Positive proteins

Drug/Lab test interactions False-positive urine glucose reactions may occur with penicillin therapy if Clinitest, Benedict s Solution, or Fehling s Solution are used. It is recommended that enzymatic glucose oxidase tests (such as Clinistix or Tes-Tape) be used. Positive Coombs tests have occurred. High urine concentrations of some penicillins may produce false-positive protein reactions (pseudoproteinuria) with the P.870... 

Marin, M.G., Fabbri, M., Rosmini, R. and Serrazanetti, G.P. (2009) Investigation of EROD, CYP1A immuno positive proteins and SOD in haemocytes of Chamelea gallina and their role in response to BaP. Comp. Biochem. Physiol. C, 149, 382-392. 

False-positive protein reactions False-positive Coombs test... 

Glucose binds in both the BII and Bill crystal forms in the deep cleft separating the two lobes of each subunit. Glucose appears to bind in the C-l (chair equatorial) a-D-glucopyranose conformation (73). All of the hydroxyls, except the 1-hydroxyl, are thus in an equatorial position. Protein side chains are hydrogen bonded to the 3-, 4-, and 6-hydroxyls and possibly to the 1-hydroxyl of glucose. The 2-hydroxyl appears to be pointing toward open space (73). This corresponds nicely with the observed substrate specificity. 

Protein Spot Positions. Protein spot positions can be measured to provide quantitative, statistical evidence of positional identity or difference for proteins in different gels. To accomplish this, the coordinates of the protein spot and of landmark (invariant) protein spots are recorded. Among six great apes 60% of the proteins were positionally invariant,6 and in a study of bears and procyonids 63% of proteins showed no positional variation.7 The mean protein spot position is determined from several gels, and outliers are defined statistically. 

While envisioned initially as a method for verifying positive protein-protein interactions, it was quickly realized that the method was well suited to screening libraries of proteins to identify new interactions [5], Now in widespread use, the Y2H assay has... 

The most interesting changes are recognized in pre- and postglomerular blood vessels. In about 50% of cases PAS positive proteins are deposited in vas affer-ens walls in a focal segmental or circumferent manner in the form of droplets, bands or granules [72, 79, 81]. 

The adsorption of positive proteins onto the epoxy capillary surface can be quantitatively evaluated by using the two on-line detector design. From the responses of the two detectors, it is possible to determine the adsorption of proteins on the surface between the two detectors. Zero-percent recoveries have been reported on an uncoated capillary at pH 7 for lysozyme, cytochrome-c, ribonuclease A, and u-chymotrypsinogen. However, most of these proteins had recoveries between 84.4% and 95%, except for lysozyme (55.5%), on an epoxy-coated capillary. Therefore, coating does reduce protein adsorption significantly. 

In patients with a positive protein or albumin dipstick test, a 24-hour urine collection with measurement of albumin excretion can be used to further define the degree of proteinuria. 

Several test strips or dipsticks are commercially available and are commonly used to assess proteinuria, but there are several limitations to their use. Highly alkaline or buffered urines give false positive protein reactions, and the test strips are primarily sensitive to changes in albumin rather than globulin fractions (Evans and Parsons... 

The nurse is reading this intradermal positive protein derivative (PPD) skin test 72 hours after it was administered. 

The nitroimidazoles, sulfonamides, and tetracyclines all present analytical challenges because of metabolism and/or chemical degradation. In the case of the nitroimidazoles, this is further complicated by the relatively low requirements for detection. Method development therefore has to take into account both metabolites as additional target compounds and low detection limits. Sulfonamide analysis has to take into account the potential for conversion of N -acetyl metabolites back to the parent compound. In contrast, in the analysis of honey, deconjugation is regarded as necessary to accurately determine sulfonamide concentrations. The facile, reversible formation of epimers is of particular concern in the analysis of those tetracyclines that can epimerize in the 4 position. Protein and metal binding are other issues that have to be overcome for successful tetracycline residue determination. 

Because the complement system is an evolutionary conserved protein cascade, the observed host specificity of bacterial complement inhibitors is very striking. The Gram-positive proteins SAK, SCIN and ScpB and the Neisserial porin molecules display strict human specificity. In case of Neisserial porin which exclusively binds human C4BP, host-spedfidty of the complement inhibitor bindii may contribute to host specificity of the infection. Understandii the basis for species specificity of complement evasion will hopefully lead to development of better animal models for infectious diseases, for example, creating transgenic mice for human complement inhibitory proteins to study pathc ens such as N. gonorrhoeae. 

This apparent equivalent weight plays a great part a) in determining the spread of cations in the reversal of charge spectrum ( 21, p. 295) b) in the extent of the antagonism CaCIg — NaCl ( 5 b, p. 314-315) c) in complex flocculation or complex coacervation with positive protein sols (see p. 374 Ch. X 2r). 

In some cases (e.g. positive proteins -f negative phosphatides) complex flocculation is established rapidly at favourable mixing proportions of the colloid components but... 

Compare the order phosphate > sulphate > carboxyl in the flocculability of acidoids with large organic cations (see note 2 on p. 405). Since proteins also appear here as organic cations the above series might be the sequence of the strength of the individual salt bond in the combinations of positive proteins with phosphate, sulphate and carboxyl colloids. 

Since this binding of anions increases in the order Cl < Br I and NO3 < CNS the order of the suppression must as a consequence of this be the one experimentally found. This therefore occurs because this action of the anions on the phosphatide in the final result predominates over the action of the anions on the positive protein component. 

On the other hand we find complex flocculation or coacervation rather at relatively low electrolyte concentrations. They are the more pronounced the greater the charge density of the colloid. The effectiveness of the ions is in the main determined by their valency over which lyotropic influences are superposed. We sometimes find here that the sequence of the ions is just the opposite of that in the normal lyotropic series (for example of the monovalent anions, with the positive proteins, compare also p. 299, Fig. 22) and we have in this a clear indication of the complex character of the flocculation. 

And finally in point 3. the same anion sequences appear as we met in the reversal of charge spectrum of positive proteins (protein cations, see p. 299). 

This already reflects the affinity sequence of these monovalent anions with respect to colloid cations. We may draw attention to the anion spectra (order of the reversal of charge concentrations) of positive proteins (Fig. 22, p 299), in which of the anions mentioned the CNS always possesses the lowest reversal of charge concentration. 

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