Human sera, testing

Both normal rabbit and human sera have been tested against two gangliosides having terminal galactose residues, namely G i and As seen in Figure 5, most of the human sera tested... 

The major purpose of the present study was to describe, and to quantify, the widespread occurrence of natural complement-fixing autoantibodies against numerous simple glycolipids. We show that every individual rabbit and human serum tested had complement-fixing autoantibodies against glycolipids that are widely distributed in circulating blood cells and other tissues. 

Sulfaphenazole (684) and sulfazamet (685) are both examples of relatively short acting sulfonamides (B-80MI40406) and their antibacterial activity has been tested against Escherichia coli, the former being more effective than the latter. Sulfaphenazole also displaces sulfonyl ureas from protein binding sites on human serum albumin and consequently increases the concentration of the free (active) drug and produces a more intense reaction that may result in hypoglycemia. 

We have isolated Rubisco small subunit promoters from several plant species and tested their strength with gusA and ALB (human serum albumin) transgenes in sprouts. The highest level of expression in Brassica napus sprouts has been obtained... 

The permeability of human skin to n-hexane has been determined in vitro in flow-through diffusion cells (Loden 1986). Pieces of full-thickness human skin were exposed to 3H -hcxane in human serum, and the appearance of label in the trans compartment measured for 0.5 or 12 hours. The skin was then sectioned with a microtome into 0.25 mm slices and the quantity of label in the skin measured. The rate of resorption (uptake of substance by the receptor fluid beneath the skin [i.e., the amount that passes through the skin]) was calculated. The rate of resorption for n-hexane through human skin was calculated to be 0.83 ( g cm2/hr). The permeability of n-hexane through human skin was much lower (approximately 100-fold) than for other chemicals tested in this study. For example, rates of resorption (in g cm2/hr) were 99 for benzene and 118 for ethylene glycol. 

The synthetic polymeric components as well as their combinations with proteins such as human serum albumin (HSA), bovine serum albumin (BSA), human serum albumin/a-interferon mixtures (HSA-IFNa) and myoglobin (MYO) did not give any negative response to in vitro and in vivo biocompatibility tests, such as platelet aggregation, complement activation, acute toxicity, and acute thromboembolic potential. 

Fig. 14.7 Correlation ofVolSurf descriptors with human serum albumin binding affinity. Two submodels indicate their predictive ability to external test sets. Ten compounds were removed by either experimental design on PCA scores (A) or literature proposals (B). Model A 0.558,...

The viability and function tests described above are used to evaluate the hepatocytes within the slice. Up to now, tests to measure the viability of the non-parenchymal cells have not been reported. The presence of the latter cell types is one of the conceptual advantages of slices as compared to isolated hepatocytes. As some drug targeting devices are designed to target non-parenchymal cells in the liver, the development of tests for the sinusoidal cell types deserves more attention. For example, the uptake of substrates such as succinylated human serum albumin (Suc-HSA,which is specifically endocytosed by endothelial cells [79]), or hyaluronic acid [80], can be used to assess the functionality of endocytotic pathways in the endothelial cells in the liver [81]. Other modified proteins that are specifically taken up by Kupffer cells such as mannosylated HSA, may be used to assess the functionality of the endocytotic pathway in Kupffer cells [79]. Another parameter which can be used to assess the functionality of these non-parenchymal liver cells, is the excretion of cytokines in response to pro-inflammatory stimuli. Non-parench5mal cell function in liver slices will be described in more detail in the Section 12.7. 

The apparent permeability of 11 test compounds was measured in the presence and absence of human serum albumin in the donor compartment, and by solving the differential equations describing the kinetics of membrane permeability, membrane retention and protein binding, the authors were able to obtain the Kd. With the protein in solution rather than immobilized and without the need for mass balance or equilibrium conditions, this approach provides an attractive alternative to existing methods with the potential to be applied to an array of other soluble proteins. 

The assay described above has a limited sensitivity (80-85%) to detect patients, especially patients with the so-called variant biochemical phenotype, and should be considered as an initial screening test [52, 55]. For increased sensitivity the cells should be cultured in medium with 10% lipoprotein-deficient medium (LPDS) for 2 days and subsequently with medium supplemented with 10% fresh human serum as described below for low-density lipoprotein (LDL)-stimulated cholesteryl ester formation. 

Beyond polyclonal antibodies, monoclonal antibodies to isoxazolyl penicillins were recently produced by immunization of mice with a cloxacillin-human serum albumin conjugate prepared by a mixed anhydride procedure (35). Sensitivity and specificity of these antibodies were tested in an indirect ELISA in which a cloxacillin-glucose oxidase conjugate prepared by an activated ester procedure served as a coating agent. It was found diat die prepared antibodies could be... 

The Western blot procedure (Experiment 7) is now used to test human serum for the presence of antibodies to the AIDS virus. Find two publications that describe procedures for this assay. 

Martino E, Bambini G, Bartalena L, Mammoli C, Aghini-Lombardi F, Baschieri L, Pinchera A. Human serum thyro-trophin measurement by ultrasensitive immunoradiometric assay as a first-line test in the evaluation of thyroid function. Clin Endocrinol (Oxf) 1986 24(2) 141-8. 

Fig. 24.4. Study of the biosensor stability with biological sample. Arrows indicate where (i.e. biological sample) a solution obtained by dialysing a human serum with the microdialysis probe was flowed in the biosensor cell. At the beginning a perfusion solution and control solution (glucose 5 mmol l-1) were used instead of the serum to test the biosensor response. Control solution of glucose was also used during and at the end of the experiment to evaluate the stability of the biosensor. Continuous flow mode 10 pi min-1). Applied potential —50 mV vs. int. ref. Reprinted from Ref. [59] with permission from Elsevier.

Most situations where proficiency evaluation is applied are rather narrowly defined as to scope. For example, clinical laboratories may be asked to demonstrate that they can determine certain constituents occurring in human serum with uncertainties not to exceed specific limits. Accrediting bodies will require successful participation in periodic proficiency tests conducted by a reference laboratory which they recognize. 

Perez-Urquiza M et al. (2003) Use of reference value for the Proficiency Test scheme in the measurement of glucose and cholesterol in human serum. 

Today peptide synthesis is a mainstream operation in many big laboratories. Several companies have in addition specialized in providing custom-ordered peptides, e.g., large-scale peptides (made in solution), peptide libraries (made on cellulose membranes), or most commonly small peptide quantities (made on resin, solid phase synthesis). Although peptides are considered rather stabile in many test assays, concerns have been raised regarding their stability in presence of human serum. 

In order to determine if lectins affect the reactions of complement mediated hemolysis subsequent to binding of antibody to the lymphocyte we have employed a synthetic particulate antigen. This was accomplished by testing the ability of lectin to inhibit the fixation of complement by the complex of anti-human serum albumin (HSA) and HSA-conjugated aminoethyl Biogel beads. The HSA-conjugated aminoethyl Biogel beads may be considered to be cell-like particles coated with a carbohydrate-free protein. 

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