin in the assay and the presence of sufficient factor IXa, phospholipid and calcium ions to stabilize factor Villa during the assay process.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

Storage of Human Blood Platelets

1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens
Keyword(s):  
Storage Temperature ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Storage Period ◽  
Serotonin Uptake ◽  
Hypotonic Shock ◽  
Glycolytic Intermediates

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.

Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

2021 ◽  
Author(s):  
Lijuan Liu ◽  
Shengting Zhang ◽  
Xiaodan Zheng ◽  
Hongmei Li ◽  
Qi Chen ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Fusobacterium Nucleatum ◽  
Living Cells ◽  
First Time ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

Factors affecting in vitro and in vivo antioxidant effects. Experimental conditions and nature of oxidants determine antioxidant efficacy

2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki
Keyword(s):  
Biological Molecules ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Beneficial Effects ◽  
Multiple Oxidants ◽  
Antioxidant Effects

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.

Antimicrobial and antibiofilm activities of meropenem loaded-mesoporous silica nanoparticles against carbapenem-resistant Pseudomonas aeruginosa

2021 ◽  
pp. 088532822110038
Author(s):  
Mohammad Yousef Memar ◽  
Mina Yekani ◽  
Hadi Ghanbari ◽  
Edris Nabizadeh ◽  
Sepideh Zununi Vahed ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Carbapenem Resistant ◽  
Toxicity In Vitro ◽  
Different Levels

The aims of the present study were the determination of antimicrobial and antibiofilm effects of meropenem-loaded mesoporous silica nanoparticles (MSNs) on carbapenem resistant Pseudomonas aeruginosa ( P. aeruginosa) and cytotoxicity properties in vitro. The meropenem-loaded MSNs had shown antibacterial and biofilm inhibitory activities on all isolates at different levels lower than MICs and BICs of meropenem. The viability of HC-04 cells treated with serial concentrations as MICs and BICs of meropenem-loaded MSNs was 92–100%. According to the obtained results, meropenem-loaded MSNs display the significant antibacterial and antibiofilm effects against carbapenem resistant and biofilm forming P. aeruginosa and low cell toxicity in vitro. Then, the prepared system can be an appropriate option for the delivery of carbapenem for further evaluation in vivo assays.

Effect of microbial isolates on microbial yield estimation in RUSITEC system

1998 ◽  
Vol 22 ◽  
pp. 306-308
Author(s):  
M. D. Carro ◽  
E. L. Miller
Keyword(s):  
Protein Synthesis ◽  
Liquid Phase ◽  
Solid Phase ◽  
Liquid Fraction ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Continuous Culture System ◽  
The One

The estimation of rumen microbial protein synthesis is one of the main points in the nitrogen (N)-rationing systems for ruminants, as microbial protein provides proportionately 0.4 to 0.9 of amino acids entering the small intestine in ruminants receiving conventional diets (Russell et al., 1992). Methods of estimating microbial protein synthesis rely on marker techniques in which a particular microbial constituent is related to the microbial N content. Marker : N values have generally been established in mixed bacteria isolated from the liquid fraction of rumen digesta and it has been assumed that the same relationship holds in the total population leaving the rumen (Merry and McAllan, 1983). However, several studies have demonstrated differences in composition between solid-associated (SAB) and fluid-associated bacteria in vivo (Legay-Carmier and Bauchart, 1989) and in vitro (Molina Alcaide et al, 1996), as well in marker : N values (Pérez et al., 1996). This problem could be more pronounced in the in vitro semi-continuous culture system RUSITEC, in which there are three well defined components (a free liquid phase, a liquid phase associated with the solid phase and a solid phase), each one having associated microbial populations.The objective of this experiment was to investigate the effect of using different bacterial isolates (BI) on the estimation of microbial production of four different diets in RUSITEC (Czerkawski and Breckenridge, 1977), using (15NH4)2 SO4 as microbial marker, and to assess what effects any differences would have on the comparison of microbial protein synthesis between diets.This study was conducted in conjunction with an in vitro experiment described by Carro and Miller (1997). Two 14-day incubation trials were carried out with the rumen simulation technique RUSITEC (Czerkawski and Breckenridge, 1977). The general incubation procedure was the one described by Czerkawski and Breckenridge (1977) and more details about the procedures of this experiment are given elsewhere (Carro and Miller, 1997).

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